CURCACYCLINE-A - A NOVEL CYCLIC OCTAPEPTIDE ISOLATED FROM THE LATEX OF JATROPHA-CURCAS L

From the latex of Jatropha curcas L. (Euphorbiaceae) a novel cyclic oc tapeptide was isolated, which we named curcacycline A. The compound wa s found to contain one threonine, one valine, two glycine, and four le ucine residues. By two-dimensional H-1-NMR spectroscopy (HOHAHA and RO ESY), its sequence was determined to be -Leu(3)-Gly(4)-Thr(5)-Val(6)-L eu(7)-Leu(8)-Gly(1). Curcacycline A displays a moderate inhibition of (i) classical pathway activity of human complement and (ii) proliferat ion of human T-cells.