© Associated Asia Research Foundation (AARF) A Monthly Double-Blind Peer Reviewed Refereed Open Access International e-Journal - Included in the International Serial Directories. Page | 98 METABOLITES GENERATION VIA OXIDATION, HYDROXYLATION, ACYLATION, DECHLORINATION, DEALKYLATION & GLUCURONIDATION OF LOSARTAN BY THERMOPHILIC FUNGUS RHIZOMUCOR PUSILLUS NRRL 28626 G. Shyam Prasad Department of Microbiology, Vaagdevi Degree and PG College, Hanamkonda, Warangal-506001 Telangana State, India K. Srisailam University College of Pharmaceutical Sciences, Satavahana University Karimnagar -505002, Telangana State, India ABSTRACT Biotransformation potential of a thermophilic fungal strain Rhizomucor pusillus NRRL 28626 was investigated using anti-hypertension drug losartan as a model drug in order to find the metabolic similarities of this fungus with that of mammals. Five metabolites viz. M1, M2, M3, M4, and M5 were detected at pH 6.0 and temp of 45ºC during four days incubation. The metabolites were detected by high-performance liquid chromatography (HPLC) and the structures were elucidated by liquid chromatography- tandem mass spectrometry (LC-MS/MS) analysis as glucuronic acid compound (M1), 3-hydroxy-N-acetyl losartan (M2), N-acetylated carboxylic acid metabolite of losartan (M4), and two novel metabolites M3 and M5. The metabolites of losartan produced were by glucuronidation, hydroxylation, acylation, dealkylation, dechlorination, and oxidation which clearly reveals that R.pusillus exhibits wide reaction diversity. The metabolites of losartan produced by this fungus are similar to those International Research Journal of Natural and Applied Sciences ISSN: (2349-4077) Impact Factor- 5.46, Volume 5, Issue 2, February 2018 Website- www.aarf.asia , Email : editor@aarf.asia , editoraarf@gmail.com