Jian-Chao Chen

Kuguacins F-S, cucurbitane triterpenoids from Momordica charantia.

Chemical investigation of the vines and leaves of Momordica charantia resulted in isolation of fourteen cucurbitane triterpenoids, kuguacins F-S (1-14), including two pentanorcucurbitacins (6 and 7), one octanorcucurbitacin (8), and two trinorcucurbitacins (11 and 12), along with six known analogues. Their structures were elucidated on the basis of extensive spectroscopic and single-crystal X-ray diffraction analyses. Compounds 1-14 exhibited weak anti-HIV-1 activities in vitro.

New Cucurbitane Triterpenoids and Steroidal Glycoside from Momordica charantia

Three new cucurbitane triterpenoids 1–3 and one new steroidal glycoside 4, were isolated together with ten known compounds from Momordica charantia. The structures of new compounds were determined to be 19(R)-n-butanoxy-5β,19-epoxycucurbita-6,23-diene-3β,25-diol 3-O-β-glucopyranoside (1), 23-O-β-allopyranosyle-cucurbita-5,24-dien-7α,3β,22(R),23(S)-tetraol 3-O-β-allopyranoside. (2), 23(R),24(S),25-trihydroxycucurbit-5-ene 3-O-{[β-glucopyranosyl(1→6)]-O-β-glucopyranosyl}-25-O-β-glucopyranoside (3), and 24(R)-stigmastan-3β,5α,6β-triol-25-ene 3-O-β-glucopyranoside (4), respectively. Their structures were elucidated by the combination of mass spectrometry (MS), one and two-dimensional NMR experiments and chemical reactions.

Three new triterpenoids containing four-membered ring from the fruiting body of Ganoderma sinense.

Methyl ganosinensate A (1), ganosinensic acid A (1a), and ganosinensic acid B (2), three new triterpenoids with an unusual four-membered ring skeleton produced by a bond across C-1 to C-11, were isolated from the fruiting body of Ganoderma sinense . Their structures were established on the basis of extensive spectroscopic methods, including 1D and 2D NMR techniques, and methyl ganosinensate A was confirmed by X-ray crystallographic analysis.

Cucurbitane-type triterpenoids from the stems and leaves of Momordica charantia

Six new cucurbitane-type triterpenoids, karavilagenin F (1), karavilosides XII and XIII (2, 3), momordicines VI, VII, and VIII (4, 5 and 6), along with four known ones, 5β,19-epoxy-25-methoxycucurbita-6,23-diene-3β,19-diol (7), 5β,19-epoxycucurbita-6, 23-diene-3β,19,25-triol (8), kuguacin R (9), and (19R,23E)-5β,19-epoxy-19-methoxycucurbita-6,23,25-trien-3β-ol (10), were isolated from the stems and leaves of Momordica charantia L. Their chemical structures were elucidated by extensive 1D NMR and 2D NMR (HSQC, HMBC, COSY, and ROESY), MS experiments, and CD spectrum. Compound 6 showed weak cytotoxicity against five human cancer cells lines with IC50 values of 14.3-20.5μmol/L.

Pregnane alkaloids from Pachysandra axillaris

Nine new pregnane alkaloids, pachysamines J-R (1-9), together with seven known ones, were isolated from Pachysandra axillaris. The chemical structures of the new alkaloids were elucidated by spectroscopic methods. All the compounds were evaluated for their inhibitory activities against HL-60, SMMC-7721, A-549, SK-BR-3, and PANC-1 cell lines. Compound 15 possessed moderate activities against A-549, SK-BR-3, and PANC-1 cells, with the IC(50) values of 11.17, 4.17, and 10.76 microM, respectively. Besides, compound 11 showed cytotoxicities against A-549 cell, with the IC(50) values as 24.94 microM.

Cytotoxic triterpenoid alkaloids from Buxus microphylla.

Five new triterpenoid alkaloids, buxmicrophyllines E-I (1-5), and six known ones (6-11) were isolated from the leaves and stems of Buxus microphylla. The structures of compounds 1-5 were elucidated by NMR and MS spectroscopic analysis, and the relative stereochemistry of 5 was determined by single-crystal X-ray crystallography. Compounds 3 and 9 were cytotoxic against HepG2 cells, with IC(50) values of 0.89 and 0.78 microM, and compounds 2, 3, 7, 8, and 9 were cytotoxic against K562 cells, with IC(50) values of 2.95, 4.44, 1.70, 5.61, and 0.37 microM, respectively.

Anti-HIV-1 Activities of Hemslecins A and B

目的:研究从药用植物金佛山雪胆分离的雪胆素A和雪胆素B两个三萜类化合物的体外抗HIV活性.方法:应用合胞体抑制实验、p24抗原产生的抑制实验、慢性感染细胞和正常细胞间的细胞融合抑制实验等技术检测化合物的体外抗HIV-l活性;利用HIV-l逆转录酶、蛋白酶抑制实验,NCp7锌离子逐出实验探讨化合物的作用机制.结果:雪胆素A和雪胆素B在体外有较好的抑制HIV-l活性,其活性主要表现为:(1)抑制HIV-l诱导合胞体形成,EC50值分别为3.09 μg·mL-1和2.53μg·mL-1;(2)抑制HIV- 急性感染的C8106细胞p24抗原产生,EC50值分别为3.97μg·mL-1和18.90μg·mL-1;(3)抑制HIV-1 慢性感染H9与正常C8166细胞间融合,EC50分别为1.76μg·mL-1和11.95μg·mL-1.雪胆素A和雪胆素B对HIV-l逆转录酶、蛋白酶、NCp7锌离子逐出均没有抑制作用.雪胆素A对HIV-1整合酶有微弱的结合活性,而雪胆素B对HIV-1整合酶没有结合活性.在共培养实验中,雪胆素A和雪胆素B预处理C8166细胞组比未经预处理细胞组能够更有效的抑制HIV-l活性.结论:化合物雪胆素A和雪胆素B体外有较好的抗HIV-1活性,可能主要作用于HIV-1病毒进入细胞阶段.

Limonoids from the leaves of Toona ciliata var. yunnanensis

Twelve limonoids, toonayunnanins A-L (1-12) and eleven known compounds (13-23) were isolated from the leaves of Toona ciliata var. yunnanensis, and their structures were elucidated by means of extensive spectroscopic analyses, particularly 1D and 2D NMR techniques. The inhibitory effects of all the isolated compounds were evaluated on human tumor cell lines, such as HL-60, SMMC-7721, A-549, MCF-7 and SW480. Cedrelone (13) and dysobinin (18) showed significant cytotoxicity, and toonayunnanin B (2) and epoxyazadiradione (14), were found to be slightly cytotoxic against the above cell lines. Furthermore, this study provides valuable information for the chemotaxonomy of T. ciliata varieties.

Cytotoxic Triterpenoids from Azadirachta indica

Two new tirucallane triterpenoids, 24,25-epoxy-3 β-hydroxy-20-oxo-7-tirucallene (1) and 22,23;24,25-diepoxy-3 β-hydroxy-7-tirucallene (2), and a new tetranortriterpenoid, 4 α-hydroperoxy-6- O-acetylnimbandiol (3), along with eight known compounds, were isolated from the branches and leaves of Azadirachta indica. Their structures were elucidated through spectroscopic and chemical methods. The cytotoxic assay showed that the abundant constituent nimbolide (8) had obvious cytotoxic activities against HL-60, SMMC7721, A549, MCF-7, and SW-480 cell lines, with IC₅₀ values of 0.8 ± 0.1, 2.2 ± 0.2, 1.9 ± 1.3, 4.5 ± 1.1, and 2.3 ± 0.1 µM, respectively.

Cucurbitane triterpenoids from Hemsleya penxianensis

Two new cucurbitacins, jinfushanencins A (1) and B (2), seven new cucurbitane glycosides, jinfushanosides E-K (3–9), along with nine known analogues, were obtained from the tubers of Hemsleya penxianensis. Their structures were elucidated on the basis of extensive spectroscopic and chemical methods. Selected isolates were tested their anti-HIV-1 activities, and compound 5 showed weak anti-HIV-1 in C8166 cell (EC50 = 5.9 µg/mL) with a selectivity index of 13.5.