Alstoscholarisine L, a novel caged monoterpenoid indole alkaloid with antifungal activity from Alstonia scholaris
Hao-Fei Yu1, Cai-Feng Ding2, Lan-Chun Zhang2
1Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education and Yunnan Province, School of Chemical Science and Technology, Yunnan University, Kunming 650091, PR China; State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, PR China; School of Pharmaceutical Sciences, Yunnan College of Modern Biomedical Industry, Department of Zoology & Yunnan Key Laboratory of Pharmacology for Natural Products, Kunming Medical University, Kunming 650500, PR China.
Abstract:
Alstoscholarisine L is an architecturally complex monoterpenoid indole alkaloid with a unique ring fusion pattern, isolated from the leaves of Alstonia scholaris. The 6/5/5/6/6/6-membered rings contain two lactonic rings and one aminal carbon and possess seven contiguous aligned stereocenters, three of which are quaternary. Its structure was elucidated by extensive spectroscopic data analyses, quantum chemical computations, and single-crystal X-ray diffraction. The unusual highly fused, cage-like skeleton is possibly derived from picrinine. The fascinating compound exhibited potential antifungal activity against Candida albicans, and its activity was roughly comparable to the first line antifungal drug fluconazole and significantly more effective than the plant-derived antibacterial drug berberine.
