Isolation, structure and HIV-1 integrase inhibitory activity of exophillic acid, a novel fungal metabolite from Exophiala pisciphila.

HIV-1 integrase is one of the three enzymes that are critical for replication and spread of HIV and its inhibition is one of the most promising new drug targets for anti-retroviral therapy with potential advantage over existing therapies. This paper describes the isolation and structure elucidation of exophillic acid, a novel dimeric 2,4-dihydroxy alkyl benzoic acid, derived from Exophiala pisciphila, a fungus isolated from a soil sample collected in Georgia, USA. Exophillic acid (1) and aquastatin A (2), a related compound, inhibited the strand transfer reaction of HIV-1 integrase with IC50 values of 68 and 50 microM, respectively.