DICARBOXYLIC ACID ESTER DERIVATIVES OF GINSENOSIDE, PHARMACEUTICAL PREPARATIONS CONTAINING THE SAME, AND

PREPARATION THEREOF

FIELD OF THE INVENTION:

[0001] The present invention relates to a series of dicarboxylic acid ester derivatives of ginsenoside, and applications of using such derivatives as medicine.

BACKGROUND OF THE INVENTION:

[0002] Ginseng has many physiological and pharmacological effects, such as anticancer, enhancing immunity, regulating blood-glucose level, anti-ageing, enhancing memory and learning capabilities, etc. The pharmacological properties of ginseng are generally attributed to its triterpene glycosides, called ginsenosides. Ginsenosides are mainly dammarane triterpenes with protopanaxadiol (PPD) and protopanaxatriol (PPT) aglycon moieties. According to the molecular structures, ginsenosides mainly can be divided into protopanaxadiols, protopanaxatriols, and oleanolic acid-type saponin, wherein Ra ₁ , Ra ₂ , Ra ₃ , Rb ₁ , Rb ₂ , Rb ₃ , Rc, Rd, F ₂ , Rg ₃ , Rg ₅ , Rh ₂ , Rh ₃ , Rk ₁ , etc. belong to protopanaxadiols, Re, Rg ₁ , Rg ₂ , Rg ₄ , Rh ₁ , Rh ₄ , etc. belong to protopanaxatriols, and Ro belongs to oleanolic acid-type saponin. Ra, Rb, Rc, Rd, and Re, etc. are ginsenosides containing at least 3-5 sugar moieties which are relatively more abundant in white ginseng have relatively better water solubility. On the other hand, other ginsenosides containing only 1-2 sugar moieties (e.g. Rg ₃ , Rg ₅ , Rh ₁ , Rh ₂ , Rh ₃ , RIc ₁ , etc.) or even free of sugar moiety (PPD, PPT, etc.) which are rare ginsenosides present only in heat treated red Panax ginseng and have stronger physiological activities, such as anti-cancer effect, but are more hydrophobic.

[0003] Ginsenoside Compound K (CK) is an important ingredient with a concentration of only a few tens of ppm in Panax ginseng. Many studies have indicated that Ginsenoside CK has excellent clinical therapeutic and preventive effects on malignant tumors. US Patent 5,919,770 and its parallel patents CN patent 1,182,433A and WO 97- 31013 have disclosed the metabolites of ginseng saponins by human intestinal bacteria and the preparation of an anticancer agent. One of the main metabolites is CK, and the preparation from said disclosure is a potential anti-cancer agent with immunity enhancement function and capable of inhibiting the vascularization of tumors and extravasation of cancer cells. CN Patent 1,417,345A and its parallel patent WO03-04383

have disclosed a method for preparing CK by enzyme hydrolysis of ginseng saponins, which is for preparing anti-cancer medicine.

[0004] US patent publication 2002-00132260 A and its parallel CN patent 1415304 A and CN patent 1225366 A disclose the use of ginsenoside Rh2 in pharamaceutical compositions used in methods of inhibiting the multiplication of cancer cells, and a method for preparing Rh2. CN patent 1417225 A discloses a method of preparing a ginsenoside Rg ₃ by acid hydrolysis, which is for a preparation of anti-tumor medicine. US patent publication No. 2003-0092638 A and its parallel WO patent WO03- 024459 disclose a use of ginsenosides PPD and PPT as an anti-cancer helper. CN patent 1418633 A discloses an application of ginsenoside PPD as an anti-cancer helper. CN patent 1280845 A discloses an anti-cancer pharmaceutical composition comprising ginsenoside Rh ₁ as an effective ingredient. US patent publication 2003-0190378 and its parallel WO patent WO03-086438, and US patent publication 2003-0190377 and its parallel WO patent WO03-086439 disclose methods for preparing rare ginsenosides such as Rk ₂ , Rh ₃ , PPD, Rg ₃ , Rg ₅ , and Rk ₁ ; and methods of using them in treating and preventing cancers or allergic diseases.

[0005] CK and other ginsenosides with a few carbohydrate moieties have low polarity and poor water solubility. Dissolution enhancers (e.g. Cremophor emulsifϊer (polyoxyethylated castor oil), dimetbylsulfoxide (DMSO), ethanol, etc.) are required for the pharmaceutical and cosmetic preparation. The toxicity of these dissolution enhancers often restricts the utilities of these ginsenosides. Thus, the present invention plans to perform a series of systematic chemical modifications on CK and the above-mentioned ginsenosides in order to enhance its water solubility and thus its utilities.

SUMMARY OF THE INVENTION:

[0006] One primary objective of the present invention is to provide a dicarboxylic acid ester derivative of ginsenoside, pharmaceutical preparation and cosmetic preparation containing the same, and preparation thereof.

[0007] Another objective of the present invention is to provide a derivative of 20-

O-β-D-glucopyranosyl-protopanaxadiol (compound K, abbreviated as CK), pharmaceutical preparation and cosmetic preparation containing the same, and preparation thereof.

[0008] In order to accomplish the aforesaid objectives, a ginseng saponin or ginsenoside is reacted with an activated dicarboxylic acid derivative, such as dicarboxylic anhydride, dicarboxylic halide or dicarboxylic ester etc. in a suitable solvent and in the presence of a catalyst to form a dicarboxilyic acid ester, the reaction of which using diacid anhydride can be represented by the following equation:

GN + → GN'-[C(O)-A-C(O)OH] _m

wherein m is a positive integer; GN is a ginsenoside; and GN' is a residual resulting from m number of hydroxyl groups of GN reacted with the diacid anhydride, i.e. -OH being converted to -O- which is bonded to -C(O)-A-C(O)OH; and A is -(CRV) _n -, wherein R ⁴ and R ⁹ independently are H or C1-C4 alkyl, and n is an integer of 0-8.

[0009] The ginsenoside, GN, suitable for use in the present invention includes (but not limited to):

wherein R ¹¹ is -OH ₅ -0-Glc or -O-Glc-Glc; R ¹² is H ₅ -OH, -O-Glc, -O-Glc-Glc or -O- Glc-Rha; R ¹³ is -OH or -O-Glc; R ¹⁴ is -OH, -O-Glc, -O-Glc-Glc, or -O-Glc-Glc-Ac; and R ¹⁵ is -H, -O-Glc, -O-Glc-Ac, or -O-Glc-Rha, wherein GIc- is

Glc-Glc- is

, wherein GIc- is defined as above; Rha-Glc-is

;

Ac-GIc- is

Ac-GIc-GIc- is

Ac-GIc-O _^ wherein Ac-GIc- is defined as above.

[0010] Typical examples of the ginsenosides, GN, are as follows:

Ginsenosides R ¹¹ R ¹² R ¹³

PPD HO- H- HO-

Rh ₂ GIc-O- H- HO-

Rg ₃ Glc-β-l,2-Glc-0- H- HO-

CK HO- H- GIc-O-

F2 GIc-O- H- GIc-O-

PPT HO- HO- HO-

Rhi HO- GIc-O- HO-

Fl HO- HO- GIc-O-

Rf HO- Glc-β-l,2-Glc-0- HO-

Rgi HO- GIc-O- GIc-O-

Rg ₂ HO- Rha-α-l,2-Glc-0- HO-

Ginsenosides R ¹⁴ R ¹⁵ R 14 R 15

Rg ₆ HO- Rha-Glc-0

Rk ₁ Glc-Glc-O- H-

Rk ₂ GIc-O- H-

Rk ₃ HO- GIc-O-

Rs ₅ Ac-Glc-Glc-O- H-

Rs ₇ HO- Ac-GIc-O-

F4 HO- Rha-Glc-0

Rgs Glc-Glc-O- H-

Rh ₃ GIc-O- H-

Rh ₄ HO- GIc-O-

Rs ₄ Ac-Glc-Glc-O- H-

Rs ₆ HO- Ac-GIc-O-

[0011] The dicarboxylic acid ester of ginsenoside synthesized in the present invention comprises at least one group of -OC(O)-A-C(O)OH which replaces -OH of the ginsenoside, wherein A is -(CR ⁴ R ⁹ V, wherein R ⁴ and R ⁹ independently are H or C1-C4 alkyl, and n is an integer of 0-8, which may be represented (but not limited to) by the following formulas:

(UL-A) (HI-B) wherein the dicarboxylic acid ester of (I) comprises the following (V), (T) or a racemic mixture thereof:

(I ¹ ) (I") wherein R ^11' is R ¹¹ , -OE, -O-Glc ¹ or -O-Glc-Glc'; R ^12' is R ¹² , -OE, -O-Glc ¹ , -O-Glc-Glc ¹ or -0-Glc-Rha ¹ ; R ¹³ ' is R ¹³ , -OE or -O-Glc ¹ ; R ^14' is R ¹⁴ , -OE ₅ -O-Glc ¹ , -O-Glc-Glc ¹ , or - O-Glc-Glc-Ac ¹ ; and R ^15' is R ¹⁵ , -O-Glc ¹ , -O-Glc-Ac ¹ , or -0-Glc-Rha', wherein R ¹¹ , R ¹² , R ¹³ , R ¹⁴ and R ¹⁵ are defined as above; E is -C(O)(CR ⁴ R ⁹ ) _n COOH, wherein R ⁴ , R ⁹ and n are defined as above; -O-Glc' is

, wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ are H or E, wherein E is defined as above; -O-Glc-Glc ¹ is

, wherein R ^5' , R ^6' , and R ^7' are H or E, wherein E and -O-Glc' are defined as above;

-O-Glc-Rha' is

are H or E, wherein E is defined as

above, and -O-Rha' is OR ⁶ OR ⁵ , wherein R ⁵ , R ⁶ , and R ⁷ are defined as above;

-O-Glc- Ac' is

, wherein R ⁵ , R ⁶ , and R ⁷ are defined as above; -O-Glc-Glc-Ac' is

^ _{wherein R} 5' _{5 R} ⁶ ' _{} R} τ _gnd .o-Glc-Ac ¹ are defined as above.

[0012] Preferably, R ⁴ and R ⁹ are H, and n is 2 or 3.

[0013] Preferably, R ¹² ' is H, and R ^{1 v} is -OH, and R ₁₃ ¹ is -O-Glc ¹ .

[0014] Preferably, R ^12' is H, and R ¹¹ ' is -O-Glc ¹ , and R ¹³ ' is -OH.

[0015] Preferably, R ¹² ' is H, and R ¹¹ ' is -O-Glc-Glc', and R ¹³ ' is -OH.

[0016] Preferably, R ^12' is H, and R ^11' is -O-Glc ¹ , and R ¹³ ' is -O-Glc ¹ .

[0017] Preferably, R ¹² ' is -O-Glc ¹ , and R ¹¹ ' is -OH, and R ¹³ ' is -OH.

[0018] Preferably, R ^12' is -O-Glc-Glc', and R ^{1 v} is -OH, and R ^13' is -OH.

[0019] Preferably, R ^12' is -OH ¹ , and R ¹¹ ' is -OH, and R ^13' is -O-Glc ¹ .

[0020] Preferably, R ¹² ' is -O-Glc ¹ , and R ¹¹ ' is -OH, and R ¹³ ' is -O-Glc ¹ .

[0021] Preferably, R ^12' is -O-Glc-Rha ^! , and R ^11' is -OH, and R ¹³ ' is -OH.

[0022] Preferably, R ¹² ' is -H, and R ¹¹ ' is -OH or -OE, and R ^13' is -OH or -OE.

[0023] Preferably, R ^12' is -OH or -OE ₅ and R ^{1 v} is -OH or -OE ₅ and R ¹³ ' is -OH or

OE.

[0024] Preferably, R ¹⁴ and R ¹⁵ are one of the following combinations:

[0025] The present invention also provides a pharmaceutical preparation, which comprises an aqueous solution, and a dicarboxylic acid ester of ginsenoside of the present invention or a pharmaceutically acceptable salt thereof, dissolved in said aqueous solution. The aqueous solution can be a buffered or non-buffered aqueous solution with or without pharmaceutically acceptable solubility enhancer of said dicarboxylic acid ester of ginsenoside, such as aliphatic alcohol, polyhydroxy alcohol, pharmaceutical or cosmetic acceptable oils, or Cremophor. In the present invention, the terms "pharmaceutical" and "pharmaceutically" also means "cosmetic" and "cosmetically", respectively. The pharmaceutical preparation may be used as a food supplement or a healthy food, and it has been proved being at least useful in the fabrication of an anti-tumor medicine. A further aspect of the present invention is a method for treating a tumor, the method comprising administering to a subject in need of treatment a dicarboxylic acid ester of ginsenoside of the present invention, or a pharmaceutically acceptable salt thereof, in an amount effective to treat said tumor. A still further aspect of the present invention is the use of a dicarboxylic acid ester of ginsenoside of the present invention or a pharmaceutically acceptable salt thereof in the preparation of a medicament for treating a tumor. The tumor is, for example, OVCAR-3 (Adenocarcinoma, ovary, human), A549 (Carcinoma, lung, human), HT-29 (Adenocarcinoma, colon, moderately well-differentiated grade II, human) or MCF-7 (Breast adenocarcinoma, pleural effusion, human).

[0026] Preferably, the concentration of said dicarboxylic acid ester of ginsenoside or a pharmaceutically acceptable salt thereof is 0.01 - 100 mg/ml in said aqueous solution. Preferably, the concentration is higher than 1 mg/ml and more preferably higher than 10 mg/ml in said aqueous solution.

DETAILED DESCRIPTION OF THE INVENTION:

[0027] According to the preferred embodiments of the present invention, derivatives of several typical ginsenosides such as 20-O-β-D-glucopyranosyl- protopanaxadiol (compound K, abbreviated as CK), PPD, PPT, and Fl are synthesized.

[0028] In one of the preferred embodiments CK reacts with a dicarboxilyic acid anhydride, in a suitable solvent and in the presence of a catalyst to form a dicarboxilyic acid ester derivative of CK, the reaction can be represented by the following equation:

(dicarboxylic acid anhydride)

wherein GIc is

A is -(CR ⁴ RV ;

R ¹ = H or -C(O)(CRV) _n COOH ;

R ² = H or -C(O)(CRV) _n COOH ;

R ³ =

wherein R ⁵ , R ⁶ , R ⁷ and R ⁸ independently are H, or -C(O)(CR ⁴ R ⁹ ) _n COOH ; wherein n is an integer of 0-8, R ⁴ and R ⁹ independently are H or C1-C4 alkyl, provided that R ¹ , R ² , R ⁵ , R ⁶ , R ⁷ and R ^s are not H at the same time.

[0029] Preferably, R ⁴ and R ⁹ are H and n is 2 or 3.

[0030] Preferably, R ² is H.

[0031] Preferably, R ¹ is H.

[0032] Preferably, R ⁵ is -C(O)(CH ₂ ) _n COOH, and R ⁶ , R ⁷ and R ⁸ are all H,.

[0033] Preferably, R ⁷ is -C(O)(CH ₂ ) _n COOH, and R ⁵ , R ⁶ and R ⁸ are all H.

[0034] Preferably, R ⁵ and R ⁷ are both -C(O)(CH ₂ ) _n COOH, and R ⁶ and R ⁸ are both H.

[0035] Preferably, R ⁵ , R ⁶ and R ⁷ are all -C(O)(CH ₂ ) _n COOH, and R ⁸ is H.

[0036] The present invention also provides a pharmaceutical preparation, which includes an aqueous solution and a CK dicarboxylic acid ester derivative of the present invention or a pharmaceutically acceptable salt thereof, which is dissolved in said aqueous solution. The aqueous solution can be a buffered or non-buffered aqueous solution with or without pharmaceutically acceptable solubility enhancer, such as aliphatic alcohol, polyhydroxy alcohol, pharmaceutical or cosmetic acceptable oils, or Cremophor.

[0037] Preferably, the concentration of said derivative or a pharmaceutically acceptable salt thereof is 0.01 - 100 mg/ml in said aqueous solution. Preferably, the concentration is higher than 1 mg/ml and more preferably higher than 10 mg/ml in said aqueous solution.

[0038] In the following Examples 1-4, the succinate and glutarate derivatives of CK are synthesized, and their anti-cancer efficacies are compared to that of CK.

[0039] The synthesis method comprises mixing CK with succinic anhydride or glutaric anhydride at a mole ratio of 1 : 0.1-100, preferably 1 : l~10; and carrying out a ring opening reaction of the dicarboxylic acid anhydride in a suitable solvent and in the presence of a catalyst. Said organic solvent can be halogenated alkane (e.g. dichloromethane, trichloromethane, dichloroethane, etc.; ether (e.g. dialkyl ether or alicyclic ether, tetrahydrofuran, dioxane); tertiary amine including tertiary alkyl amine (e.g. triethylamine, pyridine) and trialkyl diamine (e.g. N,N,N',N'-tetramethyl ethylenediamine, N,N,N',N'-tetramethyldiaminomethane); low alkyl sulfoxide (e.g. dimethyl sulfoxide, DMF); and low alkyl ketone. Said catalyst can be a base or an acid. Said base for example can be a tertiary amine, including (but not limited to) trialkyl amine, 4- (dimethylamino)pyridine, pyridine, N,N,N',N'-tetramethyl ethylenediamine, N,N,N',N'- tetramethyldiaminomethane, etc.; or solid alkali, such as Si-dimethylamine, Si-morpholine, and Si-piperidine, etc. Preferably, said organic solvent and said catalyst are all tertiary amine. Said ring opening reaction is carried out at -10°~200°C (preferably 10~120°C) under oscillation or stirring and reflux for 10 minutes to 10 days (preferably 30 minutes to 48 hours). If a water miscible solvent (e.g. tertiary amine or low alkyl sulfoxide) is used in the reaction, the solvent is evaporated first to obtain a concentrate; then partition with water and organic acid ester or ether. The organic layer is concentrated to dry to obtain a product mixture of CK succinate or glutarate. If a solvent immiscible with water is used, the reaction is terminated by directly adding ice water into the reaction solution. Next, the organic layer is obtained and then partition with water and organic acid ester or ether. The organic layer is concentrated to dry to obtain a product mixture of CK succinate or glutarate. Alternatively, a silica gel or reverse phase gel chromatographic column or a high performance liquid phase chromatographic column can be used for further purification of the product mixture.

[0040] The CK succinate or glutarate product is dissolved in acetone; followed by dripping a methanol or ethanol solution containing sodium or potassium alcoholate or hydroxide. Upon completion of precipitation, the precipitate is filtered to obtain a potassium or sodium CK succinate salt. A pharmaceutically acceptable salt of said product, e.g. ammonium salt, can also be prepared by a similar method. A CK succinate

or glutarate product can also be directly dissolved in a pharmaceutically acceptable saline or an aqueous solution of week base (sodium hydrogen carbonate or potassium hydrogen carbonate) with pH 6-9 (preferably pH 6.8-7.8) in order to form a CK succinate or glutarate saline. In case of CK succinate or glutarate salts, they can dissolve in water, or normal saline.

EXAMPLES:

EXAMPLE 1: SYNTHESIS OF CK SUCCINATE

[0041] 401 mg of CK was dissolved in 35ml of dried THF, and 257 mg (4 equivalents) of succinic anhydride was added to the resulting solution while stirring, to which 393 mg (5 equivalents) of 4-(dimethylamino)pyridine was then added. The reaction mixture was then heated under N ₂ at 40°C for 48 hours. The reaction progress was monitored by reversed-phase TLC, and the solvent was removed by rotary evaporation until dryness, when the reaction was completed. The concentrate was added with ice water and ethyl acetate for partition. The resulting water layer was discarded, and the organic layer was repetitively extracted with water twice. The organic layer was then dried with anhydrous magnesium sulfate and rotary evaporated to dryness to obtain 369.7 mg of CK succinate derivatives mixture product.

[0042] The obtained product was analyzed by an analytic HPLC (GL Sciences Inc., Inertsil ODS-3V C-18; 3.0 mm x 150 mm) where the mobile phase was 52% acetonitrile/H2θ (containing 0.02% phosphoric acid). The elution times of the main products separately were: 11.0 min (yield: 21.1%), 19.9 min (yield: 44.2%), 24.7 min (yield: 20.7%), 31.7 min (yield: 10.4%). A semi-preparative HPLC (GL Sciences Inc., Inertsil ODS-3 C-18; 10 mm x 250 mm) was used for purification separation, thereby obtaining 41.8 mg of 19.9 min product (GS- 8), which was identified by mass spectrum (MS) as a CK monosuccinate derivative with a molecular weight of 723.44. Verifications from ¹³ C-NMR, ¹ H-NMR, H-H COSY, C-H COSY indicated that succinate substituted the hydrogen of the third OH group (3 ¹ ) on the glucose group at 20 ^th of CK. Furthermore, 14.8 mg of 24.7min product (GS-9) was obtained, which was identified by MS as a CK disuccinate derivative with a molecular weight of 823.44. Verifications from ¹³ C-NMR, ¹ H-NMR and H-H COSY indicated that the two succinate groups substituted the

hydrogens at the 3 ^rd and 6 ^th OH groups (3 ',6') on the glucose group at 20 ^th of CK. Still furthermore, 11.2 mg of 31.7 min product (GS-11) was obtained, which was identified by MS as a CK trisuccinate derivative with a molecular weight of 923.46. Verifications from ¹³ C-NMR, ¹ H-NMR and H-H COSY indicated that the three succinate groups substituted the hydrogens at the 3 ^rd , 4 ^th and 6 ^th OH groups (3',4',6') on the glucose group at 20 ^th of CK.

EXAMPLE 2: SYNTHESIS OF CK SUCCINATE

[0043] 41 mg of CK and 40 mg (6 equivalents) of succinic anhydride were dissolved in 40ml of dried Et ₃ N. The resulting reaction mixture was then heated under N ₂ at 25 ⁰ C for 13 hours. The solvent was removed by rotary evaporation until dryness, when the reaction was completed. The concentrate was added with ice water and ethyl acetate for partition for at least three times. The organic layer was then dried with anhydrous magnesium sulfate and rotary evaporated to dryness to obtain 65.3 mg of a mixture product of CK succinate derivatives.

[0044] The obtained product was analyzed by a HPLC. The elution times of the main products separately were: 11.0 min (yield: 27.6%), 13.5 min (yield: 41.2%), 19.9 min (yield: 14.4%), 31.7 min (yield: 2.4%). A semi-preparative HPLC was used for purification separation, thereby obtaining 17.5 mg of 13.5 min product (GS-6), which was identified by MS as a CK mono-succinate derivative with a molecular weight of 723.44.

Verifications from ¹³ C-NMR, ¹ H-NMR, and H-H COSY indicated that succinate substituted the hydrogen of the sixth OH group (6 ¹ ) on the glucose group at 20 ^th of CK.

EXAMPLE 3: SYNTHESIS OF CK GLUTARATE

[0045] 100 mg of CK was dissolved in 30ml of dried THF, and 184 mg (10 equivalents) of glutaric anhydride was added to the resulting solution while stirring, to which 158 mg (8 equivalents) of 4-(dimethylamino)pyridine was then added. The reaction mixture was then heated under N ₂ at 60°C for 23 hours. The reaction progress was monitored by reversed-phase TLC, and the solvent was removed by rotary evaporation until dryness, when the reaction was completed. The concentrate was added with ice water and ethyl acetate for partition for at least three times. The organic layer was then dried with anhydrous magnesium sulfate and rotary evaporated to dryness to obtain 135.6mg of CK glutarate derivatives mixture product.

[0046] The obtained product was analyzed by a HPLC. The elution times of the main products separately were: 13.5 min (yield: 3.4%), 20.6 min (yield: 16.0%), 25.3 min (yield: 37.1%), 31.3 min (yield: 3.7%), 36.4 min (yield: 12.5%), and 51.4 min (yield: 25.8%). A semi-preparative HPLC was used for purification separation, thereby obtaining 9.6 mg of 20.6 min product (GS-13), which was identified by MS as a CK monoglutarate derivative with a molecular weight of 737.55. Verifications from ¹³ C-NMR, ¹ H-NMR, H- H COSY, and C-H COSY indicated that glutarate substituted the hydrogen of the 6 ^th OH group (6') on the glucose group at 20 ^th of CK. Furthermore, 18.1 mg of 25.3 min product (GS- 14) was obtained, which was identified by MS as a CK diglutarate derivative with a molecular weight of 851.59. Verifications from ¹³ C-NMR, ¹ H-NMR and H-H COSY indicated that the two glutarate groups substituted the hydrogen of the 3 ^rd and 6 ^th OH groups (3',6') on the glucose group at 20 ^th of CK. Still furthermore, 7.5 mg of 36.4 min product (GS- 15) was obtained, which was identified by MS as a CK triglutarate derivative with a molecular weight of 965.64. Verifications from ¹³ C-NMR, ¹ H-NMR and H-H COSY indicated that the three glutarate groups substituted the hydrogen at the 3 ^rd , 4 ^th and 6 ^th OH groups (3',4',6') on the glucose group at 20 ^th of CK. Still furthermore, 15.5 mg of 51.4 min product (GS-16) was obtained, which was identified by MS as a CK pentaglutarate derivative with a molecular weight of 1193.74. Verifications from ¹³ C- NMR, ¹ H-NMR and H-H COSY indicated that the five glutarate groups substituted the hydrogen of the OH group at 3 ^rd position of CK, and at the 2 ^nd , 3 ^rd , 4 ^th and 6 ^th OH groups (2',3',4',O ¹ ) on the glucose group at 20 ^th of CK.

EXAMPLE 4: SYNTHESIS OF CK GLUTARATE

[0047] 194mg of CK and 178mg (5 equivalents) of glutaric anhydride were dissolved in 150ml of dried Et ₃ N. The reaction mixture was then heated under N ₂ at 25 ⁰ C for 6 hours. The reaction progress was monitored by reversed-phase TLC, and the solvent was removed by rotary evaporation until dryness, when the reaction was completed. The concentrate was added with ice water and ethyl acetate for partition for at least three times. The organic layer was then dried with anhydrous magnesium sulfate and rotary evaporated to dryness to obtain 198mg of CK glutarate derivatives mixture product.

[0048] The obtained product was analyzed by a HPLC. The elution times of the main products separately were: 10.8 min (yield: 31.0%), 13.8 min (yield: 24.6%), 19.4

min (yield: 22.1%), 24.3 min (yield: 14.6%), and 31.0 min (yield: 5.2%). A semi- preparative HPLC was used for purification separation, thereby obtaining 34.5 mg of 10.8- min product (GS-12, CK), 30.9 mg of 13.8 min product (GS-17), 23.7 mg of 19.4 min product (GS-13), 23.2 mg of 24.3 min product (GS-14), and 14.4 mg of 31.0 min product (GS- 15). GS-17 was identified by MS as a CK monoglutarate derivative with a molecular weight of 737.55. Verifications from ¹³ C-NMR, ¹ H-NMR ₅ H-H COSY and C-H COSY indicated that glutarate substituted the hydrogen of the 6 ^th OH group (6') on the glucose group at 20 ^th of CK. Furthermore, were obtained.

[0049] CK: ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.101 (t, IH, J=5.0Hz, H-24), 4.600 (d, IH, J=8.2, H-I ¹ of 20-Glc), 3.766 (dd, 2H, J=12.5, 2.0Hz, H-6'a of 20-Glc), 3.672 (td, IH, J=9.5, 5.0Hz, H-12), 3.625 (dd, 2H, 3=12.5, 5.0Hz, H-6'b of 20-Glc), 3.346 (td, IH, J=8.2, 2.0Hz, H-3 ¹ of 20-Glc), 3.210 (m, IH, H-5 ¹ of 20-Glc), 3.29 (m,lH, H-4 ¹ of 20-Glc), 3.138 (dd, IH, J=12.5, 4.5Hz, H-3), 3.072 (t, IH, J=8.2Hz, H-2 ¹ of 20-Glc), 2.283 (td, IH, J=I LO, 8.5Hz, H-17), 2.06 (m, 2H, H-23a,b), 1.822 (dd, 2H, J=13.0, 5.0Hz, H-I lα), 1.814 (dt, 2H, J= 18.5, 7.5Hz, H-22a), 1.743 (t, IH, J=I LOHz, H-13), 1.676 (s, 3H, H-26), 1.638 (s, 3H, H-27), 1.39 (m, 2H, H-22b), 1.338 (s, 3H, H-21), 1.220 (dt, 2H, J=13.0, 9.5Hz, H- l lβ), 1.017 (s, 3H, H-29), 0.960 (s, 3H, H-28), 0.924 (s, 3H, H-30), 0.914 (s, 3H, H-18), 0.775 (s, 3H, H-19). ¹³ C-NMR (125MHz, CD ₃ OD) δ: aglycone moiety: C-I, 40.24; C-2, 27.99; C-3, 79.52; C-4, 40.03; C-5, 57.25; C-6, 19.41; C-7, 35.84; C-8, 40.96; C-9, 51.05; C-10, 38.17; C-I l, 30.99; C-12, 71.93; C-13, 49.76; C-14, 52.49; C-15, 31.64; C-16, 27.19; C-17, 53.14, C-18, 16.23; C-19, 16.72; C-20, 84.94; C-21, 22.85; C-22, 36.65; C-23, 24.26; C-24, 125.84; C-25, 132.30; C-26, 25.89; C-27, 17.95; C-28, 28.61; C-29, 16.13; C-30, 17.17; 20-Glc sugar moiety:, C-I', 98.30; C-2', 75.40; C-3', 78.19; C-4 ¹ , 71.17; C-5', 77.95; C-6', 62.50.

[0050] CK-6'-monosuccinate (GS-6) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.118 (t,

IH, J=6.5Hz, H-24), 4.582 (d, IH, J=8.3, H-I' of 20-Glc), 4.438 (d, 2H, J=I 1.4Hz, H-6'a of 20-Glc), 4.104 (dd, 2H, J=I 1.4, 7.4Hz, H-6'b of 20-Glc), 3.704 (td, IH, J=I 0.5, 4.5Hz, H-12), 3.427 (UH, J=8.3Hz, H-4' of 20-Glc), 3.344 (dd, IH, J=8.3, 7.4Hz ₅ H-5' of 20-Glc), 3.234 (t, IH, J=8.3Hz, H-3 ¹ of 20-Glc), 3.133 (dd ₅ IH, J=9.5 ₅ 4.5Hz, H-3), 3.112 (t, IH, J=8.3Hz, H-2' of 20-Glc), 2.279 (td, IH, J=I 1.0, 8.5Hz, H-17), 2.132 (dq, 2H, J=I 9, 6.5Hz, H-23a), 2.013 (dq, 2H, J=I 9, 6.5Hz, H-23b), 1.891 (dt, 2H, J= 18, 6.5Hz, H-22a), 1.783

(dd ₅ 2H ₅ J=13.3, 4.5Hz, H-llα), 1.738 (t, IH ₅ J=I LOHz, H-13), 1.671 (s, 3H, H-26), 1.611 (s, 3H, H-27), 1.345 (s, 3H ₅ H-21), 1.243 (dt, 2H ₅ J=13.3 ₅ 10.5Hz ₅ H-I lβ), 1.004 (s, 3H ₅ H-29) ₅ 0.956(s ₅ 3H ₅ H-28), 0.915(s ₅ 3H ₅ H-30), 0.907(s, 3H ₅ H-18), 0.770(s, 3H.H-19).

[0051] CK-3'-monosuccinate (GS-8) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.109 (t, IH ₅ J=7.0Hz, H-24), 4.960 (t ₅ IH ₅ J=9.5Hz, H-3 ¹ of 20-Glc), 4.71 (d, IH ₅ J=8.3, H-I ¹ of 20-Glc), 3.776 (dd, 2H, J=12.5, 1.8Hz ₅ H-6'a of 20-GIc) ₅ 3.673 (td ₅ IH ₅ J=I LO ₅ 5.0Hz ₅ H- 12), 3.649 (dd ₅ 2H ₅ J=12.5, 5.0Hz ₅ H-6'b of 20-Glc), 3.484 (t,lH, J=9.5Hz ₅ H-4 ¹ of 20-Glc), 3.29 (m, IH ₅ H-5 ¹ of 20-Glc), 3.215 (dd ₅ IH ₅ J=9.5 ₅ 7.8Hz ₅ H-2' of 20-GIc) ₅ 3.136 (dd, IH, J=I 1.5, 5.0Hz, H-3), 2.272 (td, IH, J=ILO, 8.0Hz, H-17), 2.08 (m, 2H, H-23ab), 1.913 (ddd, 2H, J= 19, 13.5, 9.5Hz, H-22a), 1.828 (dd, 2H, J=13.0, 5.0Hz, H-l lα), 1.737 (t, IH, J=I LOHz, H-13), 1.679 (s, 3H, H-26), 1.622 (s, 3H, H-27), 1.345 (s, 3H, H-21), 1.217 (dt, 2H, J=13.5, ILOHz ₅ H-I lβ), 1.012 (s, 3H, H-29), 0.958 (s, 3H, H-28), 0.916 (s, 3H, H-30), 0.910 (s, 3H ₅ H-18), 0.771 (s, 3H, H-19).

[0052] CK-3',6,-disuccinate (GS-9) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.120 (t, IH, J=7.3Hz, H-24), 4.960 (t, IH, J=9.5Hz, H-3' of 20-Glc), 4.685 (d, IH, J=8.5, H-I' of 20-Glc), 4.437 (dd, 2H, J=I 1.5, 2.0Hz, H-6'a of 20-Glc), 4.139 (dd, 2H, J=I 1.5, 6.5Hz, H- Gb of 20-Glc), 3.706 (td, IH, J=I LO, 5.5Hz, H-12), 3.537 (ddd, IH, J=9.5, 6.5, 2.0Hz, H- 5' of 20-Glc), 3.418 (t,lH, J=9.5Hz, H-4' of 20-Glc), 3.260 (dd, IH, J=9.5, 8.5Hz ₅ H-2' of 20-GIc) ₅ 3.129 (dd, IH, J=10.3, 4.8Hz, H-3), 2.274 (td, IH, J=10.5, 8.5Hz, H-17), 2.132 (dq, 2H, J=19.5, 6.8Hz, H-23a), 2.007 (dq, 2H, J=19.5, 6.8Hz, H-23b), 1.89 (m, 2H, H- 22a), 1.787 (dd, 2H, J=12.8, 5.5Hz, H-l lα), 1.727 (t, IH, J=I LOHz, H-13), 1.673 (s, 3H, H-26), 1.614 (s, 3H, H-27), 1.352 (s, 3H, H-21), 1.211 (dt, 2H, J=12.8, 11. OHz, H-I lβ), 0.999 (s, 3H, H-29), 0.954 (s, 3H, H-28), 0.906 (s, 3H, H-30), 0.906 (s, 3H, H-18), 0.769 (s, 3H, H-19).

[0053] CK-3',4',6'-trisuccinate (GS-Il) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.162

(t, IH, J=9.5Hz, H-3 ¹ of 20-Glc), 4.914 (t,lH, J=9.5Hz, H-4' of 20-Glc), 4.769 (d, IH, J=7.5, H-r of 20-Glc), 4.176 (dd, 2H, J=12.0, 2.0Hz, H-6'a of 20-Glc), 4.124 (dd, 2H, J=12.0, 6.0Hz, H-6'b of 20-Glc), 3.793 (ddd, IH ₅ J=9.5 ₅ 6.0, 2.0Hz, H-5 ¹ of 20-Glc), 3.716 (td, IH, J=ILO, 5.5Hz, H-12), 3.366 (dd, IH, J=9.5, 7.5Hz, H-2' of 20-Glc), 3.128 (dd, IH, J=I 1.5, 4.5Hz, H-3), 2.282 (td, IH, J=10.5, 8.5Hz, H-17), 2.14 (m, 2H, 6.8Hz, H-23a), 2.018 (dq, 2H, J=20.5, 6.5Hz, H-23b), 2.018 (dq, 2H, J=19.0, 6.5Hz, H-22a), 1.734 (t, IH,

J=ILOHz, H-13), 1.673 (s, 3H, H-26), 1.616 (s, 3H, H-27), 1.359 (s, 3H, H-21), 1.216 (dt, 2H ₅ J=13.0 ₅ 11.0Hz, H-I lβ), 1.179 (dd, 2H, J=13.0, 5.5Hz ₅ H-I Ia) ₅ 1.002 (s, 3H ₅ H-29), 0.954 (s, 3H ₅ H-28), 0.909 (s ₅ 3H ₅ H-30), 0.905 (s, 3H ₅ H-IS) ₅ 0.769 (s, 3H ₅ H-19).

[0054] CK-6'-monoglutarate (GS-17) : ¹ H-NMR (500MHz ₅ CD ₃ OD) δ: 5.11 (t, IH ₅ J=6.5Hz, H-24), 4.58 (d, IH, J=8, H-I ¹ of 20-Glc), 4.42 (dd, 2H ₅ J=I 1.5, IHz ₅ H-6'a of

20-GIc) ₅ 4.11 (dd, 2H ₅ J=12, 7Hz ₅ H-6'b of 20-GIc) ₅ 3.71 (td ₅ IH ₅ J=15.5, 5Hz ₅ H-12), 3.43

(broad, IH ₅ H-5' of 20-GIc) ₅ 3.35 (t, IH ₅ J=9.5Hz, H-3 ¹ of 20-Glc), 3.23 (t,lH, J=9Hz, H-4 ¹ of 20-Glc), 3.14 (dd, IH ₅ J=I 1.5, 5Hz, H-3), 3.11 (t, IH, J=8.5Hz, H-2 ¹ of 20-GIc) ₅ 1.67 (s,

3H, H-26), 1.61 (s, 3H ₅ H-27), 1.34 (s, 3H, H-21), 1.00 (s, 3H, H-29), 0.96 (s, 3H ₅ H-28), 0.91 (s, 3H ₅ H-30), 0.91 (s ₅ 3H ₅ H-18), 0.77 (s ₅ 3H, H-19).

[0055] CK-3'-monoglutarate (GS-13) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.11 (t, IH, J=7Hz, H-24), 4.96 (t, IH, J=9Hz, H-3 ¹ of 20-Glc), 4.70 (d, IH, J=7.5, H-I' of 20-Glc), 3.77 (dd ₅ 2H ₅ J=12, 2Hz, H-6'a of 20-GIc) ₅ 3.66 (td, IH, J=15.5, 5Hz ₅ H-12), 3.64 (dd, 2H ₅ J=12, 5Hz, H-6'b of 20-Glc), 3.47 (t,lH, J=9.5Hz ₅ H-4' of 20-GIc) ₅ 3.29 (broad, IH, H-5' of 20-Glc), 3.20 (dd, IH, J=9, 8Hz ₅ H-2 ¹ of 20-GIc) ₅ 3.14 (dd, IH ₅ J=I 1.5, 5Hz, H-3), 1.68 (s, 3H, H-26), 1.62 (s, 3H ₅ H-27), 1.35 (s, 3H, H-21), 1.01 (s, 3H, H-29), 0.96 (s, 3H ₅ H- 28), 0.92 (s ₅ 3H ₅ H-30), 0.91 (s ₅ 3H, H-18), 0.77 (s, 3H ₅ H-19).

[0056] CK-3',6'-diglutarate (GS-14) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.12 (t, IH ₅ J=7Hz, H-24), 4.97 (t, IH, J=9Hz, H-3' of 20-Glc), 4.69 (d ₅ IH, J=7.5, H-I' of 20-Glc), 4.43 (dd, 2H, J=12, 2Hz, H-6'a of 20-Glc), 3.71 (td, IH ₅ J=15.5, 5Hz, H-12), 4.14 (dd, 2H ₅ J=I 1.5 ₅ 6.5Hz ₅ H-6'b of 20-Glc), 3.55 (broad, IH, H-5' of 20-Glc), 3.41 (t, IH ₅ J=IOHz, H- 4' of 20-Glc), 3.25 (dd, IH, J=9.5, 8Hz, H-2 ¹ of 20-Glc), 3.14 (dd, IH, J=I 1.5, 5Hz, H-3), 1.68 (s, 3H ₅ H-26), 1.62 (s, 3H, H-27), 1.36 (s, 3H ₅ H-21), 1.01 (s, 3H ₅ H-29), 0.96 (s, 3H, H-28), 0.92 (s, 3H, H-30), 0.91 (s, 3H, H-18), 0.78 (s, 3H, H-19).

[0057] CK-3',4',6'-triglutarate (GS-15) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.35 (t,

IH ₅ J=9.5Hz, H-3' of 20-Glc), 5.12 (t, IH, J=7Hz, H-24), 4.90 (t, IH, J=IOHz, H-4 ^! of 20- Glc), 4.77 (d, IH, J=8, H-I ¹ of 20-Glc), 4.17 (dd, 2H, J=12, 5.5Hz, H-6'b of 20-GIc) ₅ 4.12 (dd, 2H ₅ J=12, 2.5Hz ₅ H-6'a of 20-Glc), 3.81 (ddd, IH, J=IO, 5.5, 2.5, H-5' of 20-Glc), 3.72 (td, IH, J=15.5, 5Hz, H-12), 3.22 (dd, IH, J=9.5, 8Hz ₅ H-2' of 20-Glc), 3.13 (dd, IH,

J=I 1.5, 5Hz, H-3), 1.67 (s, 3H, H-26), 1.61 (s, 3H, H-27), 1.36 (s, 3H, H-21), 1.00 (s, 3H, H-29), 0.95 (S, 3H, H-28), 0.91 (s, 3H, H-30), 0.90 (s, 3H, H-18), 0.77 (s, 3H, H-19).

[0058] CK-3,2',3',4',6'-pentaglutarate (GS-16) : ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.35 (t, IH, J=9.5Hz, H-3 ¹ of 20-Glc), 5.12 (t, IH, J=8Hz, H-2 ¹ of 20-Glc), 5.10 (t, IH, J=7Hz, H-24), 5.02 (t, IH, J=IOHz ₅ H-4' of 20- GIc), 4.90 (d, IH, J=8, H-I' of 20-Glc), 4.49 (dd, IH, J=I l, 5.5Hz, H-3), 3.92 (broad, IH, H-5 ¹ of 20-Glc), 3.55 (td, IH, J=15, 5Hz, H-12), 1.67 (s, 3H, H-26), 1.62 (s, 3H, H-27), 1.34 (s, 3H, H-21), 1.00 (s, 3H, H-29), 0.94 (s, 3H, H-28), 0.91 (s, 3H, H-30), 0.89 (s, 3H, H-18), 0.86 (s, 3H, H-19).

[0059] The following Table 1 and Table 2 separately list the ¹³ C-NMR analysis results of the HPLC-purified CK and CK succinate and glutarate derivatives obtained from Examples 1 to 4.

Table 1 : ¹³ C-NMR chemical shifts of CK and CK succinate derivatives

Table 2: 1 "3C-NMR chemical shifts of CK glutarate derivatives

Experiment 1 (Control): CK anti-cancer activity assays

[0060] Four human tumor cell lines, OVCAR-3 (Adenocarcinoma, ovary, human), A549 (Carcinoma, lung, human), HT-29 (Adenocarcinoma, colon, moderately well- differentiated grade II, human) and MCF-7 (Breast adenocarcinoma, pleural effusion, human) were chosen in the experiments., which were obtained from American Type Culture Collection (ATCC) under codes of ATCC HTB-161, ATCC CCL-185, ATC HTB- 38 and ATCC HTB-22, respectively. The culture medium used for OVCAR-3 was RPMI 1640 medium with 20% fetal bovine serum, which was supplemented with 0.01 mg bovine insulin per ml and 1% Antibiotice-Antimycotic. The culture medium used for A549 was F-12K nutrient mixture (Kaighn's Modification), 90%; and fetal bovine serum 10%. The culture medium used for HT-29 was McCoy's 5A medium, 90%; and fetal bovine serum, 10%. The culture medium used for MCF-7 was Minimum Essential Medium, 90%; and fetal bovine serum, 10%.

[0061] CK was dissolved in a mixed solvent of ethanol and Cremophor® RH40

(ethanol : Cremophor® RH40 = 1:1), and then diluted with sterile distilled water to obtain test solutions having CK concentrations of 10000, 1000, 100, 10, 1 μg/ml in 5% ethanol and 5% Cremophor® RH40.

[0062] Aliquots of 100 μl of cell suspension (about 1.0-3.0 x 10 ³ /well) were placed in 96-well microtiter plates in an atmosphere of 5% CO ₂ at 37°C. After 24 hours,

100 μl of growth medium and 2 μl of test solution or vehicle (5% ethanol and 5%

Cremophor® RH40) were added per respectively per well in duplicate for an additional

72-hour incubation. Thus, the final concentration of vehicle was 0.05%. The test

compound, CK, was evaluated at concentrations of 100, 10, 1, 0.1, 0.01 μg/ml. At the end of the incubation, 20 μl of alamarBlue 90% reagent was added to each well for another 6- hour incubation before detection of cell viability by fluorescent intensity. Fluorescent intensity was measured using a SPECTRAfluor Plus plate reader with excitation at 530 run and emission at 590 nm.

[0063] Experiment 2: CK succinate and CK glutarate anti-cancer activity assays

[0064] The tumor cell lines used were the same as in Experiment 1.

[0065] CK succinate and CK glutarate derivatives were directly dissolved in the phosphate buffered saline (PBS) having a pH of 7.4, and then diluted with sterile distilled water to obtain test solutions having concentrations of the CK derivative of 2000, 200, 20, 2, 0.2 μg/ml in 40% PBS -

[0066] Aliquots of 100 μl of cell suspension (about 5.0 x 10 ³ /well) were placed in 96-well microtiter plates in an atmosphere of 5% CO ₂ at 37°C. After 24 hours, 90 μl of growth medium and 10 μl of test solution or vehicle (40% PBS, pH 7.4) were added per respectively per well in duplicate for an additional 72 -hour incubation. Thus, the final concentration of vehicle was 0.05%. The test compound, CK derivative, was evaluated at concentrations of 100, 10, 1, 0.1, 0.01 μg/ml. At the end of the incubation, 20 μl of alamarBlue 90% reagent was added to each well for another 6-hour incubation before detection of cell viability by fluorescent intensity. Fluorescent intensity was measured using a SPECTRAfluor Plus plate reader with excitation at 530 nm and emission at 590 nm.

[0067] The measured results were calculated according to the following formulas:

PG (Percent Growth):

PG (%) = 100% x (Mean F _tes t - Mean F _time o) / (Mean F _ctr i - Mean F _time o) If (Mean F _tes t - Mean F _time o) < 0, then

PG (%) = 100% x (Mean F _te st - Mean F _time o) / (Mean Ft _ime0 - Mean F _b ian _k ) wherein

Mean F _t i _me o = The average of two measured fluorescent intensities of reduced alamarBlue at the time just before exposure of cells to the test compound;

Mean F _test = The average of two measured fluorescent intensities of alamarBlue after 72-hour exposure of cells to the test compound;

Mean F _ctr i ⁼ The average of two measured fluorescent intensities of alamarBlue after 72-hour incubation without the test compound;

Mean F _b i _ank ⁼ The average of two measured fluorescent intensities of alamarBlue in medium without cells after 72-hour incubation.

[0068] 50% Inhibition concentration (IC ₅₀ ): Test compound concentration where the increase in the number or mass of treated cells from time ₀ was only 50% as much as the corresponding increase in the vehicle control at the end of experiment. IC ₅₀ was determined by nonlinear regression using GraphPd Prism (GraphPad Software, USA).

[0069] IC ₅₀ of the test compounds including CK and some of the CK succinate, and glutarate derivatives purified by HPLC in Examples 1 to 3 are listed in Table 3.

Table 3: IC ₅₀ (μM) of CK, CK succinate and CK glutarate derivatives

[0070] The CK succinate and glutarate derivatives purified by HPLC in Examples 1 to 3 were dissolved in PBS to observe their solubility, and the results show that all the CK succinate and glutarate derivatives have a solubility greater than 10 mg/ml in PBS.

EXAMPLE 5: SYNTHESIS OF PPD SUCCINATE

[0071] 100 mg of PPD was dissolved in 8ml of dried THF, and 217. lmg (10 equivalents) of succinic anhydride was added to the resulting solution while stirring, to which 265.2mg (10 equivalents) of 4-(dimethylamino)pyridine was then added. The reaction mixture was then refluxed under N ₂ for 24 hours. The reaction progress was monitored by reversed-phase TLC, and the solvent was removed by rotary evaporation until dryness, when the reaction was completed. 10 ml of 0.01M HCl was then added to

the residue followed by the addition of 15 ml of ethyl acetate. The mixture was then transferred to a seperatory funnel. Drained the aqueous layer, and washed the organic layer once with 10 ml of 0.01M HCl. The organic layer was then wash with Brine, dried over sodium sulfate and rotary evaporated to dryness.

[0072] The obtained product was analyzed by HPLC where the mobile phase was 72% acetonitrile/H ₂ O (containing 0.02% phosphoric acid). The elution times of the main products separately were: 38.1 min, 40.3 min, 46.1 min, and 48.4 min. A semi-preparative HPLC was used for purification separation, thereby obtaining 5.6 mg of 38.1 min product (GS41), 39.9 mg of 40.3min product (GS42), 1.9 mg of 46.1min product (GS43), and 6.3 mg of 48.4min product (GS44). The four products GS41 to GS44 were identified by mass spectrum (MS) as a PPD monosuccinate derivative, PPD disuccinate derivateive, PPD and PPD monosuccinate derivative, respectively. Verifications from C-NMR and H-NMR indicated that GS41 has a monosuccinate which substitutes the hydrogen of the OH group at 12 ^th of PPD; and GS42 has two succinates which substitute the hydrogens of the OH groups at 3 ^rd and 12 ^th of PPD.

succinate 12 3&12

[0073] PPD: ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.134 (t, IH, H-24), 3.536 (td, IH, H-12), 3.137 (dd, IH ₅ H-3).

[0074] PPD-12-monosuccinate (GS41): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.137 (t, IH, H-24), 4.862 (td, IH ₃ H-12), 3.140 (dd, IH, H-3).

[0075] PPD-3,12-disuccinate (GS42): ¹ H-NMR (SOOMHz ₅ CD ₃ OD) δ: 5.13 (t, IH, H-24), 4.87 (dt, IH, H-12), 4.48 (dd, IH, H-3).

EXAMPLE 6: SYNTHESIS OF PPT SUCCINATE

[0076] 50 mg of PPT was dissolved in 4 ml of dried THF, and 104.9 mg (10 equivalents) of succinic anhydride was added to the resulting solution while stirring, to which 4 ml of Et ₃ N was then added. The resulting reaction mixture was then refluxed under N ₂ for 48 hours. TMs reaction progress was monitored by reversed-phase TLC, and the solvent was removed by rotary evaporation until dryness, when the reaction was completed. 10 ml of 0.01M HCl was then added to the residue followed by the addition of 15 ml of ethyl acetate. The mixture was then transferred to a seperatory funnel. Drained the aqueous layer, and washed the organic layer once with 10 ml of 0.01M HCl. The organic layer was then wash with Brine, dried over sodium sulfate and rotary evaporated to dryness.

[0077] The obtained product was analyzed by HPLC where the mobile phase was 50% acetonitrile/H ₂ O (containing 0.02% phosphoric acid). The elution times of the main products separately were: 18.3 min, 19.3 min, 26.3 min, and 32.3 min. A semi-preparative

HPLC was used for purification separation, thereby obtaining 1.5 mg of 18.3min product

(GS54), 3.5 mg of 19.3min product (GS51), 28.8 mg of 26.3min product (GS53), and 6.6 mg of 32.3min product (GS52). The four products GS51 to GS54 were identified by mass spectrum (MS) as a PPT monosuccinate derivateive, PPT disuccinate derivative, PPT trisuccinate derivateive and PPT disuccinate derivative, respectively. Verifications from

¹³ C-NMR and ¹ H-NMR indicated that GS51 has monosuccinate which substitutes the hydrogen of the OH group at 12 ^th of PPT; GS52 has two succinates which substitute the hydrogens of the OH group at 3 ^rd and 12 ^th of PPT; GS53 has three succinates which substitute the hydrogens of the OH group at 3 ^rd , 6 ^th and 12 ^th of PPT; and GS54 has two succinates which substitute the hydrogens of the OH group at 6 ^th and 12 ^th of PPT.

13 C-NMR chemical shifts of PPT and PPT-succinate derivatives

succinate 12 3&12 3&6&12 6&12

[0078] PPT: ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.13 (t, IH, H-24), 4.02 (dt, IH, H-6), 3.56 (dt, IH, H-12), 3.11 (dd, IH, H-3), 2.03 (q, 2H, H-23ab), 1.88 (broad, IH, H-16a), 1.84 (2H, H-Ha), 1.69 (s, 3H, H-26), 1.61 (s, 3H, H-27), 1.61 (s, 3H, H-18), 1.28 (s, 3H, H-28), 1.15 (s, 3H, H-21), 1.07 (s, 3H, H-19), 0.95 (s, 3H, H-30), 0.94 (s, 3H, H-29).

[0079] PPT-12-monosuccinate (GS51): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.13 (t, IH, H-24), 4.8 (IH, H-12), 4.01 (dt, IH, H-6), 3.11 (dd, IH, H-3), 1.85 (2H, H-Ha), 1.68 (s, 3H, H-26), 1.62 (s, 3H, H-27), 1.62 (s, 3H, H- 18), 1.28 (s, 3H, H-28), 1.13 (s, 3H, H- 21), 1.09 (s, 3H, H-19), 1.00 (s, 3H, H-30), 0.94 (s, 3H, H-29).

[0080] PPT-3,12-disuccinate (GS52): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.13 (t, IH,

H-24), 4.8 (IH, H-12), 4.57 (dd, IH, H-3), 4.03 (dt, IH, H-6), 1.68 (s, 3H, H-26), 1.62 (s, 3H, H-27), 1.28 (s, 3H, H-18), 1.13 (s, 3H, H-28), 1.07(s, 3H, H-19), 1.01 (s, 3H, H-30), 0.96 (s, 3H, H-29).

[0081] PPT-3,6,12-trisuccinate (GS53): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.39 (dt, IH, H-6), 5.13 (t, IH, H-24), 4.8 (IH, H-12), 4.11 (dd, IH, H-3), 1.68 (s, 3H, H-26), 1.62 (s, 3H, H-27), 1.14 (s, 3H, H-18), 1.12 (s, 3H, H-28), 1.07 (s, 3H, H-21), 1.02 (s, 3H, H- 19), 1.00 (s, 3H, H-30), 0.93 (s, 3H, H-29).

[0082] PPT-6,12-disuccinate (GS54): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.38 (dt, IH, H-6), 5.13 (t, IH, H-24), 4.8 (IH, H-12), 3.14 (dd, IH, H-3), 1.84 (2H, H-I Ia), 1.68 (s, 3H,

H-26), 1.62 (s, 3H, H-27), 1.28 (s, 3H ₅ H-18), 1.17 (s, 3H ₅ H-28), 1.13 (s, 3H, H-21), 1.12 (s, 3H ₅ H-19), 0.99 (s, 3H ₅ H-30), 0.98 (s, 3H ₅ H-29).

EXAMPLE 7: SYNTHESIS OF Fl SUCCINATE

[0083] 400 mg of Fl and 249.6 mg (4 equivalents) of succinic anhydride were dissolved in a mixed solution of 48 ml Et ₃ N and 16ml THF ₅ and the resulting solution was kept at room temperature (27 ⁰ C) under oscillation for 2~15 hours to react. White precipitate was formed and recovered by filtration, which was then dried by removing the solvent therefrom in vacuo. The obtained product was analyzed by HPLC where the mobile phase was 40% acetonitrile/H ₂ O (containing 0.02% phosphoric acid). The elution times of the main products separately were: 9.4 min, 13.6 min, 17.3 min, 25.3 min and 36.1 min. A semi-preparative HPLC was used for purification separation, thereby obtaining 65 mg of 9.4 min product (Fl), 10 mg of 13.6min product (GS31), 262 mg of 17.3 min product (GS32), 24 mg of 25.3 min product (GS33) and 14 mg of 36.1 min product (GS34). The products GS32 and GS33 were identified by mass spectrum (MS) as a Fl monosuccinate derivative and Fl disuccinate derivateive, respectively. Verifications from ¹³ C-NMR and ¹ H-NMR indicated that GS32 has monosuccinate which substitutes the hydrogen at 3 ^rd OH groups (3') on the glucose group at 20 ^th of Fl; and GS33 has two succinates which substitute the hydrogens at 3 ^rd and 6 ^th OH groups (3',6') on the glucose group at 20 ^th of Fl.

³ C-NMR chemical shifts of Fl and Fl -succinate derivatives

Fl -succinate derivatives

C atom

Fl GS32 (mono-) GS33 (di-)

1 40.10 40.12 40.10

2 30.91 30.79 30.66

3 78.27 79.50 79.57

4 47.20 47.18 47.20

5 62.13 62.13 62.15

6 68.89 68.86 68.92

7 40.14 40.16 40.14

8 42.02 41.99 42.01

succinate 3' 3'&6'

[0084] Fl: ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.11 (t, IH, H-24), 3.35 (t, IH, H-3 ^r of 20-Glc), 4.60 (d, IH, H-I ¹ of 20-Glc), 4.02 (dt, IH, H-6), 3.78 (dd, 2H, H-6'b of 20-Glc), 3.69 (dd, 2H, H-6'a of 20-Glc), 3.64 (dt, IH, H-12), 3.32 (t, IH, H-4' of 20-Glc), 3.21 (broad, IH, H-5' of 20-Glc), 3.07 (t, IH, H-2 ¹ of 20-Glc), 3.11 (dd, IH, H-3), 2.28 (q, IH, H-17), 2.08 (q, 2H, H-23ab), 1.92 (broad, IH, H-16a), 1.84 (2H, H-Ha), 1.68 (s, 3H, H- 26), 1.62 (s, 3H, H-27), 1.34 (s, 3H, H-21), 1.39 (s, 3H, H-28), 0.96 (s, 3H, H-29), 0.96 (s, 3H, H-30).

[0085] Fl-3'-monosuccinate (GS32): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.11 (t, IH, H-24), 4.96 (t, IH, H-3 ¹ of 20-Glc), 4.71 (d, IH, H-I ¹ of 20-Glc), 4.02 (dt, IH, H-6), 3.79

(dd, 2H, H-6'b of 20-Glc), 3.71 (d, 2H, H-6'a of 20-Glc), 3.67 (dt, IH, H-12), 3.49 (t, IH,

H-4 ¹ of 20-Glc), 3.30 (broad, IH, H-5 ¹ of 20-Glc), 3.22 (t, IH, H-2' of 20-GIc) ₅ 3.12 (dd,

IH, H-3), 2.28 (q, IH, H-17), 2.09 (q, 2H, H-23ab), 1.92 (dt, IH, H-16a), 1.84 (2H, H-

Ha), 1.82 (2H, H-22a), 1.68 (s, 3H ₅ H-26), 1.63 (s, 3H, H-27), 1.36 (s, 3H, H-21), 1.29 (s, 3H, H-28), 0.96 (s, 3H ₅ H-29), 0.96 (s, 3H, H-30).

[0086] Fl-3',6'-disuccinate (GS33): ¹ H-NMR (500MHz, CD ₃ OD) δ: 5.12 (t, IH ₅ H-24), 4.96 (t, IH, H-3 ¹ of 20-Glc), 4.69 (d, IH ₅ H-I' of 20-Glc), 4.14 (dd, 2H, H-6'ab of 20-Glc), 4.02 (dt, IH, H-6), 3.73 (dt, IH, H-12), 3.54 (t,lH, H-4' of 20-Glc), 3.42 (t, IH, H-5' of 20-Glc), 3.26 (t, IH ₅ H-2 ¹ of 20-Glc), 3.11 (dd, IH, H-3), 2.28 (q, IH, H-17), 1.67 (s, 3H, H-26), 1.62 (s, 3H, H-27), 1.36 (s, 3H, H-21), 1.28 (s, 3H, H-28), 0.95 (s, 3H, H- 29), 0.95 (s, 3H, H-30).

[0087] IC ₅₀ on OVCAR-3 tumor cell of some of the ginsenosides and succinate derivatives synthesized in Examples 5 to 7 are listed in Table 4.

Table 4. IC ₅ Q (μM) of ginsenosides and it's succinate derivatives on OVCAR-3 tumor cell

[0088] Although the present invention has been described with reference to specific details of certain embodiments thereof, it is not intended that such details should be regarded as limitations upon the scope of the invention. Many modifications and variations are possible in light of the above disclosure.