Efficient asymmetric synthesis of ethyl (R)-3-hydroxybutyrate by recombinant Escherichia coli cells under high substrate loading using eco-friendly ionic liquids as cosolvent.

Ionic liquids (ILs) which synthesized from bio-renewable materials have recently attracted much attention for their applications in biocatalysis. Ethyl (R)-3-hydroxybutyrate ((R)-EHB) as a versatile chiral intermediate is of great interest in pharmaceutical synthesis. This study focuses on evaluating the performances of choline chloride (ChCl)-based and tetramethylammonium (TMA)-based neoteric ILs in the efficient synthesis of (R)-EHB via the bioreduction of ethyl acetoacetate (EAA) at high substrate loading by recombinant Escherichia coli cells. It was found that choline chloride/glutathione (ChCl/GSH, molar ratio 1:1) and tetramethylammonium/cysteine ([TMA][Cys], molar ratio 1:1) as eco-friendly ILs not only enhanced the solubility of water-insoluble EAA in the aqueous buffer system, but also appropriately improved the membrane permeability of recombinant E. coli cells, thus boosting catalytic reduction efficiency of EAA to (R)-EHB. In the developed ChCl/GSH- or [TMA][Cys]-buffer systems, the space-time yields of (R)-EHB achieved 754.9 g/L/d and 726.3 g/L/d, respectively, which are much higher than neat aqueous buffer system (537.2 g/L/d space-time yield). Meanwhile, positive results have also been demonstrated in the bioreduction of other prochiral ketones in the established IL-buffer systems. This work exhibits an efficient bioprocess for (R)-EHB synthesis under 325 g/L (2.5 M) substrate loading, and provides promising ChCl/GSH- and [TMA][Cys]-buffer systems employed in the biocatalysis for hydrophobic substrate.

Study on the Predictive Value of P53 Protein Expression in Brain Metastasis in NSCLC and the Mechanism of miR-424 Reversing Platinum Resistance in NSCLC.

In order to analyze the predictive value of P53 protein expression in brain metastases in NSCLC and the mechanism of miR-424 reversing platinum resistance in NSCLC, a retrospective analysis is conducted in this study. Eighty-two NSCLC patients who received relevant diagnosis and treatment in our hospital from September 2020 to September 2021 are chosen. The prognosis of the patients is observed, and the patients were divided into two groups according to the occurrence of BMS. The comparison of clinical baseline data and the expression of P53 protein and miR-424 after surgery are performed. Furthermore, the predictive value of the P53 protein gene on the occurrence of BMS in NSCLC is analyzed by the ROC curve, and the expression of miR-424 in serum of the patients before and after drug resistance is compared. The results demonstrate that the expression of P53 protein has a high predictive value for predicting the occurrence of BRAIN metastases in NSCLC patients. Also, the high expression of miR-424 suggests that it is closely related to the occurrence of platinum resistance in NSCLC patients.

[Non-alkaloid constituents of Hymenocallis littoralis].

Perennial herb Hymenocallis littoralis(Amaryllidaceae) boasts anti-tumor, anti-virus, and anti-inflammatory activities. As the representative constituents, alkaloids have attracted much attention, whereas the non-alkaloid constituents have been rarely reported. Therefore, this study investigated the non-alkaloid constituents of H. littoralis and their contribution to the various pharmacological activities of the herb. Thirteen non-alkaloid compounds were isolated from the 95% ethanol extract of dried whole plant of H. littoralis after a series of chromatographic separation steps and spectral analysis, and they were identified as 5,7-dihydroxy-6,8-dimethoxy-2-hydroxymethyl-4H-chromoen-4-one(1), undulatoside A(2),(2S)-7,4'-dihydroxyflavane(3), naringenin(4), 4',7-hydroxy-8-methylflavanone(5), 8-methylnaringenin(6), 8-demethylfarrerol(7), 6-methyl-aromadendrin(8), 4',5,7-trihydroxy-8-methylflavanone(9), syzalterin(10), 6-methylapigenin(11), isoliquiritigenin(12), and undatuside C(13) based on the spectroscopic data analysis. Among them, compound 1 was a new chromone derivative, and compounds 2 and 4-13 were isolated form this plant for the first time.

[Effects of di-(2-ethylhexyl) phthalate exposure on reproductive development and PPARs in prepubertal female rats].

OBJECTIVE: To investigate the effects of di-(2-ethylhexyl) phthalate (DEHP) exposure on pubertal development and reproductive endocrine function in prepubertal female rats and its possible mechanisms. METHODS: 40 female SD rats at 3-week-old were randomly divided into a control group (corn oil) and three exposure groups, which were exposed consecutively for 28 days to DEHP by oral gavage at doses of 50, 150 and 500 mg/(kg x d). The onset of puberty was determined by daily examination for vaginal opening (OV), breast development and the first estrous cycle. By the end of the experiment, the rats were sacrificed during the diestrous stage. The gene expression interrelated with ovary function was detected by real-time PCR. Serum levels of follicle stimulating hormone (FSH) luteinizing hormone (LH), estradiol (E2), progesterone (P4) and testosterone (T) were measured by ELISA. The morphological change of ovaries was observed by HE staining under optical microscope. The expression of PPARgamma protein in ovary cells was measured by immuohistochemistry. RESULTS: The age of vaginal opening was advanced by DEHP exposure in 500 mg/kg group, and the body weight was increased at the time of vaginal opening in 150 and 500 mg/kg groups (P < 0.05). Compared to the control group, the level of T in all DEHP groups was decreased; the levels of FSH and E2 were decreased and the level of P4 was increased in 150 and 500 mg/kg groups (P < 0.05). The gene expression of P4S0Aromin 150 and 500 mg/kg groups was significantly decreased compared to the control group. A significant increase of atretic follicles and a significant reduction of corpora lutea were observed in 150 and 500 mg/kg groups compared to the control group. The expression of PPARgamma protein in granulosa cells of follicle and corpora lutea in 150 and 500 mg/kg groups was higher than that in the control group and 50 mg/kg group (P < 0.05). CONCLUSION: DEHP exposure can affect the pubertal development and reproductive endocrine function in prepubertal female rats, and its possible mechanism may be correlated with PPARgamma.

Bisphenol A may cause testosterone reduction by adversely affecting both testis and pituitary systems similar to estradiol.

Bisphenol A (BPA) causes reproductive toxicities, but the mechanisms are still unclear. In the present study, we sought to clarify these mechanisms in comparison with those of 17beta-estradiol (E2). Prepubertal Wistar/ST male rats (4 weeks old) were subcutaneously administered BPA (0, 20, 100 and 200 mg/kg/day) or E2 (10 and 100 microg/kg/day) for 6 weeks. Both BPA and E2 treatments decreased plasma and testicular testosterone levels, and plasma luteinizing hormone (LH), but not E2 and follicle-stimulating hormone levels, though E2 treatment increased its plasma level. In relation to the decreased testosterone levels, BPA and E2 decreased expressions of steroidogenic enzymes and cholesterol carrier protein in Leydig cells. Thus, decreased testosterone levels in plasma might have resulted from decreased expressions of these enzymes and protein as well as from decreased plasma LH levels. Interestingly, the changes in steroidogenic enzymes and carrier protein were observed at lower levels of exposure to BPA or E2 than those inhibiting plasma LH levels. Microscopically, 200 mg/kg BPA and 100 microg/kg E2 significantly decreased Leydig cell numbers in the testis. In addition, BPA and E2 also decreased expression of estrogen receptor alpha-mRNA, which might be related to the decreased numbers of Leydig cells. Thus, BPA directly affects not only the Leydig cells but also the pituitary gland, but the former may be impaired at lower exposure concentrations than the latter.

Roles of oxidative stress and Akt signaling in doxorubicin cardiotoxicity.

Cardiotoxicity is a treatment-limiting side effect of the anticancer drug doxorubicin (DOX). We have now investigated the roles of oxidative stress and signaling by the protein kinase Akt in DOX-induced cardiotoxicity as well as the effects on such toxicity both of fenofibrate, an agonist of peroxisome proliferator-activated receptor-alpha, and of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD), an antioxidant. Mice injected intraperitoneally with DOX were treated for 4 days with fenofibrate or PEG-SOD. Fenofibrate and PEG-SOD each prevented the induction of cardiac dysfunction by DOX. Both drugs also inhibited the activation of the transcription factor NF-kappaB and increase in lipid peroxidation in the left ventricle induced by DOX, whereas only PEG-SOD inhibited the DOX-induced activation of Akt and Akt-regulated gene expression. These results suggest that fenofibrate and PEG-SOD prevented cardiac dysfunction induced by DOX through normalization of oxidative stress and redox-regulated NF-kappaB signaling.

Genotoxic damage in female residents exposed to environmental air pollution in Shenyang city, China.

Air pollution has been suggested to cause genetic damage from investigations of many biological markers that measure cytogenetic damage in humans. Here, we evaluated the genotoxic effects of ambient air pollution by investigating the extent of cytogenetic damage in human blood lymphocytes from rural and industrial female residents of Shenyang city, China, using micronuclei assays and polymorphic analyses of metabolic enzyme and DNA repair genes. After adjustment for potential confounding factors including DNA polymorphisms, industrial female residents were found to have a higher micronuclei frequency. These results provide evidence that micronuclei assays are a sensitive indicator to air pollution-induced genotoxic effects in humans.