Meroterpenoids with a large conjugated system from Ganoderma lucidum and their inhibitory activities against renal fibrosis.

Baoslingzhines A – E (1–5), five new meroterpenoids were isolated from the fruiting bodies of Ganoderma lucidum. The structures including their absolute configurations were characterized by using spectroscopic and computational methods. Compound 1 is a novel trinormeroterpenoid featuring the presence of an unusual dihydronaphthalene representing an unprecedented meroterpenoid skeleton. Compounds 2–4 are mononormeroterpenoids characteristic of a large conjugated system. Among them, racemic 3 and 4 were separated by HPLC on chiral phase. Biological evaluation toward kidney fibrosis found that compounds 2 and (+) -3 could inhibit the expression of fibronectin and collagen I dose dependently in TGF- β 1-induced rat kidney proximal tubular cells (NRK-52e). Additionally, (+) -3 could also down regulate ɑ -SMA in a concentration dependent manner. Further investigation showed that 2 could inhibit Smad2 phosphorylation. [Display omitted] [ABSTRACT FROM AUTHOR]