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Abstract

Methamphetamine is one of the most popular recreational drugs in Central Europe and is often combined with ethanol. Various interactions between these two substances have been described including the influence of administered ethanol on biotransformation of methamphetamine. The aim of the present study was to describe the opposite effect - the influence of methamphetamine on biotransformation of ethanol in rats. Methamphetamine was administered for 10 days (10 mg/kg/day) i.p. and ethanol was delivered as an intragastric bolus (2 g/kg) on the10th day of experiment to both methamphetamine administered rats and control animals. The pharmacokinetic experiment on the whole animal was performed and plasma samples were drawn at the 40th, 120th, 210th and 300th minute after ethanol administration. Ethanol plasmatic levels reached significantly lower values in the 40th and 120th interval when compared to controls. Differences were insignificant in the last two intervals. Our results suggest that chronic methamphetamine administration induces ethanol biotransformation. We suppose that this effect is caused by induction of alcohol dehydrogenase metabolic activity or by allosteric interaction of methamphetamine and this enzyme. More studies have to be conducted to confirm or disprove our hypothesis.

. Nassar, A. M. Kamel and C. Clarimont, Improving the decision-making process in the structural modification of drug candidates: enhancing metabolic stability, Drug Discov. Today 9 (2004) 1020–1028. 36. E. F. Brandon, C. D. Raap, I. Meijerman, J. H. Beijnen and J. H. Schellens, An update on in vitro test methods in human hepatic drug biotransformation research: pros and cons, Toxicol. Appl. Pharmacol . 189 (2003) 233–246. 37. U. Fagerholm, Prediction of human pharmacokinetics-evaluation of methods for prediction of hepatic metabolic clearance, J. Pharm. Pharmacol

-726. Glotov AS, Nasedkina TV, Ivashchenko TE, Iurasov RA, Surzhikov SA, Pan'kov SV, Chudinov AV, Baranov VS, Zasedatelev AS. Biochip development for polymorphism analysis in biotransformation system genes. Mol Biol (Mosk) 2005; 39(3): 403-412. Nasedkina TV, Fedorova OE, Glotov AS, Chupova NV, Samochatova EV, Maiorova OA, Zemlyakova VV, Roudneva AE, Chudinov AV, Yurasov RA, Kozhekbaeva JM, Barsky VE, Krynetskiy EY, Krynetskaia NF, Cheng C, Ribeiro RC, Evans WE, Roumyantsev AG, Zasedatelev AS. Rapid genotyping of common deficient thiopurine Smethyltransferase alleles using

–44 http://dx.doi.org/10.1016/0304-4017(92)90141-U [3] Cvilink, V., Kubíček, V., Nobilis, M., Křížová, V., Szotáková, B., Lamka, J., Várady, M., Kuběnová, M., Novotná, R., Gavelová, M., Skálová, L. (2008): Biotransformation of flubendazole and selected model xenobiotics in Haemonchus contortus. Vet. Parasitol., 151: 242–248 http://dx.doi.org/10.1016/j.vetpar.2007.10.010 [4] Dayan, A. D. (2003): Albendazole, mebendazole and praziquantel. Review of non-clinical toxicity and pharmacokinetics. Acta Tropica, 86: 141–159 http://dx.doi.org/10.1016/S0001-706X(03)00031-7 [5

) Biotransformation enzymes in development of renal injury and urothelial cancer cause by aristolochic acid. Kidney Int   73 : 1209-1211. Stiborová M, Frei E, Sopko B, Wiessler M, Schmeiser HH. (2002a) Carcinogenic aristolochic acids upon activation by DT-diaphorase form adducts found in DNA of patients with Chinese herbs nephropathy. Carcinogenesis   23 : 617-625. Stiborová M, Frei E, Sopko B, Sopková K, Marková V, Laňková M, Kumstýřová T, Wiessler M, Schmeiser HH. (2003) Human cytosolic enzymes involved in the metabolic activation of carcinogenic aristolochic acid: evidence for

Abstract

Biotransformation of acetophenone to R-1-phenylethanol with Pichia capsulata immobilized in Caalginate gel beads was studied. Experiments were carried out in a batch reactor stirred on an orbital shaker (300 rpm) at 25 ℃. Based on experimental data, uncoupled parameters of reaction kinetics (measurements with free cells) and diffusion coefficients (sorption method) were estimated. The model expressing the conversion of acetophenone with immobilized cells in the batch reactor consisted of mass balance equations of acetophenone and R-1-phenylethanol in the liquid and solid phases. A satisfactory agreement between the experimental and predicted values of acetophenone and R-1-phenylethanol concentrations was achieved

Abstract

Introduction

Some azo dyes, including Sudans I–IV and Para Red, are genotoxic and may be biotransformed to cancerogenic aromatic amines. They are banned as food and feed additives, but their presence has been detected in food. Aromatic amines are also considered potentially toxic. Online EC–MS is a promising tool to study the transformation mechanisms of xenobiotics such as azo dyes. The aim of the study was to investigate emulation of how azo dyes are enzymatically transformed to amines with EC–MS.

Material and Methods

The reduction reactions of five azo dyes (Sudans I–IV and Para Red) were conducted using a glassy carbon working electrode and 0.1% formic acid in acetonitrile. Reduction results were compared with the literature and in silico to select preliminary candidates for metabolites. The LC-MS/MS method was used to confirm results obtained by electrochemical reactor.

Results

A limited number of pre-selected compounds were confirmed as azo dyes metabolites – aniline for Sudan I, aniline and 4-aminoazobenzene for Sudan III, o-toluidine for Sudan IV, and 4-nitroaniline for Para Red. No metabolites were found for Sudan II.

Conclusions

Electrochemistry–mass spectrometry was successfully applied to azo dyes. This approach may be used to mimic the metabolism of azo dyes, and therefore predict products of biotransformation.

-catalyzed kinetic resolution in a packed bed reactor: Modeling, simulation and miniplant studies. Chem. Eng. Sci. 62(9), 2375–2385. DOI: 10.1016/j.ces.2007.01.006. 4. Grubecki, I. (2016). How to run biotransformations—At the optimal temperature control or isothermally? Mathematical assessment. J. Proc. Control 44(0), 79–91. DOI: 10.1016/j.jprocont.2016.05.005. 5. Tükel, S.S., Hürrem, F., Yildirim, D. & Alptekin, Ö. (2013). Preparation of crosslinked enzyme aggregates (CLEA) of catalase and its characterization. J. Mol. Catal. B: Enzym. 97(0), 252–257. DOI: 10.1016/j.molcatb.2013

different pH values by microscopic fungi. Table 1 The amount of (1- 14 C)-TNT detected in fungi biomass, in% Culture Nutrient medium #2 Biomass, mg Total radioactivity of biomass, in % Mucor sp . T1-1 Czapek’s medium 29 53.6 Trichoderma sp N2-6 Czapek’s medium 25 51.9 Aspergillus niger N2-2 Czapek’s medium 27 52.9 Table 2 Main products of biotransformation of (1- 14 C)-Trinitrotoluene in culture liquid Strain Radioactivity, in% Organic acids Amino acids Mucor sp T1-1 72.2 27.8 Trichoderma sp N2-6 77.4 22.6 Aspergillus niger N2-2 89.8 10.2 Assimilation of (1-14C

serum concentration of escitalopram in psychiatric patients. Clin Pharmacol Ther 2008;83:322--7. Hirt D, Mentré F, Tran A, Rey E, Auleley S, Salmon D, Duval X, Tréluyer JM; COPHAR2- ANRS Study Group. Effect of CYP2C19 polymorphism on nelfinavir to M8 biotransformation in HIV patients. Br J Clin Pharmacol 2008;65:548--57. Elmaagacli AH, Koldehoff M, Steckel NK, Trenschel R, Ottinger H, Beelen DW. Cytochrome P450 2C19 loss-of-function polymorphism is associated with an increased treatment-related mortality in patients undergoing allogeneic transplantation. Bone