Uracil 6- methyl-, hydroxymethylation

Hydroxymethyl-6-methyluracil (1043) was prepared many years ago from 6-methyl-uracil and formaldehyde, or in other ways. Since 1956 it has received much attention in the USSR under the (transliterated) name pentoxyl or pentoxil. It is used in several anaemic and disease conditions. For example, a mixture of folic acid and pentoxyl quickly reduces the anaemia resulting from lead poisoning pentoxyl stimulates the supply of serum protein after massive blood loss it stimulates wound healing it stimulates the immune response in typhus infection and it potentiates the action of sulfonamides in pneumococcus infections (70MI21300). 

The bases always present in DNA are adenine, guanine, cytosine, and thymine, while in RNA the bases are adenine, guanine, cytosine, and uracil. Trace amounts of other bases are occasionally present in DNA and RNA. For example, DNA may contain 5-hydroxymethyl cytosine and several N-methyl purines. The tRNA may contain several unusual bases such as certain methyl purines or hydroxymethyl pyrimidines. 

Figure 3. OH radical-induced degradation of thymine. Oxidation involves either OH addition to the C5-06 double bond or OH-mediated hydrogen abstraction from the methyl group. Molecular oxygen then adds to the resulting carbon-centered radicals. This reaction yields hydroperoxide that further evolves into stable products, such as thymidine glycol (ThdGly), 5-hydroxymethyl-uracil (HMdUrd) and 5 formyl-uracil (5-FordUrd). N- represents the bond to the DNA backbone.

Uracil, 6-dimethoxymethyl-3-methyl-2-thio-synthesis, 3, 113 Uracil, 1,3-dimethyl-dimers, 3, 74 Uracil, 3,6-dimethyl-synthesis, 3, 106, 110 Uracil, 5-fluoro-as anticancer drug, I, 263 antineoplastic activity, 3, 152 as pharmaceutical, I, 159 reactions, 2, 59 synthesis, 3, 70 Uracil, 6-fluoro-hydrolysis, 3, 101 Uracil, 5-hydroxy-1,3-dimethyl-synthesis, 3, 133 Uracil, hydroxymethyl-oxidation, 3, 91... 

Nucleosides, Nucleotides, Derivatives, and Related Compounds. — 5-Substituted uracils were examined for conformational dependence on the substituents, uridine 5 -phosphate disodium salt, 2 -deoxyuridine 5 -phosphate disodium salt, " 6-methyl-2 -deoxyuridine, 5-C-acetyl-2 -deoxyuridine, dihydrouridine 3 -phosphate potassium salt, 5-hydroxymethyl-2 -deoxyuridine, 4-thio--uridine, 2,5 -anhydro-2, 3 -0-isopropylidene-2-thiouracil, 2,2 -an-hydro-1 - 3-D-arabinofuranosyl-2-thiouracil. ... 

Prior to the definitive experiments of Friedkin and Komberg (see below), early tracer studies with orotate and with nucleoside derivatives of uracil and cytosine had demonstrated that the pyrimidine ring of DNA thymine could be derived from these compounds. In addition, it had become apparent that the methyl group of thymine was derived from one-carbon units at the oxidation level of formaldehyde rather than at the oxidation level of formate formaldehyde and the hydroxymethyl group... 

The four bases mentioned account for most of those found in the DNA of higher forms of life. 5-methylcytosine forms the principal exception 25 per cent of the cytosine in the DNA of plants is in this form, but animals have much less, and bacteria have only 0--2 per cent (Vanyushin et al. 1968). Bacterial and viral DNAs sometimes contain other methylated bases, such as 6 -methyladenine, 2-methyladenine, or 5-hydroxymethyl-uracil. In some phages, all cytosine is replaced by 5-hydroxymethyl-cytosine, made by a virus-induced enzyme in the bacterial host (Cohen, 1963). 

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