title: Whole-Cell Mediated 11β-Hydroxylation on the Basic Limonoid Skeleton by Cunninghamella echinulata.
abstract: Regio- and stereoselective 11β-hydroxylation was achieved on the basic limonoid skeleton through microbial transformation. Whole cells of Cunninghamella echinulata efficiently converted basic limonoids such as epoxyazadiradione, azadiradione, and gedunin to their 11β-hydroxy analogues as the sole metabolite. Fermentation conditions affecting the efficiency (96%) of biotransformation including substrate concentration, incubation period, pH, and temperature were optimized. The position and stereochemistry of hydroxyl functionality on the isolated metabolites were established through extensive spectroscopic and spectrometric studies (1D, 2D NMR, ESI-MS, and MS/MS).
authors.affiliation: †Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Saikat
authors.initials: S
authors.lastname: Haldar
authors.affiliation: †Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Fayaj A
authors.initials: FA
authors.lastname: Mulani
authors.affiliation: †Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune-411008, India.
authors.forename: Thiagarayaselvam
authors.initials: T
authors.lastname: Aarthy
authors.affiliation: †Chemical Biology Unit, Division of Organic Chemistry, CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune-411008, India.|§CSIR-Institute of Genomics and Integrative Biology, Mall Road, New Delhi-110007, India.
authors.forename: Hirekodathakallu V
authors.initials: HV
authors.lastname: Thulasiram
mesh_terms: D001711:Biotransformation; D020093:Cunninghamella / Q000737:chemistry* / Q000378:metabolism*; D005285:Fermentation; D006900:Hydroxylation; D036701:Limonins / Q000737:chemistry* / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
chemical_list: D036701:Limonins; C099260:epoxyazadiradione