WO1999006388A2 - Pharmaceutical compounds isolated from aristolochia taliscana - Google Patents

Abstract

The invention relates to extracts from Aristolochia taliscana and their uses in medicine, and also to compounds, known and novel isolated from the extracts, and compositions containing the extracts and compounds. The extracts and compounds are useful inter alia as anti-mutagens, antifungal agents and cytotoxic agents. The extracts and compositions of the invention can comprise at least 10 %, preferably at least 20 %, and more preferably at least 25 % by weight of a phenylbenzfuran.

Description

PHARMACEUTICAL COMPOUNDS ISOLATED FROM ARISTOLOCHIA TALISCANA

FIELD OF THE INVENTION

This invention relates to compounds derived from the plant A stolochia taliscana and their analogues, and the uses of such compounds in medicine.

BACKGROUND OF THE INVENTION

Aristolochia taliscana, a climbing shrub found in the jungles of the southern coastal region of Mexico, is part of a family of climbing herbs and shrubs called Aristolochiaceae, numbering about six hundred species divided into eleven genera, and found mostly in tropical and sub-tropical regions. It is believed that the species Aristolochia taliscana is found only in Mexico.

Members of the Aristolochiaceae are known for their ability to synthesise phenanthrene alkaloids, and in particular the aristolactam alkaloids and the aristolochic acids, and arylpropanoid compounds such as the lignans and neolignans. Such compounds are disclosed in, for example, R. Hegnauer "Chemotaxonomie der Pf lanzen", Vol. Ill, pp 1 84-1 99, Birkhauser Verlag, Basel und Stuttgart, 1 964; R. Hegnauer "Chemotaxonomie der pflanzen", Vol. VII, pp 75-83, Birkhauser Verlag, Basel - Boston - Berlin, 1 989 and F.E. Correa er a/. "Especies Vegetales Promisorios", Vol. I, pp 440-469, Secretaria Ejecutiva del Convenio Andies Bello (SECAB), Bogota D.E. 1 989, Colombia and Lopes et al. Rev. Latinoam. Quim., 1 9 (3-4), 1 1 3-1 7, 1 988. In Lopes et al. , for example, the isolation of lignans from a number of different Aristolochiaceae is described and it is disclosed that such compounds are reported as having anti-tumour, antifungal, antibacterial and insecticidal activity. In Hinou eta/., J. Crude Drug Research, 1 990, 28(2), 149-51 , it is disclosed that aristolactam and aristolochic acid compounds isolated from Aristolochia longa have antibacterial activity and cytotoxic activity against P-388 lymphocytic leukaemia and human bronchial epidermoid carcinoma cells. The isolation and characterisation of lignans, neolignans and related compounds from a wide variety of plant species has been reviewed in a series of articles by R.S. Ward, see for example Natural Product Reports, 1 985, Vol. 5 pp 203-206; 1990, Vol. 7, pp 356-363; 1 993, Vol. 10, pp 1 -23.

However, it is clear from the available literature that the chemical structures and concentrations of arylpropanoid compounds found in Aristolochiaceae vary widely from one species to another. For example, in Lopes etal. [idem.), reference is made to the extraction of four Brazilian species of Aristolochiaceae, from which a number of dibenzyl-butyrolactone type lignans and furofuran type lignans were isolated. From studies made by the present inventors, such compounds would appear to be absent from Aristolochia taliscana.

Much of the work carried out on the Aristolochiaceae has focused on the phenanthrene alkaloid content, and in particular the aristolactam alkaloids found in the plants - see for example Crohare et al. Phytochemistry, 1 974, Vol. 13, 1957- 1 962, Priestap, Phytochemistry, 1 985, Vol. 24, 849-852, Talapatra et al. Phytochemistry, 1 988, Vol. 27, 903-906 and Houghton et al. Phytochemistry, 1 991 , Vol. 10, 253-254. Houghton et al. suggest that compounds such as aristolochic acid, the ring-opened form of aristolactam, are of interest as immunostimulants and anticancer agents.

Crude extracts from Aristolochia taliscana have been known for many years to have certain medicinal properties. A book published in the 1800's, called "Las Plantas Medicinales de Mexico" (Medicinal Plants of Mexico) makes reference to the use of Aristolochia taliscana extracts in the treatment of snake bites and it would appear that the native tribes in this region of Mexico have known about the uses of the extracts for many centuries.

In US Patent No. 4782077 it is disclosed that an alkaloid (referred to as taliscanin) extracted from the root of Aristolochia taliscana, alleviates the symptoms of Parkinsonism and related neurological disorders. It is also indicated in US 4782077 that the alkaloid taliscanin may be useful in the treatment of various other neurological disorders, including Alzheimer's disease, impotency, and neurological disorders associated with viral, bacterial, fungal and parasitic infections.

In US 4782077, an extract was prepared by pulverising Aristolochia taliscana root and subjecting the powder to soxhiet extraction with hexane and then benzene followed by column chromatography on an alumina column eluting with benzene-ether mixtures. The known aristolactam alkaloid taliscanin, was characterised on the basis of its melting point (272°-273°C) and its spectroscopic data.

However, the aristolactam alkaloid taliscanin has since been tested for its ability to interact with neurotransmitter receptors, and, somewhat surprisingly, exhibited 50% inhibition in only one receptor (the opiate mu receptor) out of twenty seven common receptor types tested, and exhibited very poor levels of inhibition with the remaining receptors. In particular, taliscanin exhibited negligible activity at the dopamine, GABA and serotonin receptors. These results suggest either that taliscanine exerts its neurological effects by a mechanism which is of a currently unknown type (which seems unlikely) or, perhaps, that there is another active principle in Aristolochia taliscana which is responsible for the reported activities.

SUMMARY OF THE INVENTION

The present applicants have been able to separate and identify the components of Aristolochia taliscana extracts and have found that the extract contains a substantial number of compounds other than aristolactams, in particular certain benzofuran neolignans, many of which are novel. Compounds found in the extracts have been found to have biological properties indicative of therapeutic utility. For example, benzofuran compounds isolated from taliscanine have been tested and have been found to be active as anti-mutagenic agents, as cytotoxic agents, and some have been found to have good antifungal activity. On this basis, it is anticipated that the compounds in question will find use in the treatment of tumours and other neoplastic diseases, as well as fungal infections.

Accordingly, in a first aspect, the invention provides the use of an extract of Aristolochia taliscana or one or more anti-mutagenically active components isolable therefrom for the manufacture of a medicament for the treatment of disease states mediated by mutagenesis.

The invention also provides the use of an extract of an Aristolochia species, preferably Aristolochia taliscana or one or more component compounds isolable therefrom, for the manufacture of a medicament for the treatment of chronic inflammatory diseases such as inflammatory bowel disease, rheumatoid arthritis, synovitis and psoriasis.

As indicated above, component compounds of Aristolochia taliscana have also been found to have good antifungal activity, and in a still further aspect, the invention provides the use of an extract of Aristolochia taliscana or one or more antifungally active compounds isolable therefrom for the manufacture of a composition for antifungal use, for example in the treatment of plants or animals.

The invention also provides pharmaceutical compositions comprising benzofuran compounds of the type found in Aήstolochia taliscana or benzofuran compounds analogous thereto, for example benzofuran compounds in which an aryl ring (such as an oxygenated phenyl ring) is attached to the heterocyclic ring of the benzofuran, and the uses of such compounds in medicine.

The invention also provides a novel group of benzofuran compounds having an oxygenated aryl ring (such as an oxygenated phenyl ring) attached to the heterocyclic ring of the benzofuran.

DESCRIPTION OF PREFERRED EMBODIMENTS

Compounds for use in Medicine - New Medical Uses of Known and Novel Compounds

In one preferred aspect, the invention provides the use of a compound for the manufacture of a medicament for use in any one or more of the therapeutic uses selected from the treatment of neoplastic diseases or diseases mediated or initiated by mutagenesis or abnormal cellular proliferation, or as a cytotoxic agent, or the treatment of chronic inflammatory conditions; the compound being of the formula (I):

wherein the dotted line signifies a single or double bond; n is 0, 1 , 2 or 3; A is a monocyclic aryl ring containing up to two heteroatoms and being optionally substituted by one or more substituent groups which may be the same or different and are selected from R³0, R³, R³S, halogen; aryl and heteroaryl, wherein R³ is hydrogen, or a hydrocarbyl group optionally substituted by a hydroxy or hydrocarbyloxy group; B is selected from carboxy, carboxaldehyde, hydrocarbyl and hydrocarbyloxy groups wherein the hydrocarbyl group is acyclic or cyclic, and optionally contains one or more heteroatoms, and is optionally substituted by one or more hydroxy, alkoxy, alkenyloxy, alkynyloxy, aryloxy, aldehyde, alkanoyl, acetal, hemiacetal and carboxy groups; R¹ is hydrogen or a hydrocarbyl group optionally including one or more heteroatoms and optionally substituted by one or more substituents selected from hydroxy, hydrocarbyloxy and aryl groups; and R² is hydroxy or a hydrocarbyl or hydrocarbyloxy group optionally substituted by one or more substituents selected from hydroxy, hydrocarbyloxy and aryl groups.

It is preferred that the monocyclic aryl ring A is attached to the 2-position of the furan ring, and it is particularly preferred that the aryl ring is a phenyl group. The phenyl ring can contain up to five substituent groups but preferably contains no more than three substituents.

Preferably, the group B is attached to the 5-position of the benzofuran group.

Preferably, there is only one group R², which is attached to the 7-position of the benzofuran ring.

Preferably, the dotted line signifies a double bond. In a particularly preferred embodiment, the invention provides the use of a compound for the manufacture of a medicament for use in the treatment of the conditions described above in relation to formula (I), the compound having the formula (II):

(ID

wherein the dotted line signifies a single or double bond, B, R¹ and R² are as hereinbefore defined, R⁴ and R⁵ are the same or different and each is selected from hydrogen, C,^ hydrocarbyl, C₅.₂₀ aryl, or C₅.₂₀ oxygen-containing heteroaryl; R⁶ is selected from hydrogen, halogen, C^o hydrocarbyl or C_1-20 hydrocarbyloxy optionally substituted by one or more hydroxy, alkoxy or aralkyloxy groups; or R⁶ is C₅.₂₅ aryl or oxygen or nitrogen-containing heteroaryl.

One preferred group of compounds are the compounds in which B is C^ alkyl or alkenyl optionally substituted by one or more substituents selected from hydroxy, CHO, or R⁷0 wherein R⁷ is a C,.₆ alkyl or alkenyl group. More preferably, the group B is selected from CH = CHCH₃, CH₂CH = CH₂, CH(OH)CH = CH₂, CH = CHCHO, CHO, CH = CHCH₂OH and CH(OH)CH(OH)CH₃. A particularly preferred group B is CH = CHCH₃.

In compounds of the formula (II) R⁴ and R⁵ are preferably selected from hydrogen, or C,^ alkyl, or R⁴ and R^δ together define an alkylene group such as -CH₂- . Preferably, at least one of R⁴ and R⁵ is hydrogen.

Particularly preferred compounds are those in which the dotted line signifies a double bond and one of R⁴ and R⁵ is hydrogen.

Examples of groups R⁶ are hydrogen, halogen (e.g. fluoro, chloro, bromo or iodo), C^e alkoxy (e.g. methoxy), a 2-benzofuranyl ring, or an aristolactam group.

In the foregoing formulae (I) and (II), examples of hydrocarbyl groups are aliphatic, alicyclic and aromatic groups such as alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkenyl, cycloalkylalkynyl, cycloalkenyl, cycloalkenylalkyl, cycloalkenylalkenyl, aryl, aralkyi, aralkenyl, aralkynyl. The hydrocarbyl groups can be optionally interrupted by one or more heteroatoms such as oxygen and sulphur.

Particular examples of alkyl groups are C,^ alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl and t-butyl.

Examples of cycloalkyl groups are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyi, cyclooctyl, bicycloheptanyl, decalinyl, adamantyl, norbornyl and bicyclooctyl.

Examples of alkenyl and alkynyl groups include vinyl, ethynyl, allyl, 1 - propenyl, propargyl, but-1 -enyl, but-2-enyl, but-3-enyl and 3-methylbutenyl.

Examples of cycloalkenyl groups are cyclopentenyl, cyclohexenyi, cycloheptenyl, and monocyclic, bicyclic and tricyclic terpene groups.

Examples of aryl groups are phenyl and naphthyl.

Examples of phenylalkyl and phenylalkenyl groups are benzyl, phenethyl, phenylpropyl, phenylbutyl and styryl groups.

First Medical Uses of Compounds Not Previously Disclosed As Having Therapeutic Utility

Many compounds of the formulae (I) and (II) have not previously been disclosed as having any therapeutic uses. Accordingly, in another embodiment, the invention provides a compound of the formula (I) or (II) as hereinbefore defined for use in medicine, for example for use in any one or more of the therapeutic uses selected from the treatment of neoplastic diseases or diseases mediated or initiated by mutagenesis or abnormal cellular proliferation, or as a cytotoxic agent, or the treatment of chronic inflammatory conditions, or as an anti-fungal agent in the treatment of plants or animals; but provided that when R¹ is 3-methyl, R² is a single methoxy group at the 7-position, and either (i) the furan ring is unsaturated and is substituted at the 2-position with a 4-hydroxy-3-methoxyphenyl group or a 3,4- methylenedioxyphenyl group; or (ii) the furan ring is a 2,3-dihydrofuran ring and is substituted at the 2-position with a 4-hydroxy-3-methoxyphenyl group, then B is other than a prop-1 -enyl group attached to the 5-position of the benzfuran ring.

Novel Compounds per se

The present invention also provides novel compounds perse of the formula (III):

wherein R¹¹ is hydrogen or

alkyl;

R¹² is selected from hydrogen,

alkyl; a cyclic terpenoid group or a group of the formula E, G or J;

R¹³ is selected from hydrogen; C ₃ alkyl or hydroxy-C_La alkyl;

R¹⁴ is selected from CH = CH-CH₃, CH(OH)CH = CH₂, CH = CH-CHO, CH = CH- CH₂OH, CH(OH)CH(OR¹⁷)CH₃, or a group L;

R¹⁵ is hydrogen or

alkyl;

R¹⁶ is hydrogen, a group M or an aristolactam group; and

R¹⁷ is hydrogen or a group T; wherein the groups E, G, L, J, M and T are represented by the formulae: )

(E) (G)

(L) (J)

(M) (T)

and pharmaceutically acceptable salts thereof; provided that when R¹¹, R¹³ and R¹⁵ are all methyl, and R¹² and R¹⁶ are both hydrogen, R¹⁴ is selected only from

CH(OH)CH = CH₂, CH = CH-CHO, CH = CH-CH₂OH, CH(OH)CH(OR¹⁷)CH₃ where R J17 is a group T, or a group L.

In one particular embodiment, there is provided a novel compound of the formula (IV):

wherein R , R¹², R¹³ R , R¹⁵ and R¹⁷ are as hereinbefore defined and X is a group:

wherein R¹⁸ is hydrogen, benzyl or

alkyl; R¹⁹ to R²⁴ are the same or different and are selected from hydrogen, hydroxy, C_1-6 alkoxy,

alkyl and

alkyl; or any two adjacent groups together form an alkylene dioxy group.

In another embodiment, the invention provides novel compounds of the formula (V):

wherein Y is a monocyclic or bicyclic terpenoid group and in particular a group of the structure:

Tetralone Compounds

In a further aspect, the invention provides tetralone compounds for use in medicine, the tetralone compounds being of the formula (VI):

wherein R²⁵ and R²⁷ are the same or different and each is C '1,.-g6 alkyl, or R²⁵ and R²⁶ together form an alkylene group (such as methylene); and R 32^z6^β is hydrogen or C,^ alkyl.

Preferably R²⁵, R²⁶ and R²⁷ are all methyl.

Tetralone compounds of the formula (VI) have biocidal activity, and in particular cytotoxic, antibacterial and antifungal activity. It is therefore anticipated that they will be useful in the treatment of proliferative and infective diseases and conditions such as cancers and bacterial and fungal infections.

Accordingly, the invention also provides a compound of the formula (VI) for use in the treatment of bacterial or fungal infections, or for use in the treatment of cancers and other proliferative diseases such as psoriasis. Compounds of the formula (VI) have previously been reported as synthetic intermediates (see loie etal. Chem. Pharm. Bull.38, 1851-56 (1990).

Particular novel compounds of the invention are: ( ± )-5-(1 -Hydroxy ally l)-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-3- methylbenzofuran (Compound 9);

2-(4-Hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-5-(E)- propenylbenzofuran (Compound 10);

2-(4-Hydroxy-3-methoxyphenyl)-7-methoxy-3-methyl-5-[(E)-3- oxopropenyljbenzofuran (Compound 11);

5-Formyl-3-(4-hydroxy-3-methoxyphenyl)-7-methoxy-3-methylbenzofuran (Compound 12);

2-(4-Hydroxy-2-methoxyphenyl)-5-[(E)-3-hydroxypropenyl]-7-methoxy-3- methylbenzofuran (Compound 13);

2-(3,4-Dihydroxyphenyl)-7-methoxy-3-methyl-5-(E)-propenylbenzofuran (Compound 14); e/yf/?O-5-(1,2-Dihydroxypropyl)- 2-(4-hydroxy-3-methoxyphenyi)-7-methoxy-3- methylbenzofuran (Compound 15);

(2R,3R)-2,3-Dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-5- (E)-propenylbenzofuran (Compound 19); ervf7O-1-(4-Acetoxy-3-methoxyphenyl)-2-[4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy]propylacetate (Compound 22); threo-λ -(4-Acetoxy-3-methoxyphenyl)-2-[4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy]propyl-acetate (Compound 23); f/7reo-1-[2-(4-Hydroxy-3-methoxyphenyl)-7-methoxy-3-methylbenzofuran-5-yl]-2-[4- ( 3-methyl- 5- (e) -pro penylbenzofuran-2-yl)-2-methoxyphenoxy]propan-1-o! (Compound 24);

2-Methoxy-4-[7-methoxy-3-methyl-5-(E)-propenylbenzofuran-2-yl]-6-[4-(7-methoxy- 3-methyl-5-(E)-propenylbenzofuran-2-yl)-2-methoxyphenoxy]phenol (Compound 25) 8.2',9.3'-Tetrahydro-bis-eupomatenoid-7 (Compound 26); 15-(Aristolactam-l-9-yl)-eupomatenoid-7 (Compound 27); 14-0-σ-Cadinyl-eupomatenoid-7 (Compound 28); and (2R,4S)-2-Hydroxy-6-methoxy-4,7-dimethyl-1 -tetralone (Compound 34). Extraction of Compounds From Aristolochia taliscana

Certain compounds of the formulae I to VI can be obtained by solvent extraction of plant material, such as roots, bark, leaves and twigs, from Aristolochia taliscana using solvents such as benzene followed by chromatographic separation of the components of the solvent extract. Atypical extraction protocol is described in detail below.

Synthesis of Compounds of the Formulae I to V

The compounds of the invention, whether naturally occurring or synthetic analogues thereof can be synthesized from readily available starting materials by synthetic methods well known to those skilled in the art.

For example, compounds of the formulae (I) or (II) can be prepared by means of the reaction scheme set out in Figure 1 .

The reaction conditions and reagents employed in the scheme set out in Figure 1 can be substantially as described in M. Watanabe etal. Chem. Pharm. Bull. 37, 2884 (1 989); //>/< . 38, 41 (1 990), and ibid. 39, 31 23 (1991 ), the contents of which are incorporated herein by reference.

An alternative synthetic scheme applicable to compounds of the formulae (I) or (II) wherein R¹ is a methyl group attached to the 3-position of the furan ring and A is an aryl group attached to the 2-position of the furan ring, is set out in Figure 2.

In the reaction scheme shown in Figure 2, the methoxymethylaryl ketone is reacted with the substituted σ-hydroxybenzaldehyde in an acidic medium (for example a mixture of hydrochloric acid and acetic acid) to give a benzpyryllium salt which is then subjected to oxidation and rearrangement in the presence of hydrogen peroxide and methanol at pH 5.8 to give a benzfuran 3-carboxy ester. The benzfuran 3-carboxyester can then be treated successively with (i) lithium aluminium hydride in an ether such as diethyl ether; (ii) manganese dioxide in a non- polar solvent such as benzene; (iii) 1 ,2 ethylene-dithiol, acetic acid and boron trifluoride etherate; and (iv) Raney nickel in an alcohol such as ethanol. The general conditions under which each of the above reactions can be carried out are disclosed in McCredie et al., Austral. J. Chem. .22, 101 1 (1 969), the contents of which are incorporated herein by reference.

Pharmaceutical Uses

The extracts and compounds of the invention are useful in a number of medical aspects. In use as therapeutic agents, the compounds or extracts can be administered in standard manner, for example orally, parenterally, transdermally, rectally, via inhalation or via buccal administration. Preferably, however, they are administered orally. The dosage employed will depend on the nature and purity of the extract and the concentrations of the active principles. For an extract that has not been fractionated, the concentration administered can be in the range from 0.5mg to 500mg (dry weight) of extract per patient per day, more usually 1 mg to 10Omg per day. If an isolated compound or synthetic analogue thereof, or mixture of such compounds is employed, the dosages of such compounds administered typically will be similarly in the range 0.5mg to 500mg per patient per day, more usually 1 mg to 10Omg per day. The extracts or compounds may be administered as single doses or multiple doses as desired. The dosages of the extracts or compounds of the invention administered will depend upon inter alia the potency of the extract or compound, and the nature and severity of the disease state or condition under treatment but ultimately, however, will be at the discretion of the physician.

Pharmaceutical Formulations

The extracts and compounds of the invention can be formulated as solutions, syrups, tablets, capsules, lozenges, inserts, patches, powders, pills, solutions for injection or drops, or aerosols such as dry powder aerosols or liquid aerosols, by way of example. Such formulations can be prepared in accordance with methods well known per se.

In a particular embodiment, the compositions of the invention can take the form of solid or semi-solid unit dosage form. For example, the compositions can take the form of tablets, granules, lozenges or capsules.

A solid or semi-solid dosage form according to the present invention can contain, for example, from 10mg to 1000mg of the extract or compounds of the invention, more typically 50mg to 500mg, e.g. 100mg to 400mg, and in particular 1 50mg to 350mg, particular unit dosages being approximately 200mg and 300mg.

A tablet composition will typically contain one or more pharmaceutically acceptable solid diluents, examples of which include sugars such as sucrose and lactose, and sugar alcohols such as xylitol, sorbitol and mannitol; lactose and sorbitol being particular examples.

The tablets will also typically contain one or more excipients selected from granulating agents, binders, lubricants and disintegrating agents.

Examples of disintegrants include starch and starch derivatives, and other swellable polymers, for example cross-linked polymeric disintegrants such as cross- linked carboxymethylcellulose, cross-linked polyvinylpyrrolidone and starch glycolates.

Examples of lubricants include stearates such magnesium stearate and stearic acid.

A capsule composition typically will comprise an outer shell or casing which may, for example, be formed from hard or soft forms of gelatin or gelatin- equivalents in conventional fashion. The outer shell is filled with an extract or a compound in accordance with the invention. The capsule filling may be in the form of a powder, or granules, or beads, or may be in the form of a liquid or semi-solid. Where the mixture is in the form of granules, the granules can consist of the extract or compound of the invention alone, or granulated together with a granulating agent, or they can additionally comprise a solid diluent, for example of the type set forth above. The granules can be wet granulated or dry granulated as desired.

When the capsule filling is in liquid or semi-solid form, the extract or compound can be dissolved or suspended in a semi-solid carrier material such as a polyethylene glycol or a liquid carrier such as a glycol, e.g. propylene glycol, or glycerol. In general, it is preferred that the capsule is in solid or semi-solid form when hard gelatin capsules are used; liquid or semi-solid forms being preferred with soft gelatin capsules.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The invention will now be illustrated, but not limited, by reference to the following examples.

GENERAL EXPERIMENTAL DETAILS AND ISOLATION PROCEDURE General

In the following examples, all melting points are uncorrected. Analytical thin layer chromatography (TLC) was performed on precoated plates (HPTLC plates, silica gel 50 F₂₅₄, Merck) using the following systems: S-1 = CHCI₃- MeOH (99:1 ), S-2 = CHCI₃-MeOH (96:4), S-3 = cyclohexane-EtOAc (1 :1 ); detection: UV, anisaldehyde reagent [E. Stahl, and U. Kaltenback, Journal of Chromatography, 1961 , 5, 351 ].

Unless otherwise stated, the optical properties and UV and IR spectra were recorded as follows: [σ]_D in CHCI₃ at 20°, CD and UV in MeOH, IR in CHCI₃.

Unless otherwise stated, ⁿH NMR were run at 360 MHz and ¹³C NMR at 90 MHz in CDCI₃ with TMS as internal standard.

EIMA were obtained at 70 eV; DCIMS with NH₃ or isobutane, respectively. Apart from key ions, the only ions listed are those with relative intensities > 10% and m/z > 100.

Column chromatography (CO and medium pressure liquid chromatography (MPLC) were carried out on silica gel 60 (Macherey-Nagel) and on LiChroprep^® RP 1 8 (40-60 μm, Merck). For CC, Fractogel PVA 500 (Merck), and Fractogel TSK HW-40 (S) (Merck) were also used.

High pressure liquid chromatography (HPLC) was performed on LiChrosorb RP 18 (7 μm, Merck).

Plant material

Roots of Aήstolochia taliscana Hook (Aristolochiaceae) were collected by Jorge Perez de la Rosa (lnstituto Tecnologico y de Estudios Superiores de Monterrey, ITESM) from Colima (Mexico) and identified by Prof. H. Sanchez. A voucher specimen is held at the Universidad de Guadalajara, lnstituto de Botanica, Guadalajara (Mexico).

EXAMPLE 1

Extraction and isolation of the Components of Aristolochia taliscana

Air dried, pulverized roots and rhizomes (3.5kg) of Aristolochia taliscana were extracted with benzene at room temperature to give 1 6g of a red-brown extract after removal of solvent. This extract was separated by column chromatography on Fractogel TSK HW 40 (S) with methanol to give 10 fractions (designated A.t.1 to A.t 10), which were then subjected to further chromatographic separation by repeated MPLC or CC using the following systems (a) silica gel, cyclohexane-ethyl acetate gradients, (b) LiChroprep RP 18, MeOH-H₂0 gradients, (c) Fractogel PVA 500, methanol. The separation scheme followed is set out in Figure 3, and the experimental conditions employed in each of the separation steps are set out in Table 2 below.

Purification and final separation was achieved by HPLC on silica gel Nucleosil 50 using cyclohexane-ethyl acetate (8:2) and high pressure liquid chromatography on silica gel RP 1 8 (LiChrosorb) using methanol-water mixtures, respectively. These procedures afforded the individual compounds 1 to 32 and 34 to 41 besides the mixtures 33, 42 and 43, whose identification was achieved by methylation or methanolysis and subsequent gas chromatographic analysis. Table 2

Abbreviations:

D: diameter, L: length, C: chloroform, CH: cyclohexane, EA: ethyl acetate, H: hexane, M: methanol, T: toluene, W: water The compounds isolated from the benzene extract are listed below in Table 3. Those compounds already known as natural products are referred to in Table 3 by their chemical names, whilst those compounds not previously recognised as natural products are identified by code number. The full chemical names and spectroscopic and other characterising data for the new natural products are given in the paragraphs following Table 3.

Table 3

Compounds isolated from the Benzene Extract of the Root of Aristolochia taliscana

o aristolochic acids were detected in the extract. The aristolactams referred to in the table have the following structural formulae:

Physico-chemical and Spectroscopic Properties of the Novel Natural Products ( + )-5-(1 -Hvdroxyallyl)-2-(4-hvdroxy-3-methoxyphenyl)-7-methoxy-3- methylbenzofuran (Compound 9). Crystals (5 mg). Mp 164-167° (from MeOH). TLC: R_f 0.42(S-1); anisaldehyde: violet. [σ]_D±0° (c.0.1). lRv„ cm^"1 :3540(OH), 3020, 1515. UV/ nm(loge):221(3.42), 305(3.38); + NaOH:212(3.82), 328(3,46). H NMR(250 M Hz) :ό^~2.00 ( 1 H ,d ,J = 3.5 Hz, O H_-8 ) , 2.41 (3H,s,Me- 3),3.99(3H,s,OMe),4.03(3H,s,OMe),5.23(1H,dt,J, = 10.5,J₂=1.5Hz,H- 10_B),5.31(1 H,m,H-8),5.41(1 H,dt,J₁ = 17,J₂ = 1.5Hz, H-10_A), 5.75(1 H,s, OH- 14),6.14(1H,ddd,J_l = 17,J₂ = 10.5,J₃ = 6Hz,H-9),6.83(1H,d,J = 1.5Hz,H- 6), 7.00(1 H,d,J = 8Hz,H-15), 7.12(1 H,d,J = 1.5Hz, H-4, 7.29 (1H,dd,J₁=8,J₂ = 2Hz,H-16), 7.33(1 H,d,J = 2Hz,H-12). ¹³C NMR (60MHz): 9.6(Me-3),56.5(2xOMe),76.5(C-8),106.6 (C-6),110.0(C- 12),110.9(C-3),111.3(C-4),114.6(C-15),116.5(C-10),121.2(C- 16), 124.5(C11), 134.1 (C3a), 140.1 (C-5), 142.6(C-9), 143.3(C-7a), 146.2(C- 7),148.1(C-14),149.2(C-13),152.9(C-2). EIMS m/z (rel. int.):

340[M] ⁺ (100), 323(14), 297(11), 295(11), 284(12).

2-(4-Hvdroxy-3-methoxyphenyl)-3-hvdroxymethyl-7-methoxy-5-(E)- propenylbenzofuran (Compound 10)

Crystals (12mg). Mp 175-179° (from MeOH). TLC:R_f0.3(S-1 ); anisaldehyde:grey. IRv_max crrr¹:3539(OH), 1600, 1515, 1466. UVΛ_max nm(loge):231 (3.38), 266 (3.44), 304 (3.34); +NaOH:240 (3.41), 295(3.25), 328(3.3). 'H NMR (250 MHz): <J1.57(1H,t,J=4Hz, OH-3), 1.90(3H,dd,J, = 6.5J₂ = 1.5Hz, Me-10), 3.95(3H,s,OMe),4.04(3H,s,OMe),4.91(2H,d,J = 4Hz,CH₂OH),5.81(1H,s,OH-14), 6.23(1H,dq,J_l = 16,J₂ = 6.5Hz,H-9), 6.48(1 H,dq,J, = 16, J₂1.5Hz,H-8), 6.83(1 H,d,J = 1.5Hz,H-6), 7.01 (1H,d,J = 8Hz,H-15), 7.18(1 H,d,J = 1.5Hz,H-4), 7.38(1 H,dd,J, = 8,J₂ = 2Hz,H-16), 7.41 (1 H,d,J = 2Hz,H-12). ¹³C NMR:<J18.4(Me- 10),55.7(CH₂OH),56.1(2xOMe), 104.8(C-6), 109.0(C-4), 110.0JC-12), 113.8(C- 3), 114.7(C-15), 121.3(C-16), 122.4(C-11 ), 124.8(C-9), 131.2(C-3a), 131.3(C-8), 123.3(C-5),142.3(C-7a),145.0(C-7),146.6(C-14),146.7(C-13),154.6(C-2).EIMS m/z(rel.int):340[M]-(100), 323(15), 291 (19), 151 (10).

2-(4-Hvdroxy-3-methoxyphenyl)-7-methoxy-3-methyl-5-[(E)-3- oxopropenvπbenzofuran (Compound 11)

Crystals (8 mg). Mp 169-170° (from MeOH). TLC:R_f0.39(S-1); anisaldehyde:blue. IR v_max cnr¹:3538(OH), 1672(CO), 1610, 1514. UV Λ_max nm(loge):213(4.04), 291 (4.91), 314(4.31); + NaOH : 215 (4.93) , 337(4.36). ¹H

NMR(250MHz):<J2.46(3H,s,Me-3), 3.99(3H,s,OMe), 4.08(3H,s,OMe), 6.73(1 H^d , = 16,J₂ = 8Hz,H-8), 7.00(1 H,d,J = 2Hz,H-6), 7.04(1 H,d,J = 2Hz,H-15), 7.30(1 H,d,J = 8Hz,H-16), 7.32(1 H,dd,J, = 8,J₂ = 2Hz,H-12), 7.33(1 H,d,J = 2Hz,H-4), 7.58(1 H,d,J = 16Hz,H-8), 9.72(1 H,d,J = 8Hz,CHO).¹³CNMR(60MHz):(J9.5(Me-3), 56.1(2xOMe), 105.7(C-6), 109.6(C-12), 110.KC-3), 113.8(C-4), 114.7(C-15), 120.8(C-16), 122.9(C-11), 124.5(C-9), 129.7(C-5), 133.5(C-3a), 144.7(C-7a), 145.4(C-7), 146.3(C-14), 146.8(C-13), 152.6(C-2), 153.9(C-8), 193.6(C-10). EIMS m/z (rel. int.):338[M] ⁺ (96), 311(19), 310(100), 295(28), 267(29), 178(10), 169(12), 165(12), 152(11). 5-Formyl-3-(4-hvdroxy-3-methoxyphenyl)-7-methoxy-3-methylbenzofuran (Compound 12)

Crystals (2 mg). Mp 162-165° (from MeOH). TLC:R,0.43(S-1 ); anisaldehyde:light blue. IR _maxcrτV¹:3540(OH),3023, 1688(CO), 1515. UVΛ_max nm(loge):231 (4.40), 283(4.61 ),307(sh,4.53);+NaOH:240(4.44), 329(4.62).¹HNMR:<J2.48(3H,s,Me- 3), 4.00(3H,s,OMe), 4.07(3H,s,OMe), 5.80(1 H,s,OH), 7.03(1H,d,J = 8Hz,H-15), 7.32(1 H,dd,J, = 8, J₂ = 2Hz,H-16), 7.33(1 H,d,J = 2Hz,H-12), 7.37(1 H,d,J = 1.5Hz,H- 4), 7.68(1H,d,J = 1.5Hz,H-6), 10.0(1 H,s,CHO). ¹³C NMR: £9.5(Me-3),

56.1(2xOMe), 104.7(C-6), 110.5(C-3), 114.6(C-4), 117.4(C-15), 120.8(C-16), 122.8(C-11), 132.9(C-3a), 133.1 (C-5), 145.8(C-7), 146.2(C-14), 146.4(C-13), 146.8(C-7a), 153.0(C-2), 192.0(CO). EIMS m/z (rel. int. ):312[M] ⁺ (100), 297(14), 269(12), 156(15).

2-(4-Hvdroxy-3-methoxyphenyl)-5-r(E)-3-hvdroxypropenvH-7-methoxy-3- methylbenzofuran (Compound 13) Crystals (7 mg). Mp 180-183° (from MeOH).

TLC:R_f0.16(S-1); anisaldehyde:violet. IRv_max cnrv¹:3540(OH), 3020, 1612, 1515. UV Λ_max nm(Ioge):232(3.16), 271(3.30), 306(sh 3.23); +NaOH:240(3.29), 291 (3,19), 329(3.33). ¹H NMR δλ .45(1 H,t,J = 5.5Hz, OH-10), 2.41 (3H,s,Me-3), 3.99(3H,s,OMe), 4.05(3H,s,OMe), 4.35(2H,dd,J₁ = 5.5,J₂= 1 Hz,CH₂OH), 5.75( 1 H,s,OJ±-14), 6.37 ( 1 H dt,J, = 16,J₂ = 5.5Hz,H-9), 6.71 (1 H,dt,J, = 16,J₂= 1 Hz,H-8), 6.88(1 H,d,J = 1.5Hz,H-6), 7.00(1 H,d,J = 8.5Hz,H- 15), 7.11(1H,d,J = 1.5Hz,H-4), 7.29(1 H,dd,J, = 8.5, J₂ = 2Hz,H-1 β), 7.32(1H,d,J = 2Hz,H-12). ¹³C NMR:c59.6(Me-3), 56.1(2xOMe), 63.8(C-10), 104.8(C-6), 109.5(C-4), 110.2(C-3 and C-12), 114.4(C-15), 120.7(C-16), 123.5(C- 11), 127.2(C-9), 132.KC-8), 132.3(C-3a), 133.2(C-5), 142.6(C-7a), 145.0(C-7), 145.8(C-14), 146.6(C-13), 151.8(C-2). EIMS m/z (rel. int.): 340[M]⁺(100), 312(12), 311(20), 297(22), 284(37), 282(15), 281(12), 279(11), 165(13), 151(14), 149(10), 55(10).

2-(3.4-Dihvdroxyphenyl)-7-methoxy-3-methyl-5-(E)-propenylbenzofuran (Compound

14)

Oil (9 mg). TLC:R_f0.15(S-2); anisaldehyde:grey. IR v_max cm^~1:3548(OH), 3015,

1600, 1523, 1483. UV λ_max nm(log ):231 (4.49), 264(4.59), 207(sh.4.46); + NaOH:242(4.60), 327(4.44). 'H NMR(CD₃OD, 250

MHz):eJ1.βδOH.dd , = 6.5,J₂= 1.5Hz,Me-10),2.37(3H,s,Me-3), 4.01 (3H,s,0Me), 6.22(1H,dq,J₁ = 16,J₂ = 6.5Hz,H-9), 6.47(1 H,dq,J, = 16, J₂= 1.5Hz,H-8), 6.85(1 H,d,J = 1.5Hz,H-6), 6.88(1 H,d,J = 8.5Hz,H-15), 7.01 (1 H,d,J = 1.5Hz,H-4), 7.14(1H,dd,J, = 8.5Hz,J, = 2Hz,H-16), 7.26(1 H,d,J = 2Hz,H-12). ¹ C

NMR(CD₃OD,60MHz):<J9.6(Me-3),18.6(Me-10), 56.7(OMe), 105.8(C-6), 110.1 (C- 4), 110.5(C-3), 114.9(C-12), 116.6(C-15), 119.9(C-16), 124.5(C-11 ), 124.8(C-9), 132.9(C-8), 134.4(C-3a), 135.KC-5), 143.3(C-71), 146.2(C-7), 146.5(C-14), 146.9(C-13), 152.9(C-2). EIMS m/z (rel. int.):310[M] ⁺ (100), 309(10).

ervthro-5-["\ ,2-Dihydroxypropyl)- 2-(4-hvdroxy-3-methoxyphenyl)-7-methoxy-3- methylbenzofuran (Compound 15)

Amorphous (3mg). TLC:R_f0.16(S-2);anisaldehyde:violet. [α)_D+ 17°(c0.2). \ v_max cm^_1:3435(OH), 2927, 1655, 1516, 1462. UV Λ_max nm(loge):216(4.16), 304(4.04): + NaOH:211 (4.80), 328(4.11 ).¹HNMR:<H .11 (3H,d,J = 6.5Hz,Me-10), 2.42(3H,s,Me-3), 2.44(1H,br d,J = 3Hz, OH-9), 2.61(1H,br d,J = 3HZ,OH-8), 3.90(1 H,m,H-9), 3.99(3H,s,OMe), 4.05(3H,s,OMe), 4.48(1

3Hz,H- 8), 5,75(1 H,s,0H-14), 6.80(1 H,d,J = 1.5Hz,H-6), 7.01 (1 H,d,J = 8Hz,H-15), 7.10(1H,d,J = 1.5Hz,H-4),7.30(1H,dd,J₁ = 8,J₂ = 2Hz,H-16),7.33(1H,d,J = 2Hz,H- 12). ¹³CNMR(60MHz):c59.6(Me-3), 16.9(Me-10), 56.1 , 56.2(2xOCH₃), 72.5(C-9), 80.1 (C-8), 105.3(C-6), 109.5(C-12), 109.9(C-4), 110.KC-3), 114.5(C-15), 120.7(C-16), 123.5(C-11), 133.0(C-3a), 136.4(C-5), 142.5(C-7a), 145.0(C-7), 145.9(C-14),146.6(C-13),152.6(C-2).EIMSm/z(rel.int.):358[M] ⁺ (100),328(16), 314(21), 313(81), 285(52), 258(11), 257(57), 253(28), 225(14), 133(13).

(2R,3R)-2,3-Dihvdro-2-(4-hvdroxy-3-methoxyphenyl)-3-hvdroxymethyl-7-methoxy-5- (E)-propenylbenzofuran (Compound 19) Amorphous (6 mg). TLC:R_f0.3(S-1); anisaldehyde:red. [σ]_D + 65°(c.0.2). CD/l_max nmΔe):235(-3.15), 260( + 3.14), 285(4-2.39). \r\v_max cm^"1:3543(OH), 3019, 1613,1518, 1499, 1466. UV^_max nm(logβ):204(4.59),218(4.49), 273(4.23); + NaOH:211 (4.93), 268(4.38). ¹H NMR(CD₃0D):cJ1.78(3H,dd,J_l = 6,J₂ = 2Hz,Me10), 3.47(1 H,m,H-3), 3,78(2H,d,J = 7Hz,CH₂0H), 3.80(3H,s,OMe), 3.86(3H,s,0Me), 5.50(1 H,d,J-6Hz,H- 2), 6.11(1H,dq,J₁ = 16,J₂ = 6.5Hz,H-9), 6.33(1 H,dq,J, = 16,J₂ = 2Hz,H-8), 6.76(1H,d,J = 8Hz,H-15), 6.82(1Λ,ύά,A, =8,J₂ = 2Hz,H-16), 6.86(1H,br s,H-4), 6.88(1 H,br s,H-6), 6.94(1 H,d,J = 2Hz,H-12). ¹³C NMR(60MHz):18.3(Me-10), 53.7(C-3), 56.0(2xOMe), 64.0(CH₂OH-3), 88.7(C-2), 108.8(C-12), 110.0(C-6), 113.9(C-4), 114.3(C-15), 119.4(C-16), 123.8(C-9), 127.9(C-11), 129.7(C-8), 132.3(C-5), 133.0(C-3a), 144.4(C-7), 145.7(C-14), 146.7(C-7a), 147.6(C-13), EIMS m/z (rel.int.):342[M] ₊ (52), 324(78), 310(20), 309(100), 293(28), 292(32), 221(10), 165(14), 152(13), 151(22), 137(17).

eryf/7ro-1-(4-Acetoxy-3-methoxyphenyl)-2-f4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy1propylacetate (Compound 22) Colourless crystals (5 mg). MP 156-158° (from MeOH). TLC:R_f0.54(S-3); anisaldehyde:grey. [σ]_D+ 18°(c.0.1). IR/_max cm^_l:3018, 1762,1741,1510. UV λ_max nm(loge):226(4.08), 266(4.10), 308(4.08). 'H NMR:£1.31 (3H,d,J = 6.5Hz, Me-9'), 1.89(3H,dd,J₁ = 6.5,J₂= 1.5Hz,Me-10), 2.11 (3H,s,MeCO-7'), 2.25(3H,s,MeCO-4'), 2.40(3H,s,Me-3), 3.83(3H,s,OMe), 3.89(3H,s,OMe), 4.01 (3H,s,0Me), 4.77(1 H,m,H-8'), 5.91 ( 1 H,d , J = 4.5 Hz,H-7'), 6.24(1H,dq,J₁ = 16,J₂ = 6Hz,H-9), 6.50(1 H,dq,J, = 16,J₂ = 1.5Hz,H-8), 6.80(1H,d,J = 1.5Hz,H-6), 6.91 (1 H,d,J = 8Hz,H-15), 6.96(1 H,d,J = 8.5Hz,H-6'), 6.97(1H,dd,J_l=8.5, J₂ = 2HzH-5'), 7.01(1H,br s,H-4), 7.08(1 H,d,J = 2Hz,H-2'), 7.29(1 H,dd,J_l=8,J₂ = 2Hz,H-16), 7.32(1 H,d,J = 2Hz,H-12).¹³CNMR:£9.6(Me-3), 15.5(Me-9'), 18.4(Me-10), 20.7(MeCO-4'), 21.2(JVIeCO-7'), 56.0,56.1 (3xOMe), 76.6(C-7'),78.0(C-8'), 104.7(C-6), 109.2(C-4), 110.8(C-3), 111.3(C-12), 112.1 (C- 2'), 117.7(C-5'), 119.6(C-15), 119.9(C-6'), 122.4(C-16), 124.4(C-9), 125.8(C-11 ), 131.5(C-8), 133.0(C-3a), 133.7(C-5), 135.9(C-1'), 139.6(C-14'), 142.2(C-7a), 144.9(C-7), 147.KC-14), 150.9(C-13), 151.3(C-3'), 168.9(MeCO-4'), 169.9(MeCO-7'). EIMS m/z (rel.int.):588[M] ₊ (6), 366(14), 325(20), 324(100), 265(31), 223(54), 181(27), 164(25).

threo-Λ -(4-Acetoxy-3-methoxyphenyl)-2-f4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy1propyl-acetate (Compound 23) Mp 155-158° (from MeOH). TLC:R_f0.54(S-3); anisaldehyde:grey.

[ )_D + 35°(c.0.D. IRv_max cnrT¹:3018,1762,1741 ,1510. UV λ_max nm(loge):226(4.08), 266(4.10), 308(4.08). Η NMR: cJ1.24(3H,d,J = 6.5Hz,Me-9'). 191(31^,^=6.5, J₂ = 2Hz,Me-10), 2.04(3H,s,MeCO-7'), 2.30(3H,s,MeCO-4'), 2.43(3H,s,Me-3), 3.85(3H,s,OMe), 3.92(3H,s,OMe), 4.04(3H,s,OMe), 4.65(1 H,m,H-8'), 5.99(1 H,d,J = 6.5Hz,H-7'), 6.22(1 H,dq,J, = 16,J₂ = 6.5Hz, H-9), 6.50(1 H,dq, J_l = 16,J₂ = 2Hz,H-8),6.84(1 H,d,J = 1.5Hz,H-6), 6.99(1 H,dd,J, = 8,J₂ = 2Hz, H-16), 7.02(1 H,d,J =8Hz,H-15), 7.03(1 H,d,J = 1.5Hz,H- 4), 7.03(1 H,d,J = 8.5Hz H-15'), 7.04( 1 H ,d , J = 2Hz, H- 12) , 7.31(1H,dd,J_l=8.5,J₂ = 2Hz,H-16'),7.35(1H,d,J = 2Hz,H-12'),¹³CNMR:<J9.6(Me- 3), 16.7(Me-9'), 20.7(MeCO-4'), 21.1 (MeCO-7'), 56.0,56.1 (3xOMe), 76.6(C-7'), 77.8(C-8'), 104.6(C-6), 109.2(C-4), 110.7(C-3), 111.2(C-12), 111.9(C-2'), 116.8(C-5'), 119.8(C-15), 119.9(C-6'), 122.7(C-16), 124.4(C-9), 125.5(C-11), 131.5(C-8), 133.0(C-3a), 133.7(C-5), 136.0(C-1'), 139.8(C-4'), 142.2(C-7a), 144.9(C-7), 147.8(C-14), 150.5(C-2), 151.0(C-13), 151.2(C-3'), 168.8(MeCO-4'), 169.9(MeCO-7'). EIMS m/z (rel.int.):588[M] ₊ (6), 366(15), 325(20), 324(100), 265(30), 223(54), 181(27), 164(25).

f?reo-1-f2-(4-Hvdroxy-3-methoxyphenyl)-7-methoxy-3-methylbenzofuran-5-yll-2-l^'4- (3-methyl-5-(e)-propenylbenzofuran-2-yl)-2-methoxyphenoxy1propan-1-ol (Compound 24)

Amorphous (3mg). TLC:R_f0.69(S-2); anisaldehyde:violet. [σ]_D + 20°(c.0.2). IRv_max cm^"1:3540(OH), 3020, 2938, 1614,1511,1466. UVΛ_max nm(loge):229(4.16),

266(4.20), 308(4.14); +NaOH: 239(4.43), 330(4.46). ' NMR:

<J0.98(3H,d,J = 6.5Hz,Me-10'),

1.5Hz,Me-10), 2.36(3H,s,Me-3'), 2.43(3H,s,Me-3),3.98,4.01 ,4.02,4.06 (12H,s.4xMe), 4.22(1H,m,H-9'), 4.69(1 H,d,J = 8.5Hz,H-8'), 5.74(1 H,s,0H.-14'), 6.20(1H,dq,J, = 16,J₂ = 6.5Hz,H-9), 6.48(1 H.dq , = 16, J₂= 1.5Hz-H-8), 6.81 (1H,d,J = 8.5Hz,H-15), 6.81 (1H,d,J = 1.5Hz,H-6), 6.89(1 H,d,J = 1.5Hz,H-6'), 7.00(1 H,d,J = 8Hz,H-15'), 7.01 (1 H,d,J = 1.5Hz,H-4), 7.07(1 H,dd,J,-8.5, J₂ = 2Hz,H- 16), 7.09(1 H,d,J = 1.5Hz,H-4'), 7.29(1H,dd, J^δ.δ^ = 2Hz,H-16'), 7.31 (1 H,d,J = 2Hz,H-12'), 7.35(1 H,d,J = 2Hz,H-12).¹³CNMR:cJ9.6(Me-3), 9.7(Me- 3'), 18.0(Me-10'), 18.4(Me-10), 56.0, 56.1 ,56.3(4xOMe), 71.8(c-9'), 91.3(C-8'), 104.7(C-6), 105.4(C-6'), 109.2(C-4), 109.6(C-12'), 110.2(C-12), 110.4(c-4'), 110.6(C-3), 110.9(C-3'), 114.5(C-15), 118.5(C-15'), 119.8(C-16), 120.8(C-16'), 123.2(C-11'), 124.5(C-9), 126.2(C-11), 131.4(C-8), 132.9(C-31 '), 133.1(C-3a), 133.7(C-5), 133.9(C-5'), 142.2(C-7a), 142.6(C-7a'), 144.9(C-7), 145.2(C-7'), 145.9(C-14'), 146.6(C-13'), 147.9(C-4), 150.7(C-13), 151.KC-2'), 151.9(C-2). DCIMS m/z (rel.int.):665[m + h] ⁺ (10), 381(9), 367(12), 343(12), 342(25), 341(100), 340(24), 326(22), 325(94), 324(44).

2-Methoxy-4-r7-methoxy-3-methyl-5-(E)-propenylbenzofuran-2-yll-6-f4-(7-methoxy- 3-methyl-5-(E)-propenylbenzofuran-2-yl)-2-methoxyphenoxy]phenol (Compound 25) Amorphous (9 mg). TLC:R_f0.83(S-1); anisaldehyde:grey. IRi^* cm^_1:3538(OH), 3 0 2 0 , 2 9 3 9 , 1 6 1 3 , 1 5 9 9 , 1 5 1 0 . U V Λ _{m a x} nm(loge):233(4.14),267(4.48),309(4.46); + NaOH:215(5.23), 316(4.41). ¹H NMR(250 MHz):*1.91 (6H,m,Me-10 and Me10'), 2.31 (3H,s,Me-3'), 2.42(3H,s,Me- 3), 3.99, 4.01 ,4.04(12H,s,4xOMe), 6.20 ( 2 H , m , H-9 and H- 9'),6.47(1H,dq,J₁ = 16,J₂=1.5Hz,H-8'), 6.50(1 H^q , = 16,₂= 1.5Hz,H- 8),6.81(1H,d,J = 1.5Hz,H6'),6.84(1H,d, J = 1.5Hz,H-6), 7.00(1 H,d,J = 1.5Hz,H- 4'),7.03(1H,d,J = 1.5Hz,H4),7.04 (1 H,d,J = 2Hz,H-12'),7.05(1 H,d,J = 8Hz,H- 15),7.18(1 H,d,J = 2Hz,H16'), 7.31 (1 H,dd,J₁ =8,J₂ = 2Hz,H- 16),7.45(1H,d,J = 2Hz,H12).¹³C NMR(60MHz): <J9.5,9.6(Me-3,Me-3'), 18.4(Me- 10,Me-10'), 56.1,56.3,56.5(4xOMe), 104.7, 104.8(C-6,C-6'), 106.1 (C-16'), 109.3,109.8(C-4,C-4'), 111.2(C-3'), 111.3(C-12), 111.5(C-3), 111.9(C-12'), 116.8(C-15), 119.9(C-16), 122.8(C-11), 124.4,124.5(C-9,C-9'), 127.6(C-11'), 132.7,132.9(C-8,C-8'), 133.7,133.8(C-3a,C-3a'), 137.3(C-14'), 142,1 ,142.3(C- 71,C-7a'), 143.8(C-14), 144.8, 144.9(C-7,C-7'), 145.8(c-15'), 148.2(C-13,C- 13'), 150.4, 150.9(C-2,C-2'). DCIMS m/z (rel.int.):647[M + H] ⁺ (100), 646(44), 473(18), 369(12), 341(26), 339(16), 326(11), 325(46), 324(23), 309(34), 308(13), 283(20), 113(19), 107(18), 105(12).

8.2',9.3'-Tetrahydro-bis-eupomatenoid-7 (Compound 26)

Crystals (4 mg). Mp 175-179° (from MeOH). TLC:R_f0.26(S-1 ); anisaldehyde:grey- blue. [α]_D±0°(c.0.D. IRv_max cm^"1 :3540(OH), 3020,1618,1465. UVΛ_maxnm(log<:) 217(5.03), 279(4.83), 297(sh 4.79), +NaOH: 261(4.76), 305(4.75), 327(sh 4.78). Η NMRό^"1.05(3H,s,Me-3'), 1.31 (3H,d,J = 6.5Hz,Me-10),

1.86(3H,dd,J₁ = 6.5,J₂=1.5Hz,Me-10'), 2.37(3H,s,Me-3),2.97(1 H,dq, J₁ = 11,J₂ = 6.5Hz,H-9), 3.50(3H,z,OMe-13'), 3.76(1 H,d,J = 11 Hz, H-8), 3.80(3H,s,OMe-7), 3.92(3H,s,OMe-13'), 4.00(3H,s,OMe-7'), 6.17(1H,dq, J, = 16,J₂ = 6.5Hz,H-9'), 6.42(1 H^q , = 16,J₂= 1.5Hz,H-8'), 6.48(1 H,s,H-6), 6.63(1H,d,J = 8.5Hz,H-15'), 6.75(1 H,d,J = 2Hz,H-12'), 6.83(1H,dd, J_{1 =}8.5, J₂ = 2Hz,H-16'),6.85(1H,d,J = 1.5Hz,H-4'),6.90(1H,d,J = 8Hz,H-15),6.94(1H,s,H- 4), 6.98(1H,d,J = 1.5Hz,H-6'), 7.22( 1 H,dd, J, = 8, J₂ = 2Hz,H-16), 7.33(1H,d,J = 2Hz,H-12). ¹³C NMR:<59.6 (Me-3), 16.2(Me-10), 18.5(Me-10'), 22.1 (Me-3'), 42.7(C-9), 56.2(C-3'), 56.5, 56.7, 57.3,58.2(4xOMe), 98.1 (C-8), 107.9(C-2'), 109.7(C-6), 110.6(C-4), 110.9(C-6'), 111.3(C-12), 111.8(C-4'), 115.5(C-15'), 116.5(C-15), 117.4(C-12'), 120.7(C-16'), 121.2(C-16), 124.1 (C-9'), 124.5(C-11), 128.8(C-11'), 132.4(C-8'), 133.7(C-5'), 134.0(C-3a), 135.3(C-5), 136.0(C-3a'), 142.5(C-7a), 146.0(C-7), 146.4(C-7'), 146.9(C-13'), 147.7(C-7a'), 148.0(C-14'), 149.2(C-14), 152.6(C-2). CIMS m/z (rel.int.):649[M + H] ⁺ (13), 648(7), 367(12), 326(25), 325(100), 324(88).

15-(Aristolactam-l-9-yl)-eupomatenoid-7 (Compound 27)

Yellow crystals (4 mg). Mp 165-170° (from MeOH). TLC:R_f0.43(S-2); anisaldehyde:green. IRv_maxcm^"1:3531, 3442, 3020,3011,1699,1610,1482,1466. UV λ_max nm(loge):256 (4.83), 267(sh 4.79), 301(4.73), 405(4.00). ¹H NMR (C₅D₅N):όW86 (3H,dd,J, = 6.5, J₂ = 1.5Hz,Me-10), 2.44(3H,s,Me-3), 3.52(3H,s,OMe-8'), 3.80 (3 H ,s, OMe- 13) , 3.96 (3H,s, OMe-7) , 6.30(1 H,dq,J, = 16, J₂ = 6.5Hz,H-9), 6.34(2H,d,J = 1Hz,OCH.₂0), 6.63(1 H,dq,J₁ = 16,J₂= 1.5Hz,H-8), 7.09(1 H,d,J = 1.5Hz,H-6), 7.13(1 H,dd,J₁ = 8,J₂=1 Hz,H-7'), 7.27(1 H,d,J = 1.5Hz,H-4), 7.57(1 H,d,J = 2Hz,H- 12), 7.58(1H,t,J = 8Hz,H-6'), 7.81 (1 H,d,J = 2Hz,H-16), 7.84(1 H,s,H-2'), 8.57(1H,dd,J_l = 8,J₂=1Hz,H-5'), 11.26(1H, br s,0H), 12.02(1H,br s, NH). ¹³C NMR(C₅D₅N):<59.8(Me-3), 18.5(C-10), 55.9, 56.4,56.5(3xOCH₃), 103.4(OCH₂O), 105.1(c-6), 106.0(C-2'), 109.6„109.7(C-4,C-12), 111.5(C-7'), 112.6(C-4a'), 113.2(C-9'), 121.0(C-1'), 121.8(C-5'), 122.4(C-16), 124.4(C-9), 125.6(C-4b'), 126.KC-6'), 127.9(C-11), 129.0(C-15), 132.3)C-8), 133.8(C-3a), 134.3(C-5), 136.KC-10'), 142.6(C-7a), 145.6(C-7), 146.6(C-14), 147.7(C-4'), 148.6(C-13), 149.0(C-3'), 152.2(C-2), 158.8(C-8'), 169.7(CO). EIMS m/z (rel. int.): 615[M] ⁺ (100), 584(12), 583(11), 308(25), 292(14), 285(10).

14-0- -Cadinyl-eupomatenoid-7 (Compound 28)

Oil (3.5 mg). TLC:R_f0.78(S-1); anisaldehyde:grey. [σ]_D + 39°(C.0.3). \ v_max cm^_l:3019, 2917, 1614,1599, 1505, 1481, 1450. UV λ_max nm(loge):

235(4.45), 265(4.48), 311(4.39).¹HNMR:cJ0.77(3H,d,J = 7Hz,Me-13'orMe-14'),

0.90(3H,d,J = 7Hz,Me-13' or Me-14'), 1.25(3H,s,Me-15'), 1.71 (3H,s,Me-11'), 1.92(3H,dd,J₁ = 6.5,J₂=1.5Hz,Me-10), 2.43(3H,s,Me-3), 3.90(3H,s,OMe-13), 4.04(3H,s,OMe-7), 5.53(1H,br s,H-4'), 6.22(1 H.dq^ = 16,J₂ = 6.5Hz,H-9), 6.51(1H,dq,J_l = 16,J₂=1.5Hz,H-8),6.83(1H,d,J = 2Hz,H-6),7.04(1H,d,J = 8Hz,H- 15), 7.05(1 H,d,J = 2Hz,H-4), 7.26( 1 H,dd, J, = 8, J₂ = 2Hz,H-12), 7.32(1H,d,J = 2Hz,H-16). ¹³C NMR:<J9.7(Me-3), 15.1 (Me-13'), 18.4(Me-10), 18.5(Me-15'),21.5(Me-14@), 21.9(C-9'), 23.1 (C-1 '), 23.9(Me-11'), 25.9(C-12'), 31.0(C-2'), 37.7(C-8'), 40.2(C-5'), 46.3(C-6'), 48.0(C-10'), 55.8,56.1 (2xOMe), 84.9(C-9'), 104.7(C-6), 109.2(C-4), 110.9(C-12), 111.8(C-3), 119.2(C-16), 122.4(C-4'), 124.4(C-9), 125.8(C-15), 127.1 (C-11), 131.5(C-8), 133.1(C-3a), 133.7(C-5), 135.2(C-3'), 142.3(C-7a), 144.9(C-14), 151.4(C-2), 154,5(C-13). DCIMS m/z (rel.int.):529[M + H] ⁺ (41), 528(14), 367(16), 326(11), 325(51), 324(100), 206(15), 205(93), 203(6).

(2R,4S)-2-Hvdroxy-6-methoxy-4,7-dimethyl-1 -tetralone (Compound 34) Amorphous (17 mg). TLC:R_f0.44(S-1); anisaldehyde:yellow. [σ]_D-39°(c.01). CDΛ_max nm(Δ<=):220( + 3.74), 270(-2.09), 295( + 3.52), 315(-143). IRv_max cm~ :3496(OH), 3016, 1674,(C0), 1609, 1497. UV λ_max nm(loge):225(4.12), 274(4.09). ¹H NMR(250 MHz):<51.46(3H,d,J = 6.5Hz,Me-e), 176(1 H,ddd,J, = 13.5, J₂ = J₃= 12.5Hz, H-3_ax), 2.21(3H,br s,Me-7), 2.48{1H,ddd,J₁ = 12.5, J₂ = J₃ = 5.5Hz,H-3_eq), 3.16(1 H,m,H-4), 3.91 (3H,s,OMe), 4.33(1H,dd,J₁ = 13.5, J₂ = 5.5Hz,H-2_ax), 6.77(1 H,br s,H-5), 7.84(1 H,br d,J = 1 Hz,H-8). ¹³C NMR(60MHz):£15.7(Me-7), 20.5(Me-4), 31.6(C-4), 40.8(C-3), 55.5(OMe), 73.0(C-2), 107.0(C-5), 122.8(C-8a), 126.KC-7), 129.7(C-8), 149.0(C-4a), 162.9(C-6), 198.5(CO). EIMS m/z (rel.int.):220[M]⁺(68), 202(25), 177(19), 176(100), 175(61), 174(31), 159(12), 148(33), 147(14), 133(37), 117(14), 115(13).

EXAMPLE 2

DETERMINATION OF MUTAGENIC AND ANTIMUTAGENIC ACTIVITY

The four major constituents of the benzene extract from Aήstolochia taliscana roots - eupomatenoid-7 (7), eupomatenoid-1 (8), eupomatenoid-8 (17), Licarin-A (16) -were tested for their mutagenic and antimutagenic properties using the Ames bio-assay (Maron, D.M. and Ames, B.N., Mutation Research, 1983, 113, 173). The test compounds have the following structural formula:

Eupomatenoid-1 R^x & R^y = OCH₂0, dotted line = double bond Eupomatenoid-7 R^x = OH, R^γ = OCH₃, dotted line = double bond Eupomatenoid-8 R^x & R^γ = OCH₂0, dotted line = single bond

Licarin-A: R^x = OH, R^y = OCH₃, dotted line = single bond

Method

Salmonella typhimu um strain TA 100 was used as the test organism and 2-amino-anthracene (2-AA) and 2-nitrofluorene (2-NF) as standard mutagens, of which 1μg were added to each test plate. In the experiments with 2-AA, "S9 Mix" (derived from phenobarbital treated rat liver cells (De Flora, S., Camoirana, A., D'Agostini, F. and Balansky, R., Mutation Research, 1992, 267, 183) was also added.

Results

None of the tested substances showed any mutagenic activity. Eupomatenoid-7 (7) exhibited strong antimutagenic effects against 2- aminoanthracene as well as against 2-nitrofluorene (Tab. 4). Licarin-A (16) and eupomatenoid-1 (8) were found to be antimutagenically active only in the experiment against 2-AA but not against 2-NF (Tab. 5). However, eupomatenoid-8 (17) did not show any antimutagenic effect in the test systems used (Tab. 6). Eupomatenoid-7 (7)

Table 4: Results from the experiments on antimutagenic activity of eupomatenoid-7 (7).

( + )-Licarin-A (6)

Table 5: Results from the experiments on antimutagenic activity of ( ± )-licarin-

A (6)

Eupomatenoid-1 (8)

Table 6: Results from the experiments on antimutagenic activity of eupomatenoid-1 (8) Eupomatenoid-8 (17)

Table 7: Results from the experiments on antimutagenic activity of eupomatenoid-8 (17).

EXAMPLE 4 CYTOTOXICITY STUDIES

The cytotoxicity of compounds isolated from Aristolochia Taliscana was assayed using the well known brine shrimp bioassay. The cytotoxicities of compounds of the invention, expressed as percentage "death rates" after 24 hours, at varying concentrations, are shown in Table 8 below.

Table 8: Cytotoxicities of Compounds in the Brine Shrimp Assay

EXAMPLE 5

ANTIFUNGAL ACTIVITY

The antifungal activities of compounds of the invention was determined using a plate diffusion method. Plates containing medium and a fungal species were made up and 1 50 microgramme aliquots of a test compound of the invention were spotted onto the plate. The diameter of inhibition of fungal growth around the test compound was then determined. The results of the tests are shown in Table 9 below.

Table 9: Antifungal Activity

Claims

1 . The use of an extract from Aristolochia taliscana or one or more antimutagenically active compounds isolable therefrom for the manufacture of a medicament for the treatment of disease states mediated by mutagenesis.

2. The use of an extract from an Aristolochia species such as Aristolochia taliscana or one or more component compounds isolable therefrom for the manufacture of a medicament for the treatment of chronic inflammatory diseases such as inflammatory bowel disease, rheumatoid arthritis, synovitis and psoriasis.

3. The use of an extract from Aristolochia taliscana or one or more antifungally active compounds isolable therefrom for the manufacture of a composition for antifungal use, for example in the treatment of fungal infections in animals, or for use in the treatment of fungal infections in plants.

4. The use according to any one of claims 1 to 3 wherein the composition contains at least 10%, preferably at least 20%, and more preferably at least 25% by weight of a phenylbenzfuran.

5. The use according to claim 4 wherein the phenylbenzfuran is a eupomatenoid.

6. The use according to claim 4 or claim 5 wherein the phenylbenzfuran contains a phenolic group.

7. The use according to claim 6 wherein the phenylbenzfuran is eupomatenoid- 7.

8. The use according to any one of the preceding claims wherein the composition contains Licarin-A.

9. The use according to any one of the preceding claims wherein the composition contains a cytotoxic tetralone compound.

10. The use according to any one of the preceding claims wherein the composition contains a 2-hydroxy-1 -tetralone compound.

1 1 . The use according to claim 9 or claim 10 wherein the tetralone compound is (2R,4S)-2-Hydroxy-6-methoxy-4,7-dimethyl-1 -tetralone.

1 2. The use according to any one of the preceding claims wherein the composition contains at least 25% by weight of a phenolic eupomatenoid compound (such as eupomatenoid-7), at least 8% of Licarin-A and at least 8% of a non-phenolic eupomatenoid compound (such as eupomatenoid-8).

1 3. The use according to any one of the preceding claims wherein the composition contains an aristolactam.

14. The use according to any one of the preceding claims wherein the extract has been prepared by extraction of plant material from the Aristolochia species with an organic solvent.

1 5. The use according to claim 14 wherein the organic solvent is an alcoholic solvent such as ethanol or methanol or a mixture thereof.

1 6. The use according to claim 14 wherein the organic solvent is benzene, the solvent having been removed from the extract prior to use.

1 7. A method of treating a disease state mediated by mutagenesis, which method comprises administering to a patient suffering from said disease state an effective antimutagenic treatment amount of an extract from an Aristolochia species or one or more antimutagenic compounds isolable therefrom, as defined in any one of the preceding claims.

1 8. A method of inhibiting mutagenesis in an organism, which method comprises administering to the organism an effective antimutagenic amount of an extract from Aristolochia taliscana or one or more antimutagenic compounds isolable therefrom, as defined in any one of the preceding claims.

1 9. A method of producing a cytotoxic effect in an organism (such as an animal), which method comprises administering to the organism in an amount effective to produce the cytotoxic effect an extract from A^ήstolochia talscana or one or more cytotoxic compounds isolable therefrom, as defined in any one of the preceding claims.

20. A method of preventing or treating a fungal infection in an animal patient such as a human, which method comprises administering to the patient an effective antifungal amount of an extract from Aristolochia taliscana or one or more antifungal compounds isolable therefrom, as defined in any one of the preceding claims.

21 . A method of preventing or treating a fungal infection in a plant, which method comprises administering to the plant an effective antifungal amount of an extract from Aristolochia taliscana or one or more antifungal compounds isolable therefrom, as defined in any one of the preceding claims.

22. A method of inhibiting fungal growth in a substrate, which method comprises administering to the substrate an antifungal effective amount of an extract from Aήstolochia taliscana or one or more antifungal compounds isolable therefrom, as defined in any one of the preceding claims.

23. A method according to claim 22 wherein the substrate is selected from animal (e.g. mammals such as humans) and plant tissues.

24. A method of treating a chronic inflammatory disease such as inflammatory bowel disease, rheumatoid arthritis, synovitis or psoriasis in a patient, which method comprises administering to the patient an effective amount of an extract from an Aήstolochia species such as Aristolochia taliscana or one or more component compounds isolable therefrom.

25. The use of a compound for the manufacture of a medicament for use in any one or more of the therapeutic uses selected from the treatment of neoplastic diseases or diseases mediated or initiated by mutagenesis or abnormal cellular proliferation, or as a cytotoxic agent, or the treatment of chronic inflammatory conditions, the compound being of the formula (I):

(I) wherein the dotted line signifies a single or double bond; n is 0, 1 , 2 or 3; A is a monocyclic aryl ring optionally substituted by one or more substituent groups which may be the same or different and are selected from R³0, R³, R³S, halogen; aryl and heteroaryl, wherein R³ is hydrogen, or a hydrocarbyl group optionally substituted by a hydroxy or hydrocarbyloxy group; B is selected from carboxy, carboxaldehyde, hydrocarbyl and hydrocarbyloxy groups wherein the hydrocarbyl group is acyclic or cyclic, and optionally contains one or more heteroatoms, and is optionally substituted by one or more hydroxy, alkoxy, alkenyloxy, alkynyloxy, aryloxy, aldehyde, alkanoyl, acetal, hemiacetal and carboxy groups; R¹ is hydrogen or a hydrocarbyl group optionally including one or more heteroatoms and optionally substituted by one or more substituents selected from hydroxy, hydrocarbyloxy and aryl groups; and R² is hydroxy or a hydrocarbyl or hydrocarbyloxy group optionally substituted by one or more substituents selected from hydroxy, hydrocarbyloxy and aryl groups.

26. The use according to claim 25 wherein the monocyclic aryl ring A is attached to the 2-position of the furan ring.

27. The use according to claim 25 or claim 26 wherein the aryl ring is a phenyl group.

28. The use according to any one of claims 25 to 27 wherein the group B is attached to the 5-position of the benzofuran group.

29. The use according to any one of claims 25 to 28 wherein there is only one group R².

30. The use according to claim 29 wherein the group R² is attached to the 7- position of the benzofuran ring.

31 . The use according to any one of claims 25 to 30 wherein the dotted line signifies a double bond.

32. The use according to claim 25 wherein the compound of the formula (I) has the formula (II):

wherein B, R¹ and R² are as defined in any one of claims 25 to 31 , R⁴ and

R⁵ are the same or different and each is selected from hydrogen, C_v 20 hydrocarbyl, C₅.₂₀ aryl, or C₅.₂₀ oxygen-containing heteroaryl; R⁶ is selected from hydrogen, halogen, C,.^ hydrocarbyl or C_1-20 hydrocarbyloxy optionally substituted by one or more hydroxy, alkoxy, aralkyloxy groups; or R⁶ is C 5-25 aryl or oxygen or nitrogen-containing heteroaryl.

33. The use according to claim 32 wherein B is C,^ alkyl or alkenyl optionally substituted by one or more substituents selected from hydroxy, CHO, or R⁷0 wherein R⁷ is a C^ alkyl or alkenyl group.

34. The use according to claim 33 wherein the group B is selected from CH = CHCH₃, CH₂CH = CH₂, CH(OH)CH = CH₂, CH = CHCHO, CHO, CH = CHCH₂OH and CH(OH)CH(OH)CH₃.

35. The use according to claim 34 wherein B is CH = CHCH₃.

36. The use according to any one of claims 25 to 35 wherein R⁴ and R⁵ are selected from hydrogen, or C^._β alkyl, or R⁴ and R⁵ together define an alkylene group such as -CH₂-.

37. The use according to claim 36 wherein at least one of R⁴ and R⁵ is hydrogen.

38. The use according to any one of claims 32 to 37 wherein R⁶ is selected from hydrogen, halogen,

alkoxy (e.g.methoxy), a 2-benzofuranyl ring, and an aristolactam group.

39. The use according to any one of claims 25 to 38 wherein each hydrocarbyl group is selected from aliphatic, alicyclic and aromatic groups.

40. The use according to claim 39 wherein the hydrocarbyl group is selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkylalkyl, cycloalkylalkenyl, cycloalkylalkynyl, aryl, aralkyi, aralkenyl, aralkynyl, optionally interrupted by one or more heteroatoms such as oxygen and sulphur.

41 . The use according to claim 40 wherein the hydrocarbyl group is a

alkyl group selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl and t- butyl; a cycloalkyl group selected from cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyi, cyclooctyl, bicycloheptanyl, decalinyl, adamantyl, norbornyl and bicyclooctyl; an alkenyl or alkynyl groups selected from vinyl, ethynyl, allyl, 1 -propenyl, propargyl, but-1 -enyl, but-2-enyl, but-3-enyl and 3-methylbutenyl; a cycloalkenyl group selected from cyclopentenyl, cyclohexenyl and cycloheptenyl; an aryl groups selected from phenyl and naphthyi; or a phenylalkyl or phenylalkenyl groups selected from benzyl, phenethyl, phenylpropyl, phenylbutyl and styryl groups.

42. A compound of the formula (I) or (II) as defined in any one of the preceding claims for use in medicine, for example for use in any one or more of the therapeutic uses selected from the treatment of neoplastic diseases or diseases mediated or initiated by mutagenesis or abnormal cellular proliferation, or as a cytotoxic agent, or the treatment of chronic inflammatory conditions, or as an anti-fungal agent in the treatment of fungal infections in plants or animals; but provided that when R¹ is 3-methyl, R² is a single methoxy group at the 7-position, and either (i) the furan ring is unsaturated and is substituted at the 2-position with a 4-hydroxy-3- methoxyphenyl group or a 3,4-methylenedioxyphenyl group; or (ii) the furan ring is a 2,3-dihydrofuran ring and is substituted at the 2-position with a 4- hydroxy-3-methoxyphenyl group, then B is other than a prop-1-enyl group attached to the 5-position of the benzfuran ring.

43. A pharmaceutical composition comprising a compound of the formula (I) or (II) as defined in claim 42 together with a pharmaceutically acceptable carrier.

44. A compound of the formula (III):

wherein R¹¹ is hydrogen or C^ alkyl;

R¹² is selected from hydrogen, C^ alkyl; a cyclic terpenoid group or a group of the formula E, G or J;

R¹³ is selected from hydrogen; C,^ alkyl or hydroxy-C,.₃ alkyl;

R¹⁴ is selected from CH = CH-CH₃, CH(OH)CH = CH₂, CH = CH-CHO, CH = CH-CH₂0H, CH(OH)CH(OR¹⁷)CH₃, or a group L;

R¹⁵ is hydrogen or C,^ alkyl;

R¹⁶ is hydrogen, a group M or an aristolactam group; and

R ⁷ is hydrogen or a group T; wherein the groups E, G, L, J, M and

T are represented by the formulae:

(G)

(L) (J)

(M) (T) and pharmaceutically acceptable salts thereof, provided that when R¹¹, R¹³ and R¹⁵ are all methyl, and R¹² and R¹⁶ are both hydrogen, R¹⁴ is selected only from CH(OH)CH = CH₂, CH = CH-CHO, CH = CH-CH₂OH, CH(OH)CH(OR ⁷)CH₃ where R¹⁷ is a group T, or a group L.

45. A compound of the formula (IV):

wherein R¹¹, R¹², R¹³ R¹⁴, R¹⁵ and R¹⁷ are as defined in claim 25 and X is a group:

wherein R¹⁸ is hydrogen, benzyl or C,^ alkyl; R¹⁹ to R²⁴ are the same or different and are selected from hydrogen, hydroxy, C,^ alkoxy, C_1-6 alkyl and hydroxy-Cτ.₆ alkyl; or any two adjacent groups together form an alkylene dioxy group.

46. A compound of the formula (V):

wherein Y is a monocyclic or bicyclic terpenoid group and in particular a group of the structure:

47. A tetralone compound of the formula (VI):

wherein R²⁵ and R²⁷ are the same or different and each is C,^ alkyl; and R²⁶ is hydrogen or C,^ alkyl, or R²⁵ and R²⁶ together form an alkylene-dioxy group.

48. A compound according to claim 48 wherein R²⁵, R²⁶ and R²⁷ are all methyl.

49. A compound according to claim 47 or 48 for use as a biocide.

50. A compound according to claim 49 for use in the treatment of fungal infections, or for use in the treatment of cancers and other proliferative diseases such as psoriasis.

1 . A compound selected from the group consisting of:

( ± )-5-(1 -Hydroxyallyl)-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-3- methylbenzofuran;

2-(4-Hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7-methoxy-5-(E)- propenylbenzofuran;

2- (4-Hyd roxy-3-m eth oxyp henyl)-7-methoxy-3-methyl-5-[(E)-3- oxopropenyl]benzofuran;

5-Formyl-3-(4-hydroxy-3-methoxyphenyl)-7-methoxy-3-methylbenzofuran;

2-(4-Hydroxy-2-rπethoxyphenyl)-5-[(E)-3-hydroxypropenyl]-7-methoxy-3- methylbenzofuran;

2-(3,4-Dihydroxyphenyl)-7-methoxy-3-methyl-5-(E)-propenylbenzofuran; e/yf 7ro-5-(1 ,2-Dihydroxypropyl)-2-(4-hydroxy-3-methoxyphenyl)-7-methoxy-

3-methylbenzofuran;

(2R,3R)-2,3-Dihydro-2-(4-hydroxy-3-methoxyphenyl)-3-hydroxymethyl-7- methoxy-5-(E)-propenylbenzofuran; eA f 7Λθ-1 -(4-Acetoxy-3-methoxyphenyl)-2-[4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy]propylacetate; f 7Λeo-1 -(4-Acetoxy-3-methoxyphenyl)-2-[4-(7-methoxy-3-methyl-5-(E)- propenylbenzofuran-2-yl)-2-methoxyphenoxy]propyl-acetate; f 7reo-1 -[2-(4-Hydroxy-3-m ethoxyphenyl)-7-methoxy-3-methylbenzofuran-5- yl]-2-[4-(3-methyl-5-(e)-propenylbenzofuran-2-yl)-2-methoxyphenoxy]propan-

1 -ol;

2-Methoxy-4-[7-methoxy-3-methyl-5-(E)-propenylbenzofuran-2-yl]-6-[4-(7- methoxy-3-methyl-5-(E)-propenylbenzofuran-2-yl)-2-methoxyphenoxy]phenol;

8.2',9.3'-Tetrahydro-bis-eupomatenoid-7;

1 5-(Aristolactam-l-9-yl)-eupomatenoid-7;

14-0-σ-Cadinyl-eupomatenoid-7; and

(2R,4S)-2-Hydroxy-6-methoxy-4,7-dimethyl-1 -tetralone.

52. A pharmaceutical composition comprising a compound as defined in any one claims 44 to 51 together with a pharmaceutically acceptable carrier.