Acylated flavonol pentaglycosides from Baphia nitida leaves

Two new acylated flavonol pentaglycosides were isolated from the butanolic extract of Baphia nitida leaves by Sephadex LH-20 and preparative HPLC. Structural elucidation of kaempferol 3-O-β-d-xylopyranosyl(1 → 3)-(4-O-E-p-coumaroyl-α-l-rhamnopyranosyl(1 → 2))[β-d-glucopyranosyl(1 → 6)]-β-d-galactopyranoside-7-O-α-l-rhamnopyranoside (1) and kaempferol 3-O-β-d-xylopyranosyl(1 → 3)-(4-O-Z-p-coumaroyl-α-l-rhamnopyranosyl(1 → 2))[β-d-glucopyranosyl(1 → 6)]-β-d-galactopyranoside-7-O-α-l-rhamnopyranoside (2) was achieved using UV, NMR, and mass spectrometry, indicating the presence of trans or cis isomers of p-coumaric acid moiety in these novel structures. The antioxidant activity of the two compounds was assessed in the peroxynitrite assay.     

New acylated flavonol glycosides from the aerial parts of Gouania longipetala

Two new flavonol diglycosides kaempferol-3-O-(6-O-E-coumaroyl)-β-d-galactopyranosyl-(1→2)-α-l-rhamnopyranoside and kaempferol-3-O-(6-O-E-feruloyl)-β-d-galactopyranosyl-(1→2)-α-l-rhamnopyranoside were isolated from the aerial parts of Gouania longipetala in addition to seven known compounds. The structure elucidation of these compounds was based on analyses of spectroscopic data including 1D- and 2D-NMR and HR-ESI-MS techniques. The abilities of these compounds to scavenge the DPPH were evaluated. Results showed that compounds 2, 3, 8 and 9 have antioxidant potential with EC₅₀ values ranging from 13.8 to 47.4 μM, compared with ascorbic acid (EC₅₀ 60 μM) which was used as positive control.     

Vavilosides A1/A2–B1/B2, new furostane glycosides from the bulbs of Allium vavilovii with cytotoxic activity

A phytochemical analysis of the bulbs of Allium vavilovii M. Pop. & Vved. was attained for the first time extensively, affording to the isolation of four new furostanol saponins, named vavilosides A1/A2–B1/B2 (1a/b–2a/2b), as two couple of isomers in equilibrium, together with ascalonicoside A1/A2 (3a/3b) and 22-O-methyl ascalonicoside A1/A2 (4a/4b), previously isolated from shallot, Allium ascalonicum. High concentrations of kaempferol, kaempferide, and kaempferol 4^I-glucoside were also isolated. The chemical structures of the new compounds, established through a combination of extensive nuclear magnetic resonance, mass spectrometry and chemical analyses, were identified as (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-galactopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside A1), (25R)-furost-5(6)-en-1β,3β,22β,26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-galactopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside A2), (25R)-furost-5(6)-en-1β,3β,22α,26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-xylopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside B1), (25R)-furost-5(6)-en-1β,3β,22β,26-tetraol 1-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-xylopyranosyl 26-O-α-l-rhamnopyranoside (vaviloside B2). The isolated saponins showed cytotoxic activity on J-774, murine monocyte/macrophage, and WEHI-164, murine fibrosarcoma, cell lines with the following rank: vaviloside B1/B2 > ascalonicoside A1/A2 > vaviloside A1/A2.     

Acylated flavonoid tetraglycoside from Planchonia careya leaves

Phytochemical investigations of the aqueous extract of Planchonia careya leaves revealed two known flavonol glycosides, kaempferol 3-O-gentiobioside (1) and quercetin 3-O-glucoside (isoquercitrin) (2), and a novel acylated kaempferol tetraglycoside, kaempferol 3-O-[α-rhamnopyranosyl(1 → 3)-(2-O-p-coumaroyl)]-β-glucopyranoside, 7-O-[α-rhamnopyranosyl-(1 → 3)-(4-O-p-coumaroyl)]-α-rhamnopyranoside (3). Structural elucidation was achieved using UV, NMR, and mass spectrometry.     

Doubly linked,A-type proanthocyanidin trimer and other constituents of Ixora coccinea leaves and their antioxidant and antibacterial properties

Phytochemical investigation of the ethyl acetate fraction of the methanol extract of the leaves of Ixora coccinea led to the isolation and identification of an A-type trimeric proanthocyanidin epicatechin-(2β → O → 7, 4β → 8)–epicatechin-(5 → O → 2β, 6 → 4β)–epicatechin named ixoratannin A-2 along with seven known compounds, epicatechin, procyanidin A2, cinnamtannin B-1, and four flavon-3-ol rhamnosides viz: kaempferol-7-O-α-l-rhamnnoside, kaempferol-3-O-α-l-rhamnoside, quercetin-3-O-α-l-rhamnopyranoside, and kaempferol-3,7-O-α-l-dirhamnoside. The structures were elucidated by the application of IR, UV, MS, 1D-, and 2D-NMR spectroscopic analyses and by comparison with literature data. Antioxidant evaluation of isolated compounds revealed that ixoratannin A-2 and cinnamtannin B-1 were the most active compounds in DPPH, inhibition of lipid peroxidation and nitric oxide radical scavenging assays. Antibacterial activities were assessed by means of agar-diffusion assays using Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Bacillus subtilis. All tested compounds inhibited the growth of B. subtilis, while only epicatechin and quercetin-3-O-α-l-rhamnopyranoside inhibited the growth of E. coli.     

Phenylethanoid glycosides from the leaves of Magnolia hodgsonii

Three new phenylethanoid glycosides, 2-(3-hydroxy-4-methoxyphenyl)ethyl 1-O-β-d-allopyranoside (hodgsonialloside A, 1), 2-(3-hydroxy-4-methoxyphenyl)ethyl 1-O-β-d-glucopyranosyl-(1 → 4)-β-d-allopyranoside (hodgsonialloside B, 2) and 2-(3-methoxy-4-hydroxyphenyl)ethyl 1-O-β-d-allopyranoside (hodgsonialloside C, 3) were isolated from the leaves of Magnolia hodgsonii in addition to six known compounds, tyrosol 4-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside (4), kaempferol 3-O-neohesperidoside (5), kaempferol 3-O-rutinoside (6), kaempferol 3-O-α-l-rhamnopyranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (7), (+)-syringaresinol O-β-d-glucopyranoside (8), and oblongionoside C (9). The structure elucidation of these compounds was based on analyses of physical and spectroscopic data including 1D and 2D NMR experiments.     

Two new penterpenoid saponins and a new diterpenoid glycoside from Hemsleya chinensis

Two new penterpenoid saponins, hemsloside-Ma4 (1) hemsloside-Ma5 (2), and a new diterpenoid glycoside, hemsloside-Ma6 (3), were isolated from the rhizomes of Hemsleya chinensis. By detailed analysis of the NMR spectra and chemical methods, the structures of new compounds were determined to be 3-O-β-l-arabinopyranosyl-(1 → 3)-O-(6′-methyl ester)-β-d-glucuropyranosyl-oleanolic acid-28-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside (1), 3-O-β-l-arabinopyranosyl-(1 → 3)-O-(6′-methyl ester)-β-d-glucuropyranosyl-oleanolic acid-28-O-β-d-xylopyranosyl-(1 → 6)-O-β-d-glucopy-ranoside (2), and 13ϵ-hydroxylabda-8(17), 14-dien-18-oic acid-18-O-α-l-rhamnopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 4)-O-α-l-rhamnopyranoside (3). Diterpenoid-type compound (3) was isolated from Hemsleya genus for the first time.     

Investigation on the flavonoid composition of Aconitum angustifolium Bernh. flowers and leaves

A new flavonol glycoside, kaempferol 7-O-(6-E-p-coumaroyl)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranoside 3-O-β-d-galactopyranoside (1), together with other five known compounds (2–6), were identified from the flowers and leaves of Aconitum angustifolium Bernh. Their chemical structures were elucidated by extensive NMR spectral studies, as well as by ESI-MS analysis.     

Differences in the floral anthocyanin content of violet–blue flowers of Vinca minor L. and V. major L. (Apocynaceae)

Two novel delphinidin 3-(tri or di)-glycoside-7-glycosides were isolated from the violet–blue flowers of Vinca minor L. and V. major L. (Family: Apocynaceae), and determined to be delphinidin 3-O-[2-O-(β-xylopyranosyl)-6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-(2^G-xylosylrobinobioside)-7-rhamnoside] as major floral anthocyanin of V. minor and delphinidin 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= delpphinidin 3-robinobioside-7-rhamnoside] as major floral anthocyanin of V. major by chemical and spectroscopic methods. In addition, chlorogenic acid and kaempferol 3-O-[6-O-(α-rhamnopyranosyl)-β-galactopyranoside]-7-O-(α-rhamnopyranoside) [= kaempferol 3-robinobioside-7-rhamnoside (robinin)] were identified in these flowers. In this paper, the relation between the structure of floral anthocyanins and classification of Vinca species was discussed.     

Triterpene glycosides from Astragalus icmadophilus

Six cycloartane-type triterpene glycosides were isolated from Astragalus icmadophilus along with two known cycloartane-type glycosides, five known oleanane-type triterpene glycosides and one known flavonol glycoside. The structures of the six compounds were established as 3-O-[α-L-arabinopyranosyl-(1 → 2)-O-3-acetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-(1 → 2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxy cycloartane, 3-O-[α-L-arabinopyranosyl-(1 → 2)-O-3,4-diacetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24(S),25-pentahydroxycycloartane, 3-O-[α-L-arabinopyranosyl-(1 → 2)-O-3-acetoxy-α-L-arabinopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,25-tetrahydroxy-20(R),24(S)-epoxycycloartane, 3-O-[α-L-arabinopyranosyl-(1 → 2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-20(R),25-epoxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-O-α-L-arabinopyranosyl-(1 → 2)-O-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-3β,6α,16β,24α-tetrahydroxy-20(R),25-epoxycycloartane by the extensive use of 1D- and 2D-NMR experiments along with ESIMS and HRMS analysis.The first four compounds are cyclocanthogenin and cycloastragenol glycosides, whereas the last two are based on cyclocephalogenin as aglycone, more unusual in the plant kingdom, so far reported only from Astragalus spp.     

Enzymatically derived aldouronic acids from Eucalyptus globulus glucuronoxylan

A glucuronoxylan was extracted from the holocellulose of Eucalyputus globulus wood with 10% KOH and subjected to hydrolysis by a commercial cellulase preparation “Meicelase”. Neutral xylooligosaccharides liberated were analyzed by size exclusion chromatography. Aldouronic acids liberated were purified by preparative anion exchange chromatography. Their structures were studied by monosaccharide analysis, comparison of volume distribution coefficients (Dvs) in anion exchange chromatography with those of the authentic samples, and ¹H and ¹³C NMR spectroscopy, resulting in the characterization of seven aldouronic acids including a novel one containing galactose residue.O-β-d-Xylp-(1 → 4)-[O-(4-O-Me-α-d-GlcAp)-(1 → 2)]-O-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1 → 4)-d-XylO-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1 → 4)-d-XylO-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-d-XylO-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1→3)-O-α-l-Rhap-(1 → 2)-O-α-l-GalAp-(1 → 4)-d-XylO-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1 → 3)-O-α-l-Rhap-(1 → 2)-d-GalAO-β-d-Xylp-(1 → 3)-O-α-l-Rhap-(1 → 2)-O-α-d-GalAp-(1 → 4)-d-XylO-β-d-Galp-(1 → 2)-O-(4-O-Me-α-d-GlcAp)-(1 → 2)-O-β-d-Xylp-(1 → 4)-O-β-d-Xylp-(1 → 4)-d-Xyl.The oligosaccharides liberated provide information on multiplicity of xylanases secreted by Trichoderma viride. The presence of the last aldouronic acid shows a structural feature of E. globulus xylan.     

Unprecedented furan-2-carbonyl C-glycosides and phenolic diglycosides from Scleropyrum pentandrum

Five unprecedented furan-2-carbonyl C-glycosides, scleropentasides A–E, and two phenolic diglycosides, 4-hydroxy-3-methoxybenzyl 4-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside and 2,6-dimethoxy-p-hydroquinone 1-O-β-d-xylopyranosyl-(1 → 6)-β-d-glucopyranoside, were isolated from leaves and twigs of Scleropyrum pentandrum together with potalioside B, luteolin 6-C-β-d-glucopyranoside (isoorientin), apigenin 8-C-β-d-glucopyranoside (vitexin), apigenin 6,8-di-C-β-d-glucopyranoside (vicenin-2), apigenin 6-C-α-l-arabinopyranosyl-8-C-β-d-glucopyranoside (isoschaftoside), apigenin 6-C-β-d-glucopyranosyl-8-C-β-d-xylopyranoside, adenosine and l-tryptophan. Structure elucidations of these compounds were based on analyses of chemical and spectroscopic data, including 1D and 2D NMR. In addition, the isolated compounds were evaluated for their radical scavenging activities using both DPPH and ORAC assays.     

Saponins in aerial parts of Helleborus viridis L.

In the search of natural compounds inhibiting methane production in ruminants three novel steroidal saponins have been isolated from the aerial parts of Helleborus viridis L. Their structures have been established based on spectral analyses as: (25R)-26-O-β-d-glucopyranosyl-5β-furostan-3β,22α,26-triol 3-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside, (25R)-26-O-β-d-glucopyranosyl-5α-furostan-3β,22α,26-triol 3-O-β-d-glucopyranosyl-(1 → 6)-O-β-d-glucopyranoside and (25R)-26-O-β-d-glucopyranosyl-furost-5-ene-1β,3β,22α,26-tetraol 1-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 3)]-6-O-acetoxy-β-d-glucopyranoside}.     

Highly glycosylated flavonols with an O-linked branched pentasaccharide from Iberis saxatilis (Brassicaceae)

Four flavonol glycosides isolated from non-flowering leafy shoots of Iberis saxatilis (Brassicaceae) were characterised by spectroscopic and chemical methods as saxatilisins A–D, the 3-O-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)[β-d-glucopyranosyl-(1 → 2)-α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside, 3-O-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside, 3-O-(6-O-E-sinapoyl)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)[β-d-glucopyranosyl-(1 → 2)-α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside, and 3-O-(6-O-E-feruloyl)-β-d-glucopyranosyl-(1 → 3)-α-l-rhamnopyranosyl-(1 → 2)[β-d-glucopyranosyl-(1 → 2)-α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside of isorhamnetin (3,5,7,4′-tetrahydroxy-3′-methoxyflavone), respectively. Analysis of ²J_HC correlations detected with the H2BC (heteronuclear two-bond correlation) pulse sequence aided the unambiguous assignment of glycosidic resonances in the ¹H and ¹³C NMR spectra of these compounds. Saxatilisins A, C, and D, are the first flavonol glycosides to be described with a pentasaccharide chain at a single glycosylation site. Several pentaglycosides of kaempferol and quercetin, tentatively assigned as saxatilisin analogues from LC–MS/MS analyses, were present as minor constituents of the extracts.     

Flavonoids from carnation (Dianthus caryophyllus) and their antifungal activity

A flavonoid glycoside, kaempferol 3-O-β-d-glucopyranosyl (1 → 2)-O-β-d-glucopyranosyl (1 → 2)-O-[α-l-rhamnopyranosyl-(1 → 6)]-β-d-glucopyranoside (1), along with two known C- and O-flavonoid glycosides (2 and 3, respectively), were isolated from carnation (Dianthus caryophyllus). The structures of the isolated compounds have been elucidated unambiguously by UV, MS, and a series of 1D and 2D NMR analyses. The isolated compounds and other flavonoid glycoside analogues exhibited antifungal activity against different Fusarium oxysporum f.sp. dianthi pathotypes.     

Steroidal saponins from Tribulus terrestris

Five new steroidal saponins were isolated from the fruits of Tribulus terrestris. Their structures were fully established by spectroscopic and chemical analysis as (23S,25S)-5α-spirostane-24-one-3β,23-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (1), (24S,25S)-5α-spirostane-3β,24-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (2), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-2α,3β,22α,26-tetraol-3-O-{β-d-glucopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside} (3), 26-O-β-d-glucopyranosyl-(25R)-5α-furostan-20(22)-en-2α,3β,26-triol-3-O-{β-d-glucopyranosyl-(1 → 2)-O-β-d-glucopyranosyl-(1 → 4)-β-d-galactopyranoside} (4), and 26-O-β-d-glucopyranosyl-(25S)-5α-furostan-12-one-22-methoxy-3β,26-diol-3-O-{α-l-rhamnopyranosyl-(1 → 2)-O-[β-d-glucopyranosyl-(1 → 4)]-β-d-galactopyranoside} (5). The isolated compounds were evaluated for cytostatic activity against HL-60 cells.     

New oleanane-type saponins: Leptocarposide B-D,from Ludwigia leptocarpa (Onagraceae)

Three new oleanane-type saponins, leptocarposide B-D (1–3), were isolated from the whole plant of Ludwigia leptocarpa (Nutt.) Hara, together with ten known compounds 4–13.The structures of these compounds were determined by interpretation of their spectral data, mainly HR-TOFESIMS, 1D-NMR (¹H, ¹³C) and 2D-NMR (¹H–¹H COSY, HSQC, HMBC, and NOESY), and by comparison with the literature data. The structures of the new compounds were established as 28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[α-l-arabinopyranosyl-(1 → 3)]-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl zanhic acid (1); 3-O-β-d-glucopyranosyl-28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl medicagenic acid (2); 3-O-β-d-glucopyranosyl-(1 → 4)-β-d-glucopyranosyl-28-O-β-d-xylopyranosyl-(1 → 4)-α-l-rhamnopyranosyl-(1 → 2)-[α-l- arabinopyranosyl-(1 → 3)]-4-O-(3′-hydroxybutanoyloxy-3-hydroxybutanoyloxy)-β-d-fucopyranosyl zanhic acid (3).     

Two new guaiane sesquiterpenes from Datura metel L. with anti-inflammatory activity

Chemical investigation of an acidic methanol extract of the whole plants of Datura metel resulted in the isolation of two new guainane sesquiterpenes, 1β,5α,7β-guaiane-4β,10α,11-triol (1) and 1α,5α,7α-11-guaiene-2α,3β,4α,10α,13-pentaol (2), along with eight known compounds: pterodontriol B (3), disciferitriol (4), scopolamine (5), kaempferol 3-O-β-d-glucosyl(1 → 2)-β-d-galactoside 7-O-β-d-glucoside (6), kaempferol 3-O-β-glucopyranosyl(1 → 2)-β-glucopyranoside-7-O-α-rhamnopyranoside (7), pinoresinol 4′′-O-β-d-glucopyranoside (8), (7R,8S,7′S,8′R)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxy-lignan-4-O-β-d-glucopyranoside (9), and (7S,8R,7′S,8′S)-4,9,4′,7′-tetrahydroxy-3,3′-dimethoxy-7,9′-epoxylignan-4-O-β-d-glucopyranoside (10). Their structures were elucidated by extensive spectroscopic methods, including 1D and 2D NMR and MS spectra. Compounds 2-4 and 6-10 were shown to have modest anti-inflammatory effects through inhibition of NO production in LPS-stimulated BV cells.     

Triterpenoid saponins from Astragalus wiedemannianus Fischer

Three cycloartane-type triterpene glycosides were isolated from Astragalus wiedemannianus together with eight known secondary metabolites namely cycloastragenol, cycloascauloside B, astragaloside IV, astragaloside VIII, brachyoside B, astragaloside II, astrachrysoside A, and astrasieversianin X. The structures were established mainly by a combination of 1D and 2D-NMR techniques as 3-O-[α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl]-25-O-β-D-glucopyranosyl-20(R),24(S)-epoxy-3β,6α,16β,25-tetrahydroxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-24-O-α-(4’-O-acetoxy)-L-arabinopyranosyl-16-O-acetoxy-3β,6α,16β,24(S),25-pentahydroxycycloartane, 3-O-[α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyl]-6-O-β-D-glucopyranosyl-24-O-α-L-arabinopyranosyl-16-O-acetoxy-3β,6α,16β,24(S),25-pentahydroxycycloartane. To the best of our knowledge, the presence of an arabinose moiety on the acyclic side chain of cycloartanes is reported for the first time.     

Triterpenoid saponins from Sesbania vesicaria

Nine oleanane saponins including three new and six known were isolated from the seeds of Sesbania vesicaria. The new saponins were established as 3-O-[α-l-rhamnopyranosyl-(1 → 3)]-β-d-glucuronopyranosyl-3β,29-dihydroxy-olean-12-en-28-oic acid, 3-O-α-l-rhamnopyranosyl-28-O-β-d-glucopyransoyl-3β-hydroxy-olean-12-en-23-al-28-oate, and 3-O-α-l-rhamnopyranosyl-28-O-β-d-glucopyransoyl-3β,23-dihydroxy-olean-12-en-28-oate. All isolated saponins were assayed for their DNA topoisomerase I inhibition ability and cytotoxicity against A549 human lung adenocarcinoma epithelial cells with no positive activity detected (IC₅₀ > 312 μM and GI₅₀ > 25 μM, respectively).