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Cytochrome P450

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https://www.readbyqxmd.com/read/28107587/p450-bm3-catalyzed-regio-and-stereoselective-hydroxylation-aiming-at-the-synthesis-of-phthalides-and-isocoumarins
#1
Claudia Holec, Ute Hartrampf, Katharina Neufeld, Joerg Pietruszka
Cytochrome P450 BM3 monooxygenases are able to catalyze the regio- and stereoselective oxygenation of a broad range of substrates with promising potential for synthetic applications. To study the ability of P450 BM3 variants for the stereoselective benzylic hydroxylation of 2-alkylated benzoic acid esters, the biotransformation of methyl 2-ethylbenzoate was investigated resulting in both enantiomeric forms of 3-methylphthalide. In case of methyl 2-propylbenzoate as a substrate the regioselectivity of the reaction was shifted towards -hydroxylation resulting in the synthesis of enantioenriched (R)- and (S)-configured 3-methylisochroman-1-one...
January 20, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28107387/neuronal-cell-death-and-degeneration-through-increased-nitroxidative-stress-and-tau-phosphorylation-in-hiv-1-transgenic-rats
#2
Young-Eun Cho, Myoung-Hwa Lee, Byoung-Joon Song
The underlying mechanisms for increased neurodegeneration and neurocognitive deficits in HIV-infected people are unclear. Therefore, this study was aimed to investigate the mechanisms of increased neurodegeneration in 5-month old male HIV-1 Transgenic (Tg) rats compared to the age- and gender-matched wild-type (WT) by evaluating histological changes and biochemical parameters of the key proteins involved in the cell death signaling and apoptosis. Histological and immunohistochemical analyses revealed decreased neuronal cells with elevated astrogliosis in HIV-1 Tg rats compared to WT...
2017: PloS One
https://www.readbyqxmd.com/read/28106743/design-synthesis-and-antifungal-activity-evaluation-of-new-thiazolin-4-ones-as-potential-lanosterol-14%C3%AE-demethylase-inhibitors
#3
Anca Stana, Dan C Vodnar, Radu Tamaian, Adrian Pîrnău, Laurian Vlase, Ioana Ionuț, Ovidiu Oniga, Brînduşa Tiperciuc
Twenty-three thiazolin-4-ones were synthesized starting from phenylthioamide or thiourea derivatives by condensation with α-monochloroacetic acid or ethyl α-bromoacetate, followed by substitution in position 5 with various arylidene moieties. All the synthesized compounds were physico-chemically characterized and the IR (infrared spectra), ¹H NMR (proton nuclear magnetic resonance), (13)C NMR (carbon nuclear magnetic resonance) and MS (mass spectrometry) data were consistent with the assigned structures...
January 17, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28105981/cryopreservation-of-hepatocyte-microbeads-for-clinical-transplantation
#4
Suttiruk Jitraruch, Anil Dhawan, Robin D, Celine Filippi, Sharon C, Leanne Glover, Ragai R
Intraperitoneal transplantation of hepatocyte microbeads is an attractive option for the management of acute liver failure. Encapsulation of hepatocytes in alginate microbeads supports their function and prevents immune attack of the cells. Establishment of banked cryopreserved hepatocyte microbeads is important for emergency use. The aim of this study was to develop an optimised protocol for cryopreservation of hepatocyte microbeads for clinical transplantation using modified freezing solutions. Four freezing solutions with potential for clinical application were investigated...
January 20, 2017: Cell Transplantation
https://www.readbyqxmd.com/read/28105513/pharmacokinetics-of-ginkgolides-a-b-and-k-after-single-and-multiple-intravenous-infusions-and-their-interactions-with-midazolam-in-healthy-chinese-male-subjects
#5
Feng Shao, Hongwen Zhang, Lijun Xie, Juan Chen, Sufeng Zhou, Jinsong Zhang, Jinru Lv, Weiwen Hao, Yunsu Ma, Yun Liu, Ning Ou, Wei Xiao
PURPOSE: Ginkgo terpene lactones meglumine injection (GMI) is a novel preparation of traditional Chinese medicine that contains ginkgolides A, B and K (GA, GB, GK, respectively) as its primary components. In this study we evaluated the safety, tolerability and pharmacokinetics of these three ginkgolides after single and multiple intravenous infusions of GMI. We also investigated the effect of GMI on cytochrome P450 3A4 (CYP3A4) in healthy Chinese volunteers. METHODS: In this open-label, placebo-controlled study 15 subjects were randomly assigned to receive GMI or matched placebo (4:1 ratio)...
January 20, 2017: European Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28105103/inhibition-of-p-glycoprotein-multidrug-resistance-associated-protein-2-and-cytochrome-p450-3a4-improves-the-oral-absorption-of-octreotide-in-rats-with-portal-hypertension
#6
Xiao-Yu Sun, Zhi-Jun Duan, Zhen Liu, Shun-Xiong Tang, Yang Li, Shou-Cheng He, Qiu-Ming Wang, Qing-Yong Chang
The aim of the present study was to increase the intestinal transport of octreotide (OCT) by targeting the first-pass impact to identify a potential method for decreasing portal vein pressure (PVP) using oral OCT. Thus, the bioavailability of intestinally absorbed OCT was evaluated in normal rats and rats with portal hypertension (PH) that had been administered P-glycoprotein/multidrug resistance-associated protein 2/cytochrome P450 3A4 (P-gp/MRP2/CYP3A4) inhibitors. The mRNA and protein expression levels of P-gp, MRP2 and CYP3A4 were evaluated in normal and PH rats with or without OCT and the inhibitors using RT-PCR, western blot and immunohistochemical analyses...
December 2016: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28104494/thoughts-on-interactions-between-pgrmc1-and-diverse-attested-and-potential-hydrophobic-ligands
#7
REVIEW
Michael A Cahill, Amy E Medlock
Progesterone Receptor Membrane Component 1 (PGRMC1) is located in many different subcellular locations with many different attested and probably location-specific functions. PGRMC1 was recently identified in the mitochondrial outer membrane where it interacts with ferrochelatase, the last enzyme in the heme synthetic pathway. It has been proposed that PGRMC1 may act as a chaperone to shuttle newly synthesized heme from the mitochondrion to cytochrome P450 (cyP450) enzymes. Here we consider potential roles that PGRMC1 may play in transferring heme, and other small hydrophobic ligands such as cholesterol and steroids, between the hydrophobic compartment of the membrane lipid bilayer interior to aqueous proteins, and perhaps to the membranes of other organelles...
January 16, 2017: Journal of Steroid Biochemistry and Molecular Biology
https://www.readbyqxmd.com/read/28103884/aryl-hydrocarbon-receptor-cytochrome-p450%C3%A2-1a1-pathway-mediates-breast-cancer-stem-cells-expansion-through-pten-inhibition-and-%C3%AE-catenin-and-akt-activation
#8
Abdullah Al-Dhfyan, Ali Alhoshani, Hesham M Korashy
BACKGROUND: Breast cancer stem cells (CSCs) are small sub-type of the whole cancer cells that drive tumor initiation, progression and metastasis. Recent studies have demonstrated a role for the aryl hydrocarbon receptor (AhR)/cytochrome P4501A1 pathway in CSCs expansion. However, the exact molecular mechanisms remain unclear. METHODS: The current study was designed to a) determine the effect of AhR activation and inhibition on breast CSCs development, maintenance, self-renewal, and chemoresistance at the in vitro and in vivo levels and b) explore the role of β-Catenin, PI3K/Akt, and PTEN signaling pathways...
January 19, 2017: Molecular Cancer
https://www.readbyqxmd.com/read/28103795/lineage-specific-duplication-of-amphioxus-retinoic-acid-degrading-enzymes-cyp26-resulted-in-sub-functionalization-of-patterning-and-homeostatic-roles
#9
João E Carvalho, Maria Theodosiou, Jie Chen, Pascale Chevret, Susana Alvarez, Angel R De Lera, Vincent Laudet, Jenifer C Croce, Michael Schubert
BACKGROUND: During embryogenesis, tight regulation of retinoic acid (RA) availability is fundamental for normal development. In parallel to RA synthesis, a negative feedback loop controlled by RA catabolizing enzymes of the cytochrome P450 subfamily 26 (CYP26) is crucial. In vertebrates, the functions of the three CYP26 enzymes (CYP26A1, CYP26B1, and CYP26C1) have been well characterized. By contrast, outside vertebrates, little is known about CYP26 complements and their biological roles...
January 19, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28103421/structure-of-the-arabidopsis-thaliana-nadph-cytochrome-p450-reductase-2-atr2-provides-insight-into-its-function
#10
Guoqi Niu, Shun Zhao, Lei Wang, Wei Dong, Lin Liu, Yikun He
Members of the cytochrome P450 family catalyze a variety of monooxygenase reactions, and for the eukaryotic membrane-bound members, NADPH is typically used as the reducing agent. The flavoprotein NADPH-cytochrome P450 reductase (CPR) enables electron transfer from NADPH to cytochrome P450 via its flavin cofactors. ATR2 is one of the two authentic CPR genes in the genome of the model plant Arabidopsis thaliana, and its product has been physiologically and kinetically characterized. Here, we report the 2.3-Å structure of ATR2 and find that the position of the two flavin cofactors differs from that of other known CPR structures...
January 19, 2017: FEBS Journal
https://www.readbyqxmd.com/read/28102888/genetic-polymorphisms-in-estrogen-metabolic-pathway-associated-with-risks-of-alzheimer-s-disease-evidence-from-a-southern-chinese-population
#11
Lu Hua Chen, Yan Hui Fan, Patrick Yu Ping Kao, Deborah Tip Yin Ho, Joyce Cheuk Tung Ha, Leung Wing Chu, You-Qiang Song
OBJECTIVES: To investigate whether genetic variations on the estrogen metabolic pathway would be associated with risk of Alzheimer's disease (AD). DESIGN: Cross-sectional study. SETTING: Individuals were recruited at the Memory Clinic, Queen Mary Hospital, Hong Kong. PARTICIPANTS: Chinese individuals with (n = 426) and without (n = 350) AD. MEASUREMENTS: All subjects underwent a standardized cognitive assessment and genotyping of four candidate genes on the estrogen metabolic pathway (estrogen receptor α gene (ESR1), estrogen receptor β gene (ESR2), cytochrome P450 19A1 gene (CYP19A1), cytochrome P450 11A1 gene (CYP11A1))...
January 19, 2017: Journal of the American Geriatrics Society
https://www.readbyqxmd.com/read/28101244/celery-extract-inhibits-mouse-cyp2a5-and-human-cyp2a6-activities-via-different-mechanisms
#12
Xiao Deng, Qianghong Pu, Erhao Wang, Chao Yu
Human cytochrome P450 (CYP) 2A6 participates in the metabolism of nicotine and precarcinogens, thus the deliberate inhibition of CYP2A6 may reduce cigarette consumption and therefore reduce the risk of developing the types of cancer associated with smoking. The inhibitory effects and mechanisms of celery (Apium graveolens) extract on mouse CYP2A5 and human CYP2A6 activity remain unclear. These effects were investigated in mouse and human liver microsomes using coumarin 7-hydroxylation in a probe reaction. Celery extract reduced CYP2A5 and CYP2A6 activities in vitro in a dose-dependent manner...
December 2016: Oncology Letters
https://www.readbyqxmd.com/read/28099882/the-35-year-odyssey-of-beta-blockers-in-cirrhosis-any-gender-difference-in-sight
#13
REVIEW
Maria Antonella Burza, Hanns-Ulrich Marschall, Laura Napoleone, Antonio Molinaro
Cirrhosis is the end-stage of chronic liver disease and leads to the development of portal hypertension and its complications such as esophagogastric varices. Non-selective beta blockers (NSBB) are the keystone for the treatment of portal hypertension since the 1980s and, over the decades, several studies have confirmed their beneficial effect on the prevention of variceal (re)bleeding. Pharmacological studies showed effects of gender, sex hormones, oral contraceptives, and pregnancy on cytochrome P450 (CYPs) enzymes that metabolise NSBB, suggesting that gender differences might exist in the effect of NSBB...
January 15, 2017: Pharmacological Research: the Official Journal of the Italian Pharmacological Society
https://www.readbyqxmd.com/read/28099803/deep-learning-to-predict-the-formation-of-quinone-species-in-drug-metabolism
#14
Tyler B Hughes, S Joshua Swamidass
Many adverse drug reactions are thought to be caused by electrophilically reactive drug metabolites that conjugate to nucleophilic sites within DNA and proteins, causing cancer or toxic immune responses. Quinone species, including quinone-imines, quinone-methides, and imine-methides, are electrophilic Michael acceptors that are of- ten highly reactive, and comprise over 40% of all known reactive metabolites. Quinone metabolites are created by cytochromes P450 and peroxidases. For example, cy- tochromes P450 oxidize acetaminophen to N-acetyl-p-benzoquinone imine, which is electrophilically reactive and covalently binds to nucleophilic sites within proteins...
January 18, 2017: Chemical Research in Toxicology
https://www.readbyqxmd.com/read/28099407/effects-of-functional-cyp2c8-cyp2c9-cyp3a5-and-abcb1-genetic-variants-on-the-pharmacokinetics-of-insulin-sensitizer-pioglitazone-in-chinese-han-individuals
#15
Sheng-Ju Yin, Hui-Min Qi, Xin Wang, Pu Zhang, Yuan Lu, Min-Ji Wei, Pu Li, Guang-Zhao Qi, Ya-Qing Lou, Chuang Lu, Guo-Liang Zhang
BACKGROUND AND OBJECTIVES: Pioglitazone is a thiazolidinedione antihyperglycemic drug with insulin-sensitizing properties. We investigated whether the variant genotypes of cytochrome P450 2C8 (CYP2C8), CYP2C9, CYP3A5 and transporter ABCB1 influence the pharmacokinetic phenotype of the substrate pioglitazone in Chinese individuals. PARTICIPANTS AND METHODS: Single-nucleotide polymorphisms were determined by the PCR-restriction fragment length polymorphism method in 244 (CYP2C8 and CYP2C9) healthy Chinese Han individuals...
January 17, 2017: Pharmacogenetics and Genomics
https://www.readbyqxmd.com/read/28098172/structural-diversity-of-anti-pancreatic-cancer-capsimycins-identified-in-mangrove-derived-streptomyces-xiamenensis-318-and-post-modification-via-a-novel-cytochrome-p450-monooxygenase
#16
He-Lin Yu, Shu-Heng Jiang, Xu-Liang Bu, Jia-Hua Wang, Jing-Yi Weng, Xiao-Mei Yang, Kun-Yan He, Zhi-Gang Zhang, Ping Ao, Jun Xu, Min-Juan Xu
Polycyclic tetramate macrolactams (PTMs) were identified as distinct secondary metabolites of the mangrove-derived Streptomyces xiamenensis 318. Together with three known compounds-ikarugamycin (1), capsimycin (2) and capsimycin B (3)-two new compounds, capsimycin C (4) with trans-diols and capsimycin D (5) with trans-configurations at C-13/C-14, have been identified. The absolute configurations of the tert/tert-diols moiety was determined in 4 by NMR spectroscopic analysis, CD spectral comparisons and semi-synthetic method...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28097004/rifampicin-decreases-exposure-to-sublingual-buprenorphine-in-healthy-subjects
#17
Nora M Hagelberg, Mari Fihlman, Tuija Hemmilä, Janne T Backman, Jouko Laitila, Pertti J Neuvonen, Kari Laine, Klaus T Olkkola, Teijo I Saari
Buprenorphine is mainly metabolized by the cytochrome P450 (CYP) 3A4 enzyme. The aim of this study was to evaluate the role of first-pass metabolism in the interaction of rifampicin and analgesic doses of buprenorphine. A four-session paired cross-over study design was used. Twelve subjects ingested either 600 mg oral rifampicin or placebo once daily in a randomized order for 7 days. In the first part of the study, subjects were given 0.6-mg (placebo phase) or 0.8-mg (rifampicin phase) buprenorphine sublingually on day 7...
December 2016: Pharmacology Research & Perspectives
https://www.readbyqxmd.com/read/28095715/an-overview-of-aldehyde-oxidase-an-enzyme-of-emerging-importance-in-novel-drug-discovery
#18
Mohammad-Reza Rashidi, Somaieh Soltani
Given the rising trend in medicinal chemistry strategy to reduce cytochrome P450-dependent metabolism, aldehyde oxidase (AOX) has recently gained increased attention in drug discovery programs and the number of drug candidates that are metabolized by AOX is steadily growing. Areas covered: Despite the emerging importance of AOX in drug discovery, there are certain major recognized problems associated with AOX-mediated metabolism of drugs. Intra- and inter-species variations in AOX activity, the lack of reliable and predictive animal models using the common experimental animals, and failure in the predictions of in vivo metabolic activity of AOX using traditional in vitro methods are among these issues that are covered in this article...
January 17, 2017: Expert Opinion on Drug Discovery
https://www.readbyqxmd.com/read/28094799/activation-of-wnt-%C3%AE-catenin-signalling-via-gsk3-inhibitors-direct-differentiation-of-human-adipose-stem-cells-into-functional-hepatocytes
#19
Jieqiong Huang, Xinyue Guo, Weihong Li, Haiyan Zhang
The generation of hepatocytes that are derived from human adipose stem cells (hASCs) represents an alternative to human hepatocytes for individualized therapeutic and pharmaceutical applications. However, the mechanisms facilitating hepatocyte differentiation from hASCs are not well understood. Here, we show that upon exposure to glycogen synthase kinase 3 (GSK3) inhibitors alone, the expression of definitive endoderm specific genes GATA4, FOXA2, and SOX17 in hASCs significantly increased in a manner with activation of Wnt/β-catenin signalling...
January 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28092943/context-matters-contribution-of-specific-dna-adducts-to-the-genotoxic-properties-of-the-tobacco-specific-nitrosamine-nnk
#20
Lisa A Peterson
The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is a potent pulmonary carcinogen in laboratory animals. It is classified as a Group 1 human carcinogen by the International Agency for Cancer Research. NNK is bioactivated upon cytochrome P450 catalyzed hydroxylation of the carbon atoms adjacent to the nitrosamino group to both methylating and pyridyloxobutylating agents. Both pathways generate a spectrum of DNA damage that contributes to the overall mutagenic and toxic properties of this compound...
January 17, 2017: Chemical Research in Toxicology
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