been reported to be a strong inhibitor of the growth of Streptococcus faecalis R. 3 but not of Adenocarci-nomu 755.* The closely related compound having an hydroxy group in place of the 7-amino group has been prepared as described below. It produces a 65% reduction in the growth of L. casei at a concentration of 0.005 mg./ml. 6 The effect can be reversed by pteroylglutamic acid or adenine. The results of screening against various tumors are to be ...
![7H-1,2,3-Triazolo[4,5-d]pyrimidin-7-one,3,4,5,6-tetrahydro-5-thioxo- Structure](https://image.chemsrc.com/caspic/073/31571-52-5.png)