Enantioselective oxidation of secondary alcohols by Candida parapsilosis ATCC 7330

Abstract

Optically pure allylic alcohols and 4-phenylbutan-2-ols were prepared by oxidative kinetic resolution using whole cells of Candida parapsilosis ATCC 7330. Only the ‘S’ enantiomer is selectively oxidized to the corresponding keto compound (yield, 37–46%) leaving the ‘R’ alcohol (yield, 37–52% and ee 46 to >99%). The biocatalytic method is carried out under mild conditions at 20 °C, pH 6.5 in phosphate buffer.

Direct observation of redox reactions in Candida parapsilosis ATCC 7330 by Confocal microscopic studies

“…Even though cells harvested at 14 h produced the same ketone at less conversion (38%), these cells were used to visualise the site of biotransformation. For several other substrates reported earlier from our lab, the 14 h harvested cells produced the desired optically pure products with maximum ee (up to >99%) 1 2 3 6 7 26 29 30 33 34 35 .…”

A fourier transform infrared spectroscopy (FTIR) based assay for Candida parapsilosis ATCC 7330 mediated oxidation of aryl alcohols

“…These are regularly analyzed by HPLC and/or GC (Kaliaperumal et al, 2011a;Sivakumari et al, 2014;Celik and Aktas, 2013). Our study on the FTIR based assay can be formulated to quantify these compounds quickly and conveniently.…”

“…GC temperature profile: 90 • C hold for 1 min, to 220 • C at the rate of 3 • C/min. Carbon tetrachloride was used as solvent for the experiment with the sample volume of 1 L. GC solution software was used to analyze the peak area of the compounds (Sivakumari et al, 2014).…”

“…More recently, this biocatalyst is being optimized for oxidation of secondary alcohols (Sivakumari et al, 2014) work, acetophenone and p-anisaldehyde are obtained by oxidation of 1-phenylethanol and p-methoxybenzylalcohol, respectively by C. parapsilosis ATCC 7330. An FTIR based assay was developed to monitor both the formation of the carbonyl group [keto or aldehyde; 1800-1650 cm −1 ] containing products and the depletion of hydroxyl group [alcohol; 3600-3300 cm −1 ] containing substrates.…”

Regio- and enantio-selective oxidation of diols by Candida parapsilosis ATCC 7330

“…21 Selective oxidation of secondary alcohols over primary alcohols for n-octane-1,2-diol, hexane-1,5-diol and 2,3-octanediol has also been reported using the alcohol dehydrogenase (ADH-'A') from Rhodococcus ruber DSM 44541 overexpressed in Escherichia coli, 22 and in 1,n-alkane diols (n ¼ 2-6) by R. ruber DSM 44541. 31 To address the selectivity in the oxidation between primary and sec alcohols, 1-phenyl-1,2-ethanediol was selected as a substrate for oxidation using the same biocatalyst in the current work. [24][25][26][27][28] Mechanistically, the deracemization using C. parapsilosis ATCC 7330 proceeds via stereo-inversion, i.e., enantioselective oxidation followed by reduction [a keto intermediate was observed using high-performance liquid chromatography (HPLC)].…”