5- ( hydroxymethyl ) chrysene ( 5-hcr ) sulfate , an active metabolite of the carcinogen 5-hcr , bound significantly in a covalent manner to the purine bases of calf thymus dna through its 5-methylene carbon with loss of a sulfate anion when incubated at ph 7.4 and 37 degrees c .
C0038720
sulfate
C0003075
anion