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Chemical Research in Toxicology 1992A reaction pathway by which thiotepa (N,N',N''-triethylenethiophosphoramide) and tepa (N,N',N''-triethylenethiophosphoramide), its major metabolite in humans, alkylate...
A reaction pathway by which thiotepa (N,N',N''-triethylenethiophosphoramide) and tepa (N,N',N''-triethylenethiophosphoramide), its major metabolite in humans, alkylate and depurinate DNA involves hydrolysis to aziridine (ethylene imine), a highly reactive monofunctional alkylating agent. Hydrolytic cleavage of an N-P bond of thiotepa releases aziridine which reacts with DNA, resulting in depurination and formation of the stable N-7 adduct 7-(2-aminoethyl)guanine and an aminoethyl adduct of adenine. Chromatographically identical alkylated products were observed in the reaction of thiotepa and tepa with individual nucleosides. Adducts with deoxycytidine or thymidine were not detected. Aziridine was measured by HPLC after derivatization with 1,2-naphthoquinone 4-sulfate. On the basis of the identity of the DNA adducts and the rate of formation of aziridine by hydrolysis in vitro, thiotepa is concluded to be a lipophilic, stabilized form of aziridine which serves as a cell-penetrating carrier of aziridine.
Topics: Alkylating Agents; Aziridines; Chromatography, High Pressure Liquid; DNA; Hydrogen-Ion Concentration; Hydrolysis; Magnetic Resonance Spectroscopy; Mass Spectrometry; Models, Molecular; Nucleosides; Spectrophotometry, Ultraviolet; Thiotepa; Triethylenephosphoramide
PubMed: 1374653
DOI: 10.1021/tx00025a016 -
Materials Science & Engineering. C,... Apr 2016Small molecules that bind genomic DNA have proven that they can be effective anticancer, antibiotic and antiviral therapeutic agents that affect the well-being of... (Review)
Review
Small molecules that bind genomic DNA have proven that they can be effective anticancer, antibiotic and antiviral therapeutic agents that affect the well-being of millions of people worldwide. Drug-DNA interaction affects DNA replication and division; causes strand breaks, and mutations. Therefore, the investigation of drug-DNA interaction is needed to understand the mechanism of drug action as well as in designing DNA-targeted drugs. On the other hand, the interaction between DNA and drugs can cause chemical and conformational modifications and, thus, variation of the electrochemical properties of nucleobases. For this purpose, electrochemical methods/biosensors can be used toward detection of drug-DNA interactions. The present paper reviews the drug-DNA interactions, their types and applications of electrochemical techniques used to study interactions between DNA and drugs or small ligand molecules that are potentially of pharmaceutical interest. The results are used to determine drug binding sites and sequence preference, as well as conformational changes due to drug-DNA interactions. Also, the intention of this review is to give an overview of the present state of the drug-DNA interaction cognition. The applications of electrochemical techniques for investigation of drug-DNA interaction were reviewed and we have discussed the type of qualitative or quantitative information that can be obtained from the use of each technique.
Topics: Alkylating Agents; Anti-Bacterial Agents; Antineoplastic Agents; Biosensing Techniques; DNA; DNA Cleavage; Electrochemical Techniques; Humans; Intercalating Agents; Nanostructures; Pharmaceutical Preparations; Pharmacogenetics
PubMed: 26838928
DOI: 10.1016/j.msec.2015.12.020 -
Angewandte Chemie (International Ed. in... Jul 2016Our cells contain common molecules, such as water or oxygen, that can damage DNA. In his studies Tomas Lindahl has shown how specific repair enzymes remove and replace... (Review)
Review
Our cells contain common molecules, such as water or oxygen, that can damage DNA. In his studies Tomas Lindahl has shown how specific repair enzymes remove and replace damaged parts of DNA in a process of vital importance.
Topics: Alkylating Agents; DNA; DNA Damage; DNA Glycosylases; DNA Methylation; DNA Repair; S-Adenosylmethionine
PubMed: 27220039
DOI: 10.1002/anie.201602159 -
Chemical Research in Toxicology Oct 1999The purpose of this study was to examine the influence of cations on the formation of the individual DNA alkylation products derived from 1-(2-chloroethyl)-1-nitrosourea...
The purpose of this study was to examine the influence of cations on the formation of the individual DNA alkylation products derived from 1-(2-chloroethyl)-1-nitrosourea (CNU). Reaction of calf-thymus DNA with [(3)H]CNU in 10 mM triethanolamine buffer produced 13 DNA adducts. Seven of these adducts were identified as N7-(2-hydroxyethyl)guanine, N7-(2-chloroethyl)guanine, 1, 2-(diguan-7-yl)ethane, N1-(2-hydroxyethyl)-2-deoxyguanosine, 1-(N1-2-deoxyguanosinyl)-2-(N3-2-deoxycytidyl)ethane, O(6)-(2-hydroxyethyl)-2-deoxyguanosine, and phosphotriesters. The ratios of the individual products indicated that the chloroethyl and hydroxyethyl adducts are derived from different alkylating intermediates. The influence of cations on the formation of these DNA alkylation products was investigated by the addition of either NaCl, MgCl(2), or spermine. The results demonstrated that (1) the levels of DNA alkylation were inversely proportional to ionic strength, (2) the extent of inhibition was dependent on the alkylation product, and (3) the order of relative effectiveness of inhibition of DNA alkylation by these cations was as follows: spermine > Mg > Na. These results support a model whereby reactions which proceed via an S(N)2 mechanism are more sensitive to the effects of ionic strength than reactions which proceed via an S(N)1 mechanism. In 9L cells treated with CNU, the same alkylation products were formed as in purified DNA; however, the product distribution was different. We interpret this to indicate that within cells, cations modify the reaction of intermediates derived from CNU with DNA.
Topics: Alkylating Agents; Alkylation; Animals; Brain Neoplasms; Cations; Cattle; Chromatography, High Pressure Liquid; DNA Adducts; DNA, Neoplasm; Ethylnitrosourea; Magnesium Chloride; Rats; Sodium Chloride; Spermine; Tumor Cells, Cultured
PubMed: 10525273
DOI: 10.1021/tx980200c -
Mutation Research. Reviews in Mutation... 2016From a risk assessment perspective, DNA-reactive agents are conventionally assumed to have genotoxic risks at all exposure levels, thus applying a linear extrapolation... (Review)
Review
From a risk assessment perspective, DNA-reactive agents are conventionally assumed to have genotoxic risks at all exposure levels, thus applying a linear extrapolation for low-dose responses. New approaches discussed here, including more diverse and sensitive methods for assessing DNA damage and DNA repair, strongly support the existence of measurable regions where genotoxic responses with increasing doses are insignificant relative to control. Model monofunctional alkylating agents have in vitro and in vivo datasets amenable to determination of points of departure (PoDs) for genotoxic effects. A session at the 2013 Society of Toxicology meeting provided an opportunity to survey the progress in understanding the biological basis of empirically-observed PoDs for DNA alkylating agents. Together with the literature published since, this review discusses cellular pathways activated by endogenous and exogenous alkylation DNA damage. Cells have evolved conserved processes that monitor and counteract a spontaneous steady-state level of DNA damage. The ubiquitous network of DNA repair pathways serves as the first line of defense for clearing of the DNA damage and preventing mutation. Other biological pathways discussed here that are activated by genotoxic stress include post-translational activation of cell cycle networks and transcriptional networks for apoptosis/cell death. The interactions of various DNA repair and DNA damage response pathways provide biological bases for the observed PoD behaviors seen with genotoxic compounds. Thus, after formation of DNA adducts, the activation of cellular pathways can lead to the avoidance of a mutagenic outcome. The understanding of the cellular mechanisms acting within the low-dose region will serve to better characterize risks from exposures to DNA-reactive agents at environmentally-relevant concentrations.
Topics: Alkylating Agents; Alkylation; Apoptosis; DNA Adducts; DNA Damage; DNA Repair; Dose-Response Relationship, Drug; Humans; Mutagenicity Tests
PubMed: 27036068
DOI: 10.1016/j.mrrev.2015.11.001 -
Analytical Chemistry Dec 2015A high-resolution/accurate-mass DNA adductomic approach was developed to investigate anticipated and unknown DNA adducts induced by DNA alkylating agents in biological...
A high-resolution/accurate-mass DNA adductomic approach was developed to investigate anticipated and unknown DNA adducts induced by DNA alkylating agents in biological samples. Two new features were added to a previously developed approach to significantly broaden its scope, versatility, and selectivity. First, the neutral loss of a base (guanine, adenine, thymine, or cytosine) was added to the original methodology's neutral loss of the 2'-deoxyribose moiety to allow for the detection of all DNA base adducts. Second, targeted detection of anticipated DNA adducts based on the reactivity of the DNA alkylating agent was demonstrated by inclusion of an ion mass list for data dependent triggering of MS(2) fragmentation events and subsequent MS(3) fragmentation. Additionally, untargeted screening of the samples, based on triggering of an MS(2) fragmentation event for the most intense ions of the full scan, was included for detecting unknown DNA adducts. The approach was tested by screening for DNA mono and cross-linked adducts in purified DNA and in DNA extracted from cells treated with PR104A, an experimental DNA alkylating nitrogen mustard prodrug currently under investigation for the treatment of leukemia. The results revealed the ability of this new DNA adductomic approach to detect anticipated and unknown PR104A-induced mono and cross-linked DNA adducts in biological samples. This methodology is expected to be a powerful tool for screening for DNA adducts induced by endogenous or exogenous exposures.
Topics: Alkylating Agents; Alkylation; Chromatography, Liquid; Cross-Linking Reagents; DNA; Tandem Mass Spectrometry
PubMed: 26509677
DOI: 10.1021/acs.analchem.5b02759 -
Teratogenesis, Carcinogenesis, and... 2000The interaction of the DNA-alkylating model compounds, ethylmethanesulfonate (EMS) and methylnitrosourea (MNU), was studied in pregnant NMRI mice by measuring DNA...
The interaction of the DNA-alkylating model compounds, ethylmethanesulfonate (EMS) and methylnitrosourea (MNU), was studied in pregnant NMRI mice by measuring DNA adduction in vivo. Previously, large-scale dose-response studies on teratogenicity as well as on DNA modification were performed using these substances. In addition, the risk of low doses in mice was estimated by comparative use of several approaches including molecular dosimetry. The risk was further analysed by combination experiments on teratogenesis with EMS and MNU. This paper describes a further approach with regard to an interaction of these compounds: the formation of DNA adducts was determined using a combined treatment regimen of [(14)C]-labelled MNU and EMS. The mutual influence of EMS and MNU on the DNA alkylation rates was found to be moderate. The dramatic increase in the teratogenic outcome following combined treatment found in previous studies was obviously not due to a massive interaction regarding the initial DNA alkylation rates. It may be explained, however, by the concept of toxic equivalency. Teratogenesis Carcinog. Mutagen. 20:27-34, 2000.
Topics: Alkylating Agents; Alkylation; Animals; DNA; DNA Damage; DNA Methylation; Drug Synergism; Embryo, Mammalian; Ethyl Methanesulfonate; Female; Guanine; Injections, Intraperitoneal; Liver; Male; Methylnitrosourea; Mice; Mice, Inbred Strains; Pregnancy
PubMed: 10607375
DOI: No ID Found -
Chemical Research in Toxicology 1992The reactions of calf thymus DNA with four 1,3-dialkyl-3-acyltriazenes were studied alone or in the presence of pig liver esterase in pH 7.4 phosphate buffer for varying...
The reactions of calf thymus DNA with four 1,3-dialkyl-3-acyltriazenes were studied alone or in the presence of pig liver esterase in pH 7.4 phosphate buffer for varying lengths of time. The best alkylating agent in the absence of esterase was determined to be 1,3-dimethyl-3-carbethoxytriazene (DMC), followed in order by 1-(2-hydroxyethyl)-3-methyl-3-carbethoxytriazene (HMC), 1-(2-hydroxyethyl)-3-methyl-3-acetyltriazene (HMA), and 1-(2- chloroethyl)-3-methyl-3-carbethoxytriazene (CMC). This order is the same as that for the rate of decomposition of the various acyltriazenes in pH 7.5 phosphate buffer. The extent of calf thymus DNA alkylation by CMC was found to be dependent on both the reaction buffer and the ionic strength of the medium. Alkylation by CMC alone in low ionic strength glycine buffer produced large quantities of 7-(2-chloroethyl)guanine and 7-(2-hydroxyethyl)guanine. The products of DNA alkylation observed at neutral pH are consistent with N(2)-N(3) heterolysis of the triazene, resulting in the N(1) alkyldiazonium ion as the sole alkylating species. In the presence of esterase, CMC showed an enhanced rate of product formation. Furthermore, the product distribution shifted dramatically from mainly hydroxyethylation to predominantly methylation. CMC is postulated to undergo initial enzymatic deacylation, leading to two different alkyldiazonium ions which competitively alkylate DNA. HMC, on the other hand, was little affected by the esterase. The enzyme-catalyzed reaction showed a small increase in methylation and a smaller decrease in hydroxyethylation.(ABSTRACT TRUNCATED AT 250 WORDS)
Topics: Alkylating Agents; Animals; Catalysis; Cattle; DNA; Esterases; Kinetics; Triazenes
PubMed: 1391620
DOI: 10.1021/tx00028a013 -
Journal of Pharmaceutical and... Jan 2023Alkylating agents were among the first anticancer drugs to be discovered and continue to be the most commonly used in chemotherapy. They are electrophiles that react... (Review)
Review
Alkylating agents were among the first anticancer drugs to be discovered and continue to be the most commonly used in chemotherapy. They are electrophiles that react with the ring nitrogen and extracyclic oxygen atoms of DNA bases, forming covalent adducts that further lead to cross-linking of DNA strands, abnormal base pairing or DNA strand breaks. The investigation and quantitative analysis of alkylating agents in biological samples are essential for monitoring the therapy progression and efficiency, understanding their pharmacokinetics and develop new more effective and specific chemotherapeutical drugs. Among biotechnological methods, electrochemical techniques are particularly important in pharmaceutical medicine, owing to their rapid detection, great sensitivity, robustness, exceptional detection limits, ability to be used with small analyte volumes in turbid biofluids, and easy adaptability to miniaturization and point-of-care (POC) testing. This article provides first an exhaustive review concerning the electrochemical methods of characterization and quantification of different classes of chemotherapeutic alkylating agents (triazenes and hydrazines, nitrosoureas, nitrogen mustards, oxazaphosphorines, alkyl alkane sulfonates and ethylene imines) in standard samples, pharmaceutical formulations and biological matrixes. The second part of the article focuses on the recent electrochemical methodologies and DNA-electrochemical biosensors developed to study the interaction of alkylating agents with DNA. These studies are relevant for obtaining real-time details about the alkylating agents' mechanism of action and for assessing the oxidative DNA damage they cause, important for the development of improved antineoplastic drugs.
Topics: Electrochemistry; Antineoplastic Agents, Alkylating; Alkylating Agents; DNA; Antineoplastic Agents; Nitrogen; Pharmaceutical Preparations
PubMed: 36244084
DOI: 10.1016/j.jpba.2022.115036 -
The Journal of Organic Chemistry Jun 2000The synthesis of 1,2,8,8a-tetrahydrocyclopropa[c]pyrrolo[3, 2-e]indol-4(5H)-one (CPI), the parent CC-1065 and duocarmycin SA alkylation subunit, is detailed. The parent...
Synthesis and evaluation of 1,2,8, 8a-Tetrahydrocyclopropa[c]pyrrolo[3,2-e]indol-4(5H)-one, the parent alkylation subunit of CC-1065 and the duocarmycins: impact of the alkylation subunit substituents and its implications for DNA alkylation catalysis.
The synthesis of 1,2,8,8a-tetrahydrocyclopropa[c]pyrrolo[3, 2-e]indol-4(5H)-one (CPI), the parent CC-1065 and duocarmycin SA alkylation subunit, is detailed. The parent CPI alkylation subunit lacks the C7 methyl substituent of the CC-1065 alkylation subunit and the C6 methoxycarbonyl group of duocarmycin SA, and their examination permitted the establishment of the impact of these natural product substituents. The studies revealed a CPI stability comparable to the CC-1065 alkylation subunit but which was 6x more reactive than the (+)-duocarmycin SA alkylation subunit, and it displayed the inherent reaction regioselectivity (4:1) of the natural products. The single-crystal X-ray structure of (+)-N-BOC-CPI depicts a near identical stereoelectronic alignment of the cyclopropane accounting for the identical reaction regioselectivity and a slightly diminished vinylogous amide conjugation relative to (+)-N-BOC-DSA suggesting that the stability distinctions stem in part from this difference in the vinylogous amide as well as alterations in the electronic nature of the fused pyrrole. Establishment of the DNA binding properties revealed that the CPI-based agents retain the identical DNA alkylation selectivities of the natural products. More importantly, the C6 methoxycarbonyl group of duocarmycin SA was found to increase the rate (12-13x) and efficiency (10x) of DNA alkylation despite its intrinsic lower reactivity while the CC-1065 C7 methyl group was found to slow the DNA alkylation rate (4x) and lower the alkylation efficiency (ca. 4x). The greater DNA alkylation rate and efficiency for duocarmycin SA and related analogues containing the C6 methoxycarbonyl is proposed to be derived from the extended length that the rigid C6 methoxycarbonyl provides and the resulting increase in the DNA binding-induced conformational change which serves to deconjugate the vinylogous amide and activate the alkylation subunit for nucleophilic attack. The diminished properties resulting from the CC-1065 C7 methyl group may be attributed to the steric impediment this substituent introduces to DNA minor groove binding and alkylation. Consistent with this behavior, the duocarmycin SA C6 methoxycarbonyl group increases biological potency while the CC-1065 C7 methyl group diminishes it.
Topics: Alkylating Agents; Alkylation; Antibiotics, Antineoplastic; Base Sequence; Crystallography, X-Ray; DNA; DNA, Viral; Duocarmycins; Indicators and Reagents; Indolequinones; Indoles; Leucomycins; Models, Molecular; Molecular Conformation; Molecular Structure; Oligodeoxyribonucleotides; Pyrroles; Quinolones
PubMed: 10866627
DOI: 10.1021/jo000297j