ABSTRACT
Chemical investigation of the culture extract of an endophytic Penicillium citrinum from Dendrobium officinale, afforded nine citrinin derivatives (1-9) and one peptide-polyketide hybrid GKK1032B (10). The structures of these compounds were determined by spectroscopic methods. The absolute configurations of 1 and 2 were determined for the first time by calculation of electronic circular dichroism (ECD) data. Among them, GKK1032B (10) showed significant cytotoxicity against human osteosarcoma cell line MG63 with an IC50 value of 3.49 µmol·L-1, and a primary mechanistic study revealed that it induced the apoptosis of MG63 cellsvia caspase pathway activation.
Subject(s)
Bone Neoplasms , Osteosarcoma , Apoptosis , Caspases , Humans , Osteosarcoma/drug therapy , PenicilliumABSTRACT
Seven rare oxylipins, siegesbeckins A-G (1-7) representing further bioactive constituents different from the general terpenyl compounds found in Siegesbeckia species, have been obtained from the aerial parts of Siegesbeckia glabrescens. These isolates were identified to be a series of methyl 4-methylpentanoates incorporating fatty acid moieties of different chain lengths, based on spectroscopic techniques, and their absolute configurations were determined via chemical degradation and comparison of experimental and theoretically calculated ECD spectra. With respect to bioactivity, antibacterial, anti-inflammatory and cytotoxic properties of selected compounds were evaluated. Compounds 1 and 5 showed moderate antibacterial activity against two Gram-positive bacteria with MIC values of 4.3 µg/mL, while 3 showed no pronounced activity in these assays.
Subject(s)
Anti-Bacterial Agents/pharmacology , Asteraceae/chemistry , Oxylipins/pharmacology , A549 Cells , Animals , Anti-Bacterial Agents/isolation & purification , Cell Line, Tumor , China , Gram-Positive Bacteria/drug effects , Humans , Mice , Microbial Sensitivity Tests , Molecular Structure , Oxylipins/isolation & purification , Phytochemicals/isolation & purification , Phytochemicals/pharmacology , Plant Components, Aerial/chemistry , RAW 264.7 CellsABSTRACT
Eleven new highly oxygenated germacrane-type sesquiterpenoids (1-11) and 16 known analogues (12-27) were isolated from the aerial parts of Sigesbeckia orientalis. Their structures, including absolute configurations, were determined by comprehensive spectroscopic methods especially NMR and ECD analyses. Compounds 13, 21 and 23 possessing an 8-methacryloxy group showed stronger in vitro cytotoxicity against human A549 and MDA-MB-231 cancer cell lines than other co-metabolites, with IC50 values ranging from 6.02 to 10.77⯵M comparable to the positive control adriamycin.