Biotransformation of a crizotinib intermediate using a mutant alcohol dehydrogenase of Lactobacillus kefir coupled with glucose dehydrogenase

Biocatalytic characterization of an alcohol dehydrogenase variant deduced from Lactobacillus kefir in asymmetric hydrogen transfer

Hydrogen transfer biocatalysts to prepare optically pure alcohols are in need, especially when it comes to sterically demanding ketones, whereof the bioreduced products are either essential precursors of pharmaceutically relevant compounds or constitute APIs themselves. In this study, we report on the biocatalytic potential of an anti-Prelog (R)-specific Lactobacillus kefir ADH variant (Lk-ADH-E145F-F147L-Y190C, named Lk-ADH Prince) employed as E. coli/ADH whole-cell biocatalyst and its characterization for stereoselective reduction of prochiral carbonyl substrates. Key enzymatic reaction parameters, including the reaction medium, evaluation of cofactor-dependency, organic co-solvent tolerance, and substrate loading, were determined employing the drug pentoxifylline as a model prochiral ketone. Furthermore, to tap the substrate scope of Lk-ADH Prince in hydrogen transfer reactions, a broad range of 34 carbonylic derivatives was screened. Our data demonstrate that E. coli/Lk-ADH Prince exhibits activity toward a variety of structurally different ketones, furnishing optically active alcohol products at the high conversion of 65-99.9% and in moderate-to-high isolated yields (38-91%) with excellent anti-Prelog (R)-stereoselectivity (up to >99% ee) at substrate concentrations up to 100 mM.

Efficacy of Crizotinib Combined with Chemotherapy in Treating Advanced Non-Small-Cell Lung Cancer and Effect on Patients’ Quality of Life and Adverse Reaction Rate

Purpose. To explore the efficacy of crizotinib combined with chemotherapy in treating advanced non-small-cell lung cancer (NSCLC) and its effect on patients’ quality of life (QOL) and adverse reaction rate (ARR). Methods. 90 advanced NSCLC patients admitted to our hospital (from 01, 2019 to 01, 2020) were chosen as the research objects and randomly split into the control group (CG) and experimental group (EG) by flipping a coin, with 45 cases each. Chemotherapy was performed to CG, and the crizotinib treatment was introduced to EG on this basis, so as to compare their clinical efficacy, ARR and 3-year survival rate, and QOL before and after intervention by the Generic Quality of Life Inventory-74 (GQOLI-74). Results. Compared with CG, EG after treatment obtained obviously higher total clinical effective rate ( $P$  < 0.001), lower total ARR ( $P$  < 0.05), higher GQOLI-74 scores ( $P$  < 0.001), and higher 3-year survival rate ( $P$  < 0.05). Conclusion. Combining crizotinib with chemotherapy to advanced NSCLC patients can effectively improve the patients’ level of quality of life, prolong the long-term survival rate, and present a better effect than single chemotherapy. Further study is conducive to establishing a better treatment scheme for advanced NSCLC patients.

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

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, post-traumatic 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.

Application of Ketoreductase in Asymmetric Synthesis of Pharmaceuticals and Bioactive Molecules: An Update (2018-2020)

With the rapid development of genomic DNA sequencing, recombinant DNA expression, and protein engineering, biocatalysis has been increasingly and widely adopted in the synthesis of pharmaceuticals, bioactive molecules, fine chemicals, and agrochemicals. In this review, we have summarized the most recent advances achieved (2018-2020) in the research area of ketoreductase (KRED)-catalyzed asymmetric synthesis of chiral secondary alcohol intermediates to pharmaceuticals and bioactive molecules. In the first part, synthesis of chiral alcohols with one stereocenter through the bioreduction of four different ketone classes, namely acyclic aliphatic ketones, benzyl or phenylethyl ketones, cyclic aliphatic ketones, and aryl ketones, is discussed. In the second part, KRED-catalyzed dynamic reductive kinetic resolution and reductive desymmetrization are presented for the synthesis of chiral alcohols with two contiguous stereocenters.

Production of high sensory quality Shiitake mushroom (Lentinus edodes) by pulsed air-impingement jet drying (AID) technique

The effect of pulsed air-impingement jet drying (AID) on the sensory qualities of Shiitake mushroom was comprehensively examined compared with hot air drying (HAD) and vacuum freeze-drying (VFD). AID considerably improved the characteristic flavors (onion-like odor and umami) of dried mushrooms by partially inhibiting enzymatic and Maillard reactions. The texture characteristics (rehydration and shrinkage) of AID mushrooms had no significant difference to VFD ones and were better than HAD ones. AID combined the advantages of HAD and VFD technologies and outperformed HAD and VFD in terms of overall quality, though the total content of free amino acids and soluble sugars of AID mushrooms dropped slightly. In summary, AID is a promising drying technology for obtaining high sensory quality Shiitake mushrooms compared to prevailing drying methods.

Impact and relevance of alcohol dehydrogenase enantioselectivities on biotechnological applications

Alcohol dehydrogenases (ADHs) catalyze the reversible reduction of a carbonyl group to its corresponding alcohol. ADHs are widely employed for organic synthesis due to their lack of harm to the environment, broad substrate acceptance, and high enantioselectivity. This review focuses on the impact and relevance of ADH enantioselectivities on their biotechnological application. Stereoselective ADHs are beneficial to reduce challenging ketones such as ketones owning two bulky substituents or similar-sized substituents to the carbonyl carbon. Meanwhile, in cascade reactions, non-stereoselective ADHs can be utilized for the quantitative oxidation of racemic alcohol to ketone and dynamic kinetic resolution.