Antifungal constituents from Nicotiana tabacum with the Wz locus infected by Phytophthora nicotianae

Seven compounds, (S)-(-)-N'-nitrosoanatabine [(S)-(-)-1], (R)-(+)-N'-nitrosoanatabine [(R)-(+)-1], nicotine (2), capsidiol (3), (1S,2E,4S,6R,7E,11E)-2,7,11-cembratriene-4,6-diol (alpha-CBT-diol, 4), (1S,2E,4R,6R,7E,11E)2,7,11-cembratriene-4,6-diol (beta-CBT-diol, 5), and (1S,2E,4S,6R,7E,10E,12R)-2,7,10-cembratriene-4,6,12-triol (6), were isolated from the whole plants of Nicotiana tabacum with Wz infected by Phytophthora nicotianae. Their chemical structures were determined by spectroscopic methods. The absolute configurations of (-)-1 and (+)-1 were elucidated by electronic circular dichroism (ECD) calculations. All isolates were evaluated for their antifungal activities against P. nicotianae. Among them, capsidiol (3) and (1S,2E,4R,6R,7E,11E)-2,7,11-cembratriene-4,6-diol (5) showed weak mycelial inhibitory activity against P. nicotianae. Moreover, this activity of compound 5 was reported for the first time.