Abstract
The structures of ebelactone A and B, esterase inhibitors produced by Streptomyces sp. MG7-G1 strain, have been determined to be 3, 11-dihydroxy-2, 4, 6, 8, 10, 12-hexamethyl-9-oxo-6-tetradecenoic 1, 3-lactone and 2-ethyl-3, 11-dihydroxy-4, 6, 8, 10, 12-pentamethyl-9-oxo-6-tetradecenoic 1, 3-lactone, respectively, by their spectral analyses.