MASS-SPECTROMETRY AND STRUCTURE ELUCIDATION OF 15-PALMITOYLSOLAMIN AND 15-OLEYLSOLAMIN, THE FIRST KNOWN FATTY-ACID ESTERS OF ACETOGENINS FROM ANNONA-MURICATA L

Separation of the less polar fractions of a methanol extract of Annona muricata L, seeds (Annonaceae) led to the purification of two new met abolites 1 and 2 in admixture, The identification of the main structur al features of the isolated compounds was obtained from the NMR data w hereas the characterization and localization of the different groups o n the acetogenin alkyl chain was achieved by using mass spectrometry, Various methods including positive and negative electrospray ionizatio n, liquid-secondary ion mass spectrometry and tandem mass spectrometry were necessary for identifying 1 and 2 as 15-palmitoylsolamin and 15- oleylsolamin, respectively. (C) 1998 John Wiley & Sons, Ltd.