Reference

Electrochemical oxidation of 5-methyl-5,6,7,8-tetrahydropterin

Electrochemical oxidation of 5-methyl-5,6,7,8-tetrahydropterin. Karber, Lionel G.; Dryhurst, Glenn (Dep. Chem., Univ. Oklahoma, Norman, OK 73019, USA). J. Electroanal. Chem. Interfacial Electrochem., 160(1-2), 141-57 (English) 1984. CODEN: JEIEBC. ISSN: 0022-0728. DOCUMENT TYPE: Journal CA Section: 72 (Electrochemistry) Section cross-reference(s): 7, 22, 28 The electrochem. oxidn. of 5-methyl-5,6,7,8-tetrahydropterin (5-MTHP) [38365-04-7] in aq. soln. was studied. At, for example, pH 4. 17838-80-1 and 123-77-3 which are cas registry numbers of chemicals are mentioned.7 the primary oxidn. reaction responsible for the 1st voltammetric oxidn. peak appears to proceed by 2 pathways. The 1st of these is a 2e--2H+ process leading to a cationic intermediate that loses a Me carbonium ion yielding the same quinonoid-dihydropterin formed on 2e--2H+ electrooxidn. of 5,6,7,8-tetrahydropterin [1008-35-1]. This quinonoid-dihydropterin then undergoes rearrangement to 7,8-dihydropterin [17838-80-1] that in its covalently hydrated form is further oxidized yielding pterin [2236-60-4] and 7,8-dihydroxanthopterin [1131-35-7]. The 2nd route does not cause demethylation of 5-MTHP and yields 5-methyl-7,8-dihydroxanthopterin [52296-11-4]. .

Liquid chromatography assay of the calcium salt of citrovorum factor

Liquid chromatography assay of the calcium salt of citrovorum factor. Temple, Carroll, Jr.; Shortnacy, Anita T.; Montgomery, John A. (Kettering-Meyer Lab., South Res. Inst., Birmingham, Ala., USA). J. Chromatogr., 140(1), 114-17 (English) 1977. CODEN: JOCRAM. DOCUMENT TYPE: Journal CA Section: 64 (Pharmaceutical Analysis) Ca citrovorum factor (I Ca salt) [1492-18-8] and its impurities were detd. by high-performance liq. chromatog. on a .mu. Bondapak C18 packing using a citrate buffer-dioxane eluting system and elemental anal. The anal. of a 10.23 .mu.g sample by the technique yielded I 78, p-aminobenzoyl-L-glutamic acid [4271-30-1] 3.1, 10-formyl-7,8-dihydrofolic acid [17435-36-8] 4.6, 10-formylfolic acid [134-05-4] <0.5, pterin-6-methanol [712-29-8] 0.6, pterin [2236-60-4] 0.4, solvent (water + EtOH) 9.8, and unidentified material 3.0%. On an anhyd. basis the anal. gave 86% I and 14% impurities.