Withaperuvin O, a new withanolide from Physalis peruviana L.

Physalis peruviana L. (Solanaceae) has been used in tropical and subtropical countries of the world as medicinal and fruit trees. In this study, a new withanolide named withaperuvin O (1) and seven known ones, including physalolactone B-3-O-ß-D-glucopyranoside (2), withanolide J (3), physapruin A (4), physaperuvin G (5), withaperuvin (6), withaperuvin C (7) and 28-hydroxywithaperuvin C (8), were isolated from the whole plants of P. peruviana. Their structures were elucidated based on extensive spectroscopic analyses including NMR and HR-ESI-MS. The bioactivities of these compounds against lipopolysaccharide (LPS)-induced NO production in RAW264.7 cells and cytotoxicity against HepG2 were tested. Compound 3 showed strong anti-inflammatory activities with IC50 3.55 ± 0.12 µM (compared to positive control L-NMMA 7.72 ± 0.46 µM). Compounds 3 and 4 inhibited HepG2 cell line with the IC50 values of 2.01 ± 0.12 µM, 0.96 ± 0.05 µM, respectively (Ellipticine, 0.32 ± 0.02 µM). Our study indicated that compounds 3 and 4 could be new potential natural products for the development of anti-inflammatory and anti-cancer agents.

Stigmastane-type steroid saponins from the leaves of Vernonia amygdalina and their α-glucosidase and xanthine oxidase inhibitory activities.

Two new vernonioside K (1) and vernonioside L (2) and four known Δ7,9(11) stigmastane-type steroidal saponins-vernonioside B2 (3), vernoniacum B (4), vernonioside B1 (5), and vernoamyoside A (6)-were isolated from the leaves of Vernonia amygdalina. Their structures were determined by comprehensive spectroscopic analysis with one-dimensional nuclear magnetic resonance, two-dimensional nuclear magnetic resonance, and high-resolution mass spectrometry. All isolated compounds (1-6) were evaluated to determine their inhibitory effects on α-glucosidase and xanthine oxidase. Among them, two new compounds 1 and 2 showed significant inhibition of α-glucosidase with IC50 values of 78.56 ± 7.28 and 14.74 ± 1.57 (µM), respectively, comparable with acarbose as a positive control (127.53 ± 1.73 µM); none of these compounds inhibited xanthine oxidase activity. Compounds 1 and 2 are promising candidates for the development of antidiabetic agents from natural sources.

Chemical constituents of Trichosanthes kirilowii and their cytotoxic activities.

One new lignan, trichobenzolignan (1), and seven known compounds, ligballinol (2), (-)-pinoresinol (3), ehletianol C (4), luteolin 7-O-ß-D-glucopyranoside (5), chrysoeriol-7- O-ß-D-glucopyranoside (6), 10α-cucurbita-5,24-dien-3ß-ol (7), and arvenin I (8). Their structures were established on the basis of spectral and chemical evidence, which were in agreement with those reported in literature. The cytotoxic activities of these compounds were evaluated on four cancer cell lines such as A-549 (human lung cancer), HT-29 (human colon adenocarcinoma), OVCAR (human ovarian carcinoma), and MCF-7 (human breast cancer). As the results, compound 7 showed significant activity on HT-29 and OVCAR cancer cell lines with IC50 of 4.1 and 6.5 µM, respectively. Compounds 1, 5, 6, and 8 exhibited moderate activities in all cancer cell lines with IC50 ranging from 11.3 to 42.8 µM.