Biotin is an organic heterobicyclic compound that consists of 2-oxohexahydro-1H-thieno[3,4-d]imidazole having a valeric acid substituent attached to the tetrahydrothiophene ring. The parent of the class of biotins. It has a role as a prosthetic group, a coenzyme, a nutraceutical, a human metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite, a cofactor and a fundamental metabolite. It is a member of biotins and a vitamin B7. It is a conjugate acid of a biotinate.