2,4-diaminohypoxanthine [ 2,4-DAHP,2,4-diamino-6-hydroxypyrimidine,2,4-diaminohypoxanthine sulfate,DHAP-2,4 ] do not confuse abbreviation DAHP with various dehydro-deoxy-arabino-heptulosonic acid phosphates which also use DAHP; RN given refers to parent cpd; structure