Inhibition of the Dimerization and Active Site of HIV-1 Protease by Secondary Metabolites from the Vietnamese Mushroom Ganoderma colossum

A new farnesyl hydroquinone, ganomycin 1 (1), was isolated along with ganomycin B (2) from the chloroform extract of the fruiting bodies of the Vietnamese mushroom Ganoderma colossum. These compounds inhibited HIV-1 protease with IC50 values of 7.5 and 1.0 mu g/mL, respectively. Kinetic studies using Zhang-Poorman and Lineweaver plots revealed that compound 2 competitively inhibited the active site of the enzyme, whereas the tetracyclic triterpene schisanlactone A, previously isolated from the same fungus, was a dimerization inhibitor, with an IC50 value of 5.0 mu g/mL. The previous findings were also confirmed by the virtual docking of both Compounds with HIV-1 protease crystal structure.