CYCLOGOSSINE-A - A NOVEL CYCLIC HEPTAPEPTIDE ISOLATED FROM THE LATEX OF JATROPHA-GOSSYPIFOLIA

From the latex of Jatropha gossypifolia L. (Euphorbiaceae) a novel cyc lic heptapeptide was isolated, which we named cyclogossine A. A combin ation of amino acid analysis, FAB mass spectrometry, and two dimension al H-1-NMR spectroscopy (TOCSY and ROESY) was used to determine the pr imary structure. The com pound was found to contain one glycine, one a lanine, one valine, two leucine, one threonine, and one tryptophan res idue; its amino acid sequence is: Leu 1 - Ala 2 - Thr 3 - Trp 4 - Leu 5 - Gly 6 - Val 7. The absolute configurations of the amino acids were determined by chiral gas chromatography; all have the L-configuration .