Nents, such as S-adenosylmethionine, or after reacting with two general classes of environmental and laboratory chemicals. S N 1 agents include alkylnitrosourea (e.g., MNU, ENU) and N-alkyl-N-nitro-N-nitrosoguanidine (e.g., MNNG) that react with the N7 position of guanine, N3 of adenine, O6 of guanine, O2 or O4 of pyrimidines, and the non-phosphodiester oxygen atoms of the phosphate backbone. In contrast, SN2 agents such as methyl methanesulfonate and dimethyl sulfate react primarily with the N1 position of adenine (1-Methyl-2’deoxyadenosine) and N3 of cytosine.11 To overcome the mutagenic and toxic effects of these modifications, cells produce a variety of DNA repair enzymes. For example, E.coli ogt and ada genes encode O6-methylguanine methyltransferases, while ada also encodes O4-methylthymine methyltransferase and methylphosphotriester methyltransferase activities, and alkB encodes an oxidative demethylase that directly reverses 1alkyladenine and 3-alkylcytosine lesions in DNA or RNA.12,13 The availability of m 1A 2`-deoxynucleoside (m1dA) phosphoramidite (2) will now enable researchers to synthesize substrate or prototype more easily. The m1dA phosphoramidite coupled very well (99%) at all coupling times tested with 0.45M 1H-Tetrazole in acetonitrile as activator, so a standard coupling method can be used for this amidite. We conducted a series of deprotection experiments on the deoxynucleoside to confirm the literature results and to see if we could use an alternate deprotection reagent.528-48-3 SMILES Since this m1dA is sensitive to rearrangement to m 6dA when using standard NH 4OH deprotection methods, we recommend the use of UltraMild phosphoramidites for the synthesis of oligonucleotides containing this sensitive modified base. We have found that deprotection of oligos containing m1dA using 2M anhydrous ammonia in methanol gave good results and a 24h deprotection time seems to be optimal. Again, the use of the UltraMild Cap A containing phenoxyacetic anhydride (Pac2O) is also to be recommended.
Other DNA Repair Substrates This addition to our catalogue is just another example of our commitment to provide the researcher interested in DNA damage and repair with the largest range of products in this field. We would like to review these products as follows. As mentioned above, DNA exposed to reagents like nitrosourea or dimethylsulfate result in different sorts of alkylation lesions. Most of these lesions modify the base pairing properties of the nucleobase (e.1599432-08-2 IUPAC Name g., DNA polymerases readily insert T opposite O6methyl-dG). We offer amidites that enable the incorporation of O6-methylguanine, N-6 methyladenine and O4-methylthymine.PMID:27809430 The 8-oxo purine monomers allow investigation of the structure and activity of oligonucleotides containing an 8-oxo mutation, which is formed naturally when DNA is subjected to oxidative conditions or ionizing radiation. 5,6-Dihydro pyrimidines are naturally occurring compounds that are structural components of alanine transfer RNA. Dihydrouracil and the hydroxy pyrimidines are major base damage products formed by exposure of DNA to ionizing radiation. 8-Amino-G is formed along with 8-oxoG as the major mutagenic lesions formed in DNA damage caused by 2-nitropropane. 2-Nitropropane is an industrial solvent and a component of paints, dyes and varnishes, and is also present in cigarette smoke. Thymine glycol (5,6-dihydroxy-5,6dihydrothymine) is formed when thymine is subjected to oxidative stress, including ionizing radiation.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com