SI20274A - Novel polyketides, anthrone derivatives - Google Patents

Abstract

The present invention relates to novel polyketides, anthrone derivative's of the general formula (I) wherein R1 represents -CH2-CONH2 or -CH3, R2 represents -OH or -OCH3, and to a process for the preparation thereof as well as to the use thereof in the preparation of novel biologically active compounds, having a potential therapeutic action.

Description

FIELD OF THE INVENTION

The present invention relates to polyketides, anthron derivatives, and to a process for their preparation that includes techniques for recombinant DNA and the biosynthesis of recombinants thus obtained. The novel polyketides can be used alone or as intermediates in the preparation of novel biologically active compounds that have potential therapeutic efficacy.

The state of the art

Polyketides are known to be a large, structurally distinct family of natural compounds with many biological and pharmacological properties. Some important examples include antibiotics such as oxytetracycline and erythromycin, antifungal agents such as amphotericin and nystatin, cancer drugs such as tetracenomycin and doxorubicin, immunosuppressants such as rapamycin and substance FK506, cholesterol-lowering agents such as mevinolin and lovastatin avermectin and doramectin, the animal growth promoter monensin and salinomycin, the natural insecticide daptomycin and many others. Polyketides are the metabolites of actinomycetes, which include the genera Streptomyces, Actinomadura, Micromonospora, Saccharopolyspora and Nocardia. It has been estimated that by 1985, about 4,600 antibiotics of actinomycetic origin were characterized, of which 74 were in clinical use (eg see references in: Hranueli, Food Technology Biotechnology Rev. 27: 163, 1989).

An additional 1,100 metabolites, approximately 40% of which have a polyketide structure, have been described between 1988 and 1992 (Barr et al., WO application 98/27203, 1998).

The polyketides are prepared using enzyme complexes of polyketide synthetases (PKS) in a biosynthetic manner similar to the mode of fatty acids prepared using the enzyme complexes of fatty acid synthetases (FAS). PKS systems catalyze the condensation of simple carboxylic acids activated by coenzyme A with decarboxylation condensation. The great diversity of natural polyketide structures is due to the difference in chain length, choice of initial and extended units, and different reduction cycles, all of which determine their final structure. Similarities in the sequence of amino acid groups (derived from DNA sequences) and the mechanism of action between PKS gene products led to their division into type I and type II PKS by the classification system used for FAS (Hopwood and Sherman, Annu. Rev. Genet. 24:37, 1990). Modular type I PKSs responsible for the biosynthesis of complex polyketides, such as erythromycin, avermectin, and rapamycin, are multifunctional enzymes containing many unique active sites, organized in the form of a module. In contrast, type II PKSs responsible for biosynthesis of aromatic polyketides, such as actinorodin, tetracenomycin, phrenolicin, griseusin, and pigment spores (the product of a whi gene assembly whose structure has yet to be determined), consist of 4 to 6 mono- or bifunctional proteins, whose active sites are used sequentially for the early synthesis and modification of the polyketide chain. In complex polyketides, complete alignment of the active sites and structure of the biosynthetic products of modular PKS have promoted a rational model of novel complex polyketides by altering the PKS genes by genetic manipulation (e.g., Kao et al., J. Am. Chem. Soc. 117: 9105, 1995, and Pacey et al., J. Antibiot. 11: 1029, 1998). However, the approach to a rational model of novel simple aromatic polyketides cannot be so direct. This is due to a fundamental difference in the way in which PKS genes responsible for biosynthesis of aromatic and complex polyketides control the structure of the product. Unlike the complete alignment between the active sites and the structure of the PKS type I gene products, the PKS type II genes are all structurally very similar. Therefore, based on the primary structure of the PKS type II genes, the polyketide structure of their products cannot be assumed. As a result, they have designed a special vector host system for the expression of genetically modified genes

Type II SCC. It consists of the plasmid pRM5 and the Streptomyces coelicolor CH999 strain, from which the entire set of actinrodine biosynthesis genes (act genes) have been removed. In attempts to combine the genes of PKS, producers of different aromatic polyketides, this system was used to synthesize many new aromatic polyketide substances and to develop a strategy for their rational model. These experiments have shown that the carbon chain length in aromatic polyketides is responsible for the product of the clf gene (e.g., see references in: Khosla et al., WO prij. 96/40968; US 5,935,340, 1996; Hopwood, Chem.Rev. 97: 2465, 1997, and Barr et al., WO at 98/27203, 1998).

S. rimosus, the manufacturer of the antibiotic oxytetracycline (OTC), is one of the most genetically described bacteria among the industrially important streptomycetes. Two strains were studied extensively: M4018, studied in the UK, and R6, studied in Zagreb. A set of OTC biosynthesis genes (otc genes) were cloned from strain M15883, a derivative of strain M4018, and their restriction map was made [Hunter and Hill, in Biotechnology of Antibiotics (2nd Edition), W.R. Strohl (Ed.) Marcel Decker, New York, p. 21, 1997], DNA sequencing of the entire cluster has revealed the function of many genes, and for some, the function remains to be determined. The gene set of otc strain R6 was also cloned. Its restriction map is indistinguishable from that of strain M15883 (Hranueli et al., Food Technol. Biotechnol. 37 (2): 1999, in press). Therefore, the data obtained for strain M15883 and strain R6 can be completely compared. Inactivation of the chromosomal copy of the o / cDl gene (whose product participates in the folding, cyclization, and aromatization of the hypothetical nonacetide intermediate of OTC biosynthesis) of strain 5 rimosus R6 has led to an invention describing novel polyketides, pyranone derivatives (Petkovic et al., Croatia patent application P960131 A, 1998). In contrast, the otcC gene product hydroxylates the nonacetide intermediate of OTC biosynthesis many stages after the polyketide chain has been prepared and folded [Hunter and Hill, in Antibiotics Biotechnology (2nd Edition), W.R. Strohl (Ed.) Marcel Decker, New York, p. 21, 1997],

The essence of the invention

The present invention relates to novel polyketides, anthrone derivatives of general formula (I):

And in which

R ¹ represents -CH ₂ -CONH ₂ or -CH ₃ ,

R ² represents -OH or -OCH 3, and to a process for their preparation as well as for use in the preparation of novel biologically active compounds with potential therapeutic action.

DETAILED DESCRIPTION OF THE INVENTION

From the genetically engineered strain of S. rimosus R6-ZGL1 (deposited as Streptomyces rimosus R6-ZGL1 (otcC :: gmr) in the NCAIM collection under accession number NCAIM (P) B 001282) (with the inactivated otcC gene), new polyketides, anthrone derivatives, are isolated. of the general formula I wherein R ¹ represents -CH ₂ -CONH ₂ or -CH ₃ and R ² represents -OH or -OCH 3 obtained by fermentation, extraction, concentration, purification on silica gel and finally by gel filtration on Sephadex LH-20 columns.

According to available data, the compounds obtained so far have not been described. The new anthron derivatives are characterized by the fact that they all contain a carboxyl group and different carbon chain lengths in the structure, although in the genetically engineered strain (R6-ZGL1) the gene clf responsible for the carbon chain length is unchanged (see references in: Khosla et al ., WO Application 96/40968; US 5,935,340, 1996).

Bacterial strains, plasmids and growing conditions

The S. rimosus R6 strain (Hranueli et al., J. Gen. Microbiol. 114: 295, 1979) was used to inactivate the otcC gene. The genetic construction of S. rimosus R6-ZGL1 strain (otcC :: gmr) is described below. All cloning was performed in Escherichia coli TG1 cells (Gibson, PhD thesis, University of Cambridge, UK, 1984). PGLW75 double vector plasmid DNA was introduced into E. coli NM544 (deni) tube cells from which unmethylated DNA of this plasmid was isolated before transformation of S. rimosus cells (Marinus and Palmer, Gene 143: 1. 1994).

The plasmid pPFZ46 was used as the source of the otcC gene and adjacent parts of the otc DNA (Butler et al., Mol. Gen. Genet. 215: 231, 1989). The position of the gene in the otc gene set was determined by i.e. reverse genetic approaches using a degenerate oligonucleotide modeled on the amino-terminal peptide sequence of the purified ATC oxygenase enzyme (Binnie et al. J. Bacteriol. 171: 887. 1989). The plasmid pIBI24 of E. coli was used to inactivate the otcC gene by inserting the gmr gene into its structure (Dente et al., Nucl. Acids Res. JU: 1645, 1983). The gmr gene, which is the product responsible for antibiotic resistance gentamicin (Skeggs et al., J. Gen. Microbiol 133: 915, 1987), was obtained from plasmid p504 of E. coli (Garven, PhD, University of Glasgow, Great Britain, 1995). (Figure 1). A plasmid of the Streptomyces genus, pIJ486 (Ward et al., Mol. Gen. Genet. 203: 468. 1986), which contains the genetic marker tsr, which is the product responsible for antibiotic resistance to thiostrepton, was used to construct a double vector that can reproduce in cells of E. coli as well as in cells of the genus Streptomyces. The construction of all plasmids is described below.

E. coli strains were grown and maintained under standard conditions (Sambrook et al., Molecular Cloning, a Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989). Complete liquid (LM) and solid (CM) nutrient media for the cultivation and maintenance of S. rimosus cells and fermentation media (FM) for polyketide biosynthesis have already been described (Hranueli et al., J. Gen. Microbiol 114: 295). 1979, and Vešligaj et El., Appl. Environ. Microbiol. 41: 986. 1981).

Handling DNA and microorganisms

Methods for the isolation and purification of chromosomal and plasmid DNA, DNA digestion with restriction endonucleases, agarose gel electrophoresis, transfer of DNA to the membrane, DNA labeling with digoxigenin, and hybridization and detection have been described by Sambrook et al. (Molecular Cloning, a Laboratory Manual. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989).

E. coli cells were transformed using a DNA plasmid using an electroporation apparatus (Bio-Rad Pulsing apparatus) according to the manufacturer's instructions, while cells of strain 5. rimosus R6 were transformed using the same apparatus by the method described in Pigac and Schrempf (Appl. Environ. Microbiol. 61: 352, 1995).

Construction of pGLW75 plasmids containing the inactivated otcC gene

Plasmid p508x was obtained from plasmid p508 (Garven, PhD Thesis, University of Glasgow, UK, 1995). This plasmid (based on the pIBI24 vector, which is present in a large number of copies in E. coli cells) contains a portion of the otc gene assembly from the Pstlyj restriction site to the 5flcl ₂ i restriction site. The DNA segment between the restriction sites Kpnl ^ and Kpn (. _{] 9} was replaced by a DNA linker containing the unique restriction site of the enzyme Xbal (junction of the blunt ends). plasmid p508x to obtain plasmid pGLW72 In a parallel construct, a 2.3 kb fragment of the otc gene cluster (from restriction site S / P / 2I14 to restriction site Ρό '/ Ιπ) was cloned from plasmid pPFZ46 (Butler et al. Mol Gen. Genet 215: 231, 1989) to PIBI24 plasmid to obtain plasmid pGLW73.This plasmid was then subcloned with Pst \ -Sac [a 3.9 kb DNA fragment from pGLW72 plasmid containing the gmr marker. the insertion was performed by partially digesting the DNA of plasmid pGLW72. The partially digested DNA fragment was then purified from agarose gel, digested with Sac \ endonuclease and linked to plasmid vector pGLW73. The resulting plasmid was named pGLW74 (Fig. 1) The plasmid pGLW74 contains the gmr genetic marker cloned within the otc gene C and bounded by DNA fragments from S. rimosus R6 strain, i.e. 2.7 kb down and

1.8 kb upstream of the otcC gene. The plasmids described so far have been constructed using vectors containing the origin for DNA replication in E. coli.

The final DNA strand in the double vector construct was the unstable plasmid pIJ486, which contains a source for DNA replication into a Streptomyces genus. Plasmid pGLW74 contains a unique restriction site for the Sad enzyme used to linearize it. The linearized plasmid was then ligated with plasmid pIJ486 digested within its unique restriction site for the Sad enzyme. The resulting double vector was named pGLW75 containing the inactivated otcC gene (Fig. 1).

Construction of strain X rimosus R6-ZGL1

An inactivated gene copy (otcC :: gmr present on plasmid pGLW75) was introduced into S. rimosus R6 strain cells by electroporation. Plasmid pGLW75 contained the genetic markers gmr and tsr. The transformants obtained were selected for antibiotic resistance thiostrepton. Antibiotic resistance with thiostrepton was used for primary selection of transformants, whereas antibiotic resistance with gentamicin in S. rimosus species was only used for secondary selection. Subsequent transplantation of the transformants to the gentamicin-containing CM medium confirmed the presence of a complete gmr genetic marker in their cells. Following the growth of S. rimosus R6 strain transformant cells in LM medium under non-selective conditions (in the absence of antibiotics) at the time when recombination between the DNA plasmid and the DNA chromosome of S. rimosus was assumed, the transformant cells were planted on CM medium , which also contains no antibiotics. In such a system, the plasmid is often lost during cell division [segregation instability of plasmid pIJ486 in the absence of selection is well described (Ward et al., Mol. Gen. Genet. 203: 468, 1986)]. Inactivation of the hydroxylase gene (otcC gene) is performed within the chromosome of S. rimosus R6 strain. Chromosome gene inactivation occurs when a copy of the otcC: .gmr gene replaces the original otcC gene in the chromosome upon loss of the pIJ486 vector and associated DNA strands. To confirm the inactivation plausibility, chromosomal DNA was isolated from selected colonies of transformants (gentamicin resistant and thiostreptone sensitive), digested with FcoRI and Sad restriction endonucleases, transferred to the membrane (Sambrook et al., Molecular Cloning, a Laboratory Manual Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, 1989) and hybridized with a probe containing the otcC gene (or a portion of DNA from Kpnl _{] 9} to Sph [ ₂ o) · We constructed the S. rimosus strain in this way R6-ZGL1.

Biosynthesis of novel polyketides

The S. rimosus R6-ZGL1 strain (otcC :: gmr) stored in 40% glycerol at -70 ° C was transplanted onto solid CM media in petri dishes containing gentamicin (500 pg / mL) [CM medium contains: 10. 0 g malt extract, 4.0 g yeast extract, 4.0 g glucose, 2% agar (w / v), distilled water up to 1.0 1; The pH was adjusted to 7.2 with 10% NaOH; sterilization for 40 minutes at 110 ° C]. Petri dishes were incubated in a thermostat for 5 to 7 days (at 25 - 30 ° C), after which individual streptomycin colonies grew. One colony of streptomycetes was seeded with 50 ml of gentamicin-containing LM liquid medium (500 pg / ml) [LM-medium containing: 40.0 g of dextrin, 16.0 g of CSL (com steep liquor; about 50% solids), 7 , 0 g CaCO ₃ , 2.0 g (NH 4 SO ^ distilled water to 1.0 l; pH was adjusted to 7.2 with 10% NaOH; sterilization for 30 minutes at 120 ° C] and the resulting suspension was incubated on a rotary shaker (150 - 300 rpm) for 48 to 72 hours at 25 to 30 ° C. FM medium for biosynthesis of polyketide containing gentamicin (500 pg / ml), [FM medium contains: 55 g of corn starch, 7.5 g CSS (com steep solid), 7.0 g CaCO ₃ , 8.5 g (NH ^ SO ^ 2.0 g N ^ Cl, 0.14 g COC1 ₂ x 6H ₂ O, 10.0 g soybean oil, tap water up to 1.0 l; natural pH; sterilization for 40 minutes at 120 ° C] was seeded with 10% streptomycet biomass from LM medium. Biosynthesis (fermentation) was performed on a rotary shaker (150 - 300 rpm ) for 5 to 7 days at a temperature of 25 to 30 ° C.

Extraction, thickening and purification of new polyketide substances

The fermentation liquor (2.0 L) of strain 5. rimosus R6-ZGL1 was saturated with the addition of an inorganic salt, e.g. with sodium dihydrogen phosphate, and extracted with a water miscible organic solvent, e.g. with n-butanol, n-octanol, chloroform, ethyl acetate, methyl iso-butyl ketone, etc., preferably ethyl acetate. The solvent was evaporated under reduced pressure and temperature from 35 to 50 ° C. The various substances present in the resulting solid were separated into silica gel column chromatography eluting with two solvent systems (A: chloroform-methanol, B: n-hexane-ethyl acetate). The fractions eluted with System A (8-16% methanol) were combined and the solvent was evaporated under reduced pressure. Separation was continued by filtration on a Sephadex LH20 column and eluted again with solvent system A. The fractions eluted with system A (6% methanol) contained substance 1 (35 mg). The fractions eluted with System B (30-45% ethyl acetate) were combined and the solvent was evaporated under reduced pressure. The resulting solid was dissolved in 2 ml of methanol and cooled to + 4 ° C. After 20 hours, substance 3 (7 mg) precipitated as a yellow precipitate. The fractions eluted with System B (65-80% ethyl acetate) were also combined and the solvent was evaporated under reduced pressure. The resulting solid was dissolved in 2 ml of methanol and cooled to + 4 ° C. Substance 2 (11 mg) precipitated as a light yellow precipitate after 24 hours.

Extraction, concentration, and purification of polyketides 1 to 3 were monitored by thin layer chromatography (TLC) on silica gel plates (Merck, cat. No. 15684) using a solvent mixture of chloroform-methanol-water (9: 4: 0,1) as mobile phase.

Chemical characterization of new polyketides

The chemical structure of the obtained polyketides was determined on the basis of 2D homonuclei and heteronuclei studies using the COSY-45 technique for the direct determination of HH coupling (Williams and Fleming, Methods and Organic Chemistry, 5th edition, McGraw-Hill Publishing Co, London, UK, 1997 ), HC-COBI techniques for determining single-bond HC interaction ( ^! J) (Sanders and Hunter, Modem NMR Sprectroscopy: A Guide for Chemists, Oxford University Press, UK, 1987), and HMBC techniques for determining single-bond HC interaction ( ² J) and three bonds (J) (Williams and Fleming, Methods in Organic Chemistry, 5th edition, McGraw-Hill Publishing Co, London, UK, 1997).

The IR spectrum detected a number of absorption bands between 1675 and 1615 cm &^lt; ^-1 &^gt;, indicating the presence of polyketide-specific carbonyls.

The preparation of new anthrone derivatives is illustrated by the following examples, which are by no means a limiting factor for the invention.

Example 1

-carbamoylmethyl-1,8,10-trihydroxy-10-methyl-9-oxo-9,10-dihydroanthracene-2carboxylic acid (1), or

3-Carbamoylmethyl-1,8,10-trihydroxy 10-methyl-anthrone-2-carboxylic acid (1)

One colony of S. rimosus R6-ZGL1 strain (otcC :: gmr) was seeded with 50 ml of gentamicin-containing LM medium (500 pg / ml). The resulting microbial suspension was grown on a rotary shaker (200 rpm) for 72 hours at 28 ° C. Gentamicin-containing polyketide (FM) biosynthesis medium (FM) (500 pg / ml) is seeded with 10% microbial biomass from LM medium. Biosynthesis (fermentation) was performed on a rotary shaker (200 rpm) for 7 days at 28 ° C. The fermentation broth (2.0 L) was saturated with the addition of sodium dihydrogen phosphate (1.2 kg) and extracted three times with the same volume (2.0 L) of ethyl acetate. The organic layers were combined and evaporated under reduced pressure at 40 ° C to dry residue. The dry residue (2.0 g) was partitioned by silica gel column chromatography eluting with solvent system A (chloroform-methanol). The fractions eluted with System A (8-16% methanol) were combined and concentrated by evaporation under reduced pressure. Continue the separation on a Sephadex LH-20 column by eluting again with chloroform-methanol (6% methanol).

The fractions for which TLC was shown to contain compound 1 were collected and concentrated by evaporation under reduced pressure to give 35 mg of compound I as a yellow powder.

≪ 1 > H NMR: (400MHz, DMSO-d6); 12.41 (2H, br. S, NH ₂ ), 11.97 (1H, s, 2-COOH), 7.77 (1H, s, 8-OH), 7.64 (1H, s, 1- OH), 7.69 (1H, t, J = 8.0 Hz, H-6), 7.42 (1H, dd;

J = 7.6 Hz, H-5), 7.40 (1H, s, H-4), 6.95 (1H, d, J = 8.4 Hz, H-7), 6.29 (1H , s, 10OH), 3.72 (2H, ABq, J = 16 Hz, 3-CH ₂ -), 1.51 (3H, s, 10-CH ₃ ).

¹³ C NMR: (100MHz, DMSO-d6); 191.5 (C-9), 171.1 (3-CH2-CO-NH ₂ ), 166.9 (2COOH), 161.5 (C-8), 158.3 (Cl), 152.0 ( C-10a), 151.5 (C-4a), 141.8 (C-3), 137.4 (C-6), 126.2 (C-2), 119.1 (C-4), 117.1 (C-5), 116.0 (C-7), 113.0 (C-8a), 111.6 (C-9a),

69.4 (3-CH _? -CO-NH _? ), 38.7 (IO-CH3).

Example 2

1.8.10- trihydroxy-3,10-dimethyl-9-oxo-9,10-dihydroanthracene-2-carboxylic acid (2) or

1.8.10- Trihydroxy-3,10-dimethyl-anthrone-2-carboxylic acid (2)

After fermentation and isolation as described in Example 1, the separation of the dry residue is carried out by chromatography on a silica gel column, eluting with solvent system B (n-hexane-ethyl acetate). The fractions eluted with System B (65-80% ethyl acetate) were combined and concentrated by evaporation under reduced pressure. The resulting solid was dissolved in 2 ml of methanol and cooled to + 4 ° C. After 24 hours, substance 2 (11 mg) precipitated as a light yellow precipitate.

Ή NMR: (400MHz, DMSO-d6); 12.00 (1H, br. S, 2-COOH), 7.81 (1H, s, 8-OH), 7.53 (1H, s, 1-OH), 7.68 (1H, ζ J = 8.0 Hz, H-6), 7.42 (1H, dd, J = 7.6 Hz, H-5), 7.28 (1H, s, H-4), 6.93 (1H, d , J = 8.2 Hz, H-7), 6.23 (1H, s, 10-OH), 2.37 (3H, s, 3-CH ₃ ), 1.50 (3H, s, 10- CH ₃ ).

¹³ C NMR: (100MHz, DMSO-d6): 191.4 (C-9), 167.4 (2-COOH), 161.5 (C-8 and Cl), 152.0 (C-10a). 151.3 (C-4a), 144.8 (C-3), 137.3 (C-6), 126.5 (C-2), 118.4 (C-4), 117.5, 116 , 0 (C-5 and C-7), 113.0 (C-8a), 110.9 (C-9a), 38.7 (10-CH ₃ ), 20.0 (3-CH ₃ ).

Example 3

3-Carbamoylmethyl-1,8-dihydroxy-10-methoxy-10-methyl-9-oxo9,10-dihydroanthracene-2-carboxylic acid (3) or

3-Carbamoylmethyl-1,8-dihydroxy-10-methoxy-10-methylantrone-2-carboxylic acid (3)

After fermentation and isolation as described in Example 1, substance 3 (7 mg) was obtained by separating the dry residue by chromatography on a silica gel column eluting with solvent system B (30-45% n-hexane-ethyl acetate). As in Example 2, the fractions containing substance 3 were combined and concentrated by evaporation under reduced pressure and also dissolved in 2 ml of methanol. The solution was cooled to +4 ° C. After 20 hours, substance 3 precipitates as a yellow precipitate.

≪ 1 > H NMR: (400MHz, DMSO-d6); 12.41 (2H, br. S, NH ₂ ), 11.94 (1H, s, 2-COOH), 7.76 (1H, s, 8-OH), 7.60 (1H, s, 1- OH), 7.69 (1H, t, J = 8.0 Hz, H-6), 7.42 (1H, dd, J = 7.6 Hz, H-5), 7.39 (1H, s , H-4), 6.95 (1H, d, J = 8.4 Hz, H-7), 3.81 (2H, ABq, J = 16 Hz, 3-CH2-), 3.61 (3H , s, 10-OCH ₃ ), 1.51 (3H, s, 10-CH ₃ ).

¹³ C NMR: (100MHz, DMSO-d6): 191.5 (C-9), 170.2 (3-CH ₂ -CO-NH ₂ ) 166.8 (2COOH), 161.6 (C-8) 158.3 (Cl), 152.0 (C-10a), 151.7 (C-4a), 141.1 (C-3), 137.6 (C-6), 126.2 (C-2) ), 119.2 (C-4), 117.2 (C-5), 116.1 (C-7), 113.0 (C-8a), 111.9 (C-9a),

69.4 (3-CH ₂ -CO-NH ₂ ), 51.8 (10-O-CH ₃ ), 38.7 (IO-CH 3).

Claims (6)

Patent claims 1. New polyketides, anthron derivatives, of general formula I And in which R ¹ represents -CH 2 -CONH 2 or -CH 3, R ² represents -OH or -OCH ₃ . A new compound according to claim 1, wherein R ¹ represents -CH 2 -CONH 2, R ² represents -OH. A new compound according to claim 1, wherein R represents -CH ₃ and R represents -OH. 1 o The new compound of claim 1, wherein R represents -CH ₂ -CONH ₂ and R represents -OCH ₃ . Process for the preparation of new polyketides, anthrone derivatives according to claim 1, characterized in that the S. rimosus R6-ZGL1 strain is constructed using plasmids pPFZ46, pIBI24, p504, p508x and pIJ486, and then fermented for 5 to 7 days at a temperature 25 to 30 ° C on a rotary shaker, then isolation by extraction with a water miscible organic solvent and their separation by silica gel column chromatography using two conventional solvent systems, such as chloroform-methanol or n-hexane- ethyl acetate, followed by separation on a Sephadex LH-20 column by elution with a mixture of the yarns of said solvents or by precipitation in methanol. 6. New polyketides, anthrone derivatives, for use as biologically active compounds or as intermediates in the preparation of novel biologically active compounds that have potential therapeutic efficacy.