Abstract
Two novel cyclic depsipeptides were isolated from axenic cultures of the terrestrial cyanobacterium Scytonema hofmanni PCC 7110 and designated scyptolin A and B. Amino acid analyses in context with mass and 1H/ 13C NMR spectroscopies revealed a composition typical for heterologous cyanopeptolins but containing the uncommon residue 3′-chloro- N-methyl-Tyr (cmTyr) and a unique sidechain. Scyptolin A and B both consist of the N-acylated peptide But 1-Ala 2-Thr 3-Thr 4-Leu 5-Ahp 6 (3-amino-6-hydroxy-2-oxo-1-piperidine)-Thr 7-cmTyr 8-Val 9, which forms a 19-membered ring by esterification of the carboxyl of Val 9 with the hydroxyl of Thr 4. In scyptolin B, the hydroxyl of the Thr 3 residue is additionally esterified with N-butyroyl-Ala. Both scyptolin A and B exhibit selective inhibition of porcine pancreatic elastase in vitro with IC 50 values of 3.1 μg/ml.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
