Dicitrinones E and F, citrinin dimers from the marine derived fungus Penicillium citrinum HDN-152-088.

• Two new two new citrinin dimers with rare C-7/C-7′ carbon-bridges were isolated from a marine derived fungus. • Compound 2 was the first citrinin dimer consisted of two mono-benzene monomers. • Compound 1 displayed antioxidant activity. Two new citrinin dimers named dicitrinones E and F (1 and 2), together with one biogenetically related known citrinin monomer (3), were isolated from the marine derived fungus Penicillium citrinum HDN-152-088. All structures including the absolute configurations were elucidated on the basis of comprehensive spectroscopic data, and assisted by ECD calculations. Among them, compounds 1 and 2 belong to the class of citrinin dimers with a rare carbon-bridged C-7/C-7′ linkage. Compound 1 displayed antioxidant activity with IC 50 value of 23.73 μM. [ABSTRACT FROM AUTHOR]