Leishmanicidal cycloartane-type triterpene glycosides from Astragalus oleifolius

Two new cycloartane-type glycosides oleifoliosides A (1) and B (2) were isolated from the lower stem parts of Astragalus oleifolius. Their structures were identified as 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-xylopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane and 3-O-[beta-xylopyranosyl-(1 --> 2)-alpha-arabinopyranosyl]-6-O-beta-glucopyranosyl-3beta,6alpha,16beta,24(S),25-pentahydroxycycloartane, respectively, by means of spectroscopic methods (IR, 1D and 2D NMR, ESI-MS). Three known cycloartane glycosides cyclocanthoside E (3), astragaloside II (4) and astragaloside IV (5) were also isolated and characterized. All five compounds were evaluated for in vitro trypanocidal, leishmanicidal and antiplasmodial activities as well as their cytotoxic potential on primary mammalian (L6) cells. Except for the compound 5, all compounds showed notable growth inhibitory activity against Leishmania donovani with IC50 values ranging from 13.2 to 21.3 microg/ml. Only weak activity against Trypanosoma brucei rhodesiense was observed with the known compounds astragaloside II (4, IC50 66.6 microg/ml) and cyclocanthoside E (3, IC50 85.2 microg/ml), while all compounds were inactive against Trypanosoma cruzi and Plasmodium falciparum. None of the compounds were toxic to mammalian cells (IC50's > 90 microg/ml). This is the first report of leishmanicidal and trypanocidal activity of cycloartane-type triterpene glycosides.     

Cycloartane glycosides from Astragalus aureus

Eight cycloartane-type triterpene glycosides (1-8) were isolated from Astragalus aureus Willd along with ten known cycloartane-type glycosides (9-18). Their structures were established by the extensive use of 1D and 2D-NMR experiments along with ESIMS and HRMS analyses. Compounds 1-5 are cyclocanthogenin glycosides, whereas compounds 6-8 are based on cyclocephalogenin as aglycon, more unusual in the plant kingdom, so far reported only from Astragalus spp. Moreover, for the first time monoglycosides of cyclocanthogenin (5) and cyclocephalogenin (7, 8) are reported. All of the compounds tested for their cytotoxic activities against a number of cancer cell lines. Among the compounds, only 8 exhibited activity versus human breast cancer (MCF7) at 45 μM concentration.     

Cycloartane glycosides from Astragalus campylosema Boiss. ssp. campylosema

Four cycloartane glycosides, 3-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-xylopyranosyl]-3β,6α,16β,23α,25-pentahydroxy-20(R),24(S)-epoxycycloartane (1), 3-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-xylopyranosyl]-16-O-hydroxyacetoxy-23-O-acetoxy-3β,6α,25-trihydroxy-20(R),24(S)-epoxycycloartane (2), 3-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-xylopyranosyl]-3β,6α,23α,25-tetrahydroxy-20(R),24(R)-16β,24;20,24-diepoxycycloartane (3), 3-O-[α-l-arabinopyranosyl-(1 → 2)-β-d-xylopyranosyl]-25-O-β-d-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane (4), along with three known cycloartane glycosides were isolated from the MeOH extract of the roots of Astragalus campylosema ssp. campylosema. Their structures were established by the extensive use of 1D- and 2D-NMR experiments along with ESIMS and HRMS analysis. The occurrence of the hydroxyl function at position 23 (1-2) and of the ketalic function at C-24 (3) are very unusual findings in the cycloartane class.     

27-Nor-triterpenoid glycosides from Mitragyna inermis

From the bark of Mitragyna inermis, two 27-nor-triterpenoid glycosides, named inermiside I (1) and II (2), were isolated and their structures determined based on extensive 2D-NMR and MS spectral analysis as 6-deoxy-beta-D-glucopyranosyl-[3-O-beta-D-glucopyranosyl-(1-->6)-beta-D-glucopyranosyl]-pyrocincholate and 6-deoxy-beta-D-glucopyranosyl-pyrocincholate, respectively. In addition, the known quinovic acid (6), 3-O-[beta-D-glucopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl]-quinovoic acid (3),beta-D-glucopyranosyl-[3-O-(beta-D-glucopyranosyl)]-quinoviate (4) and cytotoxic 3-O-(beta-D-6-deoxy-glucopyranosyl)-quinovic acid (5) were also isolated.     

Cycloartane-type glycosides from Astragalus amblolepis

Five cycloartane-type triterpene glycosides were isolated from the methanol extract of the roots of Astragalus amblolepis Fischer along with one known saponin, 3-O-β-D-xylopyranosyl-16-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane. Structures of the compounds were established as 3-O-β-D-xylopyranosyl-25-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 3-O-[β-D-glucuronopyranosyl-(1 → 2)-β-D-xylopyranosyl]-25-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 3-O-β-D-xylopyranosyl-24,25-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 6-O-α-L-rhamnopyranosyl-16,24-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane, 6-O-α-L-rhamnopyranosyl-16,25-di-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy-cycloartane by using 1D and 2D-NMR techniques and mass spectrometry. To the best of our knowledge, the glucuronic acid moiety in cycloartanes is reported for the first time.     

Four new steroidal glycosides from Solanum torvum and their cytotoxic activities

Two novel C-22 steroidal lactone saponins, namely solanolactosides A, B (1, 2) and two new spirostanol glycosides, namely torvosides M, N (3, 4) were isolated from ethanol extract of aerial parts of Solanum torvum. Their structures were characterized as solanolide 6-O-[α-l-rhamnopyranosyl-(1 → 3)-O-β-d-quinovopyranoside] (1), solanolide 6-O-[β-d-xylopyranosyl-(1 → 3)-O-β-d-quinovopyranoside] (2), yamogenin 3-O-[β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside] (3) and neochlorogenin 3-O-[β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside] (4) on the basis of spectroscopic analysis. The cytotoxicities of the saponins (1-4) were evaluated in vitro against a panel of human cancer cell lines. Compounds 3 and 4 showed significant cytotoxic activity with the cell lines.     

Five new C21 steroidal glycosides from the stems of Marsdenia tenacissima

Five new C₂₁ steroidal glycosides (1-5) were isolated from the stems of Marsdenia tenacissima. The chemical structures and relative configurations of the new compounds were elucidated by mass spectrometry and NMR spectroscopy. Cellular assay of these compounds showed that they are weak cytotoxic to various cell lines.     

Triterpenoid saponins from the fruits and galls of Sapindus mukorossi

Six saponins, sapinmusaponin K (1) [hederagenin-3-O-(3-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin L (2) [hederagenin-3-O-(4-O-acetyl-alpha-L-arabinopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabino-pyranoside], sapinmusaponin M (3) [hederagenin-3-O-(2,3-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin N (4) [hederagenin-3-O-(2,4-O-diacetyl-beta-D-xylopyranosyl)-(1-->3)-alpha-L-rhamnopyranosyl-(1-->2)-alpha-L-arabinopyranoside], sapinmusaponin O (5) [3,7,20(S)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-glucopyranoside], and sapinmusaponin P (6) [3,7,20(R)-trihydroxydammar-24-ene-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-d-glucopyranoside], along with seven known saponins (7-13), were isolated from fruits and the galls of Sapindus mukorossi. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques and acid hydrolysis. Biological evaluation indicated that saponins 1-4 and 7-13 showed moderate cytotoxicity against several human tumor cell lines.     

A new Astragalus (Leguminosae) from Argentina, notable for placentation of its seeds

From the Patagonian region in ArgentinaAstragalus neocarpus is described and illustrated. The false septum of its fruit is formed by union of the seed-funicles with the endocarp.

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Se describe e ilustraAstragalus neocarpus de la región Patagónica de Argentina, su principal característica distintiva es la morfología del fruto, donde el falso tabique que divide en dos a la cavidad está formado por la unión de largos funículos de las semillas con el endocarpo.

     

Furanoflavonoid glycosides from Pongamia pinnata fruits

Pongamia pinnata fruits afforded three new furanoflavonoid glucosides, pongamosides A-C (1-3), and a new flavonol glucoside, pongamoside D (4). The structures of these compounds were established on the basis of spectroscopic studies. This is the first time that furanoflavone glucosides have been found as naturally occurring compounds.     

Oleanolic glycosides from Pometia ridleyi

Six triterpenoid saponins were isolated from the stem bark of Pometia ridleyi along with two known saponins, acutoside A and calenduloside C. Their structures were established using one- and two-dimensional NMR and mass spectrometry as 3-O-beta-D-apiofuranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-alpha-L-arabinopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-beta-D-glucopyranosyl-, 3-O-alpha-L-arabinopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-, 3-O-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-, 3-O-beta-D-apiofuranosyl-(1-->3)-beta-D-galactopyranosyl-(1-->3)-[beta-D-glucopyranosyl-(1-->2)]-alpha-L-arabinopyranosyl-oleanolic acid. The EtOH and EtOAc extracts of the stem bark showed no cytotoxic activity. At a concentration of 23 microg/ml, the saponin mixture showed haemolytic activity and caused 50% haemolysis of a 10% suspension of sheep erythrocytes.     

Triterpene glycosides of Lupinus angustifolius

Investigation of whole seeds of Lupinus angustifolius L. (Leguminosae) yielded the two triterpenoid saponins with branched monosaccharide chain 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranoside (3) and 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->3)-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside (4) along with the known compounds soyasaponin I (1) and 3 beta,21 beta,22 beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside (2). The structures of the compounds were elucidated using hydrolysis, FAB-MS and extensive NMR experiments. Compounds 2-4 showed moderate antifungal activity against Candida albicans with MIC values of 25, 25 and 30 microg/ml, respectively. Only soyasaponin I was found weakly hemolytic (HC(50) >500 microg/ml).     

Amurensiosides A-K, 11 new pregnane glycosides from the roots of Adonis amurensis

Five new pregnane tetraglycosides, amurensiosides A-E (1-5), two new pregnane hexaglycosides, amurensiosides F (6) and I (9), two new 18-norpregnane hexaglycosides, amurensiosides G (7) and H (8), and two new pregnane octaglycosides, amurensiosides J (10) and K (11), were isolated from the MeOH extract of the roots of Adonis amurensis. The structures of the new compounds were determined on the basis of extensive spectroscopic analysis, including two-dimensional (2D) NMR data, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HSC-2 human oral squamous cell carcinoma cells.     

Steroidal glycosides from the rhizomes of Ruscus hypophyllum

Seven steroidal glycosides, along with one known glycoside, were isolated from the rhizomes of Ruscus hypophyllum (Liliaceae). Comprehensive spectroscopic analysis, including 2D NMR spectroscopy, and the results of acid hydrolysis allowed the chemical structures of the compounds to be assigned as (23S,25R)-23-hydroxyspirost-5-en-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->4)-beta-d-glucopyranoside (1), 1beta-hydroxyspirosta-5,25(27)-dien-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->4)-beta-d-glucopyranoside (2), (22S)-16beta,22-dihydroxycholest-5-en-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->4)-beta-d-glucopyranoside (3), (22S)-16beta-[(beta-d-glucopyranosyl)oxy]-22-hydroxycholest-5-en-3beta-yl O-alpha-l-rhamnopyranosyl-(1-->4)-beta-d-glucopyranoside (4), (22S)-16beta-[(beta-d-glucopyranosyl)oxy]-22-hydroxycholest-5-en-3beta-yl beta-d-glucopyranoside (5), (22S)-16beta-[(beta-d-glucopyranosyl)oxy]-3beta,22-dihydroxycholest-5-en-1beta-yl O-alpha-l-rhamnopyranosyl-(1-->2)-(3,4-di-O-acetyl-beta-d-xylopyranoside) (6), and (22S)-16beta-[(beta-d-glucopyranosyl)oxy]-3beta,22-dihydroxycholest-5-en-1beta-yl O-alpha-l-rhamnopyranosyl-(1-->2)-O-[beta-d-xylopyranosyl-(1-->3)]-beta-d-xylopyranoside (7), respectively. This is the first isolation of a series of cholestane glycosides from a Ruscus species.     

Two flavonoid glycosides and a miscellaneous flavan from the bark of Guibourtia coleosperma

Two flavonoid glycosides, 7-O-beta-D-xylopyranosyl-epicatechin and epicatechin-(4beta-->8)-7-O-beta-D-xylopyranosyl-epicatechin both as their acetate and methyl ether acetate derivatives and a miscellaneous flavan Epicatechin-(7,8-bc)-9beta-(3-methoxy-4-acethoxyphenyl)-dihydro-2(3H)-pyranone as its acetate derivative were isolated from the bark of Guibourtia coleosperma. Their structures were established by spectroscopic methods.     

Furostanol saponins and quercetin glycosides from the leaves of Helleborus viridis L

Phytochemical analysis of the polar extracts of the leaves of Helleborus viridis (Ranunculaceae) resulted in the isolation of two new furostanol saponins (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-[6-acetyl-beta-D-glucopyranosyl-(1-->3)]-O-beta-D-glucopyranoside (1) and (25R)-26-[(alpha-L-rhamnopyranosyl)oxy]-22alpha-methoxyfurost-5-en-3beta-yl O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranosyl-(1-->3)-O-beta-D-glucopyranoside (2) and three new quercetin glycosides, quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside-7-O-beta-d-glucopyranoside (3), quercetin 3-O-(2-E-caffeoyl)-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (4), and quercetin 3-O-alpha-L-arabinopyranosyl-(1-->2)-beta-D-galactopyranoside (5). The structures of the new compounds were determined by spectroscopic analysis, including 2D NMR data and mass spectrometry.     

Spirostanol saponins from the rhizomes of Tacca chantrieri and their cytotoxic activity

The rhizomes of Tacca chantrieri have been analysed for steroidal saponin constituents, resulting in the isolation of four new spirostanol saponins (1-4), along with one known saponin (5); their structures were elucidated on the basis of extensive spectroscopic analysis, including 2D NMR, and the results of hydrolytic cleavage. The isolated compounds were evaluated for their cytotoxic activity against HL-60 human promyelocytic leukemia cells.     

Gerronemins A-F, cytotoxic biscatechols from a Gerronema species

The gerronemins A-F (1-6) were isolated as the cytotoxic components of an extract of a Gerronema species detected in a screening for new cytotoxic metabolites from basidiomycetes. Their structures were elucidated by spectroscopic techniques, and they are composed of a C12-C16 alkane or alkene substituted at both ends by 2,3-dihydroxyphenyl groups. The gerronemins blocked the inducible expression of a hCOX-2 and iNOS promoter driven reporter gene with IC50-values of 1-5 microg/ml. In addition, cytotoxic activities were observed which were due the inhibition of cellular macromolecular syntheses.     

Triterpenoidal lupin saponins from the Chilean legume Lupinus oreophilus Phil

Two lupin saponins, 3beta,21alpha,22beta,24-tetrahydroxyolean-12-en-3-O-alpha-L-rhamnopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-arabinopyranoside and 3beta,21alpha,22beta,24-tetrahydroxyolean-12-en-3-O-beta-D-galactopyranosyl-(1-->2)-beta-D-glucuronopyranosyl-21-O-alpha-L-rhamnopyranoside, along with eight other saponins and one triterpene previously reported from other legumes, were isolated from the aerial parts of Lupinus oreophilus collected in northern Chile. The structures of the isolated compounds were established with the help of extensive spectroscopic techniques.