p-terphenyl compound, polyozellic acid (1), and its acetone adduct (3), along with a known p-terphenyl compound, thelephoric acid (2), were isolated from the mushroom Polyozellus multiplex. Their molecular structures were determined by spectroscopic analysis, X-ray crystallographic analysis, and chemical modification. In some assays related to angiogenesis, compounds 1 and 2 in particular showed inhibitory