Resorcinosides A and B, Glycosylated Alkylresorcinols from a Marine-Derived Strain of the Fungus Penicillium janthinellum

Two new glycosylated alkylresorcinols, resorcinosides A (1) and B (2), were isolated from a strain of the fungus Penicillium janthinellum derived from a marine sediment sample collected from Cu Lao Cham Island, Vietnam. The structures of 1 and 2 were established by interpretation of 1D and 2D NMR and high-resolution ESIMS data, and their absolute configurations were confirmed by the coupling constant of the anomeric proton, acid hydrolysis, subsequent HPLC analysis, Mosher's method, and quantum-mechanics-based computational analysis of NMR chemical shifts. The structure elucidation indicated that 1 and 2 are new alkylresorcinols with D-glucose, and 2 has an a-pyrone moiety attached to the aromatic ring. Compound 1 exhibited cytotoxic activity against the NUGC-3 cancer cell line with a GI(50) value of 9.3 mu M.