1
|
Spyrou A, Tzamaria A, Dormousoglou M, Skourti A, Vlastos D, Papadaki M, Antonopoulou M. The overall assessment of simultaneous photocatalytic degradation of Cimetidine and Amisulpride by using chemical and genotoxicological approaches. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 838:156140. [PMID: 35605860 DOI: 10.1016/j.scitotenv.2022.156140] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/15/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
Pharmaceutical Active Compounds (PhACs) are of particular interest among the emerging contaminants detected in the aquatic environment. Commonly, PhACs exist as complex mixtures in aquatic systems, causing potential adverse effects to the environment and human health than those of individual compounds. Based on the increasing interest in the contamination of water resources by PhACs, the photocatalytic degradation of Cimetidine and Amisulpride as a mixture in combination with their toxic and genotoxic effects before and after the treatment were evaluated for the first time. The toxic, genotoxic and cytotoxic effects were investigated using the Trypan Blue Exclusion Test and the Cytokinesis Block MicroNucleus (CBMN) assay in cultured human lymphocytes. The photocatalytic degradation of the PhACs was studied in ultrapure water and environmentally relevant matrices using UV-A and visible (Vis) irradiation and C-TiO2 (TiO2 Kronos vlp 7000) as photocatalyst. High removal percentages were observed for both compounds under UV-A and Vis irradiation in ultrapure water. In lake and drinking water a slower degradation rate was shown that could be attributed to the complex composition of these matrices. Scavenging experiments highlighted the significant role of h+ and O2●- in the degradation mechanisms under both irradiation sources. Oxidation, dealkylation and deamination were the main degradation pathways. Regarding the individual compounds, Amisulpride was found to be more cytotoxic than Cimetidine. No significant differences of the genotoxic effects during the treatment were observed. However, a slight increase in cytotoxicity was observed at the first stages of the process. At the end of the process under both UV-A and Vis light, non-significant cytotoxic/toxic effects were observed. Based on the results, heterogeneous photocatalysis can be considered as an effective process for the treatment of complex mixtures without the formation of harmful transformation products.
Collapse
Affiliation(s)
- Alexandra Spyrou
- Department of Environmental Engineering, University of Patras, GR-30100 Agrinio, Greece
| | - Anna Tzamaria
- Department of Environmental Engineering, University of Patras, GR-30100 Agrinio, Greece
| | | | - Anastasia Skourti
- Department of Environmental Engineering, University of Patras, GR-30100 Agrinio, Greece
| | - Dimitris Vlastos
- Department of Biology, Section of Genetics Cell Biology and Development, University of Patras, GR-26500 Patras, Greece
| | - Maria Papadaki
- Department of Environmental Engineering, University of Patras, GR-30100 Agrinio, Greece
| | - Maria Antonopoulou
- Department of Environmental Engineering, University of Patras, GR-30100 Agrinio, Greece.
| |
Collapse
|
2
|
Seid MG, Lee C, Cho K, Hong SW. Degradation of ranitidine and changes in N-nitrosodimethylamine formation potential by advanced oxidation processes: Role of oxidant speciation and water matrix. WATER RESEARCH 2021; 203:117495. [PMID: 34388496 DOI: 10.1016/j.watres.2021.117495] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/21/2021] [Accepted: 07/28/2021] [Indexed: 06/13/2023]
Abstract
This study investigated the effects of thirteen (photo/electro) chemical oxidation processes on the formation potential (FP) of N-nitrosodimethylamine (NDMA) during the chloramination of ranitidine in reverse osmosis (RO) permeate and brine. The NDMA-FP varied significantly depending on the pretreatment process, initial pH, and water matrix types. At higher initial pH values (> 7.0), most pretreatments did not reduce the NDMA-FP, presumably because few radical species and more chloramine-reactive byproducts were generated. At pH < 7.0, however, electrochemical oxidation assisted by chloride and Fe2+/H2O2, catalytic wet peroxide oxidation and peroxydisulfate-induced pretreatments removed up to 85% of NDMA-FP in the RO brine. Ultraviolet (UV) irradiation or prechlorination alone did not reduce the NDMA-FP effectively, but combined UV/chlorine treatment effectively reduced the NDMA-FP. In contrast, after UV irradiation (2.1 mW cm-2 for 0.5 h) in the presence of H2O2 and chloramine, NDMA formation increased substantially (up to 26%) during the post-chloramination of the RO permeate. Mass spectrometric analysis and structural elucidation of the oxidation byproducts indicated that compared with the reactive nitrogen species generated by UV/NH2Cl, sulfate radicals and (photo/electro)chemically generated reactive chlorine species were more promising for minimizing NDMA-FP. Unlike, the hemolytic •OH driven by UV/H2O2, the •OH from Fe(IV)-assisted pretreatments showed a significant synergistic effect on NDMA-FP reduction. Overall, the results suggest the need for a careful assessment of the type of radical species to be used for treating an RO water system containing amine-functionalized compounds.
Collapse
Affiliation(s)
- Mingizem Gashaw Seid
- Water Cycle Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea; Division of Energy and Environment Technology, KIST-School, University of Science and Technology, Seoul 02792, Republic of Korea
| | - Changha Lee
- School of Chemical and Biological Engineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Kangwoo Cho
- Division of Environmental Science and Engineering, Pohang University of Science and Technology (POSTECH), Pohang 790-784, Republic of Korea; Institute for Convergence Research and Education in Advanced Technology (I-CREATE), Yonsei University International Campus, Incheon 21983, Republic of Korea.
| | - Seok Won Hong
- Water Cycle Research Center, Korea Institute of Science and Technology, Seoul 136-791, Republic of Korea; Division of Energy and Environment Technology, KIST-School, University of Science and Technology, Seoul 02792, Republic of Korea.
| |
Collapse
|
3
|
Kislyuk S, Kroonen J, Adams E, Augustijns P, de Witte P, Cabooter D. Development of a sensitive and quantitative UHPLC-MS/MS method to study the whole-body uptake of pharmaceuticals in zebrafish. Talanta 2017; 174:780-788. [PMID: 28738654 DOI: 10.1016/j.talanta.2017.06.075] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 06/23/2017] [Accepted: 06/27/2017] [Indexed: 10/19/2022]
Abstract
An analytical procedure to measure the whole-body uptake of pharmaceuticals in zebrafish has been developed using state-of-the-art methodologies. A sample preparation procedure for 9 pharmaceuticals displaying a variety in physicochemical properties was developed using 10-day old zebrafish (TG898). For an efficient homogenization of the samples and subsequent recovery of the compounds of interest, different amounts of organic solvents in combination with acidic modifiers were added to zebrafish samples. Samples were subsequently processed using a powerful bath sonicator and centrifuged. Supernatant was then removed and evaporated in a vacuum oven before being reconstituted in a mobile phase-like solvent. Samples were analyzed using ultra-high performance liquid chromatography (UHPLC) on an Acquity BEH C18 column (100 × 2.1mm, dp=1.7µm) coupled to a Waters Xevo TQ-S mass spectrometer. For this purpose, a generic gradient was run, wherein the percentage of acetonitrile was varied from 3% to 82% in 10.5min at a flow rate of 0.41mL/min. Linearity of the method was demonstrated for all compounds (R2 > 0.997) in a practically relevant concentration range. Matrix effects were between 81% and 106%, except for amitriptyline (51%). Using this method, it was demonstrated that a sample pretreatment using 1:2 (v/v) water:methanol in combination with 0.1% formic acid resulted in acceptable recoveries between 74% and 100% for all compounds. Together with the obtained lower limits of quantification of the analytical method (between 0.005 and 1.5ng/mL), this allowed the use of a single zebrafish to study the whole-body uptake of a particular drug, after incubating zebrafish at the maximum tolerated concentration for this drug.
Collapse
Affiliation(s)
- Stanislav Kislyuk
- University of Leuven (KU Leuven), Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium
| | - Jerome Kroonen
- Diagenode Belgium, Rue Bois Saint-Jean 3, 4102 Seraing (Ougrée), Belgium
| | - Erwin Adams
- University of Leuven (KU Leuven), Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium
| | - Patrick Augustijns
- University of Leuven (KU Leuven), Drug Delivery and Disposition, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium
| | - Peter de Witte
- University of Leuven (KU Leuven), Molecular Biodiscovery, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium
| | - Deirdre Cabooter
- University of Leuven (KU Leuven), Pharmaceutical Analysis, Department of Pharmaceutical and Pharmacological Sciences, Herestraat 49, 3000 Leuven, Belgium.
| |
Collapse
|
4
|
Ruokolainen M, Gul T, Permentier H, Sikanen T, Kostiainen R, Kotiaho T. Comparison of TiO2 photocatalysis, electrochemically assisted Fenton reaction and direct electrochemistry for simulation of phase I metabolism reactions of drugs. Eur J Pharm Sci 2015; 83:36-44. [PMID: 26690045 DOI: 10.1016/j.ejps.2015.12.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Revised: 12/03/2015] [Accepted: 12/08/2015] [Indexed: 01/23/2023]
Abstract
The feasibility of titanium dioxide (TiO2) photocatalysis, electrochemically assisted Fenton reaction (EC-Fenton) and direct electrochemical oxidation (EC) for simulation of phase I metabolism of drugs was studied by comparing the reaction products of buspirone, promazine, testosterone and 7-ethoxycoumarin with phase I metabolites of the same compounds produced in vitro by human liver microsomes (HLM). Reaction products were analysed by UHPLC-MS. TiO2 photocatalysis simulated the in vitro phase I metabolism in HLM more comprehensively than did EC-Fenton or EC. Even though TiO2 photocatalysis, EC-Fenton and EC do not allow comprehensive prediction of phase I metabolism, all three methods produce several important metabolites without the need for demanding purification steps to remove the biological matrix. Importantly, TiO2 photocatalysis produces aliphatic and aromatic hydroxylation products where direct EC fails. Furthermore, TiO2 photocatalysis is an extremely rapid, simple and inexpensive way to generate oxidation products in a clean matrix and the reaction can be simply initiated and quenched by switching the UV lamp on/off.
Collapse
Affiliation(s)
- Miina Ruokolainen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland.
| | - Turan Gul
- Analytical Biochemistry, Department of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Hjalmar Permentier
- Analytical Biochemistry, Department of Pharmacy, University of Groningen, A Deusinglaan 1, 9713 AV Groningen, The Netherlands.
| | - Tiina Sikanen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland.
| | - Risto Kostiainen
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland.
| | - Tapio Kotiaho
- Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, P.O. Box 56 (Viikinkaari 5E), FI-00014, Finland; Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P.O. BOX 55 (A.I. Virtasen aukio 1), FI-00014, Finland.
| |
Collapse
|
5
|
Ruokolainen M, Valkonen M, Sikanen T, Kotiaho T, Kostiainen R. Imitation of phase I oxidative metabolism of anabolic steroids by titanium dioxide photocatalysis. Eur J Pharm Sci 2014; 65:45-55. [DOI: 10.1016/j.ejps.2014.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 08/15/2014] [Accepted: 08/19/2014] [Indexed: 01/13/2023]
|
6
|
Influence of cimetidine and its metabolites on Cisplatin—Investigation of adduct formation by means of electrochemistry/liquid chromatography/electrospray mass spectrometry. J Chromatogr A 2013; 1279:49-57. [DOI: 10.1016/j.chroma.2012.12.069] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 12/03/2012] [Accepted: 12/24/2012] [Indexed: 11/17/2022]
|
7
|
Radjenović J, Sirtori C, Petrović M, Barceló D, Malato S. Characterization of intermediate products of solar photocatalytic degradation of ranitidine at pilot-scale. CHEMOSPHERE 2010; 79:368-376. [PMID: 20207392 DOI: 10.1016/j.chemosphere.2010.02.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 02/05/2010] [Accepted: 02/05/2010] [Indexed: 05/28/2023]
Abstract
In the present study the mechanisms of solar photodegradation of H(2)-receptor antagonist ranitidine (RNTD) were studied in a well-defined system of a pilot plant scale Compound Parabolic Collector (CPC) reactor. Two types of heterogeneous photocatalytic experiments were performed: catalysed by titanium-dioxide (TiO(2)) semiconductor and by Fenton reagent (Fe(2+)/H(2)O(2)), each one with distilled water and synthetic wastewater effluent matrix. Complete disappearance of the parent compounds and discreet mineralization were attained in all experiments. Furthermore, kinetic parameters, main intermediate products, release of heteroatoms and formation of carboxylic acids are discussed. The main intermediate products of photocatalytic degradation of RNTD have been structurally elucidated by tandem mass spectrometry (MS(2)) experiments performed at quadrupole-time of flight (QqToF) mass analyzer coupled to ultra-performance liquid chromatograph (UPLC). RNTD displayed high reactivity towards OH radicals, although a product of conduction band electrons reduction was also present in the experiment with TiO(2). In the absence of standards, quantification of intermediates was not possible and only qualitative profiles of their evolution could be determined. The proposed TiO(2) and photo-Fenton degradation routes of RNTD are reported for the first time.
Collapse
Affiliation(s)
- Jelena Radjenović
- Department of Environmental Chemistry, IDAEA-CSIC, c/Jordi Girona 18-26, 08034 Barcelona, Spain
| | | | | | | | | |
Collapse
|
8
|
|
9
|
Lohmann W, Karst U. Biomimetic modeling of oxidative drug metabolism. Anal Bioanal Chem 2007; 391:79-96. [DOI: 10.1007/s00216-007-1794-x] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 12/03/2007] [Accepted: 12/04/2007] [Indexed: 10/22/2022]
|
10
|
Latch DE, Stender BL, Packer JL, Arnold WA, McNeill K. Photochemical fate of pharmaceuticals in the environment: cimetidine and ranitidine. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2003; 37:3342-3350. [PMID: 12966980 DOI: 10.1021/es0340782] [Citation(s) in RCA: 194] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The photochemical fates of the histamine H2-receptor antagonists cimetidine and ranitidine were studied. Each of the two environmentally relevant pharmaceuticals displayed high rates of reaction with both singlet oxygen (1O2, O2(1delta(g))) and hydroxyl radical (*OH), two transient oxidants formed in sunlit natural waters. For cimetidine, the bimolecular rate constant for reaction with *OH in water is 6.5 +/- 0.5 x 10(9) M(-1) s(-1). Over the pH range 4-10, cimetidine reacts with 1O2 with bimolecular rate constants ranging from 3.3 +/- 0.3 x 10(6) M(-1) s(-1) at low pH to 2.5 +/- 0.2 x 10(8) M(-1) s(-1) in alkaline solutions. The bimolecular rate constants for ranitidine reacting with 1O2 in water ranges from 1.6 +/- 0.2 x 10(7) M(-1) s(-1) at pH 6-6.4 +/- 0.2 x 10(7) M(-1) s(-1) at pH 10. Reaction of ranitidine hydrochloride with *OH proceeds with a rate constant of 1.5 +/- 0.2 x 10(10) M(-1) s(-1). Ranitidine was also degraded in direct photolysis experiments with a half-life of 35 min under noon summertime sunlight at 45 degrees latitude, while cimetidine was shown to be resistant to direct photolysis. The results of these experiments, combined with the expected steady-state near surface concentrations of 1O2 and *OH, indicate that photooxidation mediated by 1O2 is the likely degradation pathway for cimetidine in most natural waters, and photodegradation by direct photolysis is expected to be the major pathway for ranitidine, with some degradation caused by 1O2. These predictions were verified in studies using Mississippi River water. Model compounds were analyzed by laser flash photolysis experiments to assess which functionalities within ranitidine and cimetidine are most susceptible to singlet-oxygenation and direct photolysis. The heterocyclic moieties of the pharmaceuticals were clearly implicated as the sites of reaction with 1O2, as evidenced by the high relative rate constants of the furan and imidazole models. The nitroacetamidine portion of ranitidine has been shown to be the moiety active in direct photolysis.
Collapse
Affiliation(s)
- Douglas E Latch
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, USA
| | | | | | | | | |
Collapse
|
11
|
Kirkova M, Atanassova M, Russanov E. Effects of cimetidine and its metal complexes on nitroblue tetrazolium and ferricytochrome c reduction by superoxide radicals. GENERAL PHARMACOLOGY 1999; 33:271-6. [PMID: 10480660 DOI: 10.1016/s0306-3623(99)00015-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The effects of cimetidine, a potent histamine-H2-receptor antagonist and a good -OH scavenger, on the kinetics of ferricytochrome c and NBT reduction by superoxide anions were studied. The drug dose-dependently inhibited ferricytochrome c and NBT reduction by O2- radicals, generated either in xanthine oxidase system or photochemically or directly by KO2. The inhibitory effect of cimetidine remained unchanged in the presence of catalase or mannitol. Cimetidine and its complexes with Cu(II) and Fe(III) ions inhibited ferricytochrome c and NBT reduction even when metal chelators were added to the reaction medium. The results suggest the reaction of cimetidine with O2-radicals.
Collapse
Affiliation(s)
- M Kirkova
- Institute of Physiology, Bulgarian Academy of Sciences, Sofia
| | | | | |
Collapse
|
12
|
Ching TL, Haenen GR, Bast A. Cimetidine and other H2 receptor antagonists as powerful hydroxyl radical scavengers. Chem Biol Interact 1993; 86:119-27. [PMID: 8095439 DOI: 10.1016/0009-2797(93)90116-g] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Hydroxyl radical scavengers are able to compete with deoxyribose for the hydroxyl radicals generated in a reaction mixture. We found that the H2 receptor antagonists like cimetidine, burimamide, ranitidine, famotidine and tiotidine except for being good inhibitors in histamine-stimulated gastric acid secretion, were also very powerful hydroxyl radical scavengers. Rate constants for reaction of these drugs with hydroxyl radicals ranged from 7.7 x 10(9) Ms-1 to 14.8 x 10(9) M-1 s-1. These rate constants are much higher than for the well-known hydroxyl radical scavenger mannitol (1.7 x 10(9) M-1 s-1). In this study we investigated which part of the cimetidine molecule might be responsible for its potent hydroxyl radical scavenging activity. Testing fragments of the cimetidine molecule revealed that the guanidine moiety of cimetidine had little hydroxyl radical scavenging activity. However the other part of the molecule, the methylated imidazole with a sulfur and amino group containing side chain appeared to be a powerful hydroxyl radical scavenger.
Collapse
Affiliation(s)
- T L Ching
- Faculty of Chemistry, Department of Pharmacochemistry, Vrije Universiteit, Amsterdam, The Netherlands
| | | | | |
Collapse
|
13
|
Zbaida S, Kariv R. Simulation of the hepatic metabolism of stilbene and its tricyclic derivatives by Fenton and Ruff reagents: models for cytochrome P-450 activation of chemical carcinogens. Biopharm Drug Dispos 1990; 11:39-51. [PMID: 2322636 DOI: 10.1002/bdd.2510110105] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Reactions of trans-stilbene, cis-stilbene, 5H-dibenzo [a,d] cyclo-heptene 5-one and 5H-dibenz [b,f] azepine (iminostilbene) with Fenton reagent [Fe (II)/H2O2] clearly simulate their hepatic metabolism. Expoxidation on the corresponding ethylenic linkage was found to be a common pathway of these compounds. Epoxides of trans-stilbene, cis-stilbene, and 5H-dibenzo[a,d]cycloheptene 5-one were further oxidized to dihydrodiols, alpha-hydroxyketones, diketones, and finally cleavage of the ethylenic bonds to the formation of the corresponding aldehydes. However, the unstable epoxide of iminostilbene gave 9-acridinecarbaldehyde that is further oxidized to 9-acridone. Reaction of both trans- and cis-stilbene with Ruff reagent [Fe III)/H2O2] gave the same oxidative products to that obtained from Fenton reagent. The radical scavenger 2,6 bis (1,1-dimethylethyl)-4-methyl phenol (BHT) decreases the total yield conversion and increases the formation ratio of both cis-epoxide and d,l-hydrobenzoin from cis-stilbene.
Collapse
Affiliation(s)
- S Zbaida
- Department of Pharmacy, School of Pharmacy, Hebrew University of Jerusalem, Israel
| | | |
Collapse
|
14
|
Abstract
The microsomal mixed function oxidase system contains the cytochrome P-450 oxidative drug metabolizing family of enzymes. The catalytic cycle of cytochrome P-450 is believed to involve the formation of an active iron-oxygen species which is responsible for oxygen transfer to the substrate. This assumption is supported by the fact that a number of peroxidative agents can replace NADPH, the reductase, and oxygen as co-reactants in most oxidative reactions of microsomal cytochrome P-450. We have found that a mixture of either ferrous or ferric ions with hydrogen peroxide (Fenton and Ruff reagents) can serve as biomimetic models for cytochrome P-450 in hydroxylation, exposidation, sulfoxidation, and N-demethylation of various drugs. The existance of an iron-oxo active species in both Fenton and Ruff type reactions has been postulated and provides reaction cycles similar to those of cytochrome p-450. Other model systems for the hepatic hydroxylation and epoxidation using transition metal complexes with porphyrin are also discussed. The present paper reviews the various biomimetic models of the heme cytochrome P-450 and emphasizes their simulation of hepatic drug metabolism and their potential medical and industrial applications.
Collapse
Affiliation(s)
- S Zbaida
- Department of Pharmacy, School of Pharmacy, Hebrew University of Jerusalem, Israel
| | | |
Collapse
|
15
|
Zbaida S, Kariv R, Fischer P. The role of iron chelates on the selectivity of Fenton reagent in hydroxylation, N-demethylation, and sulfoxidation of cimetidine: a novel biomimetic model for the regioselectivity of cytochrome P-450. Arch Biochem Biophys 1988; 261:12-5. [PMID: 3341769 DOI: 10.1016/0003-9861(88)90098-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The effect of iron chelates on the reaction of cimetidine with Fenton reagent [Fe(II)/H2O2] has been investigated. Iron chelates with high affinity to ferrous ions inhibited this reaction. However, iron chelates with high affinity to ferric ions selectively promote either hydroxylation, N-demethylation, or sulfoxidation of cimetidine. These results indicate that the oxidation of cimetidine with hydrogen peroxide activated by various chelated ferrous ions serves as a biomimetic model for the regioselectivity of multiple forms of cytochrome P-450 in the metabolism of cimetidine.
Collapse
Affiliation(s)
- S Zbaida
- Department of Pharmacy, School of Pharmacy, Hebrew University of Jerusalem, Israel
| | | | | |
Collapse
|