MOLECULE

Cytidine

Cytidine, also known as Cyd or cytosine riboside, belongs to the class of organic compounds known as pyrimidine nucleosides. Pyrimidine nucleosides are compounds comprising a pyrimidine base attached to a ribosyl or deoxyribosyl moiety. APOBEC is a family of enzymes that has been discovered with the ability to deaminate cytidines on RNA or DNA. Cytidine is a nucleoside that is composed of the base cytosine linked to the five-carbon sugar D-ribose. Cytidine is an extremely weak basic (essentially neutral) compound (based on its pKa). In humans, cytidine is involved in the metabolic disorder called the congenital disorder of glycosylation cdg-iid pathway. An efficient mechanism mediating the brain uptake of circulating cytidine has not yet been demonstrated. The human apolipoprotein B mRNA-editing enzyme, catalytic polypeptide-like 3G protein (APOBEC3G, or hA3G), provides cells with an intracellular antiretroviral activity that is associated with the hypermutation of viral DNA through cytidine deamination. It is a precursor of cytidine triphosphate (CTP) needed in the phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthetic pathways. The transport of cytidine into the brain's extracellular fluid, and then into neurons and glia, are essential prerequisites for cytidine to be utilized in the brain. These variations probably reflect the species differences in cytidine deaminase, the enzyme that converts cytidine to uridine in the body. The enzyme that converts CTP to endogenous CDP-choline (CTP:phosphocholine cytidylyltransferase) is unsaturated at physiological brain CTP levels. Cytidine is expected to be in Cannabis as all living plants are known to produce and metabolize it.