6-Methylmercaptopurine ribonucleoside

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. 

FIGURE 4. The effect of pretreatment with 6-methylmercapto-purine ribonucleoside on the nucleotide profiles of Sarcoma 180 cells treated with 6-thioguanine. Sarcoma 180 cells were removed from mice 1 hour after incubation with 6-thioguanine. The dotted line indicates cells from mice that had been pretreated for 12 hours with 6-methylmercaptopurine ribonucleoside, and the solid line indicates cells from mice that had not been pretreated (12). 

Vogt MH, Stet EH, De Abreu RA et al. The importanee of methylthio-imp for methylmercaptopurine ribonucleoside (Me-MPR) eytotoxieity in molt F4 human malignant T-lymphoblasts. Biochim Biophys Acta 1993 1181 189-194. 

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