New saponins from Sechium mexicanum

The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (1) and {3‐O‐β‐D ‐glucopyranosyl (1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐[β‐D ‐apiosyl‐(1 → 3)]‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (2), together with the known compounds {3‐O‐β‐D ‐glucopyranosyl‐(1 → 3)‐β‐D ‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐O‐α‐L ‐rhamnopyranosyl‐(1 → 3)‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐α‐L ‐arabinopyranoside} (3), tacacosides A₁ (4) and B₃ (5). The structures of saponins 1 and 2 were elucidated using a combination of ¹H and ¹³C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium, while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright © 2009 John Wiley & Sons, Ltd.     

Two new complex triterpenoid saponins from Gledistsia dolavayi Franch.

Two new triterpenoid saponins, gledistside A ( 1 ) and gledistside B ( 2 ), isolated from the fruits of Gledistsia dolavayi Franch., were characterized as the 3,28‐O‐bisdesmoside of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of spectroscopic and chemical evidence, their structures were elucidated as 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2,6‐dimethyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 1 ) and 3‐O‐β‐D ‐xylopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranosyl‐28‐O‐β‐D ‐xylopyranosyl‐(1→3)‐β‐D ‐xylopyranosyl‐(1→4)‐[β‐D ‐galactopyranosyl‐(1→2)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐{6‐O‐[2‐hydroxymethyl‐6‐methyl‐6(S)‐hydroxy‐2‐trans‐2,7‐octadienoyl]}‐β‐D ‐glucopyranosylechinocystic acid ( 2 ). The complete ¹H and ¹³C assignments of saponins 1 and 2 were achieved on the basis of 2D NMR spectra including HMQC‐TOCSY, TOCSY, ¹H–¹H COSY, HMBC, ROESY and HMQC spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Flavonol Glycosides and Cytotoxic Triterpenoids from Alphitonia Philippinensis

Three new flavonol glycosides, namely, isorhamnetin 3‐O‐(6″‐O‐(Z)‐p‐coumaroyl)‐β‐D ‐glucopyranoside ( 1 ), quercetin 3‐O‐α‐L ‐rhamnopyranosyl(1 → 2)‐α‐L ‐arabinopyranosyl(1 → 2)‐α‐L ‐rhamnopyranoside ( 2 ), and quercetin 3‐O‐α‐L ‐arabinopyranosyl(1 → 2)‐α‐L ‐rhamnopyranoside ( 3 ), were isolated from the stems of Alphitonia philippinensis. Their structures were established by spectral analysis. In addition, NMR data were assigned for ceanothenic acid ( 11 ). Some of the isolated triterpenoids and flavonoid glycosides showed cytotoxicity against human PC‐3 cells and hepatoma HA22T cells, and inhibition of replication on herpes simplex virus type‐1.     

Four new ursane‐type saponins from Morina nepalensis var. alba

Four new ursane‐type saponins, monepalosides C–F, together with a known saponin, mazusaponin II, were isolated from Morina nepalensis var. alba Hand.‐Mazz. Their structures were determined to be 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside C, 1 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[alpha;‐L ‐rhamnopyranosyl‐(1 → 2)]‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside D, 2 ), 3‐O‐α‐L ‐arabinopyranosyl‐(1 → 3)‐&[beta;‐D ‐glucopyranosy‐(1 → 2)]‐α‐L ‐arabinopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranoside (monepaloside E, 3 ) and 3‐O‐β‐D ‐xylopyranosylpomolic acid 28‐O‐β‐D ‐glucopyranoside (monepaloside F, 4 ) on the basis of chemical and spectroscopic evidence. 2D NMR techniques, including ¹H–¹H COSY, HMQC, 2D HMQC‐TOCSY, HMBC and ROESY, and selective excitation experiments, including SELTOCSY and SELNOESY, were utilized in the structure elucidation and complete assignments of ¹H and ¹³C NMR spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Structure elucidation of new acacic acid‐type saponins from Albizia coriaria

Three new acacic acid derivatives, named coriariosides C, D, and E ( 1–3 ) were isolated from the roots of Albizia coriaria. Their structures were elucidated on the basis of extensive 1D‐ and 2D‐NMR studies and mass spectrometry as 3‐O‐[β‐D ‐xylopyranosyl‐(1 → 2)‐β‐D ‐fucopyranosyl‐(1 → 6)‐2‐(acetamido)‐2‐deoxy‐β‐D ‐glucopyranosyl]‐21‐O‐{(2E,6S)‐6‐O‐{4‐O‐[(2E,6S)‐2,6‐dimethyl‐ 6‐O‐(β‐D ‐quinovopyranosyl)octa‐2,7‐dienoyl]‐4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐O‐(β‐D ‐quinovopyranosyl)octa‐2,7‐dienoyl]‐β‐D ‐quinovopyranosyl}‐2,6‐dimethylocta‐2,7‐dienoyl}acacic acid 28‐O‐β‐D ‐xylopyranosyl‐(1 → 4)‐α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl ester ( 1 ), 3‐O‐{β‐D ‐fucopyranosyl‐(1 → 6)‐[β‐D ‐glucopyranosyl‐(1 → 2)]‐β‐D ‐glucopyranosyl}‐21‐O‐{(2E,6S)‐6‐O‐{4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐O‐(β‐D ‐quinovopyranosyl)octa‐2,7‐dienoyl]‐4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐O‐(β‐D ‐quinovopyranosyl)octa‐2,7‐dienoyl]‐β‐D ‐quinovopyranosyl}‐2,6‐dimethylocta‐2,7‐dienoyl}acacic acid 28‐O‐α‐L ‐rhamno pyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl ester ( 2 ), and 3‐O‐[β‐D ‐fucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranosyl]‐21‐O‐{(2E,6S)‐6‐O‐{4‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐O‐(β‐D ‐quinovopyranosyl)octa‐2,7‐dienoyl)‐β‐D ‐quinovopyranosyl]octa‐2,7‐dienoyl}acacic acid 28‐O‐β‐D ‐glucopyranosyl ester ( 3 ). Copyright © 2010 John Wiley & Sons, Ltd.     

Flavonoid Glycosides from the Leaves of Machilus philippinensis

Thirteen flavonoid glycosides ( 1‐7 , 11‐13 , 15 , 17 , and 18 ) were isolated from the EtOH extract of the leaves of Machilus philippinensis. Of these, kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐α‐L ‐rhamnopyranoside ( 1 ) and kaempferol 3‐O‐(2‐O‐β‐D ‐apiofuranosyl)‐a‐L ‐arabinofuranoside ( 2 ) are new natural products. By application of HPLC‐SPE‐NMR hyphenated technique, five additional flavonol glycosides were characterized ( 8‐10 , 14 , and 16 ). Their structures were elucidated based on spectroscopic analysis. Of these, quercetin 3‐O‐(6‐O‐α‐L ‐rhamnopyranosyl)‐β‐D ‐galactopyranoside ( 5 ) and kaempferol 3‐O‐α‐L ‐arabinopyranoside ( 15 ) showed moderate inhibitory activity against α‐glucosidase type IV from Bacillus stearothermophilus with the IC₅₀ values of 19.5 and 19.0 μM, respectively.     

Tetrapterosides A and B,two new oleanane‐type saponins from Tetrapleura tetraptera

From the stem bark of Tetrapleura tetraptera, two new oleanane‐type saponins, tetrapteroside A 3‐O‐{6‐O‐[(2E,6S)‐2,6‐dimethyl‐6‐hydroxyocta‐2,7‐dienoyl]‐β‐D ‐glucopyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl‐(1 → 3)‐β‐D ‐glucopyranosyl‐(1 → 4)‐[β‐D ‐glucopyranosyl‐(1 → 2)]‐β‐D ‐glucopyranosyl}‐3,27‐dihydroxyoleanolic acid (1), and tetrapteroside B 3‐O‐{ β‐D ‐glucopyranosyl‐(1 → 2)‐6‐O‐[(E)‐feruloyl]‐β‐D ‐glucopyranosyl‐(1 → 3)‐β‐D ‐glucopyranosyl‐(1 → 4)‐[β‐D ‐glucopyranosyl‐(1 → 2)]‐β‐D ‐glucopyranosyl}‐3,27‐dihydroxyoleanolic acid (2), were isolated. Further extractions from the roots led to the isolation of four known oleanane‐type saponins. Their structures were elucidated by the combination of mass spectrometry (MS), one and two‐dimensional NMR experiments. Copyright © 2009 John Wiley & Sons, Ltd.     

Structure elucidation and total assignment of 1H and 13C NMR data for a new bisdesmoside saponin from Cordia piauhiensis

Extensive 1D (¹H NMR, HBBD‐¹³C NMR, DEPT‐¹³C NMR) and 2D (COSY, TOCSY, NOESY, HMQC and HMBC) NMR analysis was used to characterize the structure of a new bisdesmoside saponin isolated from the methanol extract of stems of Cordia piauhiensis Fresen as 3β‐O‐[α‐L ‐rhamnopyranosyl‐(1 → 2)‐β‐D ‐glucopyranosyl]ursolic acid 28‐O‐[β‐D ‐glucopyranosyl‐(1 → 6)‐β‐D ‐glucopyranosyl] ester. Copyright © 2003 John Wiley & Sons, Ltd.     

Three New Kaempferol Glycosides from Cardamine leucantha

Three new kaempferol glycosides, kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside ( 1 ), kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 2 ), and kaempferol 3‐O‐β‐D ‐glucopyranosyl‐(1→6)‐β‐D ‐galactopyranosyl‐7‐O‐β‐D ‐glucopyranosyl‐(1→3)‐α‐L ‐rhamnopyranoside ( 3 ), were isolated from the whole herbs of Cardamine leucantha, along with three known kaempferol glycosides, kaempferol 7‐O‐α‐L ‐rhamnopyranoside, kaempferitrin, and kaempferol 3‐O‐β‐D ‐galactopyranosyl‐7‐O‐α‐L ‐rhamnopyranoside. Their structures were elucidated on the basis of spectroscopic methods.     

Insulin Secretagogues from Moringa oleifera with Cyclooxygenase Enzyme and Lipid Peroxidation Inhibitory Activities

Bioassay‐directed isolation and purification of the methanol extract of Moringa oleifera fruits yielded bioactive N‐benzyl thiocarbamates, N‐benzyl carbamates, benzyl nitriles, and a benzyl ester. Among these, methyl 2‐[4‐(α‐L ‐rhamnopyranosyl)phenyl]acetate ( 2 ), N‐[4‐(β‐L ‐rhamnopyranosyl)benzyl]‐1‐O‐α‐D ‐glucopyranosylthiocarboxamide ( 3 ), 1‐O‐phenyl‐α‐L ‐rhamnopyranoside ( 5 ), and 4‐[(β‐D ‐glucopyranosyl)‐(1→3)‐(α‐L ‐rhamnopyranosyl)]phenylacetonitrile ( 6 ) are novel, and their structures were determined by spectroscopic methods. The known compounds isolated and characterized from the MeOH extract were niazirin (=4‐(α‐L ‐rhamnopyranosyl)phenylacetonitrile; 1 ), niazicin A (=methyl N‐{4‐[(4′‐O‐acetyl‐α‐L ‐rhamnopyranosyl)benzyl]}thiocarbamate; 4 ), methyl N‐{4‐[(α‐L ‐rhamnopyranosyl)benzyl]}carbamate ( 7 ), and methyl N‐{4‐[(4′‐O‐acetyl‐α‐L ‐rhamnopyranosyl)benzyl]}carbamate ( 8 ). The combined yield of these compounds from dried M. oleifera fruits was 1.63%. In rodent pancreatic β‐cells (INS‐1), compounds 4, 5, 6, 7 , and 8 at 100 ppm significantly stimulated insulin release. Cyclooxygenase‐1 (COX‐1) and cyclooxygenase‐2 (COX‐2) enzyme inhibition assays revealed that 5 and 6 were most active at 83 ppm. Compound 6 , however, demonstrated greater specificity for inhibition of COX‐2 enzyme (46%) than COX‐1 enzyme. Lipid peroxidation assays revealed that 4 and 6 at 50 ppm inhibited peroxidation reactions by 80 and 95%, respectively, while 3 and 8 inhibited lipid peroxidation by 35%. These compounds did not inhibit the cell growth when tested with human breast (MCF‐7), central nervous system (CNS, SF‐268), lung (NCI‐H460), or colon (HCT‐116) cancer cell lines. Moreover, these compounds were not cytotoxic at the concentrations tested.     

Bidesmosidic Oleanane Saponins from Xerospermum noronhianum

Three new oleanane‐type triterpenoid saponins, 3‐O‐(α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐fucopyranosyl)‐28‐O‐{[α‐L ‐rhamnopyranosyl(1→2)] [β‐D ‐fucopyranosyl(1→6)]‐β‐D ‐glucopyranosyl} oleanolic acid ( 1 ), 3‐O‐[α‐L ‐rhamnopyranosyl(1→3)‐β‐D ‐fucopyranosyl]‐28‐O‐[α‐L ‐rhamnopyranosyl(1→4)‐β‐D ‐glucopyranosyl] oleanolic acid ( 2 ), and 3‐O‐{α‐L ‐rhamnopyranosyl(1→2)‐[3′,4′‐diacetoxy‐β‐D ‐fucopyranosyl]}‐28‐O‐[α‐L ‐rhamnopyranosyl(1→2)‐β‐D ‐glucopyranosyl] oleanolic acid ( 3 ) have been isolated from the stems of Xerospermum noronhianum. The structures of the saponins were determined as a series of bidesmosidic oleanane saponins based on spectral evidence. The anticholinesterase activity of the saponins 1 – 3 was also evaluated.     

Xanthone O‐Glycosides from the Roots of Pteris Multifida

Two new xanthone glycosides and six known compounds were isolated from the roots of Pteris multifida. Based on spectroscopic and chemical methods, the structures of the new compounds were elucidated as 1‐hydroxy‐4,7‐dimethoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 1 ), and 1,3‐dihydroxy‐7‐methoxy‐8‐(3‐methyl‐2‐butenyl)‐6‐O‐α‐L‐rhamnopyranosyl‐(1 →2)‐[β‐D‐glucopyranosyl‐(1→3)]‐β‐D‐glucopyranosylxanthone ( 2 ), respectively.     

Two new acylated flavonoid glycosides from Morina nepalensis var. alba Hand.‐Mazz.

From the whole plant of Morina nepalensis var. alba Hand.‐Mazz., two new acylated flavonoid glycosides ( 1 and 2 ), together with four known flavonoid glycosides ( 3–6 ), were isolated. Their structures were determined to be quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (monepalin A, 1 ), quercetin 3‐O‐[2″′‐O‐(E)‐caffeoyl]‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐glucopyranoside (monepalin B, 2 ), quercetin 3‐O‐α‐L ‐arabinopyranosyl‐(1→6)‐β‐D ‐galactopyranoside (rumarin, 3 ), quercetin 3‐O‐β‐D ‐galactopyranoside ( 4 ), quercetin 3‐O‐β‐D ‐glucopyranoside ( 5 ) and apigenin 4^′‐O‐β‐D ‐glucopyranoside ( 6 ). Their structures were determined on the basis of chemical and spectroscopic evidence. Complete assignments of the ¹H and ¹³C NMR spectra of all compounds were achieved from the 2D NMR spectra, including H–H COSY, HMQC, HMBC and 2D HMQC‐TOCSY spectra. Copyright © 2002 John Wiley & Sons, Ltd.     

Development of a high‐performance liquid chromatography procedure to identify known and detect novel C‐13 oligosaccharide moieties in diterpene glycosides from Stevia rebaudiana (Bertoni) Bertoni (Asteraceae): Structure elucidation of rebaudiosides V and W

As an aid for structure elucidation of new steviol glycosides, reversed‐phase C18 high‐performance liquid chromatography method was developed with several previously characterized diterpene glycosides, to identify known and detect novel aglycone‐C13 oligosaccharide moieties and indirectly identify C‐19 interlinkages. Elution order of several diterpene glycosides and their aglycone‐C13 oligosaccharide substituted with different sugar arrangements were also summarized. Comparison of the retention time of a product obtained after alkaline hydrolysis with the aglycone‐C‐13 portions of known compounds reported herein allowed us to deduce the exact positions of the sugars in the C‐13 oligosaccharide portion. The elution position of several steviol glycosides with an ent‐kaurene skeleton was helpful to describe an identification key. Two previously uncharacterized diterpene glycosides together with two known compounds were isolated from a commercial Stevia rebaudiana leaf extract. One was found to be 13‐[(2‐O‐β‐d ‐xylopyranosyl‐ 3‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl)oxy]ent‐kaur‐16‐en‐19‐oic acid‐(2‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl) ester (rebaudioside V), whereas the other was determined to be 13‐[(2‐O‐β‐d ‐xylopyranosyl‐ 3‐O‐β‐d ‐glucopyranosyl‐β‐d‐ glucopyranosyl)oxy]ent‐kaur‐16‐en‐19‐oic acid‐(2‐O‐α‐l ‐rhamnopyranosyl‐3‐O‐β‐d ‐glucopyranosyl‐β‐d ‐glucopyranosyl) ester (rebaudioside W). Previously reported compounds were isolated in gram quantities and identified as rebaudioside J and rebaudioside H. In addition, a C‐19 sugar‐free derivative was also prepared from rebaudioside H to afford rebaudioside H₁. Chemical structures were partially determined by the high‐performance liquid chromatography method and unambiguously characterized by using one‐dimensional and two‐dimensional nuclear magnetic resonance experiments.     

DOSY NMR applied to analysis of flavonoid glycosides from Bidens sulphurea

2D DOSY ¹H NMR has proved to be a useful technique in the identification of the molecular skeleton of the four major compounds of ethyl acetate extract of aerial parts of Bidens sulphurea (Asteraceae). The combination of this technique with HPLC, mass spectrometry and other NMR techniques enabled the identification of four flavonoid glycosides: quercetin‐3‐O‐β‐D ‐galactopyranoside, quercetin‐3‐O‐β‐D ‐glycopyranoside, quercetin‐3‐O‐α‐L ‐arabinofuranoside and quercetin‐3‐O‐β‐D ‐rhamnopyranoside. Copyright © 2009 John Wiley & Sons, Ltd.     

Five New Medicagenic Acid Saponins from Muraltia ononidifolia

Five new triterpene saponins 1 – 5 were isolated from the roots of Muraltia ononidifolia E. Mey along with the two known saponins 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester and 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester (medicagenic acid=(4α,2β,3β)‐2,3‐dihydroxyolean‐12‐ene‐23,28‐dioic acid). Their structures were elucidated mainly by spectroscopic experiments, including 2D‐NMR techniques, as 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐[O‐β‐ D ‐apiofuranosyl‐(1→3)‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 1 ), 3‐O‐(β‐D ‐glucopyranosyl)medicagenic acid 28‐{[O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 2 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐{O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐[β‐D ‐apiofuranosyl‐(1→3)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl} ester ( 3 ), 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid 28‐[O‐α‐L ‐rhamnopyranosyl‐(1→2)‐α‐L ‐arabinopyranosyl] ester ( 4 ), and 3‐O‐[O‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranosyl]medicagenic acid ( 5 ).     

New Acylated Triterpene Saponins from Polygala arenaria

Eight new acylated triterpene saponins 1 – 8 were isolated from the roots of Polygala arenaria as four inseparable (E)/(Z) mixtures of the 4‐methoxycinnamoyl and 3,4‐dimethoxycinnamoyl derivatives by repeated MPLC over silica gel. Their structures were established mainly by 600‐MHz 2D‐NMR techniques (¹H,¹H‐COSY, TOCSY, NOESY, HSQC, HMBC) as 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐(O‐β‐D ‐galactopyranosyl‐(1→4)‐O‐[β‐D ‐glucopyranosyl‐(1→3)]‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐4‐methoxycinnamoyl]}‐β‐D ‐fucopyranosyl) ester and its (Z)‐isomer ( 1 / 2 ), 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐(O‐β‐D ‐galactopyranosyl‐(1→4)‐O‐[β‐D ‐glucopyranosyl‐(1→3)]‐O‐β‐D ‐xylopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]}‐β‐D ‐fucopyranosyl) ester and its (Z)‐isomer ( 3 / 4 ), 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐(O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐α‐L ‐arabinopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐4‐methoxycinnamoyl]}‐β‐D ‐fucopyranosyl) ester and its (Z)‐isomer ( 5 / 6 ), and 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐(O‐β‐D ‐glucopyranosyl‐(1→3)‐O‐α‐L ‐arabinopyranosyl‐(1→4)‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐{4‐O‐[(E)‐3,4‐dimethoxycinnamoyl]}‐β‐D ‐fucopyranosyl) ester and its (Z)‐isomer ( 7 / 8 ) (presenegenin=(2β,3β)‐2,3,27‐trihydroxyolean‐12‐ene‐23,28‐dioic acid). In our in vitro lymphocyte proliferation assay (Jurkat T‐leukemia cells), a fraction containing 1 – 4 showed a concentration‐dependent immunomodulatory effect. This effect was not found for the prosapogenin (tenuifolin=3‐O‐(β‐D ‐glucopyranosyl)presenegenin), underlining the importance of the acyl? oligosaccharidic moiety.     

Structure elucidation of new oleanane‐type glycosides from three species of Acanthophyllum

From the roots of three species of Acanthophyllum (Caryophyllaceae), two new gypsogenic acid glycosides, 1 and 2, were isolated, 1 from A. sordidum and A. lilacinum, 2 from A. elatius and A. lilacinum, together with three known saponins, glandulosides B and C, and SAPO50. The structures of 1 and 2 were established mainly by 2D NMR techniques as 23‐O‐β‐D ‐galactopyranosylgypsogenic acid‐28‐O‐β‐D ‐glucopyranosyl‐(1→3)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐galactopyranoside (1) and gypsogenic acid‐28‐O‐β‐D ‐glucopyranosyl‐(1→3)‐[β‐D ‐glucopyranosyl‐(1→6)]‐β‐D ‐galactopyranoside (2). The cytotoxicity of several of these saponins was evaluated against two human colon cancer cell lines (HT‐29 and HCT 116). Copyright © 2010 John Wiley & Sons, Ltd.     

New Acylated Presenegenin Saponins from Two Species of Muraltia

Six new acylated bisdesmosidic triterpene glycosides 1 – 6 were isolated from the roots of Muraltia heisteria (L.) DC., as three inseparable mixtures 1 / 2, 3 / 4 , and 5 / 6 of the (E)‐ and (Z)‐3,4,5‐trimethoxycinnamoyl derivatives. The compound pair 1 / 2 along with four known saponins were also isolated from the roots of Muraltia satureioides DC. Their structures were elucidated mainly by spectroscopic experiments including 2D‐NMR techniques as 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐β‐D ‐apiofuranosyl‐(1→3)‐O‐[β‐D ‐xylopyranosyl‐(1→4)]‐O‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[6‐O‐acetyl‐β‐D ‐galactopyranosyl‐(1→3)]‐4‐O‐[(E)‐3,4,5‐trimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 1 ) and its (Z)‐isomer 2 , 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐6‐O‐acetyl‐β‐D ‐galactopyranosyl‐(1→3)‐O‐[3‐O‐acetyl‐α‐L ‐rhamnopyranosyl‐(1→2)]‐4‐O‐[(E)‐3,4,5‐trimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 3 ) and its (Z)‐isomer 4 , and 3‐O‐(β‐D ‐glucopyranosyl)presenegenin 28‐{O‐3‐O‐acetyl‐α‐L ‐rhamnopyranosyl‐(1→2)‐O‐[β‐D ‐xylopyranosyl‐(1→3)]‐4‐O‐[(E)‐3,4,5‐trimethoxycinnamoyl]‐β‐D ‐fucopyranosyl} ester ( 5 ) and its (Z)‐isomer 6 , respectively.     

Two New Kaempferol Glycosides from Androsace umbellata

Two new kaempferol glycosides, 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L ‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl 2‐O‐acetyl‐3‐O‐β‐D ‐glucopyranosyl‐α‐L ‐rhamnopyranoside ( 1 ) and 5‐hydroxy‐2‐(4‐hydroxyphenyl)‐4‐oxo‐7‐(α‐L ‐rhamnopyranosyloxy)‐4H‐chromen‐3‐yl β‐D ‐glucopyranosyl‐(1→2)‐6‐O‐[(2E)‐3‐(4‐hydroxyphenyl)prop‐2‐enoyl]‐β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐glucopyranoside ( 2 ), along with ten known compounds, were isolated from the 95% EtOH extract of the whole plant of Androsace umbellata. The structures of the new glycosides were determined on the basis of detailed spectroscopic analyses, including 1D‐ and 2D‐NMR, MS, and chemical methods.