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In this study, five novel triterpenes were isolated from hydrolyzate of total saponins from Gynostemma pentaphyllum and identified as gypensapogenin H (1), gypensapogenin I (2), gypensapogenin L (3), gypensapogenin J (4) and gypensapogenin K (5), three of which (1-3) possess unprecedented ring A. All the isolated compounds were evaluated for cytotoxic activities in five cell lines and all the tested compounds showed significant anti-cancer activities against a series of human cancer cell lines, while having much weaker effect on the growth of normal cell. Among them, compound 1 showed strong inhibition toward MCF-7 human breast cancer cells (IC50 values 6.85 μM). Further mechanistic study demonstrated that compound 1 significantly induced MCF-7 cell apoptosis. Our results indicated that compound 1 may be a promising lead agent for further study., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

(20R)-25-Methoxyl-dammarane-3β,12β,20-triol (25-OCH₃-PPD) is a dammarane-type sapogenin showing anti-proliferative potential. In our study, two series of analogs substituted at the C-3 or C-3 and C-12 positions with fatty acids were prepared conveniently. The cytotoxic activity of these compounds was evaluated using four different human tumor cell lines (A549, Hela, HT-29 and MCF-7) and a normal cell line (IOSE144). As compared with 25-OCH₃-PPD, compounds 1a, 1b, 2a and 2b showed better anti-proliferative activities against all tumor cell lines and all the derivatives, with low toxicities in the normal cell line. Compound 1a (C-3 monoformiate) exhibited the strongest activity with the IC₅₀ value of 5.2 μM towards HT29 cells. The results indicated that the difference in the substituents may affect the anti-proliferative activity of the compounds. The longer the side chain of 25-OCH₃-PPD is, the lower the anti-proliferative activity would be. This information may be useful for evaluating the structure-activity relationship of other dammarane-type sapogenins and for development of novel antineoplastic agents., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Protein tyrosine phosphatase 1B (PTP1B) is an important factor in non-insulin-dependent diabetes mellitus (type-2 diabetes), and a promising target for treatment of diabetes and obesity. Therefore, the aim of this study is to investigate the inhibitory activities of constituents (three new together with twelve known triterpenes compounds) isolated from the hydrolyzate of total saponins from Gynostemma pentaphyllum. Their structures were accomplished mainly base on the spectroscopic methods, and then were further confirmed by X-ray crystal diffraction. All the compounds were evaluated for inhibitory activity against PTP1B. Current data suggested that the compounds 1, 3, 12, 13 and 14 were considered to be potential as antidiabetic agents, in which they could significantly inhibit the PTP1B enzyme activity in a dose-dependent manner., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Four new dammarane-type triterpene saponins, 1-4, were isolated from the aerial parts of Gynostemma pentaphyllum (Thunb.) Makino. Their structural elucidations were accomplished mainly on the basis of spectroscopic methods, such as IR, HR-TOF-MS, and NMR. Compounds 1-4 showed moderate cytotoxic activities against cancer cell lines HL-60, Colon205, and Du145 in vitro.

Two novel noroleanane saponins, tubeimoside A ( 1) and tubeimoside B ( 2), and a new dammarane triterpene saponin, tubeimoside C ( 3), together with two known compounds, 4 and 5, were isolated from the bulbs of Bolbostemma paniculatum ( Maxim.) Franquet. Compound 4 was found in this genus for the first time. Based on spectroscopic methods, including IR, NMR (DEPT, COSY, HMQC, HMBC, and TOCSY), and MS experiments, and chemical reactions, the structures of the new compounds were elucidated as 3 β-[ β- D-glucopyranosyl-(1→2)- β- D-glucopyranosyloxy]-2 β,23-dihydroxy-28-norolean-12-en-16-one ( 1), 3 β-[ β- D-glucopyranosyl-(1→2)- β- D-glucopyranosyloxy]-2 β,23-dihydroxy-28-norolean-12-en-22-one ( 2), (3 β,7 β)-7,18,20-trihydroxydammar-24-en-3-yl 2- O- α- L-arabinopyranosyl- β- D-glucopyranoside ( 3). [ABSTRACT FROM AUTHOR]

Isolation and structure determination of five novel triterpenes, gypensapogenins H (Ia), I (Ib), L (II), J (III), and K (IV) are reported. [ABSTRACT FROM AUTHOR]

isolation and structure determination of two novel noroleanane saponins, tubeimoside A (I) and regioisomeric tubeisomide B, and a new dammarane triterpene saponin, tubeimoside C (II), together with two known compounds [ABSTRACT FROM AUTHOR]

Abstract: Four new cucurbitane-type triterpene sapogenins, compounds 1–4, together with other eight known compounds were isolated from the acid-hydrolyzed fruits extract of Momordica charantia L. Their chemical structures were established by NMR, mass spectrometry and X-ray crystallography. Compounds 1–7 and 9–12 were evaluated for their inhibitory activities toward protein tyrosine phosphatase 1B (PTP1B), a tyrosine phosphatase that has been implicated as a key target for therapy against type II diabetes. Compounds 1, 2, 4, 7 and 9 were shown inhibitory activities of 77%, 62%, 62% 60% and 68% against PTP1B, respectively. All of these tested compounds were exhibited higher PTP1B inhibition activities than that of the Na3VO4, a known PTP1B inhibitor used as positive control in present study. Structure activity relationship (SAR) analysis indicated that the inhibition activity of PTP1B was associated with the presence and number of –OH groups. [Copyright &y& Elsevier]