Assignment of ¹³C-NMR Spectra of Grayanotoxin-I and -III

Abstract

As the first step towards the biosynthetic studies on grayanotoxins with the aid of ¹³C isotope, the ¹³C-NMR spectra of grayanotoxin-I and III were assigned. Unambiguous assignments were achieved except for the C-9 and C-I 3 resonances in G-I by selective proton decoupling technique as well as by comparison with chemical shift values of the related com-pounds.