Structural confirmation of 15-norlubiminol and 15-norepilubiminol, isolated from Solanum aethiopicum, by chemical conversion from lubimin and epilubimin, and their antifungal activity.
15-Norlubiminol and 15-norepilubiminol were obtained from Solanum aethiopicum as an inseparable 1:1 mixture in a relatively poor yield to that of the major phytoalexins, lubimin and epilubimin. Their structures were confirmed by chemical conversion starting from lubimin and epilubimin. Baeyer-Villiger oxidation of the protected lubimins with m-chloroperoxybenzoic acid provided the desired formates. Deoxygenation with triphenylphosphine selenide and subsequent methanolysis provided 15-norlubiminols, whose 1H-NMR spectra were respectively identical with that of the corresponding isomer in the natural 15-norlubiminol mixture. The antifungal activity of 15-norlubiminols would be weaker than that of lubimins.
Watanabe
A
A
Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
Toshima
H
H
Nagase
H
H
Nagaoka
T
T
Yoshihara
T
T
D000935:Antifungal Agents / Q000737:chemistry* / Q000633:toxicity*; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008826:Microbial Sensitivity Tests; D012717:Sesquiterpenes / Q000138:chemical synthesis* / Q000737:chemistry* / Q000633:toxicity*; D019657:Solanaceae / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013172:Spores, Fungal / Q000737:chemistry; D013237:Stereoisomerism; D000094162:Phytoalexins
D000935:Antifungal Agents; D007202:Indicators and Reagents; D012717:Sesquiterpenes; C448761:15-norepilubiminol; C448760:15-norlubiminol; C448762:epilubimin; C044124:lubimin; D000094162:Phytoalexins