ABSTRACT
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.
Subject(s)
Saponins , Vernonia , alpha-Glucosidases , Vernonia/chemistry , Xanthine Oxidase , Saponins/pharmacology , Saponins/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistry , Steroids/chemistryABSTRACT
One new triterpenoid, hexagonin F (1) was characterized from the fruiting bodies of Hexagonia tenuis with the assistance of spectroscopic and spectrometric analytical methods. In addition, two triterpenoids and two steroids were also identified by comparison of their physical and spectroscopic data with those reported. The purified compounds were examined for their cytotoxicity against five tumor cell lines, however, only weak cytotoxicity was demonstrated.
Subject(s)
Polyporaceae/chemistry , Steroids/chemistry , Steroids/pharmacology , Triterpenes/chemistry , Triterpenes/pharmacology , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Drug Screening Assays, Antitumor , Fruiting Bodies, Fungal/chemistry , Hep G2 Cells , Humans , Magnetic Resonance Spectroscopy , Molecular Structure , Spectrometry, Mass, Electrospray Ionization , VietnamABSTRACT
Ten compounds (1-10) were purified from the extract of lichens C. faveomaculata, and among these one new triterpenoid, cryptothecin A (1) was characterized through mass spectrometric and 2D NMR spectroscopic analyses. Some of the isolated compounds were assessed for their antimicrobial (1, 6, and 8) and cytotoxic activity (1, 4-5, and 7-9), but only weak inhibitory effects were observed.
