Takahashi_2014_Bioorg.Med.Chem.Lett_24_3373

Kynapcin-12 is a prolyl oligopeptidase (POP) inhibitor isolated from Polyozellus multiplex, and its structure was assigned as 1 having a p-hydroquinone moiety by spectroscopic analyses and chemical means. This Letter describes the total syntheses of the proposed structure 1 for kynapcin-12 and 2',3'-diacetoxy-1,5',6',4''-tetrahydroxy-p-terphenyl 2 isolated from Boletopsis grisea, revising the structure of kynapcin-12 to the latter. These syntheses involved double Suzuki-Miyaura coupling, CAN oxidation, and LTA oxidation as key steps. The inhibitory activities of synthetic compounds against POP and cancer cells were also evaluated.