QUINOLINE ALKALOIDS FROM PSYCHOTRIA-GLOMERULATA

Three new quinoline alkaloids have been isolated from the aerial parts of Psychotria glomerulata from Panama. The major alkaloid, glomerulat ine A, was identified as 8-8a,8'-8'a tetradehydro(-)-calycanthine on t he basis of spectral data including H-1, C-13, COSY-45, HMBC, HMQC and ROESY techniques. Computerized H-1 NMR analysis was used to establish that glomerulatine A possessed the calycanthine- and not the iso-caly canthine-type structure. Two minor alkaloids, glomerulatines B and C, were also isolated and on the basis of spectroscopic evidence it is pr oposed that they are 8-8a,8'-8'a-tetrahydro-N'-demethyl(-)-calycanthin e and 8-8a-didehydro-(-)-calycanthine, respectively. Copyright (C) 199 7 Elsevier Science Ltd.