Two new noroleanane-type triterpenoid saponins from the stems of Stauntonia chinensis

Two new noroleanane-type triterpenoid saponins, 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-L-fucopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (1) and 3β,20α,24-trihydroxy-29-norolean-12-en-28-oic acid 24-O-β-D-glucopyranosyl-(1→2)-[α-L-arabinopyranosyl-(1→3)]-β-D-glucopyranoside (2) were isolated from the stems of Stauntonia chinensis DC., together with three known compounds, brachyantheraoside B₂ (3), eupteleasaponin Ⅷ (4) and fargoside B (5). Their structures were elucidated by spectroscopic and chemical methods. The cytotoxic activities of compounds 1 and 2 were evaluated against five human tumor cell lines (HCT-116, HepG2, BGC-823, NCI-H1650, and A2780). Compounds 1 and 2 showed moderate cytotoxic activities toward the tested cell lines with IC₅₀ values ranging from 12.71 to 32.04 μM.     

A new triterpenoid saponin from Gleditsia sinensis and its antiproliferative activity

Chemical investigation of the anomalous fruits of Gleditsia sinensis led to the isolation and identification of a new triterpenoid saponin, 3-O-β-D-xylopyranosyl-(1 → 2)-α-L-arabinopyranosyl-(1 → 6)-β-D-glucopyranosyl oleanolic acid 28-O-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyrano--syl-(1 → 4)-β-D-xylopyranosyl-(1 → 4)-α-L-rhamnopyranosyl-(1 → 3)-β-D-glucopyranosyl ester (1), along with other nine known compounds (2–10). All the isolates from this species were reported for the first time. The structure of Compound 1 was determined by a detailed analysis using various analytical techniques, including 1D and 2D NMR. In vitro antiproliferative activities of Compound 1 on MCF-7 and Hep-G2 tumor cell lines were evaluated. IC₅₀ values against the two cell lines were 9.5 and 11.6 μM, respectively.     

Novel dammarane-type saponins from Gynostemma pentaphyllum and their neuroprotective effect

Abstract

Three novel dammarane-type saponins, 2α,3β,12β,20(S),24(S)-pentahydroxydammar-25-ene-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-20-O-β-D-glucopyranoside (1, namely gypenoside J1), 2α,3β,12β,20(S),25-pentahydroxydammar-23-ene-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-20-O-β-D-glucopyranoside (2, namely gypenoside J2) and 2α,3β,12β,20(S)-tetrahydroxydammar-25-en-24-one-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-20-O-β-D-xylopyranosyl-(1→6)-β-D-glucopyranoside (3, namely gypenoside J3) along with one known gypenoside (gypenoside LVII) were isolated from the aerial parts of G. pentaphyllum using various chromatographic methods. Their structures were elucidated on the basis of IR, 1D- (¹H and ¹³C), 2D-NMR spectroscopy (HSQC, HMBC and COSY), and mass spectrometry (ESI-MS/MS). Their activity was tested using CCK-8 assay. These four compounds showed little anti-cancer activity with IC₅₀ values more than 100?μM against four types of human cancer lines. The effects of them against H₂O₂-induced oxidative stress in human neuroblastoma SH-SY5Y cells were evaluated and they all showed potential neuroprotective effects with 3.64–18.16% higher cell viability than the H₂O₂-induced model group.     

Antibacterial activity of a triterpenoid saponin from the stems of Caesalpinia pulcherrima Linn.

A new compound 1 was isolated from the methanolic extract of the stems of the Caesalpinia pulcherrima Linn. along with a reported compound (2) 3-O-β-D-glucopyranosyl-(1→4)-β-D-xylopyranosyl-(1→3)-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl hederagenin 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester. The new compound 1 has m.p. 272–274°C, m.f. C₄₆H₇₄O₁₇, [M]⁺ m/z 898. It was characterised as 3-O-β-D-glucopyranosyl-(1→4)-α-L-arabinopyranosyl hederagenin 28-O-β-D- xylopyranosyl ester by various colour reactions, chemical degradations and spectral analyses. Antibacterial activity of compound 1 was screened against various Gram-positive and Gram-negative bacteria and showed significant results.     

Two antifungal active triterpenoid saponins from the seeds of Lathyrus plants

Two novel triterpenoid glycosides have been isolated from butanolic seeds extract of two varieties of Lathyrus plants, i.e. Lathyrus ratan and Lathyrus aphaca. Their structures were elucidated as 3-O-[β-D-glucuronopyranosyl-(1?→?4)-α-L-arabinopyranosyl-(1?→?2)-α-L-arabinopyranosyl]-olean-11,13(18)-dien-28-oic acid (1) and 3-O-{β-D-xylopyranosyl-(1 → 2)-β-D-glcopyranosyl-(1?→?4)-[β-D-glucopyranosyl-(1?→?2)]-β-D-xylopyranosyl}-2,16α-dihydroxy-4-hydroxymethyl urs-12-en-28-oic acid (2) on the basis of spectral evidences, i.e. FTIR, (1)H-NMR, (13)C-NMR, ESI-MS and FAB-MS data. The isolated saponins were tested for their antifungal activity. Compound 1 showed maximum inhibition against Colletotrichum dematium (77.8%), whereas compound 2 showed maximum inhibition against Alternaria alternata (53.9%).     

New Triterpene Saponins from Herniaria glabra

Three new saponins 1–3 were isolated from Herniaria glabra by means of prep. HPLC and TLC. The structures were established mainly by a combination of 2D-NMR techniques (COSY, TOCSY, ROESY, HMQC, and HMBC) as O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1-→6)-O-[β-D -glucopyranosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 4; 1 ), O-β-D -glucopyranosyl-(1→3)-O-α-L -rhamnopyranosyl-(1→2)-O-[β-(3R)-D -apiofuranosyl-(1→3)]-β-D -4-O-acetylfucopyranosyl 3-O-(β-D -glucuronopyranosyl)-16α-hydroxymedicagen-28-ate (herniaria saponin 5; 2 ), and O-α-L -rhamnopyranosyl-(1→4)-O-β-D -glucopyranosyl-(1→6)-O-[β-D -6-O-acetylglucopyra nosyl-(1→2)]-β-D -glucopyranosyl medicagen-28-ate (herniaria saponin 6; 3 ).     

Structural determination of two new acacic acid-type saponins from the stem barks of Albizia zygia (DC.) J. F. Macbr

As a continuation of our interest in the study of triterpenoid saponins from Albizia zygia, phytochemical investigation of its stem barks led to the isolation of two new oleanane-type saponins, named zygiaosides C–D (1–2). Their structures were established on the basis of extensive analysis of 1D and 2D NMR (1H-, 13C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as, 3-O-[ β-d-glucopyranosyl-(1→2)-[α-l-arabinopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-d-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (1) and 3- O-[β-d-glucopyranosyl-(1→2) -[ β-d-fucopyranosyl-(1→6)]-β-d-glucopyranosyl]-21-O-[(2E,6S)-2,6-dimethyl-6-O-(β-D-quinovopyranosyl) octa-2,7-dienoyl]acacic acid 28-O-α-l-arabinofuranosyl-(1→4)-[β-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-β-d-glucopyranosyl ester (2).     

A new furostanol saponin from Dendrobium chrysanthum Lindl. with cytotoxic activity

A new furostanol saponin, (25R)-26-O-(α-d-glucopyranosyl)-(1→2)-α-l-rhamnopyranosyl-furost-5-ene-3β, 22α, 26-triol-3-O-α-d-glucopyranoside (1), together with four known compounds 2–5 were isolated from the ethanolic extract of the stems of Dendrobium chrysanthum Lindl. The structures of these new compounds were identified by extensive spectroscopic analysis including 1D and 2D NMR and HR-ESI-MS, as well as chemical methods. Compounds 1–3 were isolated from D. chrysanthum for the first time. Furthermore, the inhibitory effects of the compounds on tumor cells were evaluated, and compounds 1–2 exhibited significant cytotoxic activities potentially against SPC-A1, MCF-7 and HeLa human cancer cell lines. Compounds 3–5 showed inhibitory activity against the SPC-A1 and MCF-7.     

Triterpenoid saponins with hepatoprotective effects from the fresh leaves of Metapanax delavayi

Abstract

The fresh leaves of Metapanax delavayi (Araliaceae) have been used as a common wild vegetable for salad and soup, and also herbal tea by the local people living in its growing areas of Yunnan province, China. Detailed chemical investigation led to the identification of a new triterpenoid saponin, 3-O-α-L-arabinopyranosyl-28-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl-3β-hydroxyolean-12-ene-28,29-dioic acid (1) from the fresh leaves, together with 11 known compounds, including six triterpenoid saponins (2–7), two caffeoylquinic acid derivatives (8–9), and three flavonoid glycosides (10–12). Their structures were determined on the basis of spectroscopic analysis and acidic hydrolysis. Compounds 3–5 and 8–12 were isolated from M. delavayi for the first time. Moreover, the known saponins 3-O-β-D-xylopyranosyl-3β-hydroxyolean-12-ene-28,29-dioic acid (3) and yiyeliangwanoside IV (5) exhibited protective effects on HepG2 cells damaged by the alcohol intakes, at a concentration of 1.0?µg/mL. The results indicated M. delavayi is an ideal dietary vegetable and herbal tea with potential hepatoprotective activity.

     

Two new steroidal glucosides from Ophiopogon.japonicus （L.f.） Ker-Gawl

Two new steroidal glucosides, 26-O-β-D-glucopyranosyl （25S）-furost-5-ene-1β,3β,22α,26-tetraol l-O-β-D-xylopyranosyl- （1 → 3）-[α-h-rhamnopyranosyl-（1 → 2）]-[β-D-fueopyranoside and （25R） spirost-5-ene-3β,14α-diol-3-β-O-β-L-rhanmopyranosyl- （1 → 2）-[β-D-xylopyranosyl（1 → 4）]-[-β-D-glucopyranoside, were isolated from the Ophiopogon japonicus （L.f.） Ker-Gaw. Their structures were elucidated by spectroscopic methods.     

Synthesis of a Single Repeat Unit of Type VIII Group B Streptococcus Capsular Polysaccharide 1

Abstract

We have synthesized a single repeat unit of type VIII Group B Streptococcus capsular polysaccharide, the structure of which is {L-Rhap(β1→4)-D-Glcp(β1→4)[Neu5Ac(α2→3)]-D-Galp(β→4)}_n. The synthesis presented three significant synthetic challenges namely: the L-Rhap(β→4)-D-Glcp bond, the Neu5Ac(α2→3)-D-Galp bond and 3,4-D-Galp branching. The L-Rhap bond was constructed in 60% yield (α:β 1:1.2) using 4-O-acetyl-2,3-di-O-benzoyl-α-L-rhamnopyranosyl bromide 6 as donor, silver silicate as promotor and 6-O-benzyl-2,3-di-O-benzoyl-1-thio-β-D-glucopyranoside as acceptor to yield disaccharide 18. The Neu5Ac(α2→3) linkage was synthesized in 66% yield using methyl [phenyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5-dideoxy-2-thio-D-glycero-D-galacto-nonulopyranosid]onate as donor and triol 2-(trimethylsilyl) ethyl 6-O-benzyl-β-D-galactopyranoside as acceptor to give disaccharide 21. The 3,4-D-Galp branching was achieved by regioselective glycosylation of disaccharide diol 21 by disaccharide 18 in 28% yield to give protected tetrasaccharide 22. Tetrasaccharide 22 was deprotected to give as its 2-(trimethylsilyl)ethyl glycoside the title compound 1a. In addition the 2-(trimethylsilyl)ethyl group was cleaved and the tetrasaccharide coupled by glycosylation (via tetrasaccharide trichloroacetimidate) to a linker suitable for conjugation.

     

Ursane-type triterpenoid saponins from Elsholtzia bodinieri

Investigation of the n-BuOH extract of the aerial parts of Elsholtzia bodinieri led to the isolation of two new ursane-type triterpenoid saponins, bodiniosides O (1) and P (2), along with five known saponins, rotungenoside (3), 3,28-O-bis-β-d-glucopyranosides of 19α-hydroxyarjunolic acid (4), oblonganosides I (5), rotungenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-β-d-glucopyranoside (6), and bodinioside M (7) isolated from the species. The structures of compounds 1 and 2 were characterized by spectroscopic data as well as acid hydrolysis and GC analysis as 3-O-β-d-xylopyranosyl-23-acetoxy-urs-12(13)-en-28-oic acid 28-O-β-d-xylopyranosyl-(1→6)-[β-d-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)]-β-d-glucopyranoside and 3-O-β-d-xylopyranosyl-23-hydroxy-urs-12(13)-en-28-oic acid 28-O-β-d-glucopyranosyl-(1→6)-β-d-glucopyranoside. Compounds 1 and 2 exhibited potent anti-HCV activities in vitro with a selective index of 30.63 and 9.08, respectively.     

地奥心血康中的两个新甾体皂苷

通过正相和反相硅胶柱层析, 从地奥心血康药粉的正丁醇萃取物中分离纯化出2个微量的新甾体皂苷, 通过MS和NMR(包括HMQC, HMBC和NOESY)等波谱解析, 结合化学降解分析将其结构鉴定为3β,26-二醇-25(R)-Δ^5,20(22)-二烯-呋甾-26-O-β-D-吡喃葡萄糖苷(1)和26-O-β-D-吡喃葡萄糖基-3β,20α,26-三醇-25(R)-Δ^5,22-二烯-呋甾-3-O-α-L-吡喃鼠李糖基(1→2)-[α-L-吡喃鼠李糖基(1→4)]-β-D-吡喃葡萄糖苷(2).     

Triterpenoid saponins from the buds of Lonicera similis

Four new lupane triterpenoid saponins, along with one known lupane and eight hederagenin saponins, were isolated from the EtOH extract of the buds of Lonicera similis Hemsl. The structures of the new compounds were established as 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside A, 1), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl 23-hydroxybetulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside B, 2), 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl ester (lonisimilioside C, 3) and 3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→6)-β-D-glucopyranosyl betulinic acid 28-O-β-D-glucopyranosyl ester (lonisimilioside D, 4), respectively. The cytotoxic activities of the isolates against human cancer cell lines HepG2, MCF-7 and A-549 were evaluated. Only the monodesmosidic saponin with a free carboxyl group at C-28 (12) exhibited significant cytotoxicities against HepG2, MCF-7 and A-549 cell lines with the IC₅₀ values of 8.98 ± 0.19, 12.48 ± 0.45 and 11.62 ± 0.54 μM, respectively. Furthermore, Hoechst fluorescence 33342 staining was used to demonstrate that 12 could induce HepG2 and A-549 cells apoptosis significantly.     

Synthesis of Polyacrylamide Copolymers Containing (1→6)-Branched (1→3)-β-D-Linked Tri- and Tetra-Saccharides Related to Schizophyllan

Abstract

The allyl β-glycosides of a trisaccharide O-β-D-Glcp-(1→3)-O-[β-D-Glcp-(1→6)]-β-D-Glcp and of a tetrasaccharide O-β-D-Glqp-(1→3)-O-[β-D-Glqp-(1→6)]-O-β-D-Glcp-(1→3)-β-D-Glcp, corresponding to the branching point or the repeating unit of antitumor (1→6)-branched-(1→3)-β-D-glucans, have been synthesized starting from ethyl 2-O-benzoyl-4,6-O-benzylidene-l-thio-α-D-glucopyranoside and copolymerized in a radical reaction with acrylamide to obtain polyacrylamide copolymers containing the tri-and tetra-saccharides for immunochemical studies of schizophyllan.     

Lebbeckoside C,a new triterpenoid saponin from the stem barks of Albizia lebbeck inhibits the growth of human glioblastoma cells

One new acacic acid-type saponin, named lebbeckoside C (1), was isolated from the stem barks of Albizia lebbeck. Its structure was established on the basis of extensive analysis of 1D and 2D NMR (¹H, ¹³C NMR, DEPT, COSY, TOCSY, ROESY, HSQC and HMBC) experiments, HRESIMS studies, and by chemical evidence as 3-O-[β-d-xylopyranosyl-(l→2)-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-[β-d-quinovopyranosyl-(l→3)-[α-l-arabinofuranosyl-(l→4)]-α-l-rhamnopyranosyl-(l→2)-β-d-glucopyranosyl] ester. The isolated saponin (1) displayed significant cytotoxic activity against the human glioblastoma cell line U-87 MG and TG1 stem-like glioma cells isolated from a patient tumor with IC₅₀ values of 1.69 and 1.44 μM, respectively.     

Three new oleanane-type triterpenoid saponins from the seeds of Celosia cristata L.

Phytochemical investigation of the 1-butanol soluble fraction of 60% ethanol extract of the seeds of Celosia cristata L. led to the identification of three new oleanane-type triterpenoid saponins. Using ¹D and ²D NMR experiment methods, ESI-MS analysis and acid hydrolysis, their structures were identified as 3-O-[β-D-xylopyranosyl-(1 → 3)-β-D-glucuronopyranosyl]-2β-hydroxy-oleanolic acid-28-O-β-D-glucopyranoside (1), 3-O-[β-D-xylopyranosyl-(1 → 3)-β-D-glucuronopyranosyl]-2β, 23-dihydroxy-oleanolic acid-28-O-β-D-glucopyranoside (2) and 3-O-[β-D-glucopyranosyl-(1 → 4)-β-D-glucopyranosyl]-2-hydroxyl-medicagenic acid-28-O-β-D-glucopyranosyide (3), respectively.     

Synthesis of Methyl 2-O-, 3-O-, 4-O-, 6-O-, 2,3-Di-O- and 4,6-Di-O-β-D-Galactopyranosyl-β-D-glucopyranoside

Abstract

Synthesis of methyl O-β-D-galactopyranosyl-(1→2)-β-D-glucopyranoside 1, methyl O-β-D-galactopyranosyl-(1→3)-β-D-glucopyranoside 2, methyl O-β-D-galactopyranosyl-(1→4)-β-D-glucopyranoside 3, methyl O-β-D-galactopyranosyl-(1→6)-β-D-glucopyranoside 4, methyl O-β-D-galactopyranosyl-(1→4)-[O-β-D-galactopyranosyl-(1→6)]-β-D-glucopyranoside 5, and methyl O-β-D-galactopyranosyl-(1→2)-[O-β-D-galactopyranosyl-(1→3)]-β-D-glucopyranoside 6, using 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl trichloroacetimidate or 2,3,4,6 tetra-O-acetyl-α-D-galactopyranosyl bromide as a glycosyl donor and selectively protected derivatives of methyl O-β-D-glucopyranoside as glycosyl acceptors are described.     

Three new triterpenoid saponins from the roots of Ardisia crenata and their cytotoxic activities

Three new triterpenoid saponins, ardisicrenoside O (1), ardisicrenoside P (2) and ardisicrenoside Q (3) together with three known compounds, 3β,16α-dihydroxy-30-methoxy-28, 30-epoxy-olean-12-en, cyclamiretin A 3-O-β-d-glucopyranosyl-(1→2) -α-l-arabinopyranoside and cyclamiretin A 3-O-β-d-glucopyranosyl-(1→4) -α-l-arabinopyranoside were isolated from the roots of Ardisia crenata Sims. Their structures were determined by one- and two-dimensional NMR techniques, including HSQC, HMBC and TOCSY experiments, as well as acid hydrolysis and GC analysis. All isolates were evaluated for the cytotoxic activities on two human cancer cell lines and compounds 3, 5 and 6 showed significant cytotoxicity.     

Two new triterpenoids from the seeds of blackberry (Rubus fructicosus)

Two new ursane-type triterpenoids (1, 2) attached to isopropylidenedioxy group were isolated from the seeds of blackberry (Rubus fructicosus L., Rosaceae) along with two known ursane-type triterpenoids, 2,3-O-isopropylidenyl-2α,3α,19α-trihydroxyurs-12-en-28-oic acid (3) and 1β-hydroxyeuscaphic acid (4). The chemical structures of 1 and 2 were determined to be 2,3-O-isopropylidene-1β,2β,3β,19α-tetrahydroxyurs-12-en-28-oic acid and 1,2-O-isopropylidene-1β,2α,3α,19α-tetrahydroxyurs-12-en-28-oic acid, respectively, based on spectroscopic data. Additionally, their cytotoxic activity towards HL-60 human leukaemia cells was evaluated. Among them, 3 demonstrated a clear cytotoxic activity with 72.8 μM of IC₅₀ value.