A sulphur-containing indole alkaloid, glypetelotine, has been isolated fi om the leaves of the endemic Vietnamese plant Glycosmis petelotii Guill. (Rutaceae). The structure of glypetelotine was determined to be S-methyl N,N-2-[(1H)-indol-3-ethyl]methyl thiocarbamate from the spectroscopic evidence including UV, IR, MS,H-1- and C-13-NMR, NOESY, HETCOR and DQF-H-1-H-1 COSY. Conformational isomerism of the compound, resulting from the tertiary amide-like unit, was studied by dynamic H-1-NMR spectroscopy carried out in different solvents and at different temperatures. (C) 1999 Elsevier Science Ltd. All rights reserved.