The first total Synthesis of the 7,7-dimethylaporphinoid, 4,5-didehydroguadiscine (6), originally isolated from the stems and roots of Hornschuchia oblique (Annonaceae), was achieved by the condensation of homopiperonylamine (7) with an alpha,alpha-dimethylphenylacetic acid derivative (8) and subsequent Pschorr reaction of the resulting benzylisoquinoline intermediate (22). The reported C-13 NMR data were partially revised on the basis of the analysis of HMBC spectra measured under different conditions. The melanogenesis inhibitory activity (IC50 = 4.7 mu M) of 6 was 40 times stronger than that of arbutin (174 mu M), which was used as reference standard. Furthermore, 6 was the most potent natural melanogenesis inhibitor Within this class of compounds.
RAJANBABU, T. V.;REDDY, G. S.;FUKUNAGA, TADAMICHI, J. AMER. CHEM. SOC., 1985, 107, N 19, 5473-5483
作者:RAJANBABU, T. V.、REDDY, G. S.、FUKUNAGA, TADAMICHI
DOI:——
日期:——
RAJANBABU, T. V.;CHENARD, B. L.;PETTI, M. A., J. ORG. CHEM., 1986, 51, N 10, 1704-1712