Adenosylcobalamin is a biologically active form of vitamin B12 .It is a cofactor for methylmalonyl CoA mutase.?It belongs to the corrinoid group of compounds, which contain a corrin macrocycle, and is produced only by certain bacteria and archaea.?

2'-Deoxyguanosine (Guanine deoxyriboside) is a purine nucleoside that is recognized by members of the 2'-dG-II family.2'-Deoxyguanosine has been associated with aging, mutation, and carcinogenesis, and is oxidized by molecular oxygen.

1-Methylhistamine dihydrochloride is a major metabolite of histamine by histamine N-methyltransferase in the pathway of histidine metabolism.?It has been used as a biomarker of histaminergic system activity in the brains of Alzheimer's disease patients as well as those with hypersomnia and other neurological conditions.