Purine 6-mercapto

Purine, 6-iodo-alkylation, 5, 530 synthesis, 5, 563, 597 Purine, 6-iodo-9- -D-(2,3,5-tri-0-acetyl)ribofuranosyl-synthesis, 5, 598 Purine, 9-isopropyl-deuterium-hydrogen exchange, 5, 527 Purine, 9-(2,3-0-isopropylidene-/3-D-ribofuranosyl)-6-methoxy-synthesis, 5, 584 Purine, 6-mercapto-biological activity, 5, 604 metabolism, 1, 237 as pharmaceutical, 1, 159 tautomerism, 5, 509 Purine, 2-methoxy-synthesis, 5, 596 Purine, 6-methoxy-irradiation, 5, 543 riboside... 

According to the systematic nomenclature these substances were first named l-f-triazolo[d] pyrimidines in compliance with the general principles of the Ring Index/ More recent papers and Chemical Abstracts indexes use the term i -triazolo[4,5-d]pyrimidine (147) in accord with the lUPAC nomenclature. The numbering of substituents when using the last-mentioned name is different from that of the 8-aza analogs. For the formulas of oxygen and sulfur derivatives names derived from the lactim or thiolactim form are almost exclusively in use (in common with the purine derivatives). These derivatives are thus described as hydroxy and mercapto derivatives, respectively. The name 1,2,3,4,6-pentaazaindene is used only rarely for this system. 

Mercaptopurine probably exists in a thione form (e.g., 167) since its ultraviolet spectrum is different from that of 2-(methylthio)pur-ine. Purine-2-thione and its 6-amino derivative were assigned thione structures on the basis of their infrared spectra.8-Mercapto-9-methyl- and b-mercapto-T-methjd-purine exist at least partially in thione forms, presumably 168 and 169, respectively, since their in-... 

Deficiency of thiopurine S-methyl transferase (TPMT) is another phenotype that exhibits inter-ethnic differences in frequency. TPMT is an enzyme that catalyzes methylation of therapeutic agents used in the treatment of acute lymphoblastic leukemia, rheumatoid arthritis, and autoimmune/inflammatory diseases, as well as in organ transplantation. Patients who have TPMT deficiency experience less efficient methylation and are at greater risk of fatal toxicity when treated with standard doses of fhiopurines. TPMT phenotype is defined by erythrocyte 6-mercapto-purine methylation. African American populations exhibit a 20% lower erythrocyte TPMT than Caucasian Americans, and persons of Chinese descent tend to exhibit greater activity than either of these other American subpopulations. 

Mercapto- - purine analogue antimetabolite predominantly S-phase ... 

Although demethylation, which occurs in the liver, is normally considered to be a catabolic process, it may result in conversion of an inactive form of a drug to the active form. Thus 6-(methylthio)purine (XXXIX) is demethylated by the rat to 6-mercaptopurine [205]. This demethylation occurs in the liver micro-somes and is an oxidative process which converts the methyl group to formaldehyde [204, 207]. The 1-methyl derivative of 4-aminopyrazolo[3,4-d] pyrimidine (XLI) is demethylated slowly, but 6-mercapto-9-methylpurine (XLII) not at all [208]. The A -demethylation of puromycin (XLlIl) [209, 210], its aminonucleoside (XLIV) [211], and a number of related compounds, including V-methyladenine and V,V-dimethyladenine, occurs in the liver microsomes of rodents [212]. In the guinea-pig the rate-limiting step in the metabolism of the aminonucleoside appears to be the demethylation of the monomethyl compound, which is the major urinary metabolite [213]. The relationship of lipid solubility to microsomal metabolism [214], and the induction of these demethylases in rats by pre-treatment with various drugs have been studied [215]. 

Vivoni etal. [207] have employed SERS to determine orientation of 6-mercapto-purine (6MP) molecules adsorbed on the roughened Ag electrode. It has been concluded that 6MP are attached head-on via N1 atom when the molecule is adsorbed onto a silver electrode surface. 

Basosi, R., Gaggelli, E., Tiezzi, E., and Valensin, G. (1975). Nitrosyliron complexes with mercaptO purines and -pyrimidines studied by nuclear magnetic and electron spin resonance spectroscopy. J. Chem. Soc. Perkin Trans. 2, 423-428. 

Mononuclear complex formation was confirmed for the adduct of zinc(II) salt with 2-mercaptobenzothiazole and o-phenanthroline (253). The t/-S coordination is observed in the complexes of triphenylphos-phine gold with 2-mercapto-l-methylimidazole (254) (88JOM119), 8-mercaptotheophilline (255) (91IC3743), 2-mercaptobenzoxazole (256) [94AX(C)1420], and purine-6-thiol (257) (94AJC577). 

Thiols and disulfides Cyclic and acyclic sulfides Mercapto-purines, -pyrimidines, -imidazoles Dithio acids and dithiocarbamides Thiocarbamides and thioamides... 

AZATHIOPRINE CHLORAMBUCIL, CISPLATIN, CYCLOPHOSPHAMIDE, CYTARABINE, DACTINOMYCIN (ACTINO-MYCIN D), DAUNORU-BICIN, DOCETAXEL, DOXORUBICIN, ETOPO-SIDE, FLUOROURACIL, MELPHALAN, MERCAPTO-PURINE, MITOXANTRONE, VINCA ALKALOIDS t risk of myelosuppression and immunosuppression. Deaths have occurred following profound myelosuppression and severe sepsis Additive myelotoxic effects. Azathioprine is metabolized to 6-mercatopurine in vivo, which results in additive myelosuppression, immunosuppression and hepatotoxicity Avoid co-administration... 

H-Purin 2-(N-Methyl-hydroxyami-no)-6-mercapto- E16a, 109 (N-Hetaryl.)... 

H-Purin 1-Ethyl-2,7-dimethyl-8-mercapto-6-oxo-1,6-dihydro-E9b/2, 377 [5-COOR-4-(NH-Ac) —1-R —2-SH —imidazol 4-R-NH2]... 

METHYLNITROIMIDAZOLYLMERCAPTOPURINE 6-(T-METHYL-4 -NITRO-5 -IMIDAZOLYL)-MERCAPTO-PURINE 6-(METHYL-p-NITRO-5-IMIDAZOLYL)-THIOPURINE 6-(l-METHYL-p-NITRO-5-IMIDAZOL-YL)-THIOPURINE 6-((l-METHYL-4-NITROIMIDAZOL-5-YL)THIO)PURINE 6-(l-METHYL-4-NITROIMIDAZ-OL-5-YLTHIO)PURINE 6-((l-METHYL-4-NITRO-lH-IMDAZOL-5-YL)THIO)-lH-PURINE NCI-C03474 NSC-39084 RORASUL... 

SYNS l,7-DIHYDRO-6H-PURINE-6-THIONE ISMIPUR LEUKERAN LEUPURIN MERC-ALEUKIN MERCAPTOPL RIN (GERMAN) 6-MERCAPTOPURIN 6-MERCAPTOPURINE 7-MERCAPTO-l,3,4,6-TETRAZAINDENE MERCAPURIN... 

Rhodanines, as intermediates, in synthesis of amino adds peptides and purines, 167 Rhodaninic acid, see 2-Mercapto-4-hydroxy-thiazole Rhodanine Rhodanine, modes of preparation, 19 /V-phenyl, preparation, 19 /V-substituted, preparation, 20 structure of, 19... 

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