Schisanlactone A

J Nat Prod. 2009 Nov;72(11):2019-23.

Inhibition of the dimerization and active site of HIV-1 protease by secondary metabolites from the Vietnamese mushroom Ganoderma colossum.[Pubmed: 19813754 ]

METHODS AND RESULTS:
A new farnesyl hydroquinone, ganomycin I (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 microg/mL, respectively.
CONCLUSIONS:
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 microg/mL. The previous findings were also confirmed by the virtual docking of both compounds with HIV-1 protease crystal structure.

Fitoterapia. 2013 Dec;91:125-7.

Cattienoids A-C, three novel steroids from the mushroom Tomophagus cattienensis.[Pubmed: 24001711 ]

METHODS AND RESULTS:
Three novel steroids (1-3), named cattienoids A-C together with Schisanlactone A (4), were isolated from fruiting bodies of Tomophagus cattienensis (Ganodermataceae)-a new mushroom recently collected from Cattien National Park, in Viet Nam. They possess an unusual seven membered lactone ring, derived from lanostane-type triterpenoids. Their structures were determined by spectroscopic methods. In addition, compounds 2 and 4 showed cytotoxicity against KB (a human epidermal carcinoma) cells with their IC50 values of 91.2 and 63.3 μM, respectively.
CONCLUSIONS:
These compounds have neither antimicrobial activity nor inhibition of the tyrosinase.

Chem Pharm Bull (Tokyo). 2006 Jan;54(1):129-32.

Three new lignans, longipedunins A-C, from Kadsura longipedunculata and their inhibitory activity against HIV-1 protease.[Pubmed: 16394567]

METHODS AND RESULTS:
Three new lignans, longipedunins A (1), B (2) and C (3), together with three known compounds, benzoyl-binankadsurin A (4), acetyl-binankadsurin A (5) and Schisanlactone A (6), were isolated from Kadsura longipedunculata. Their structures and stereochemistry were determined by spectral and single-crystal X-ray analyses.
CONCLUSIONS:
Compounds 1 and 6 showed appreciable inhibitory activity against HIV-1 protease with IC50 values of 50 and 20 microM, respectively.