Adenine 1,3-dimethyl

Adenine, 9-( 5-2,3-dihydroxypropyl)-biological activity, 5, 603 Adenine, 1,9-dimethyl-synthesis, 5, 585 Adenine, 2,8-dimethyl-synthesis, 5, 570 Adenine, 3,9-dimethyl-synthesis, 5, 586 Adenine, N, AT -dimethyl-... 

UV photoelectron spectra, 5, 517 Adenine, N ,9-dimethyl-UV photoelectron spectra, 5, 517 Adenine, 9-ethyl-IR spectra, 5, 518... 

Cleavage at A or G If the DNA is first treated with acid, dimethyl sulfate methylates adenine at the 3-position as well as guanine at the 7-position (not shown). Subsequent reaction with OH and piperidine triggers degradation and displacement of the methylated A or G purine base and strand scission, essentially as indicated here for reaction of dimethyl sulfate with guanine. 

B-i = Benzylated Adenine, B2 = Thymine Bi = Benzylated Cytosine, B2 = Thymine Z = Dimethyl Triptophan, B- = B2 = Thymine... 

The macrolide erythromycin inhibits protein synthesis and resistance is induced by N -dimethyl-ation of adenine within the 23S rRNA, which results in reduced affinity of ribosomes for antibiotics related to erythromcin (Skinner et al. 1983). Sulfonamides function by binding tightly to chromosomal dihydropteroate synthetase and resistance to sulfonamides is developed in the resistance plasmid through a form of the enzyme that is resistant to the effect of sulfonamides. 

Pd(PPh3)4 and N,N -dimethyl-NfNf-propylene urea (DMPU). The product of this reaction 315 was a key intermediate in the synthesis of (Z)-olefinic RNA containing adenine and thymine as bases. 

Knowledge of the coenzyme forms of vitamin Bi2 has increased steadily. The first coenzyme of Bi2 isolated from bacteria had similarities to pseudovitamin Bi2 it contained adenylic acid instead of 5,6-dimethyl-benzimidazole, but differed in lacking cyanide and having an extra molecule of adenine which was assumed to be bound to the cobalt atom by the coordination site, often occupied by cyanide (B24). This coenzyme, adenylcobamide, was completely inactive for Ochromonas malhamensis, but active for Escherichia coli 113-3. 

Dimethyl sulfate is an effective methylating agent (see Section 7.13.1). Methylation of the purine rings in gnanine and adenine makes them susceptible to hydrolysis and snbseqnent rnptnre. This, in tnm, makes the glycosidic bond vnlnerable to attack, and the heterocycle is displaced from the phosphodiester. The phosphodiester bond can then cleaved by basic hydrolysis (aqueons piperidine). 

LSDl, also known as BHCllO, is the first lysine specific demethylase that was discovered. It has been assigned to group I of lysine demethylases (KDMl) [90, 91]. LSDl contains an amine oxidase domain responsible of the enzymatic activity and has been isolated as a stable component from several histone modifying complexes. The enzymatic characterization of this protein revealed that FAD (flavine adenine dinucleotide) is required as a cofactor for the removal of the methyl group. Furthermore, LSDl requires a protonated nitrogen in order to initiate demethylation so that this enzyme is only able to demethylate mono- or dimethylated substrates but not trimethylated substrates [98, 99]. 

Riboflavin (vitamin Bj) is chemically specified as a 7,8-dimethyl-10-(T-D-ribityl) isoalloxazine (Eignre 19.22). It is a precnrsor of certain essential coenzymes, such as flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD) in these forms vitamin Bj is involved in redox reactions, such as hydroxylations, oxidative carboxylations, dioxygenations, and the reduction of oxygen to hydrogen peroxide. It is also involved in the biosynthesis of niacin-containing coenzymes from tryptophan. 

The template polymerization was carried out at GO C in dimethyl sulfoxide/ethylene glycol mixture using AIBN as radical initiator. It was found that under these conditions interaction between adenine and uracil groups is remarkable. 

ATP, adenosine 5 -triphosphate BH4, 5,6,7,8-tetrahydrobiopterin BMPO, 5- er -butoxycarbonyl-5-pyrroline A-oxide DBNBS, 3,5-dibromo-4-nitrosoben-zene sulfonate DEPMPO, 5-diethoxyphosphoryl-5-methyl-l-pyrroline A-ox-ide DMPO, 5,5-dimethyl- 1-pyrroline A-oxide EMPO, 5-ethoxycarbonyl-5-methyl-l-pyrroline A-oxide GSH, glutathione (y-L-glutamyl-L-cysteinyl-glycine) HRP, horseradish peroxidase MNP, 2-methyl-2-nitrosopropane MPO, myeloperoxidase NAD(P)H, fl-nicotinamine adenine dinucleotide (3 -phosphate), reduced from NMDA, A-methyl-D-aspartic acid PBN, N-tert-butyl-a-phenylnitrone PMN, polymorphonuclear lymphocyte POBN, a-(4-pyridyl-l-oxide)-A-fer -butylnitrone SOD, superoxide dismutase TEMP,... 

Abbreviations used in this table MPT designates molybdopterin MGD designates MPT guanine dinucleotide MCD designates MPT cytosine dinucleotide N-His, O-Ser, S-Cys, Se-Cys designate attachments from protein residues histidine, serine, cysteine and selenocysteine. b Flavin adenine dinucleotide — FAD. c Dimethyl sulfoxide — DMSO. 

There are two symmetry-independent molecules in N(6),N(9) dimethyl adenine [DMADEN10] (Fig. 15.20) with very similar, simple hydrogen bonding. Both have the N(6) methyl group cis to N(l), and this conformation gives rise to an intramolecular NH- N(7) bond as minor componnt of a three-center bond. As with the preceding structure, /N(3) is not an acceptor. 

DMADEN10. N(6),N(9)-Dimethyl-adenine ( HjNj). Sternglanz H, Bugg CE (1978) J Cryst Mol Struct 8 263... 

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