(E)-(1S,4S,10S,21R)-7-[(Z)-Ethylidene]-4,21-diisopropyl-2- oxa-12,13-dithia-5,8,20,23-tetraazabicyclo[8.7.6]tricos-16-ene-3,6,9,19,22-pentone 128517-07-7 Antibiotic FR 901228 Depsipeptide L-Valine, N-(3-hydroxy-7-mercapto-1-oxo-4-heptenyl)valyl- cysteinyl-2,3-didehydro-2-aminobutanoyl-,.xi.-lactone, cyclic (1.fwdarw.2)-disulfide NSC630176 OXA-12,13-DITHIA-5,8,20,23-TETRAZABICYCLO[8.7.6]TRICOSANE, CYCLIC PEPTIDE DERIV.