Two new farnesyl hydroquinones from Pestalotiopsis diploclisia (BCC 35283), the fungus associated with algae

Two new hydroquinones bearing a 1,3-enyne moiety, pestalotioquinols G and H, together with four known compounds, including pestalotioquinol A, phomonitroester, (R)-4,6,8-trihydroxy-3,4-dihydronaphthalen-1(2H)-one, and scylatone were isolated from the marine fungus Pestalotiopsis diploclisia (BCC 35283). The structures of these compounds were elucidated by analysis of 2D-NMR and HR-MS data. The known pestalotioquinol A displayed antimalarial activity against Plasmodium falciparum K1 with an IC₅₀ value of 19.0 μM, while pestalotioquinol G displayed weak cytotoxic activity against Vero cell lines with an IC₅₀ value of 47.9 μM.