New furostanol saponins from Allium ascalonicum L

An analysis of the polar extracts from Allium ascalonicum L. led to the isolation of two new furostanol saponins (compound 1 and 2) and two known furostanol saponins (compound 3 and 4). On the basis of 1D and 2D NMR (including (1)H, (13)C NMR, (1)H--(1)H COSY, HSQC, TOCSY, HMBC, and NOESY), FAB-MS spectrometry, and chemical methods, their structures were elucidated as (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside C, 1), (25R)-26-O-beta-D-glucopyranosyl-22-methoxy-5alpha-furost-2-one-3beta, 5, 6beta, 26-tetraol- 3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside (ascalonicoside D, 2), (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (dichotomin, 3), and (25R)-26-O-beta-D-glucopyranosyl-22-hydroxy-5-ene-furostan-3beta, 26-diol-3-O-alpha-L-rhamnopyranosyl-(1-->2)-[alpha-L-arabinofuranosyl-(1-->4)]-beta-D- glucopyranoside (parisaponin I, 4).     

Complete (1)H and (13)C assignments of the four major saponins from Dioscorea villosa (wild yam)

Complete (1)H and (13)C spectral assignments for the four major steroidal saponins isolated by methanolic extraction of the roots of Dioscorea villosa, collected in North Carolina, United States (in summer and autumn), are presented in this paper. The structures were determined by a combination of (1)H, (13)C and 2D NMR techniques and were found to be ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22-methoxyfurost-5-en-3-yl-O-beta-D-glucopyranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1) (or methyl parvifloside), ((3beta,25R)-26-(beta-D-glucopyranosyloxy)-22 methoxyfurost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-D-gluco- pyranosyl-(1 --> 4)]-beta-D-glucopyranoside (2) (or methyl protodeltonin), (3beta,25R)-spirost-5-en-3-yl-O-beta-D-glucopy ranosyl-(1 --> 3)-O-beta-D-glucopyranosyl-(1 --> 4)-O-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (3) (or Zingiberensis saponin I) and (3beta,25R)-spirost-5-en-3-yl-O-alpha-L-rhamnopyranosyl-(1 --> 2)-O-[beta-Ds-glucopyranosyl -(1 --> 4)]-beta-D-glucopyranoside (4) (or deltonin).     

Studies on the constituents of solanaceous plants. (46). Steroidal glycosides from the fruits of Solanum anguivi

Three new glycosides named anguiviosides A-C were isolated from the fruits of Solanum anguivi and characterized as follows:3-O-beta-chacotrioside (1), 3-O-[4-O-maloyl-alpha-L-rhamnopyranosyl(1-->2)]-alpha-L-rhamnopyra nosyl(1-->4)-beta-D-glucopyranoside (2) and 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-xylopyranosyl(1-->3)]-beta-D-+ ++glucopyranoide (3), of (25R,26R)-spirost-5-en-3beta,26-diol.     

Structures of two new steroidal glycosides, soladulcosides A and B from Solanum dulcamara

The structures of two new steroidal glycosides named soladulcosides A and B, isolated from the aerial parts of Solanum dulcamara including new sapogenols, were elucidated as (22R, 25R)-3 beta, 15 alpha, 23 alpha-trihydroxy-5 alpha-spirostan-26-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-beta-D-glucopyranoside and (22R, 25R)-3 beta,23 alpha-dihydroxy-5 alpha-spirostan-26-one 3-O-alpha-L-rhamnopyranosyl-(1----2)-[alpha-L-rhamnopyranosyl-(1----4)]- beta-D-glucopyranoside, respectively.     

Three new steroidal saponins from the rhizome of Paris polyphylla

A mixture of a pair of stereoisomeric new spirostanol saponins (1a and 1b) and a new cholestane saponin (2) were isolated from the rhizome of Paris pollyphylla Smith var. yunnanensis. Their structures were elucidated as (25R)-spirost-5-en-3beta, 7beta-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1a), (25R)-spirost-5-en-3beta, 7alpha-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (1b) and 26-O-beta-D-glucopyranosyl-(25R)-Delta(5(6), 17(20))-dien-16, 22-dione-cholestan-3beta, 26-diol-3-O-alpha-L-arabinofuranosyl-(1 --> 4)-[alpha-L-rhamnopyranosyl-(1 --> 2)]-beta-D-glucopyranoside (2) by a combination of HR-ESI-MS, FAB-MS, 1D and 2D NMR techniques (including (1)H-NMR, (13)C-NMR, (1)H--(1)H COSY, HSQC, HMBC and NOESY).     

Two new monodesmosidic triterpene saponins from Gypsophila oldhamiana

Two new monodesmosidic triterpene saponins were isolated from the roots of Gypsophila oldhamiana (Caryophyllaceae). Their structures were elucidated on the basis of spectral data to be quillaic acid, alpha-L-arabinopyranosyl-(1-->4)-alpha-L-arabinopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (1), and vaccaric acid, beta-D-glucopyranosyl-(1-->3)-[beta-D-xylopyranosyl-(1-->4)]-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-fucopyranosyl ester (2). Compound 1 showed a significant enhancement of granulocyte phagocytosis in vitro.     

Minor triterpenoid saponins from Ardisia crenata

Two minor triterpenoid saponins, ardisicrenoside G [3 beta-O-{alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranosyl-(1-->4)- [beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl}-16 alpha,28-dihydroxyolean-12-en-30-oic acid] and ardisicrenoside H [3 beta-O-{beta-D-xylopyranosyl-(1-->2)-beta-D- glucopyranosyl-(1-->4)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L- arabinopyranosyl}-16 alpha,28-dihydroxyolean-12-en-30-oic acid] were isolated from the roots of Ardisia crenata. Structural assignments are based on NMR, MS and chemical reactions.     

Pregnane glycosides and steroid saponins from Smilax bockii Warb. and their NGF-potentiating activity

The chemical constituents of the roots of Smilax bockii Warb. were investigated and two pregnane glycosides and three steroid saponins were isolated. Their structures were established as 3beta-hydroxypregna-5,16-dien-20-one-3-O-alpha-L-rhamnopyranosyl(1 --> 4)-alpha-L-rhamnopyranosyl(1 --> 4)-[alpha-L-rhamnopyranosyl(1 --> 2)]-beta-D-glucopyranoside (1), 3beta-hydroxypregna-5,16-dien-20-one-3-O-alpha-L-rhamnopyranosyl(1 --> 2)-[alpha-L-rhamnopyranosyl(1 --> 4)]-beta-D-glucopyranoside (2), dioscin (3), methyl protodioscin (4), 26-O-beta-D-glucopyranosyl-22alpha-methoxyl-(25R)-furost-5-en-3beta, 26-diol 3-O-alpha-L-rhamnopyranosyl(1 --> 4)-alpha-L-rhamnopyranosyl(1 --> 4)-[alpha-L-rhamnopyranosyl(1 --> 2)]-beta-D-glucopyranoside (5) on the basis of spectral analysis and chemical methods. Compound 1 is a new natural product and compounds 2, 5 were first isolated from the genus Smilax. Compound 5 showed enhancing activity of nerve growth factor (NGF)-induced neurite outgrowth in PC 12D cells.     

Fargosides A-E, triterpenoid saponins from Holboellia fargesii

Five new triterpenoid saponins, fargosides A, B, C, D, and E, were isolated from the roots of Holboellia fargesii. The structures of fargosides A-E were elucidated on the basis of chemical and physicochemical evidence and found to be 3beta,20alpha-dihydroxy-29-norolean-12-en-28-oic acid 3-O-beta-D-xylopyranosyl-(1-->2)-beta-D-glucopyranoside (1), 3beta,20alpha,24-trihydroxy-29-norolean-12-en-28-oic acid 23-O-beta-D-fucopyranosyl-(1-->2)-[alpha-L-arabinopyranosyl-(1-->3)]-beta-D-glucopyranoside (2), 3beta,23-dihydroxy-30-norolean-2,20(29)-dien-28-oic acid 3-O-alpha-L-arabinopyranosyl-(1-->2)-[beta-D-glucopyranosyluronic acid-(1-->3)]-alpha-L-arabinopyranoside (3), 3beta,23-dihydroxy-30-norolean-12,20(29)-dien-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (4), and 3beta,23-dihydroxy-olean-12-en-28-oic acid 3-O-methyl beta-D-glucopyranosyluronate-(1-->3)-alpha-L-arabinopyranoside (5), respectively.     

Bioactive saponins and glycosides. XVI. Nortriterpene oligoglycosides with gastroprotective activity from the fresh leaves of Euptelea polyandra Sieb. et Zucc. (1): structures of Eupteleasaponins I, II, III, IV, V, and V acetate

The saponin fraction from the fresh leaves of Euiptelea polyandra Sieb. et Zucc. was found to exhibit potent gastroprotective activity. Fourteen new nortriterpene saponins called eupteleasaponins were isolated from the saponin fraction with gastroprotective activity. The structures of eupteleasaponins I, I1, III, IV, V, and V acetate were determined on the basis of chemical and physicochemical evidence as 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1-->2)-[alpha-L-rhamnopyranosyl(1 -->4)-beta-D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D- D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1 -->4)-beta-D-glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosyl(1 -->2)-[alpha-L-arabinopyranosyl(1-->4)-alpha-L-rhamnopyranosyl(1-- >4)]-beta-D- glucopyranosyl(1-->3)-beta-D-xylopyranosylakebonoic acid 28-O-beta-D-glucopyranosyl ester, 3-O-alpha-L-rhamnopyranosvl(1-->2)-[alpha-L-arabinopyranosyl (1 -->4)-beta-L-rhamnopyranosyl(1 -->4)]-beta-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosylakebonoic acid, 3-O-alpha-L-rhamnopyranosyl(1 -->2)-beta-D-glucopyranosvl(1-->3)-beta-D-xylopyranosyleupteleo genin, and 3-O-alpha-L-rhamnopyranosyl(1-->2)-6"-O-acetyl-gamma-D-glucopyranosyl(1 -->3)-beta-D-xylopyranosyleupteleogenin.     

Syntheses of 2-chloro-4-nitrophenyl beta-D-maltopentaosides with bulky modification and their application to the differential assay of human alpha-amylases.

Four novel maltopentaosides, 2-chloro-4-nitrophenyl O-(6-O-p-toluenesulfonyl-alpha-D-glucopyranosyl)-(1-->4)-tris[O- alpha-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside (4), 2-chloro-4-nitrophenyl O-[6-O-(tert-butyldimethyl)silyl-alpha-D- glucopyranosyl]-(1-->4)-tris[O-alpha-D-glucopyranosyl-(1-->4)]-beta-D- glucopyranoside (5), 2-chloro-4-nitrophenyl O-[6-deoxy-6-(phenyl)sulfonyl-alpha-D- glucopyranosyl]-(1-->4)-tris[O-alpha-D-glucopyranosyl-(1-->4)]-beta-D- glucopyranoside (10), and 2-chloro-4-nitrophenyl O-(6-deoxy-6-phthalimido-alpha-D-glucopyranosyl)- (1-->4)-tris[O-alpha-D-glucopyranosyl-(1-->4)]-beta-D-glucopyranoside (11) were synthesized. Substrates 4, 5, 10, and 11 were hydrolyzed by human pancreatic alpha-amylase (HPA) from 1.1 to 2.9-fold faster than by human salivary alpha-amylase (HSA). Taking advantage of the difference in the hydrolytic rate of 5 (2.9-fold faster), we developed a new method for the differential assay of these two human alpha-amylases.     

A new steroidal saponin from Dioscorea cayenensis

The new 26-O-beta-D-glucopyranosyl-3beta,26-dihydroxy-20,22-seco-25(R)-furost-5-en-20,22-dione-3-O-alpha-L-rhamnopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->4)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside (1), along with the known methyl protodioscin (2), asperoside (3) and prosapogenin A of dioscin (4) were isolated from the rhizomes of Dioscorea cayenensis LAM.-HOLL (Dioscoreaceae). Their structures were established mainly on the basis of 600 MHz 2D-NMR spectral data. 4 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs of 20.8, 6.25, 25 microg/ml, respectively), whereas saponins 1-3 were inactive.     

Five new bidesmoside triterpenoid saponins from Stauntonia chinensis

Eleven triterpenoid saponins (1-11) were isolated from Stauntonia chinensis DC. (Lardizabalaceae), including five new compounds, yemuoside YM(21-25) (1-3, 6, 7) structures of which were elucidated by chemical methods and a combination of MS, 1D- and 2D- NMR experiments including DEPT, (1)H--(1)H COSY, HSQC, HMBC, TOCSY, and NOESY as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonicacid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (1), 3-O-beta-D-xylopyranosyl-(1 --> 3)-alpha-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (2), 3-O-beta-D-glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl-akebonic acid-28-O-alpha-L-rhamnopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (3), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-rhamnopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (6), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[alpha-L-arabinopyranosyl-(1 --> 2)-]alpha-L-arabinopyranosyl-akebonic acid-28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranosyl ester (7).     

Two new triterpenoid saponins isolated from Polygala japonica

Bioassay guided investigation of whole parts of Polygala japonica afforded two new triterpenoid saponins, characterized as 3-O-beta-D-glucopyranosyl medicagenic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (1), 3-O-beta-D-glucopyranosyl 2-oxo-olean-12-en-23, 28-dioic acid 28-O-{beta-D-xylopyranosyl(1-->4)-[beta-D-apiofuranosyl(1-->3)]-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl} ester (2), together with four known triterpenoid saponins (3-6). Their structures were elucidated by spectroscopic and chemical methods. Saponins 3, 4 and 5 showed significant anti-inflammation effects on carrageenan-induced acute paw edema in mouse.     

Medicinal foodstuffs. XVII. Fenugreek seed. (3): structures of new furostanol-type steroid saponins, trigoneosides Xa, Xb, XIb, XIIa, XIIb, and XIIIa, from the seeds of Egyptian Trigonellafoenum-graecum L

Six new furostanol-type steroid saponins called trigoneosides Xa, Xb, XIb, XIIa, XIIb, and XIIIa were isolated from the seeds of Egyptian Trigonella foenum-graecum L. (Leguminosae) together with six known furostanol-type steroid saponins: trigoneosides Ia, Ib, and Va, glycoside D, trigonelloside C, and compound C. The structures of trigoneosides Xa, Xb, Xlb, XIIa, Xllb, and XIIIa were determined on the basis of chemical and physicochemical evidence as 26-O-beta-D-glucopyranosyl-(25S)-5alpha-furostane-2alpha+ ++,3beta,22xi,26-tetraol 3-O-alpha-L-rhamnopyranosyl(1-->2)-,beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-5alpha-furostane-2 alpha,beta,22xi,26tetraol 3-O-alpha-L-rhamnopyranosyl(l -->2)-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-5alpha-furostane2alpha++ +,beta,22xi,26-tetraol 3-O-beta-D-xylopyranosyl(l -->4)-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25S)-furost-4-ene-3beta,22xi,26- triol 3-O-Ca-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranoside, 26-O-beta-D-glucopyranosyl-(25R)-furost-4-ene-3beta,22xi+ ++,26-triol 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranoside, and 26-O-beta-D-glucopyranosyl(25S)-furost-5-ene-3beta,22xi,26-t riol 3-O-alpha-L-rhamnopyranosyl(1-->2)-beta-D-glucopyranosyl (1-->3)-beta-D-glucopyranosyl(1--4)]-beta-D-glucopyranoside, respectively.     

The NMR studies on two new furostanol saponins from Agave sisalana leaves

The detailed NMR studies and full assignments of the 1H and 13C spectral data for two new furostanol saponins isolated from Agave sisalana leaves are described. Their structures were established using a combination of 1D and 2D NMR techniques including 1H, 13C, 1H-1H COSY, TOCSY, HSQC, HMBC and HSQC-TOCSY, and also FAB-MS spectrometry and chemical methods. The structures were established as (25S)-26-(beta-D-glucopyranosyl)-22 xi-hydroxyfurost-12-one-3beta-yl-O-alpha-L-rhamnopyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl-(1-->4)-beta-D-galacto- pyranoside (1) and (25S)-26-(beta-D-glucopyranosyl)-22xi-hydroxyfurost-5-en-12-one-3beta-yl-O-alpha-L-rhamno- pyranosyl-(1-->4)-beta-D-glucopyranosyl-(1-->3)-O-[O-beta-D-glucopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl- (1-->4)-beta-D-galactopyranoside (2).     

New saponins from the seeds of Aesculus chinensis

Eight new acylated polyhydroxyoleanene triterpenoidal saponins, aesculiosides A-H (1-8), along with four known ones, have been isolated from the seeds of Aesculus chinensis. On the basis of extensive NMR studies, the structures of the new compounds were determined to be 21-O-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]- beta-D-glucuronopyranosyl acid (1), 21-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (2), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-d-glucopyranosyl- (1-->4)]-beta-D-glucuronopyranosyl acid (3), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-beta-D-glucuronopyranosyl acid (4), 21,22-O-ditigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl- (1-->2)][beta-D-glucopyranosyl-(1-->4)]-methyl beta-d-glucuronopyranosate (5), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)-[beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (6), 21-O-tigloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (7) and 21-O-angeloyl-28-O-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl-(1-->2)][beta-D-glucopyranosyl-(1-->4)]-methy l beta-D-glucuronopyranosate (8).     

Studies on Balanites aegyptiaca fruits, an antidiabetic Egyptian folk medicine

An aqueous extract of mesocarps of the fruits of Balanites aegyptiaca exhibited a prominent antidiabetic activity by oral administration in streptozotocin induced diabetic mice. From one of the active fractions of this extract, two new steroidal saponins were isolated, and their structures were determined as 26-O-beta-D-glucopyranosyl-(25R)-furost-5-ene-3 beta,22,26-triol 3-O-[alpha-L-rhamnopyranosyl-(1----2)]-[beta-D-xylopyranosyl-(1---- 3)]-[alpha-L-rhamnopyranosyl-(1----4)]-beta-D-glucopyranoside and its 22-methyl ether. In addition, two known saponins, 26-O-beta-D-glucopyranosyl-(25R)-furost-5-ene-3 beta,22,26-triol 3-O-(2,4-di-O-alpha-L-rhamnopyranosyl)-beta-D-glucopyranoside and its methyl ether were isolated and identified. It was revealed that the individual saponins did not show antidiabetic activity, while the recombination of these saponins resulted in significant activity. From an ethanolic extract of the epicarps, two known flavonol glycosides, isorhamnetin-3-O-robinobioside and isorhamnetin-3-O-rutinoside were isolated and identified.     

Three new triterpene saponins from the seeds of Aesculus chinensis

Three new triterpenoid saponins were isolated from the seeds of Aesculus chinensis, and characterized as 22-tigloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVg, 1), 22-angeloylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin IVh, 2) and 16-angeloyl-21-acetylprotoaescigenin 3-O-[beta-D-glucopyranosyl (1-->2)] [beta-D-glucopyranosyl (1-->4)]-beta-D-glucopyranosiduronic acid (escin VIb, 3), together with two known compounds, escin IIIa (4) and desacylescin 1 (5). Their structures were established on the basis of spectroscopic and chemical evidence.