New azoles with antifungal activity: Design, synthesis, and molecular docking

In order to search for many target compounds with excellent activities, a series of 1-(1H-1,2,4-triazol-1-yl)-2-(2,4-difluoro-phenyl)-3-[(4-substituted phenyl)-piperazin-1-yl]-propan-2-ols were designed, synthesized, and evaluated as antifungal agents. Results of preliminary antifungal tests against eight human pathogenic fungi in vitro showed that all the title compounds exhibited excellent activities with broad spectrum. Moreover, a molecular model for the binding between 5a and the active site of CACYP51 was provided based on the computational docking results.     

Molecular dynamic modeling of CYP51B in complex with azole inhibitors

Cytochrome P450 14α-sterol demethylase (CYP51), the key enzyme in sterol biosynthesis pathway, is an important target protein of cholesterol-lowering agents, antifungal drugs, and herbicides. CYP51B enzyme is one of the CYP51 family members. In the present study, we have chosen four representative inhibitors of CYP51B: diniconazole (Din), fluconazole (Flu), tebuconazole (Teb), and voriconazole (Vor), and launched to investigate the binding features of CYP51B-inhibitor and gating characteristics via molecular docking and molecular dynamics (MD) simulations. The results show that the ranking of binding affinities among these inhibitors is Din > Teb > Vor > Flu. Din shows the strongest binding affinity, whereas Flu shows the weakest binding affinity. More importantly, based on the calculated binding free energy results, we hypothesize that the nonpolar interactions are the most important contributors, and three key residues (Thr77, Ala258, and Lys454) play crucial role in protein-inhibitor binding. Besides, residue Phe180 may play a molecular switch role in the process of the CYP51B-Teb and CYP51B-Vor binding. Additionally, Tunnel analysis results show that the major tunnel of Din, Flu, and Teb is located between helix K, FG loop, and β4 hairpin (Tunnel II).The top ranked possible tunnel (Tunnel II) corresponds to Vor exits through helix K, F and helix J. This study further revealed the CYP51B relevant structural characteristics at the atomic level as well as provided a basis for rational design of new and more efficacious antifungal agents.     

Cloning, sequencing, and characterization of CYP1A1 cDNA from leaping mullet (Liza Saliens) liver and implications for the potential functions of its conserved amino acids

A 2,037 bp CYP1A1 cDNA (GenBank AF072899) was cloned through screening of a lambdaZipLox cDNA library constructed from the liver of a leaping mullet (Liza saliens) fish captured from Izmir Bay on the Aegean coast of Turkey using rainbow trout CYP1A1 cDNA as a probe. This clone has a 130 bp 5'-flanking region, a 1,563 bp open reading frame (ORF) encoding a 521-amino acid protein (58,972 Da), and a 344 bp 3'-untranslated region without a poly (A) tail. Alignment of the deduced amino acids of CYP1A1 cDNAs showed 58% and 69-96% identities with human and 12 other fish species, respectively. Southern blot analysis suggested that this CYP1A1 cDNA was from a single-copy gene. Based on the comparison with CYP1A1 genes reported for fish and mammals, the leaping mullet CYP1A1 gene is probably split into 7 exons. The intron insertion sites were predicted. Alignment of the CYP1A1 cDNA encoded amino acids from 13 fish and 7 mammalian species disclosed differences in highly conserved amino acids between aquatic and land vertebrates. The possible associated secondary structure; conserved motifs and substrate-binding sites were discussed. The phylogenetic relationships of CYP1A1s among 13 fish species were analyzed by a distance method.     

椰心叶甲CYP4基因的克隆及绿僵菌侵染后的诱导表达研究

根据细胞色素P450家族4（CYP4）的氨基酸保守序列设计1对简并引物,从椰心叶甲Brontispa longissima成虫总RNA中扩增得到5个cDNA片段（GenBank登录号: DQ238840－DQ238844）。以3′-RACE法获得片段BLWH4的3′端序列,推导的氨基酸序列表明其结构中含有CYP家族的特征性保守序列： 螺旋K区的ETLR和血红素结合区的F××G×××C×G。以18S 为对照的RT-PCR分析表明,BLWH4在成虫的mRNA表达量远大于幼虫。绿僵菌Metarhizium anisopliae菌株MA-3和MA-4侵染椰心叶甲成虫及5龄幼虫后,BLWH4的mRNA表达增强,提示BLWH4可能具有增强椰心叶甲抵抗绿僵菌侵染的作用。     

New bile alcohols - synthesis of (22R)- and (22S)-5beta-cholestane-3alpha,7alpha,12alpha,22,25-pentols.

The synthesis of (22R)- and (22S)-5beta-cholestane-3alpha,7alpha,12alpha,22,25-pentols is described. Bisnorcholyl aldehyde was prepared from cholic acid and converted into the cholestane-pentols by a Grignard reaction with 3-methyl-3-(tetrahydropyran-2-yloxy)-butynylmagnesium bromide followed by hydrogenation and acid hydrolysis. One of the synthetic pentols, the 22R-isomer was identical with a metabolite of 5beta-cholestane-3alpha,7alpha,25-triol formed in the rabbit.     

Loss of small heterodimer partner expression in the liver protects against dyslipidemia

Multiple studies suggest increased conversion of cholesterol to bile acids by cholesterol 7alpha-hydroxylase (CYP7A1) protects against dyslipidemia and atherosclerosis. CYP7A1 expression is repressed by the sequential activity of two nuclear hormone receptors, farnesoid X receptor (FXR) and small heterodimer partner (SHP). Here we demonstrate 129 strain SHP(-/-) mice are protected against hypercholesterolemia resulting from either a cholesterol/cholic acid (chol/CA) diet or from hypothyroidism. In a mixed 129-C57Bl/6 background, LDLR(-/-) and LDLR(-/-)SHP(-/-) mice had nearly identical elevations in hepatic cholesterol content and repression of cholesterol regulated genes when fed a Western diet. However, the LDLR(-/-)SHP(-/-) mice had greatly reduced elevations in serum VLDL and LDL cholesterol levels and triglyceride (TG) levels as compared with LDLR(-/-) mice. Additionally, the hepatic inflammation produced by the Western diet in the LDLR(-/-) mice was abolished in the LDLR(-/-)SHP(-/-) mice. CYP7A1 expression was induced 10-fold by the Western diet in the LDLR(-/-)SHP(-/-) mice but not in the LDLR(-/-) mice. Finally, hepatocyte-specific deletion of SHP expression was also protective against dyslipidemia induced by either a chol/CA diet or by hypothyroidism. While no antagonist ligands have yet been identified for SHP, these results suggest selective inhibition of hepatic SHP expression may provide protection against dyslipidemia.     

Parity-induced mammary epithelial cells are multipotent and express cell surface markers associated with stem cells

Parity-induced mammary epithelial cells (PI-MECs) are defined as a pregnancy hormone-responsive cell population that activates the promoter of late milk protein genes during the second half of pregnancy and lactation. However, unlike their terminally differentiated counterparts, these cells do not undergo programmed cell death during post-lactational remodeling of the gland. We previously demonstrated that upon transplantation into an epithelial-free mammary fat pad, PI-MECs exhibited two important features of multipotent mammary epithelial progenitors: a) self-renewal, and b) contribution to ductal and alveolar morphogenesis. In this new report, we introduce a new method to viably label PI-MECs. Using this methodology, we analyzed the requirement of ovarian hormones for the maintenance of this epithelial subtype in the involuted mammary gland. Furthermore, we examined the expression of putative stem cell markers and found that a portion of GFP-labeled PI-MECs were part of the CD24(+)/CD49f(high) mammary epithelial subtype, which has recently been suggested to contain multipotent stem cells. Subsequently, we demonstrated that isolated PI-MECs were able to form mammospheres in culture, and upon transplantation, these purified epithelial cells were capable of establishing a fully functional mammary gland. These observations suggest that PI-MECs contain multipotent progenitors that are able to self renew and generate diverse epithelial lineages present in the murine mammary gland.     

The variability of arsenic in blood and urine of humans

BackgroundHumans are exposed to inorganic and organic arsenic. The total arsenic (As) concentration in urine is a commonly used biomarker of exposure. However, little is known about variability of As in biological fluids and the diurnal variation of As excretion.ObjectivesMain objectives were to assess the variability of As in urine, plasma (P-As), whole blood (B-As), and the blood cell fraction (C-As), and to assess diurnal variation of As excretion.MethodsSix urine samples were collected at fixed times during 24 h on two different days around one week apart among 29 men and 31 women. Blood samples were collected when the morning urine samples were delivered. The intra-class correlation coefficient (ICC) was calculated as the ratio of the between-individuals variance to the total observed variance.ResultsGeometric mean (GM) 24 h urinary excretions of As (U-As_24 h) were 41 and 39 µg/24 h on the two days of sampling. Concentrations of B-As, P-As and C-As were highly correlated with U-As_24 h and As in first void morning urine. No statistically significant differences were observed for the urinary As excretion rate between the different sampling times. A high ICC was observed for As in the cellular blood fraction (0.803), while ICC for first morning urine corrected for creatine was low (0.316).ConclusionsThe study suggests that C-As is the most reliable biomarker for use in exposure assessment of individual exposure. Morning urine samples have low reliability for such use. No apparent diurnal variation was observed in the urinary As excretion rate.