Seven new polyketides, named tanzawaic acids R-X (1-6, 11), along with seven known analogues (7-10 and 12-14), were isolated from Penicillium steckii HDN13-279. Their structures, including the absolute configurations, were elucidated by NMR, MS, X-ray diffraction, circular dichroism (CD) analyses and chemical derivatization. Five compounds (2, 3, 6, 10 and 12) significantly decreased the oleic acid (OA)-elicited lipid accumulation in HepG2 liver cells at the concentration of 10 μM, among which, four compounds (3, 6, 10 and 12) significantly decreased intracellular total cholesterol (TC) levels and three Compounds (3, 6, and 10) significantly decreased intracellular triglyceride (TG) levels. Moreover, the TG-lowering capacities of compounds 6 and 10 were comparable with those of simvastatin, with the TG levels being nearly equal to blank control. This is the first report on the lipid-lowering activity of tanzawaic acid derivatives.
Keywords: Penicillium steckii; lipid-lowering activity; tanzawaic acid derivatives.