Biocatalytic asymmetric synthesis of (R)‐1‐tetralol using Lactobacillus paracasei BD101

Abstract

Asymmetric bioreduction of ketones is a fundamental process in the production of organic molecules. Compounds containing tetralone rings are found in the structure of many biologically active and pharmaceutical molecules. Biocatalytic reduction of ketones is one of the most promising and significant routes to prepare optically active alcohols. In this study, the reductive capacity of Lactobacillus paracasei BD101 was investigated as whole-cell biocatalyst in the enantioselective reduction of 1-tetralone (1). In biocatalytic reduction reactions, the conversion of the substrate and the enantiomeric excess (ee) of the product are significantly affected by optimization parameters such as temperature, agitation rate, pH, and incubation time. Effects of these parameters on ee and conversion were investigated comprehensively. (R)-1-tetralol ((R)-2), which can be used to treat disorder such as obsessive compulsive, posttraumatic stress, premenstrual dysphoric, and social anxiety, was manufactured in enantiopure form, high yield and gram-scale, using whole-cell biocatalysts of L. paracasei BD101. The 7.04 g of (R)-2 was obtained in optically pure form with 95% yield. Also, to our knowledge, this is the first report on production of (R)-2 using whole-cell biocatalyst in excellent yield, conversion, enantiopure form and gram scale. This is a clean, eco-friendly and cheap method for the synthesis of (R)-2 compared with chemical catalyst.

Enzymatic Synthesis of Indole‐Based Imidazopyridine using α‐Amylase

“…Also, further increment in the quantity of catalyst did not result in any enhancement in the yield of the reaction (entries 4–6, Table 4). [14g–h] Following the optimization of catalyst loading, a series of control tests were conducted to investigate the specific function of the immobilized catalyst (Table 5). Initially, the reaction was evaluated in the absence of a catalyst providing only a trace amount of product (entry 1, Table 5).…”

Microbial alcohol dehydrogenases: recent developments and applications in asymmetric synthesis

“…In addition, another cyclic ketone, 1-tetralone, was also efficiently reduced by L. paracasei BD101, using 50 mmol substrate, to ( R )-1-tetralol ( 9 ) with 99% ee and 95% yield. 44 The same biocatalyst was also known for the asymmetric bioreduction of a variety of bulky ketones, namely, phenyl(pyridin-2-yl)methanone, 45 cyclohexyl(phenyl)methanone, 46 2-methyl-1-phenylpropan-1-one 47 and 1-(furan-2-yl)ethanone, 48 to produce their corresponding chiral alcohols ( S )-phenyl(pyridin-2-yl)methanol ( 10 ), ( S )-cyclohexyl(phenyl)methanol ( 11 ), ( R )-2-methyl-1-phenylpropan-1-ol ( 12 ) and ( R )-1-(furan-2-yl)ethanol ( 13 ) respectively with good bioconversion and ee (Fig. 2).…”

A porphyrin-based molecular cage guided by designed local-electric field is highly selective and efficient

“…Thus, (R)-1-tetralol is extensively used to treat several disorders such as obsessivecompulsive disorder, post-traumatic stress, premenstrual dysphoric disorder, and social anxiety. [43][44][45] Can the chosen cage produce (R)-1-tetralol? Can it produce, on demands, also (S)-1tetralol?…”