6-mercaptopurine ribonucleoside

It is particularly interesting that 6-mercaptopurine ribonucleoside (XXI) [158] is an inhibitor of, but not a substrate for, the kinase [47] but 6-(methylthio)purine ribonucleoside (XXII) [159, 160], resulting from the... 

Mercaptopurine ribonucleoside triphosphate is a potent inhibitor of adenylyl transfer to nicotinamide mononucleotide and is itself converted to the NAD analogue in vitro [355, 356]. Since it has not been established that 6-mercaptopurine is converted to its triphosphate in vivo, the significance of these observations is uncertain. It has also been suggested, but not established, that 6-mercaptopurirfe may interfere with co-factor A [357,358]. 

Certain derivatives of 6-mercaptopurine, such as 6-(methylthio)purine, 6-mercaptopurine-3-oxide [448a], and 6-mercaptopurine ribonucleoside and its acylated derivatives apparently owe their activity to their in vivo conversion to 6-mercaptopurine [11,13]. It would appear, however, that the 9-alkyl derivatives of 6-mercaptopurine, and its arabinosyl and xylosyl derivatives, are not metabolized-except in the case of the 9-alkyI derivatives, to a limited extent to their 5-glucuronides—and that their mechanism of action is quite different from that of 6-mercaptopurine. 

One of the first applications of CI-SIM to drug analysis involved the development of an analytical technique to quantitate selected anti-neoplastic agents (20). To test the method, an equimolar mixture of 5-fluoro-2 -deoxyuridine, 6-mercaptopurine ribonucleoside and arabinosylcytosine were added to mouse serum. Extraction and flash methylation yielded the methylated derivatives (15, 16 and respectively Fig. 7) which could be separated by GC. Th selected ion profiles of this extract, obtained by monitoring the MH of each derivative are shown in Fig. 8. This method has been used for the quantitation of arabinosylcytosine in mice serum (20). 

MERCAPTO-6-PROPYL-4-PYRIMIDONE see PNXOOO 2-MERCAPTO-6-PROPYLPYRIMID-4-ONE see PNXOOO 6-MERCAPTOPURIN see POKOOO MERCAPTOPURIN (GERMAN) see POKOOO 6-MERCAPTOPURINE see POKOOO MERCAPTOPURINE RIBONUCLEOSIDE see MCQ500... 

SYNS 6-MERCAPTOPURINE RIBOSIDE NSC-4911 RIBOFURANOSIDE, 9H-PURINE-6-THIOL-9 RIBOSYL-6-THIOPURINE THIONOSINE 6-THIOPURINE RIBONUCLEOSIDE 6-THIOPURINE RIBOSIDE TIOINOSINE... 

A series of 4 -substituted derivatives of 5-hydroxy-2-form ylpyridine thiosemi-carbazone (17) has been synthesized and evaluated as inhibitors of alkaline phosphatase activity of a murine ascitic cell line of Sarcoma 180 resistant to the antileukemic agents, 6-mercaptopurine and 6-thioguanine [23]. These agents were also tested as inhibitors of ribonucleoside diphosphate reductase from the... 

A number of purine nucleotide analogues can mimic the effects of natural purine ribonucleotides on PP-ribose-P amidotransferase and thereby effect feedback inhibition of the entire pathway (69, 60). Such nucleotide analogues may be synthesized by cells from purine bases or nucleosides presented to them. A number of compounds with potent inhibitory properties, such as 6-mercaptopurine, 6-thioguanine, and 6-methylmercaptopurine ribonucleoside, inhibit purine biosynthesis de novo in this way, although it is not known whether this action is responsible for the growth inhibition. 

Mercaptonurine - 5-Formamide-l-B-ribofuranosylthioimidazole-4-carboxamide 2, 3, 5 -triformate, is comparable with 6-mercaptopurine (6-MP) for the treatment of leukemias.33 it is cross-resistant with 6-MP. Conversion of 6-MP ribonucleoside to 6-MeMP ribonucleotide has been shown in L-1210 leukemia cells, adenocarcinoma 755 cells, H. Ep. No. 2 cells and other systems. 6-MeMP ribonucleotide is responsible for the inhibition of purine synthesis produced by 6-MP.3 Metabolism of 6-MeMP in Ehrlich ascites cells has been studied.Breakdown of the active nucleotide form of the 6-thlopurines by alkaline phosphohydrolase is probably responsible... 

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