Euphorbiaceae are known as a rich source of cyclic peptides from higher plants. One of cyclic peptides was isolated from the latex of Jatropha curcas, namely curcacycline A (C37H66N8O9) [1]. In the past different techniques have been applied to determine the structure of curcacycline A. In a new approach the structure of the isolated curcacycline A confirmed by more sophisticated bioanalytical techniques (HPLC-MS, 2D-NMR, COSY, APT, HSQC, IR). For the first time the structure was confirmed by a full synthetic approach and first biological assays have been carried out to shed light on the pharmacological activity of curcacycline A as representative of a rather unknown group of cylicpeptides. The analytical data indicate that curcacycline A consists of 8 amino acids, while ESI-MS data showed complete sequencing of amino acid c(Gly-Leu-Leu-Leu-Gly-Thr-Val-Leu-Leu-Gly). Screening of antibiotic activity of curcacycline A were done against several bacteria (Bacillus subtilis, Staphyloccus aureus, Eschericia coli, Pseudomonas aeruginosa) and fungi (Candida albicans) using the agar diffussion method. Curcacycline A inhibits the growth of B. subtillis and P. aeruginosa. Cytotoxic effect was tested to two cell lines, human ovarian cancer cell-line OVCAR-3 (ATCC®) and human colon cancer cell-line (Colo205). Curcacycline A decreased the level of OVCAR 3at a concentration of 1mg/mL, while no effect was found on Colo205 (ATCC®). Curcacycline A had no mutagenic activity in the non-activated and activated AMES test.
References: 1. van den Berg, A. J., S. F. Horsten, et al. (1995). FEBS Lett 358(3): 215–8.
