<prompt> In humans, end product of purine metabolism -AllantoinUric acidCO,None  <response>: Ans. is b i.e., Uric acid Catabolism of purine nucleotideso Humans catabolize purines adenine and guanine to uric acid.o In mammals other than higher primates in non primate mammals, uric acid is converted to water soluble allantion by enzyme uncase. However, human lack uricase, therefore the end product of purine catablism is uric acid, which is excreted. 