CA2288361C - Process for preparing natural product derivatives from plants in a single step - Google Patents
Process for preparing natural product derivatives from plants in a single step Download PDFInfo
- Publication number
- CA2288361C CA2288361C CA 2288361 CA2288361A CA2288361C CA 2288361 C CA2288361 C CA 2288361C CA 2288361 CA2288361 CA 2288361 CA 2288361 A CA2288361 A CA 2288361A CA 2288361 C CA2288361 C CA 2288361C
- Authority
- CA
- Canada
- Prior art keywords
- cndot
- nitrate
- birch
- betula
- derivative
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K36/00—Medicinal preparations of undetermined constitution containing material from algae, lichens, fungi or plants, or derivatives thereof, e.g. traditional herbal medicines
- A61K36/18—Magnoliophyta (angiosperms)
- A61K36/185—Magnoliopsida (dicotyledons)
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07J—STEROIDS
- C07J71/00—Steroids in which the cyclopenta(a)hydrophenanthrene skeleton is condensed with a heterocyclic ring
Landscapes
- Health & Medical Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Natural Medicines & Medicinal Plants (AREA)
- General Health & Medical Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Medical Informatics (AREA)
- Mycology (AREA)
- Biotechnology (AREA)
- Botany (AREA)
- Engineering & Computer Science (AREA)
- Medicinal Chemistry (AREA)
- Microbiology (AREA)
- Alternative & Traditional Medicine (AREA)
- Pharmacology & Pharmacy (AREA)
- Epidemiology (AREA)
- Animal Behavior & Ethology (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Steroid Compounds (AREA)
- Compounds Of Unknown Constitution (AREA)
Abstract
A process is disclosed, for preparing a derivative of a targeted natural product from plants. The targeted natural product is extracted from the desired part of the plant and the targeted natural product is transformed into the desired derivative(s). Both the extraction and transformation are carried out in a single step consisting of macerating the desired part of the plant in a composition comprising an organic solvent and a reactive agent. This process is particularly useful for preparing derivatives of betulin or lupeol from bark of birch.
Description
PROCESS FOR PREPARING NATURAL PRODUCT DERIVATIVES
FROM PLANTS IN A SINGLE STEP
Field of the invention The present invention relates to a process for preparing derivatives of targeted natural product from a desired part of a plant in one step. This io process is characterized in that the extraction of the targeted natural product from the desired part of the plant and the transformation of the targeted natural product into the desired derivative(s) thereof are carried out in a single step.
Background It was been well established that the outer bark of most white-barked birch, such as Betula papyrifera Marsh. species, are rich in pentacyclic triterpenoid compounds, particulary betulin. Betulin and other natural triterpenoids has 2o been extracted in good yields (20 to 30% of dry weight) from the bark of birch with organic solvents. The betulin is the major triterpenoid compound in bark of white birch and represents about 70% of the total triterpene.
The major interest in betulin lies in that it is a synthetic precursor of triterpenoid compounds having important pharmacological properties. To obtain these triterpenoid compounds, betulin must be subjected to some chemical reactions. This approach involves a step of purification of the extracted betulin and one or more steps of chemical reactions to produce the desired compound. These reactions are often non-quantitative (yield inferior to 100%) and an additional step of purification is necessary after each chemical reaction. This approach provides generally a low yield of triterpenoid compounds.
FROM PLANTS IN A SINGLE STEP
Field of the invention The present invention relates to a process for preparing derivatives of targeted natural product from a desired part of a plant in one step. This io process is characterized in that the extraction of the targeted natural product from the desired part of the plant and the transformation of the targeted natural product into the desired derivative(s) thereof are carried out in a single step.
Background It was been well established that the outer bark of most white-barked birch, such as Betula papyrifera Marsh. species, are rich in pentacyclic triterpenoid compounds, particulary betulin. Betulin and other natural triterpenoids has 2o been extracted in good yields (20 to 30% of dry weight) from the bark of birch with organic solvents. The betulin is the major triterpenoid compound in bark of white birch and represents about 70% of the total triterpene.
The major interest in betulin lies in that it is a synthetic precursor of triterpenoid compounds having important pharmacological properties. To obtain these triterpenoid compounds, betulin must be subjected to some chemical reactions. This approach involves a step of purification of the extracted betulin and one or more steps of chemical reactions to produce the desired compound. These reactions are often non-quantitative (yield inferior to 100%) and an additional step of purification is necessary after each chemical reaction. This approach provides generally a low yield of triterpenoid compounds.
Summary of the invention The object of the invention is to provide a process for preparing one or more natural product derivatives which is less time-consuming and/or gives at a higher yield than the known processes.
More particularly, the object of the invention is to provide a process for preparing a derivative of a targeted natural product by extraction of the io targeted natural product from a desired part of a plant and transformation of the so extracted targeted natural product into said derivative, wherein the extraction and transformation are carried out in a single step consisting of macerating the desired part of the plant in a composition comprising:
- an organic solvent; and - an reactive agent.
According to a preferred embodiment of the invention, the process is used for preparing a derivative of betulin by extraction of betulin from bark of white birch and transformation of the so extracted betulin into a derivative thereof, wherein the extraction and transformation are carried out in a single step consisting of macerating the bark of white birch in a composition comprising:
- an organic solvent; and - an oxidative agent.
The invention and its advantages will be better understood upon reading the non restrictive description of a preferred embodiment thereof, made with reference to the appended drawings.
Brief description of the drawings Figure 1 shows five derivatives of betulin and one derivative of lupeol.
More particularly, the object of the invention is to provide a process for preparing a derivative of a targeted natural product by extraction of the io targeted natural product from a desired part of a plant and transformation of the so extracted targeted natural product into said derivative, wherein the extraction and transformation are carried out in a single step consisting of macerating the desired part of the plant in a composition comprising:
- an organic solvent; and - an reactive agent.
According to a preferred embodiment of the invention, the process is used for preparing a derivative of betulin by extraction of betulin from bark of white birch and transformation of the so extracted betulin into a derivative thereof, wherein the extraction and transformation are carried out in a single step consisting of macerating the bark of white birch in a composition comprising:
- an organic solvent; and - an oxidative agent.
The invention and its advantages will be better understood upon reading the non restrictive description of a preferred embodiment thereof, made with reference to the appended drawings.
Brief description of the drawings Figure 1 shows five derivatives of betulin and one derivative of lupeol.
Figure 2 is a schema of the process according to a preferred embodiment of the invention where the molecular structure of betulin is shown.
Detailed description of the invention As aforesaid, the present invention is concerned with a process for preparing a derivative of a targeted natural product by extraction of the targeted natural product from a desired part of a plant and transformation of the so extracted io targeted natural product into said derivative. The extraction and transformation are carried out in a single step consisting of macerating the desired part of the plant in a composition comprising an organic solvent and a reactive agent.
is Barks of birch are preferably used in the process, since they contain a plurality of interesting natural product. Of course, other parts and other plants can be used in the process of the invention.
Barks of white birch (Betula papyrifera Marsh) are preferably used in the 20 present invention since they present a high content of betulin therein and its important bioavailability in the south area of the province of Quebec in Canada. Other kinds of birch can also be used such as the yellow birch (Betula alleghaniensis) which contains an appreciable amount of lupeol therein. However, different types of birch can be used such as the following 25 ones: Betula papyrifera Marsh (white birch), Betula verrucosa (white birch), Betula pubescens (white birch), Betula populifolia Marsh. (gray birch), Betula cordifolia Regel. (mountain paper birch), Betula X caerulea Blanch. (blue birch), Betula alleghaniensis (yellow birch) and Betula platyphylla var.
japonica. The type of birch listed in Hayer, E.W.H. et al., Phytochemistry, Vol.
3o 28, No. 9, pp. 2229-2242, 1989, can also be used in the process of the invention.
__~
Detailed description of the invention As aforesaid, the present invention is concerned with a process for preparing a derivative of a targeted natural product by extraction of the targeted natural product from a desired part of a plant and transformation of the so extracted io targeted natural product into said derivative. The extraction and transformation are carried out in a single step consisting of macerating the desired part of the plant in a composition comprising an organic solvent and a reactive agent.
is Barks of birch are preferably used in the process, since they contain a plurality of interesting natural product. Of course, other parts and other plants can be used in the process of the invention.
Barks of white birch (Betula papyrifera Marsh) are preferably used in the 20 present invention since they present a high content of betulin therein and its important bioavailability in the south area of the province of Quebec in Canada. Other kinds of birch can also be used such as the yellow birch (Betula alleghaniensis) which contains an appreciable amount of lupeol therein. However, different types of birch can be used such as the following 25 ones: Betula papyrifera Marsh (white birch), Betula verrucosa (white birch), Betula pubescens (white birch), Betula populifolia Marsh. (gray birch), Betula cordifolia Regel. (mountain paper birch), Betula X caerulea Blanch. (blue birch), Betula alleghaniensis (yellow birch) and Betula platyphylla var.
japonica. The type of birch listed in Hayer, E.W.H. et al., Phytochemistry, Vol.
3o 28, No. 9, pp. 2229-2242, 1989, can also be used in the process of the invention.
__~
The process can be advantageously used for preparing a derivative of betulin or a derivative of lupeol. It should be understand that the invention is not limited to betulin and lupeol as targeted natural product.
The organic solvent is preferably selected from the group consisting of chloroform (CHCI3), dichloromethane (CH2CI2), diethyl ether ((CH3CH2)20), tetrahydrofurane, acetone, pyridine and dimethylformamide (DMF).
According to a preferred embodiment of the invention, the betulin is targeted io and the following derivatives can be prepared at different yield:
allobetulin, betulinic aidehyde, betulonic aldehyde, betulinic acid and betulonic acid which are illustrated in Figure 1. Other derivatives can also be prepared by the process of this preferred embodiment such as betulone. Preferably, the derivatives of betulin prepared by the process are comprised in a group of the triterpenoid compounds including those mentioned above. This preferred embodiment of the invention is schematized in Figure 2.
According to another preferred embodiment of the invention, lupeol is targeted and the prepared derivative thereof is lupenone.
Different reactive agents can be used in the invention and the necessary one to prepare the above mentioned derivatives of betulin and derivative of lupeol is an oxidative agent.
Preferably, the oxidative agent is selected from the group consisting of iron nitrate ((FeNO3)3=9H20), copper nitrate (Cu(N03)2=2,5 H20), chromium nitrate (Cr(N03)3=9H20), zinc nitrate (Zn(N03)2=6H20), mercury nitrate (Hg(N03)2=H20), cerium nitrate (Ce(N03)3=6H20), manganese nitrate (Mn(N03)2=6H20), silver nitrate (AgNO3), chromium oxyde (CrO3), ferric chloride (FeCI3=6H20), silver chloride (AgC13), Jone's reagent, pyridinium chlorochromate (PCC), pyridinium dichromate (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permangante (KMnO4), barium manganate (BaMnO4), silver carbonate (Ag2CO3), ruthenium chloride (RuCI3) . and, 2,2,6,6-fetramethylpiperidinyl-1.-ox)c (TEMPO). Since betulin is-a preferred targeted natural product, the groups of betulin principally modified by.the oxidative agents are the two alcohol groups (see numbers 9 and 2 in Figure 2) and-the 5 alkene group (see number 3 in Figure 2). To prepare the derivatives shown in Figure 1, betulin is subjected to a transformation which is an oxidation or a.
rearrangement.
Depending on which oxidative age.nt or combination of oxidative agents is io present in the organic solvent, the identity and the yield- of the desired derivative or derivatives may. . vary. Generally, only one oxidative agent is used but a combination of two or more oxidative agents can be used in the process of the invention. L=~: . _ . .
Preferabiy, the oxidative agents are adsorbed onto a soiid support prior to .carrying out the extraction and transformation step.'The solid support may be siiica gel, alumina, montmorillonite K-10 or other solid supports. However, the Jones-'reagent and the PCC are preferably not adsorbed prior to be used in the process. . - . , 20 ln accordance with the invention, the maceration of the process is preferably camed out at a temperature from -80 C to 160 C and, more particuiariy, :.. from -5 C to 50 C. Also preferably, . the maceration is canied out for a-period varying between .1 minute and 24 hours. By varying the time of maceration, one can modulate the identity of the. detivative prepared by the , . ..... .,. -process. Preferred intervals of temperature and time have been 'deterrnined with respect of the preferred organic solvents and the prefen=ed oxi_dative agents listed above. However, it is to be understood that the maceration can be carried out at a temperature and for a period of time different than the ones described above without departing from the scope of the invention. _ Also according to the invention, the maceration of the process may be carried out under the ambient air or an inert gas such as nitrogen, argon or helium and possibly in presence of oxygen in order to modulate the identity of the desired derivatives prepared by the process or to optimize the resulting yield of the desired natural product derivative.
In practice, one or more desired derivatives can be prepared by the process at the same time. For example, using bark of white birch, the process can used to prepare betulinic aldehyde and betulonic aldehyde at the same time.
According to a preferred embodiment of the invention, the solution resulting lo from the process of extraction and transformation can be subjected to an additional treatment with reactive agent. More particularly, the remaining solution containing the organic solvent and all the soluble components contained therein can be isolated from the residual parts of plant and an additional amount of reactive agent can be added to the remaining solution in order to obtain a desired derivative. Such additional treatment is exemplified in Example 4.
In use, the extraction and transformation step of the process is preferably followed by a step of purification of the desired derivative or derivatives of 2o betulin. The purification may be achieved by precipitation, recrystallization, flash chromatography on silica gel or any other techniques of purification.
Exemple 1- Preparation of betulonic aidehyde 1.00 g of bark of white birch (Betula papyrifera Marsh) and 1.02 g of chromium oxyde being adsorbed on silica gel (CrO3/SiO2, 1:4) are deposited in 60 ml of chloroform at room temperature. The heterogeneous solution is agitated during 100 minutes and then the residual bark and silica gel are 3o removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 2 or 3 batches of 20 ml of chloroform. The chloroform recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and = 7 an oil is so obtained. This oil is submitted to flash chromatography on silica.
gel using dichloromethane: The less polar and more abundant product (Rf 0.68, 2% CH3OH1CH2C12on silica gel) is recovered in the-first fractions. After evaporating the solvent from the first fractions, a white solid is obtained which corresponds to a total extraction-transformation yield of 5,9 % of betulonic -aldehyde. The analysis by capillary gas chromatography of these first fractions shows that, the level of purity of the desired recovered product is higher than 95 %. 'The identity of the recovered product is determined by proton nuclear magnetic resonance (1H NMR) and by.mass spectrometry -ao (MS). The identity is confirmed by comparing the obtained spectroscopic results to the published data in Hua, Y. et aL, J. of Wood Chem, and,Tech.
11'503-517 (1991).
. ~ - . .
'H NMR (CDC13, 300 MHz, 5 in ppm): 9.67 *(d, J 2 Hz, 1 H, 28-H), 4.76 (m, = 15* 1 H, 29-H), 4.64 (irm, 1. H, 29-H), 2.87 (m, I H; 19-H), 2.45. (m, 2 H, 2-H), 1.70 (s, 3 H, 30-CH3), 0.93, 0.96, 0.99, 1.02, 1.07 (all singlets, 15 H, 5 x CH3)..
El-MS: 438 (M , 6), 55 (100), 81 (83), 41 (80), 67 (73), 79 (72), 69 (70). 93 (68), 95 (68), 107 (66). 91 (65), 43 (64). 20 Exemple 2- Preparation of betulinic aidehyde 1.00 g of bark of white birch (Betula papyrifera Marsh) and 0,68 g of 25 chromium oxide being adsorbed on silica gel .(CrOs/SiO2, 1:4) are deposited in 50 ml of chloroform at room temperature: The heterogeneous solution is agitated during a period of 20 minutes and then the -residual bark and silica gel are removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 3o 2 or 3 batches of 20 ml of chloroform. -The chloroform recovered' from the maceration and the rinse steps is distilled by evaporation under vacuum and the oil is so obtaine is submitted to flash chromatography on silica gel using dichloromethane. The fractions containing the second less polar product of the extracted oil (Rf = 0.38, 2% CH3OH/CH2CI2 on silica gel) are combined.
After evaporating the solvent from these fractions, a white solid is obtained which corresponds to a total extraction-transformation yield of 3,7 %. The analysis by capillary gas chromatography of these fractions shows that the level of purity of the desired recovered product is higher than 95 %. The identity of the recovered product is determined by proton nuclear magnetic resonance (1H NMR) and by mass spectrometry (MS). The identity is confirmed by comparing the obtained spectroscopic results to the published io data in Pathak, N.K.R. et al., Indian J. Pharm. Sci., Vol. 30, pp. 124-125.
'H NMR (CDCI3, 300 MHz): 5 9.68 (d, J = 1 Hz, 1 H, 28-H), 4.75 (m, I H, 29-H), 4.63 (m, 1 H, 29-H), 3.17 (m, 1 H, 3-H), 2.87 (m, I H, 19-H), 1.00-2.10 (complexe, CH2, CH), 1.70 (s, 3 H, 30- CH3), 0.75, 0.82, 0.92, 0.96, 0.98 (all singlets, 15 H, 5 x CH3).
El-MS: 440 (M , 7), 43 (100), 55 (97), 81 (96), 189 (96), 95 (89), 69 (86), 41 (85), 93 (84), 135 (80), 67 (78), 107 (78).
Exemple 3 - Preparation of Allobetulin 1.01 g of bark of white birch (Betula papyrifera Marsh) and 0.40 g of iron chloride being adsorbed on silica gel (FeCI3/SiO2, 1:4) are deposited in 50 ml of dichloromethane at room temperature. The heterogeneous solution is agitated during 20 minutes and then the residual bark and the silica gel are removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 2 or 3 batches of 20 ml of chloroform. The chloroform and the dichloromethane 3o recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and an oil is so obtained which is submitted to flash chromatography on silica gel using dichloromethane. The fractions containing the second less polar product from the extracted oil (Rf=0.25, 1 /a CH3OH in CH2CI2 on silic,a gel),are combined. After evaporating the solvent from these fKacfions, a white 'solid is obtained which corresponds to an extraction-transformation yield of 11.9 The : analysis by capillary gas chromatography of these fractions shows that the level of purity of the s desired recovered product is higher than 95 %. The identity of the recovered product is determined by proton nuclear, magnetic resonance-('H NMR) and by mass spectrometry (MS). The identity is confirmed by ccimparing the obtained spectroscopic -results to the published data in Lugemwa, F. N. et al., J. Agric. Food Chem. 38:493-496 (1990).
10.
'H NMR (CDCI3, 300'MHz); 5 3.76 (d, J = 8 Hz, 1 H, 28-H), 3.52 (s, I H, 19-H), 3.42 (d, J 8 Hz, I H, 28 H), 3.20 (m, 1_H, 3=H), 1.01-1.78 (complexe, CH2, CH), 0.96, 0.92, 0.91, 0.83, 0.78, 0.75, (all singlets, 21 H, 7 x CH3).
15 El-MS: 442 (M , 14), 107 (1.00), 189 (95), 135 (79), 121 (78), 207 (58), (35), 220 (16), 424 (13),.371 (9), 411 (7).
Exemple 4 - Preparation of betulinic acid 20 . . :
5.00 g of bark of white birch (Betula papyrifera Marsh) and 11.3 g chromium :
oxyde being adsorbed on alumina (Cr03/AI203 1:4) are deposited in 100 ml of dichloromethane at room temperature. The heterogeneous solution is agitated during 20 minutes and then the residual bark and alumina are 25 rernoved'from the maceration medium by filtration. In order to minimise the.
loss of products, the residual bark and alumina are rinsed with 2 or 3 batches of 50 ml of chloroform. The chloroform and the dichloromethane recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and a white powder is obtained. This powder is dissolved in 100 ml 30 of acetone and 0.67 g of potassium permanganate are added therein. The resulting solution is agitated at reom temperature during 1 hour. Then, 200 ml of water are added in the solution and the aqueous phase is extracted 3 times with 60 ml, of dichl'oromethane. The organic phase is washed with 3 batches of 50 ml of water, dried with anhydrous MgSO4 and then filtrated by gravity. The so resulting solution is concentrated and submitted to flash chromatography on silica gel using dichloromethane and methanol (1 %
methanol / dichloromethane). The identity of the betulinic acid is confirmed by 5 comparison of mass spectra of methyl ester derivates with authentic sample from Aldrich .
Although a preferred embodiment of the invention has been described in detail herein and illustrated in the accompanying drawings, and only four examples have been given, it is to be understood that the invention is not limited to this preferred embodiment and examples, and that various changes and modifications could be made without departing from the scope or spirit of the invention.
The organic solvent is preferably selected from the group consisting of chloroform (CHCI3), dichloromethane (CH2CI2), diethyl ether ((CH3CH2)20), tetrahydrofurane, acetone, pyridine and dimethylformamide (DMF).
According to a preferred embodiment of the invention, the betulin is targeted io and the following derivatives can be prepared at different yield:
allobetulin, betulinic aidehyde, betulonic aldehyde, betulinic acid and betulonic acid which are illustrated in Figure 1. Other derivatives can also be prepared by the process of this preferred embodiment such as betulone. Preferably, the derivatives of betulin prepared by the process are comprised in a group of the triterpenoid compounds including those mentioned above. This preferred embodiment of the invention is schematized in Figure 2.
According to another preferred embodiment of the invention, lupeol is targeted and the prepared derivative thereof is lupenone.
Different reactive agents can be used in the invention and the necessary one to prepare the above mentioned derivatives of betulin and derivative of lupeol is an oxidative agent.
Preferably, the oxidative agent is selected from the group consisting of iron nitrate ((FeNO3)3=9H20), copper nitrate (Cu(N03)2=2,5 H20), chromium nitrate (Cr(N03)3=9H20), zinc nitrate (Zn(N03)2=6H20), mercury nitrate (Hg(N03)2=H20), cerium nitrate (Ce(N03)3=6H20), manganese nitrate (Mn(N03)2=6H20), silver nitrate (AgNO3), chromium oxyde (CrO3), ferric chloride (FeCI3=6H20), silver chloride (AgC13), Jone's reagent, pyridinium chlorochromate (PCC), pyridinium dichromate (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permangante (KMnO4), barium manganate (BaMnO4), silver carbonate (Ag2CO3), ruthenium chloride (RuCI3) . and, 2,2,6,6-fetramethylpiperidinyl-1.-ox)c (TEMPO). Since betulin is-a preferred targeted natural product, the groups of betulin principally modified by.the oxidative agents are the two alcohol groups (see numbers 9 and 2 in Figure 2) and-the 5 alkene group (see number 3 in Figure 2). To prepare the derivatives shown in Figure 1, betulin is subjected to a transformation which is an oxidation or a.
rearrangement.
Depending on which oxidative age.nt or combination of oxidative agents is io present in the organic solvent, the identity and the yield- of the desired derivative or derivatives may. . vary. Generally, only one oxidative agent is used but a combination of two or more oxidative agents can be used in the process of the invention. L=~: . _ . .
Preferabiy, the oxidative agents are adsorbed onto a soiid support prior to .carrying out the extraction and transformation step.'The solid support may be siiica gel, alumina, montmorillonite K-10 or other solid supports. However, the Jones-'reagent and the PCC are preferably not adsorbed prior to be used in the process. . - . , 20 ln accordance with the invention, the maceration of the process is preferably camed out at a temperature from -80 C to 160 C and, more particuiariy, :.. from -5 C to 50 C. Also preferably, . the maceration is canied out for a-period varying between .1 minute and 24 hours. By varying the time of maceration, one can modulate the identity of the. detivative prepared by the , . ..... .,. -process. Preferred intervals of temperature and time have been 'deterrnined with respect of the preferred organic solvents and the prefen=ed oxi_dative agents listed above. However, it is to be understood that the maceration can be carried out at a temperature and for a period of time different than the ones described above without departing from the scope of the invention. _ Also according to the invention, the maceration of the process may be carried out under the ambient air or an inert gas such as nitrogen, argon or helium and possibly in presence of oxygen in order to modulate the identity of the desired derivatives prepared by the process or to optimize the resulting yield of the desired natural product derivative.
In practice, one or more desired derivatives can be prepared by the process at the same time. For example, using bark of white birch, the process can used to prepare betulinic aldehyde and betulonic aldehyde at the same time.
According to a preferred embodiment of the invention, the solution resulting lo from the process of extraction and transformation can be subjected to an additional treatment with reactive agent. More particularly, the remaining solution containing the organic solvent and all the soluble components contained therein can be isolated from the residual parts of plant and an additional amount of reactive agent can be added to the remaining solution in order to obtain a desired derivative. Such additional treatment is exemplified in Example 4.
In use, the extraction and transformation step of the process is preferably followed by a step of purification of the desired derivative or derivatives of 2o betulin. The purification may be achieved by precipitation, recrystallization, flash chromatography on silica gel or any other techniques of purification.
Exemple 1- Preparation of betulonic aidehyde 1.00 g of bark of white birch (Betula papyrifera Marsh) and 1.02 g of chromium oxyde being adsorbed on silica gel (CrO3/SiO2, 1:4) are deposited in 60 ml of chloroform at room temperature. The heterogeneous solution is agitated during 100 minutes and then the residual bark and silica gel are 3o removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 2 or 3 batches of 20 ml of chloroform. The chloroform recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and = 7 an oil is so obtained. This oil is submitted to flash chromatography on silica.
gel using dichloromethane: The less polar and more abundant product (Rf 0.68, 2% CH3OH1CH2C12on silica gel) is recovered in the-first fractions. After evaporating the solvent from the first fractions, a white solid is obtained which corresponds to a total extraction-transformation yield of 5,9 % of betulonic -aldehyde. The analysis by capillary gas chromatography of these first fractions shows that, the level of purity of the desired recovered product is higher than 95 %. 'The identity of the recovered product is determined by proton nuclear magnetic resonance (1H NMR) and by.mass spectrometry -ao (MS). The identity is confirmed by comparing the obtained spectroscopic results to the published data in Hua, Y. et aL, J. of Wood Chem, and,Tech.
11'503-517 (1991).
. ~ - . .
'H NMR (CDC13, 300 MHz, 5 in ppm): 9.67 *(d, J 2 Hz, 1 H, 28-H), 4.76 (m, = 15* 1 H, 29-H), 4.64 (irm, 1. H, 29-H), 2.87 (m, I H; 19-H), 2.45. (m, 2 H, 2-H), 1.70 (s, 3 H, 30-CH3), 0.93, 0.96, 0.99, 1.02, 1.07 (all singlets, 15 H, 5 x CH3)..
El-MS: 438 (M , 6), 55 (100), 81 (83), 41 (80), 67 (73), 79 (72), 69 (70). 93 (68), 95 (68), 107 (66). 91 (65), 43 (64). 20 Exemple 2- Preparation of betulinic aidehyde 1.00 g of bark of white birch (Betula papyrifera Marsh) and 0,68 g of 25 chromium oxide being adsorbed on silica gel .(CrOs/SiO2, 1:4) are deposited in 50 ml of chloroform at room temperature: The heterogeneous solution is agitated during a period of 20 minutes and then the -residual bark and silica gel are removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 3o 2 or 3 batches of 20 ml of chloroform. -The chloroform recovered' from the maceration and the rinse steps is distilled by evaporation under vacuum and the oil is so obtaine is submitted to flash chromatography on silica gel using dichloromethane. The fractions containing the second less polar product of the extracted oil (Rf = 0.38, 2% CH3OH/CH2CI2 on silica gel) are combined.
After evaporating the solvent from these fractions, a white solid is obtained which corresponds to a total extraction-transformation yield of 3,7 %. The analysis by capillary gas chromatography of these fractions shows that the level of purity of the desired recovered product is higher than 95 %. The identity of the recovered product is determined by proton nuclear magnetic resonance (1H NMR) and by mass spectrometry (MS). The identity is confirmed by comparing the obtained spectroscopic results to the published io data in Pathak, N.K.R. et al., Indian J. Pharm. Sci., Vol. 30, pp. 124-125.
'H NMR (CDCI3, 300 MHz): 5 9.68 (d, J = 1 Hz, 1 H, 28-H), 4.75 (m, I H, 29-H), 4.63 (m, 1 H, 29-H), 3.17 (m, 1 H, 3-H), 2.87 (m, I H, 19-H), 1.00-2.10 (complexe, CH2, CH), 1.70 (s, 3 H, 30- CH3), 0.75, 0.82, 0.92, 0.96, 0.98 (all singlets, 15 H, 5 x CH3).
El-MS: 440 (M , 7), 43 (100), 55 (97), 81 (96), 189 (96), 95 (89), 69 (86), 41 (85), 93 (84), 135 (80), 67 (78), 107 (78).
Exemple 3 - Preparation of Allobetulin 1.01 g of bark of white birch (Betula papyrifera Marsh) and 0.40 g of iron chloride being adsorbed on silica gel (FeCI3/SiO2, 1:4) are deposited in 50 ml of dichloromethane at room temperature. The heterogeneous solution is agitated during 20 minutes and then the residual bark and the silica gel are removed from the maceration medium by filtration. In order to minimise the loss of products, the residual bark and silica gel are rinsed with 2 or 3 batches of 20 ml of chloroform. The chloroform and the dichloromethane 3o recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and an oil is so obtained which is submitted to flash chromatography on silica gel using dichloromethane. The fractions containing the second less polar product from the extracted oil (Rf=0.25, 1 /a CH3OH in CH2CI2 on silic,a gel),are combined. After evaporating the solvent from these fKacfions, a white 'solid is obtained which corresponds to an extraction-transformation yield of 11.9 The : analysis by capillary gas chromatography of these fractions shows that the level of purity of the s desired recovered product is higher than 95 %. The identity of the recovered product is determined by proton nuclear, magnetic resonance-('H NMR) and by mass spectrometry (MS). The identity is confirmed by ccimparing the obtained spectroscopic -results to the published data in Lugemwa, F. N. et al., J. Agric. Food Chem. 38:493-496 (1990).
10.
'H NMR (CDCI3, 300'MHz); 5 3.76 (d, J = 8 Hz, 1 H, 28-H), 3.52 (s, I H, 19-H), 3.42 (d, J 8 Hz, I H, 28 H), 3.20 (m, 1_H, 3=H), 1.01-1.78 (complexe, CH2, CH), 0.96, 0.92, 0.91, 0.83, 0.78, 0.75, (all singlets, 21 H, 7 x CH3).
15 El-MS: 442 (M , 14), 107 (1.00), 189 (95), 135 (79), 121 (78), 207 (58), (35), 220 (16), 424 (13),.371 (9), 411 (7).
Exemple 4 - Preparation of betulinic acid 20 . . :
5.00 g of bark of white birch (Betula papyrifera Marsh) and 11.3 g chromium :
oxyde being adsorbed on alumina (Cr03/AI203 1:4) are deposited in 100 ml of dichloromethane at room temperature. The heterogeneous solution is agitated during 20 minutes and then the residual bark and alumina are 25 rernoved'from the maceration medium by filtration. In order to minimise the.
loss of products, the residual bark and alumina are rinsed with 2 or 3 batches of 50 ml of chloroform. The chloroform and the dichloromethane recovered from the maceration and the rinse steps is distilled by evaporation under vacuum and a white powder is obtained. This powder is dissolved in 100 ml 30 of acetone and 0.67 g of potassium permanganate are added therein. The resulting solution is agitated at reom temperature during 1 hour. Then, 200 ml of water are added in the solution and the aqueous phase is extracted 3 times with 60 ml, of dichl'oromethane. The organic phase is washed with 3 batches of 50 ml of water, dried with anhydrous MgSO4 and then filtrated by gravity. The so resulting solution is concentrated and submitted to flash chromatography on silica gel using dichloromethane and methanol (1 %
methanol / dichloromethane). The identity of the betulinic acid is confirmed by 5 comparison of mass spectra of methyl ester derivates with authentic sample from Aldrich .
Although a preferred embodiment of the invention has been described in detail herein and illustrated in the accompanying drawings, and only four examples have been given, it is to be understood that the invention is not limited to this preferred embodiment and examples, and that various changes and modifications could be made without departing from the scope or spirit of the invention.
Claims (23)
1. A process for preparing a derivative of a targeted natural product selected from the group consisting of betulin or lupeol, the process comprising a single step of:
macerating a desired part of a plant known to contain the targeted natural product into a composition comprising:
an organic solvent causing extraction of the targeted natural product from the desired part of the plant; and a reactive agent causing transformation of the extracted natural product into said derivative, said transformation being an oxidation or a rearrangement,
macerating a desired part of a plant known to contain the targeted natural product into a composition comprising:
an organic solvent causing extraction of the targeted natural product from the desired part of the plant; and a reactive agent causing transformation of the extracted natural product into said derivative, said transformation being an oxidation or a rearrangement,
2. A process as claimed in claim 1, wherein the plant is a birch and the part thereof is a bark.
3. A process as claimed in claim 2, wherein the birch is selected from the group consisting of Betula papyrifera Marsh (white birch), Betula verrucosa (white birch), Betula pubescens (white birch), Betula populifolia Marsh (gray birch), Betula cordifolia Regel (mountain paper birch), Betula X caerulea Blanch (blue birch), Betula alleghaniensis (yellow birch) and Betula platyphylla var. japonica.
4. A process as claimed in any one of claims 1 to 3, wherein the organic solvent is selected from the group consisting of chloroform (CHCl3), dichloromethane (CH2Cl2), diethyl ether ((CH3CH2)2O), tetrahydrofuran, acetone, pyridine and dimethylformamide (DMF).
5. A process as claimed in any one of claims 1 to 4, wherein the reactive agent is an oxidative agent.
6. A process as claimed in claim 5, wherein the oxidative agent is selected from the group consisting of iron nitrate ((FeNO3)3.cndot.9H2O), copper nitrate (Cu(NO3)2.cndot.2, 5H2O), chromium nitrate (Cr(NO3)3.cndot.9H2O), zinc nitrate (Zn(NO3)2.cndot.6H2O), mecury nitrate (Hg(NO3)2.cndot.H2O, cerium nitrate (Ce(NO3)3.cndot.6H2O), manganese nitrate (Mn(NO3)2.cndot.6H2O), silver nitrate (AgNO3), chromium oxide (CrO3), ferric chloride (FeCl3.cndot.6H2O), silver chloride (AgCl3), Jones reagent, pyridinium chlorochromate (PCC), pyridinium dichromete (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permanganate (KMnO4), barium managanate (BaMnO4), silver carbonate (Ag2CO3), ruthenium chloride (RuCl3) and 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO).
7. A process as claimed in claim 5, wherein, the oxidative agent is adsorbed onto a solid support, and the oxidative agent is selected from the group consisting of iron nitrate ((FeNO3)3.cndot.9H2O), copper nitrate ((Cu(NO3)2.cndot.5H2O), chromium nitrate (Cr(NO3)3.cndot.9H2O), zinc nitrate (Zn(NO3)2.cndot.6H2O), mercury nitrate (Hg(NO3)2.cndot.H2O), cerium nitrate (Ce(NO3)3.cndot.6H2O), manganese nitrate (Mn(NO3)2.cndot.6H2O), silver nitrate (AgNO3), chromium oxide (CrO3), ferric chloride (FeCl3.cndot.6H2O), silver chloride (AgCl3), pyridinium chlorochromate (PCC), pyridinium dichromate (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permanganate (KMnO4), barium manganate (BaMnO4), silver carbonate (Ag2CO3), and ruthenium chloride (RuCl3).
8. A process as claimed in claim 7, wherein the solid support is silica gel, alumina or montmorillonite K-10.
9. A process as claimed in any one of claims 1 to 8, wherein the maceration is carried out at a temperature from -80°C to 160°C.
10. A process as claimed in any one of claims 1 to 8, wherein the maceration is carried out at a temperature from -5°C to 50°C.
11. A process as claimed in any one of claims 1 to 10, wherein the maceration is carried out under ambient air or an inert gas.
12. A process as claimed in claim 11, wherein the inert gas is selected from the group consisting of nitrogen, argon and helium.
13. A process as claimed in claim 11, wherein the maceration is carried out in the presence of oxygen.
14. A process as claimed in any one of claims 1 to 13, wherein the maceration is carried out for one minute to 24 hours.
15. A process as claimed in any one of claims 1 to 14, wherein the maceration step is followed by a step of purification of the derivative of the targeted natural product.
16. A process as claimed in claim 15, wherein the purification is achieved by precipitation or recrystallization of the derivative of the targeted natural product.
17. A process as claimed in any one of claims 1 to 16, wherein the targeted natural product is betulin and the derivative of betulin is selected from the group consisting of allobetulin, betulinic aldehyde, betulonic aldehyde, betulinic acid and betulonic acid.
18. A process as claimed in claim 17, wherein the plant is Betula papyrifera Marsh (white birch).
19. A process as claimed in any one of claims 1 to 16, wherein the targeted natural product is lupeol and the derivative of lupeol is lupenone.
20. A process as claimed in claim 19, wherein the plant is Betula alleghaniensis (yellow birch).
21. A process as claimed in any one of claims 1 to 4, wherein the reactive agent is selected from the group consisting of iron nitrate ((FeNO3)3.cndot.9H2O), copper nitrate (Cu(NO3)2.cndot.2, 5H2O), chromium nitrate (Cr(NO3)3.cndot.9H2O), zinc nitrate (Zn(NO3)2.cndot.6H2O), mercury nitrate (Hg(NO3)2.cndot.H2O), cerium nitrate (Ce(NO3)3.cndot.6H2O), manganese nitrate (Mn(NO3)2.cndot.6H2O), silver nitrate (AgNO3), chromium oxide (CrO3), ferric chloride (FeCl3.cndot.6H2O), silver chloride (AgCl3), Jones reagent, pyridinium chlorochromate (PCC), pyridinium dichromate (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permanganate (KMnO4), barium manganate (BaMnO4), silver carbonate (Ag2CO3), ruthenium chloride (RuCl3) and 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO).
22. A process as claimed in any one of claims 1 to 4, the reactive agent is adsorbed onto a solid support, and the reactive agent is selected from the group consisting of iron nitrate ((FeNO3)3.cndot.9H2O), copper nitrate (Cu(NO3)2.cndot.2, 5H2O), chromium nitrate (Cr(NO3)3.cndot.9H2O), zinc nitrate (Zn(NO3)2.cndot.6H2O), mercury nitrate (Hg(NO3)2.cndot.H2O), cerium nitrate (Ce(NO3)3.cndot.6H2O), manganese nitrate (Mn(NO3)2.cndot.6H2O), silver nitrate (AgNO3), chromium oxide (CrO3), ferric chloride (FeCl3.cndot.6H2O), silver chloride (AgCl3), pyridinium chlorochromate (PCC), pyridinium dichromate (PDC), chromia-pillared montmorillonite catalyst (Cr-PILC), potassium ferrate (K2FeO4), potassium manganate (K2MnO4), potassium permanganate (KMnO4), barium manganate (BaMnO4), silver carbonate (Ag2CO3), and ruthenium chloride (RuCl3).
23. A process for preparing a derivative of betulin, the process comprising a single step of: macerating a bark of Betula papyrifera Marsh (white birch) in a composition comprising:
an organic solvent causing extraction of betulin from said bark of white birch; and a reactive agent causing transformation of the betulin into said derivative, said transformation being an oxidation or a rearrangement;
wherein the derivative of betulin is selected from the group of allobetulin, betulinic aldehyde, betulonic aldehyde, betulinic acid and betulonic acid.
an organic solvent causing extraction of betulin from said bark of white birch; and a reactive agent causing transformation of the betulin into said derivative, said transformation being an oxidation or a rearrangement;
wherein the derivative of betulin is selected from the group of allobetulin, betulinic aldehyde, betulonic aldehyde, betulinic acid and betulonic acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2288361 CA2288361C (en) | 1998-11-02 | 1999-11-02 | Process for preparing natural product derivatives from plants in a single step |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA002250481A CA2250481A1 (en) | 1998-11-02 | 1998-11-02 | Betulinol derivatives preparation process using silver birch bark |
| CA2,250,481 | 1998-11-02 | ||
| CA 2288361 CA2288361C (en) | 1998-11-02 | 1999-11-02 | Process for preparing natural product derivatives from plants in a single step |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2288361A1 CA2288361A1 (en) | 2000-05-02 |
| CA2288361C true CA2288361C (en) | 2009-03-24 |
Family
ID=31716467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2288361 Expired - Fee Related CA2288361C (en) | 1998-11-02 | 1999-11-02 | Process for preparing natural product derivatives from plants in a single step |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2288361C (en) |
-
1999
- 1999-11-02 CA CA 2288361 patent/CA2288361C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CA2288361A1 (en) | 2000-05-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6280778B1 (en) | Process for preparing natural product derivatives from plants in a single step | |
| Goh et al. | Alkaloids of Leuconotis griffithii and L. eugenifolia (Apocynaceae) | |
| Bovicelli et al. | Oxidation of natural targets by dioxiranes. Oxyfunctionalization of steroids | |
| KITAGAWA et al. | Saponin and Sapogenol. XXV. Steroidal Saponins from the Starfish Acanthaster planci L.(Crown of Thorns).(1). Structures of two genuine Sapogenols, Thornasterol A and Thornasterol B, and their sulfates | |
| Siddiqui et al. | Triterpenoidal constituents from Eucalyptus camaldulensis var. obtusa leaves | |
| Khan et al. | A steroid from Calotropis procera | |
| Glotter et al. | Steroidal constituents of Physalis minima (Solanaceae) | |
| JP2019509332A (en) | Baicalin magnesium compound, its production method and use | |
| Neogi et al. | Withacoagin, a new withanolide from Withania coagulans roots. | |
| CN107325140B (en) | A kind of chromone ketoside compounds isolated and purified from green bamboo mark and extracting method | |
| Fukuyama et al. | 11-Deoxyalisol C and alisol D: new protostane-type triterpenoids from Alisma plantago-aquatica | |
| Callies et al. | Distinct sesquiterpene pyridine alkaloids from in Salvadoran and Peruvian Celastraceae species | |
| CA2288361C (en) | Process for preparing natural product derivatives from plants in a single step | |
| Seto et al. | Synthesis and biological evaluation of extra-hydroxylated brassinolide analogs | |
| Shi et al. | Applying Mosher's method to acetogenins bearing vicinal diols. The absolute configurations of muricatetrocin C and rollidecins A and B, new bioactive acetogenins from Rollinia mucosa | |
| Brooks et al. | Daphnane diterpenes of Thymelaea hirsuta | |
| CN107973835B (en) | Natural mixed phytosterol catechin, preparation method and application | |
| Awasthi et al. | Madhuca butyracea. Constituents of the fruit-pulp and the bark | |
| Chaves et al. | Acetogenins from Porcelia macrocarpa: Stereochemical determination of 2-alkyl-3-hydroxy-4-methyl γ-lactones by 13C NMR spectroscopy | |
| Kobayashi et al. | Identification of a major cytokinin in coconut milk | |
| Kumar et al. | Tirucallane derivatives from Paramignya monophylla fruits | |
| Singh et al. | Isomotiol, a new triterpene from Strychnos potatorum | |
| Keinan et al. | Reductive elimination of vicinal oxygen functions with palladium (0). Applications in the withanolide series | |
| Ye et al. | Longifolicin, longicoricin, and gigantetroneninone, three novel bioactive mono-tetrahydrofuran annonaceous acetogenins from Asimina longifolia (annonaceae) | |
| Lontsi et al. | Seco-ring-A-triterpenoids from the rootwood of Musanga cecropioides |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| MKLA | Lapsed |
Effective date: 20191104 |