Theoretical Analysis of Selectivity Differences in Ketoreductases toward Aldehyde and Ketone Carbonyl Groups.

Lactobacillus kefir alcohol dehydrogenase (LkADH) and ketoreductase from Chryseobacterium sp. CA49 (ChKRED12) exhibit different chemoselectivity and stereoselectivity toward a substrate with both keto and aldehyde carbonyl groups. LkADH selectively reduces the keto carbonyl group while retaining the aldehyde carbonyl group, producing optically pure R-alcohols. In contrast, ChKRED12 selectively reduces the aldehyde group and exhibits low reactivity toward ketone carbonyls. This study investigated the structural basis for these differences and the role of specific residues in the active site. Molecular dynamics (MD) simulations and quantum chemical calculations were used to investigate the interactions between the substrate and the enzymes and the essential cause of this phenomenon. The present study has revealed that LkADH and ChKRED12 exhibit significant differences in the structure of their respective active pockets, which is a crucial determinant of their distinct chemoselectivity toward the same substrate. Moreover, residues N89, N113, and E144 within LkADH as well as Q151 and D190 within ChKRED12 have been identified as key contributors to substrate stabilization within the active pocket through electrostatic interactions and van der Waals forces, followed by hydride transfer utilizing the coenzyme NADPH. Furthermore, the enantioselectivity mechanism of LkADH has been elucidated using quantum chemical methods. Overall, these findings not only provide fundamental insights into the underlying reasons for the observed differences in selectivity but also offer a detailed mechanistic understanding of the catalytic reaction.

Optimization of green deep eutectic solvent (DES) extraction of Chenopodium quinoa Willd. husks saponins by response surface methodology and their antioxidant activities.

Quinoa saponins have outstanding activity, and there are an increasing number of extraction methods, but there are few research programs on green preparation technology. The extraction conditions of quinoa saponins with deep eutectic solvents (DESs) were optimized by single-factor experiments combined with response surface methodology. The antioxidant capacity of saponins extracted by DESs and traditional methods was evaluated by the DPPH clearance rate, iron ion chelation rate and potassium ferricyanide reducing power. The results show that the optimal DES is choline chloride: 1,2-propylene glycol (1 : 1), and its water content is 40%. The optimal extraction conditions were as follows: the solid-to-solvent ratio was 0.05 g mL-1, the extraction time was 89 min, and the extraction temperature was 75 °C. Under these conditions, the extraction of quinoa saponins by DES was more effective than the traditional extraction methods. The saponins extracted by DES and traditional methods were analyzed by UPLC-MS, and five main saponins were identified. Quantitative analysis by HPLC-UV showed that Q1 (m/z = 971) and Q2 (m/z = 809) had higher contents of saponins. In vitro antioxidant experiments showed that all DES saponin extracts showed good antioxidant capacity. This study provides new insight into the development and utilization of quinoa saponins.

Therapeutic effect of Jinghuosu on oligospermia and asthenospermia / 中华男科学杂志

Objective@#To investigate the effects of the compound preparation Jinghuosu on oligospermia and asthenospermia.@*METHODS@#This multi-centered clinical study included 120 cases of mild to moderate idiopathic oligospermia or asthenospermia, all treated with oral Jinghuosu once a bag, bid, for 3 successive months. Before and at 1, 2 and 3 months after treatment, we detected sperm concentration, total sperm motility, progressive sperm motility and normal sperm morphology of each ejaculate, and recorded whether the patients had any adverse reactions.@*RESULTS@#After 3 months of treatment, all the patients showed obvious improvement in semen parameters, most significantly in sperm concentration, total sperm motility, and the percentages of progressive motile sperm and morphologically normal sperm (P <0.05). No significant adverse reactions were observed during the 3 months of medication.@*CONCLUSIONS@#Jinghuosu has a significant efficacy and no obvious adverse effect in the treatment of mild to moderate oligospermia and asthenospermia.

Clinical correlation analysis of placenta growth factor expression in human seminal plasma and oligoasthenospermia / 第二军医大学学报

Objective To explore the correlation between placental growth factor (P1GF) expression and sperm quality in seminal plasma, and to evaluate its clinical significance in patients with oligoasthenospermia and azoospermia. Methods A total of 88 patients undergoing seminal fluid detection were enrolled from the Department of Reproductive Medicine Center of Changhai Hospital of Second Military Medical University fromSep. 2014 to Nov. 2014. The patients were divided into three groups according to the test results: ten cases with normal semen (normal group), 68 cases with oligoasthenospermia (oligoasthenospermia group), and ten cases with azoospermia (azoospermia group). Semen samples from five patients with normal semen and 5 patients with oligoasthenospermiawere collected and assayed for cytokine-related proteinmicroarray. The contents of P1GF in seminal plasma were detected by ELISA. The correlations between P1GF concentration and the sperm concentration and activity in seminal plasma and the age of patients were analyzed by Pearson correlation analysis. Results The contents of P1GF in seminal plasma in the normal group were significantly higher than that in the oligoasthenospermia and azoospermia groups (P<0. 05). The level of P1GF in seminal plasma was related to the concentration and activity of sperm (r=0.362, 0.253; P<0.05), but not to the age of patients. Conclusion The levll of P1GF in seminal plasma is correlated with the sperm concentration, providing reference for diagnosis and treatment of oligoasthenospermia and azoospermia in clinic.