Tisupurine is more water-soluble than mercaptopurine (6-MP). Easily release 6-MP under acidic condition or the existing of sulfhydryl compounds, has selectivity to tumor tissue.

• 磺巯嘌呤钠增加了药物的水溶性。遇酸性和巯基化合物均易释放出6-MP，对肿瘤组织有一定的选择性。