Xenobiotica; the fate of foreign compounds in biological systems

Isolation and identification of phase I metabolites of butyrolactone I in rats.

PMID 27604497


1. Butyrolactone I (BL-I), one of the major secondary metabolites of fungus Aspergillus terreus, is a selective cdc2 kinase inhibitor. In the present study, the metabolism of BL-I in male Wistar rats was investigated by characterizing metabolites excreted into feces. 2. Following an oral dose of 40 mg/kg BL-I, 10 phase I metabolites were isolated from the feces of rats, and their structures were identified on the basis of a range of spectroscopic data and ICD analysis. These metabolites were fully characterized as butyrolactone VI (M1), aspernolide E (M2), 7''S-hydroxy-9''-ene-butyrolactone I (M3), 7''R-hydroxy-9''-ene-butyrolactone I (M4), 7″S, 8″R-dihydroxy-aspernolide E (M5), 7″R, 8″S-dihydroxy-aspernolide E (M6), 7″R-acetyl-8″S-hydroxy-aspernolide E (M7), 7″S-acetyl-8″R-hydroxy-aspernolide E (M8), 7″R-methoxy-8″S-hydroxy-aspernolide E (M9), butyrolactone V (M10), respectively. It is the first time to describe the metabolites of BL-I in vivo, and metabolites M3 to M9 are new compounds. 3. BL-I and metabolites M2 to M10 were evaluated for their antimicrobial activity and in vitro antiproliferative activities. Only M-3 and M-4 showed inhibitory effect against staphylococcus aureus both with MIC of 125 μg/ml. BL-I and metabolites M-4 and M-5 exhibited potent cancer cell growth inhibitory activities against HL-60 (human leukemia) cell lines with the IC