Chapter 13 Biomimetic synthesis of natural products isolated from Bignoniaceae

摘要: Publisher Summary Pinnatal and isopinnatal were isolated from tropical trees that belong to the plant family of Bignoniaceae. was found in a root bark extract Kigelia pinnata. Ethnobotanic investigation into pinnata led isolation isopinnatal, kigelinol, isokigelinol. Isopinnatal kigelinols have been evaluated for their cytotoxicity antiprotozoal, antimalarial activity. Structurally, these related natural products share modified hydroxy-naphthoquinone core fused variety carbo- heterocycles. Pinnatal, sterekunthal B bear complex caged heterotricyclic system, while pyranokunthones A display relatively simple mono- or bicyclic pyrans. The remaining members feature carbocycles naphthoquinone core. an unusual cross-conjugated π-system. cycloreversion pinnatal leads chromene, which when opened sense 6π-electrocyclization gives alkylidene trione. In turn, trione would arise aldol condensation aldehyde 1,2,4-trione.