Broussonin C

Bioorg Med Chem. 2009 Jan 1;17(1):35-41.

Tyrosinase inhibitory effects of 1,3-diphenylpropanes from Broussonetia kazinoki.[Pubmed: 19046886]

METHODS AND RESULTS:
Six 1,3-diphenylpropanes exhibiting inhibitory activities against both the monophenolase and diphenolase actions of tyrosinase were isolated from the methanol (95%) extract of Broussonetia kazinoki. These compounds, 1-6, were identified as kazinol C (1), D (2), F (3), Broussonin C (4), kazinol S (5) and kazinol T (6). The latter two species (5 and 6) emerged to be new 1,3-diphenylpropanes which we fully spectroscopically characterized. The IC(50) values of compounds (1, 3-5) for monophenolase inhibition were determined to range between 0.43 and 17.9 microM. Compounds 1 and 3-5 also inhibited diphenolase significantly with IC(50) values of 22.8, 1.7, 0.57, and 26.9 microM, respectively.
CONCLUSIONS:
All four active tyrosinase inhibitors (1, 3-5) were competitive inhibitors. Interestigly they all mainfested simple reversible slow-binding inhibition against diphenolase. The most potent inhibitor, Broussonin C diplayed the following kinetic parameters k(3)=0.0993 microM(-1)min(-1), k(4)=0.0048 min(-1), and K(i)(app)=0.0485 microM.

Chemistry Letters , 1980 (11) :1459-1460.

The co-occurrence of flavan and 1,3-diphenylpropane derivatives in wounded paper mulberry.[Reference: WebLink]

METHODS AND RESULTS:
Two antifungal compounds, designated as broussin and Broussonin C, were isolated from wounded xylem tissues of paper mulberry shoots and identified as flavan and 1,3-diphenylpropane derivatives, respectively.