Nucleotides and Nucleosides

Definition of Nucleosides

Pentose and purine bases or pyrimidine bases are linked by glycosidic bonds called nucleosides. The nucleosides in RNA are composed of ribose as the sugar group and are called ribonucleosides. The sugar group in DNA is deoxyribose, so it is called deoxyribonucleoside. There are adenine deoxynucleosides, guanine deoxynucleosides, thymine deoxynucleosides and cytosine deoxynucleosides in DNA. In various nucleosides, the first carbon atom (C-1) of the sugar group is connected to the base through the N atom of the base. If the base is pyrimidine, the first nitrogen atom (N-1) of the base is bound; if the base is purine, the 9th nitrogen atom (N-9) of the base is bound.

Definition of Nucleotide

The pentose hydroxyl group in the nucleoside and the phosphoric acid are linked together in the form of a phosphate bond to form a nucleotide. Nucleotides in most organisms are first phosphorylated by the hydroxyl group on C-5 of ribose or deoxyribose to form nucleoside monophosphates. The nucleoside monophosphate is further phosphorylated to produce nucleoside diphosphate and nucleoside triphosphate. Take ribonucleotides as an example. In addition to AMP, there are two forms of adenosine diphosphate (ADP) and adenosine triphosphate (ATP). The diphosphates and triphosphates of nucleotides are mostly metabolic intermediates related to nucleotides or regulatory substances of enzyme activity and metabolism, and they are also important forms of physiological energy storage and provision of energy.

Antiviral mechanism of nucleoside and nucleotide analogs (NAs)

Nucleoside and nucleotide analogs (NAs) are an important class of drugs clinically used to treat viral infectious diseases, tumors, and AIDS. NAs account for more than half of the antiviral drugs currently on the market, which play an important role in antiviral therapy. NAs are used as viral polymerase or reverse transcriptase inhibitors. After entering the cell, they are gradually phosphorylated into nucleoside triphosphate analogs to exert antiviral effects. NAs inhibit virus replication through one or more non-mutation mechanisms. First, the incorporation of exogenous nucleotides during viral genome replication may cause the termination of replication. Secondly, NAs may bind to the extended nucleotide chain, causing natural nucleotide mismatches or substitutions, thereby introducing mutations and impairing RNA synthesis or protein expression. Through these mechanisms, NAs change the genetic composition of the virus, leading to the death of the virus. Creative Peptides is committed to providing customers with a rich variety of nucleotides and nucleosides analogs.