Gafner S, Wolfender J L, Nianga M, Stoeckli-Evans H, Hostettmann K
Institut de Pharmacognosie et Phytochimie, Université de Lausanne, Switzerland.
Phytochemistry. 1996 Jul;42(5):1315-20. doi: 10.1016/0031-9422(96)00135-5.
From a dichloromethane extract of Newbouldia laevis roots, four new (6-hydroxydehydroiso-alpha-lapachone, 7-hydroxydehydroiso-alpha-lapachone, 5,7-dihydroxydehydroiso-alpha-lapachone and 3-hydroxy-5-methoxydehydroiso-alpha-lapachone) and six known naphthoquinones have been isolated. Their structures were established by spectroscopic methods (UV, EI mass spectrometry, 1H and 13C NMR) and that of 7-hydroxydehydroiso-alpha-lapachone was confirmed by X-ray crystallography. All naphthoquinones showed antifungal activity against Cladosporium cucumerinum and Candida albicans, and activity against the bacteria Bacillus subtilis and Escherichia coli.
