Penicacids A–C, three new mycophenolic acid derivatives and immunosuppressive activities from the marine-derived fungus Penicillium sp. SOF07

Abstract

Three new mycophenolic acid derivatives, penicacids A–C (1–3), together with two known analogues, mycophenolic acid (MPA, 4) and 4′-hydroxy-MPA (5), were isolated from a fungus Penicillium sp. SOF07 derived from a South China Sea marine sediment. The structures of compounds 1–3 were elucidated on the basis of MS and NMR (1H, 13C, HSQC and HMBC) data analyses and comparisons with the known compounds. Structure–activity relationship studies of compounds 1–5 focused on inosine-monophosphate dehydrogenase inhibition revealed that hydroxylation at C-4′, methylation at C-7-OH, dual hydroxylation at C-2′/C-3′ double bond of MPA diminished bioactivity whereas glucosyl hydroxylation at C-4′ correlated to bioactivity comparable to that observed for MPA.