Lakshminine, a New Rare Oxoisoaporphine Alkaloid from Sciadotenia toxifera, and Structural Revisions of Telazoline and Teladiazoline, Two Related Oxoaporphines from Telitoxicum peruvianum and T. glaziovii

Lakshminine (1), a novel oxoisoaporphine alkaloid possessing a C-6 amine substituent, was isolated from a basic fraction from the woody vines (collected from two bush-ropes) of Sciadotenia toxifera. This compound represents the first documented occurrence of an oxoisoaporphine from any Menispermaceae species other than Menispermum dauricum. The structures of two related aporphine alkaloids, telazoline (3) and teladiazoline (5), were revised on the basis of a comparison of their spectral data with that of lakshminine (1).