Terphenylquinone inhibitors of the src protein tyrosine kinase from Stilbella sp.

Three new secondary metabolites, 2,5-dihydroxy-3-(3,4-dihydroxyphenyl)-6-phenyl-1,4-benzoquinone (3), 2,5-dihydroxy-3-phenyl-6-(3,4,5-trihydroxyphenyl)-1,4-benzoquinone (4), and 2,7,8-trihydroxy-3-phenyl-1,4-dibenzofurandione (5), as well as two known natural products were isolated from the fungus Stilbella sp. strain 1586. The structures of these compounds were established by spectroscopic and chemical methods. The terphenylquinones 3-5 exhibited significant activity against human src protein tyrosine kinase.