Nutrition Guide

Uridine is found is a variety of foods. Sugarcane extract is rich in nucleosides, especially uridine.[2] Tomatoes also (about 500-1000 mg. of uridine per kilogram of dry matter).[3]

Brewer’s yeast is also a good source of uridine, as yeast is high in RNA (ribonucleic acid), which after digestion is broken down into ribosyl pyrimidines (uridine and cytidine), which are absorbed intact [4]. About 3 percent of yeast (dry weight) results in digestion uridine products. This assumes the usual 9% RNA content found in Brewer’s yeast. Alternatively, drinking beer also results in increased plasma uridine [5]. The ingestion of one liter of beer results in increased plasma uridine at a level that is comparable to those reached after ingestion of CDP-choline (citicoline) (as in [6], the increase is measured as a percent change relative to baseline plasma uridine). Alternative uridine/cytidine sources include other high RNA foods such as organ meats (liver, pancreas, etc) or broccoli [7]. High RNA foods may result in high blood purine levels, which may increase uric acid production in humans, which may aggravate conditions such as gout. Because of this, it has been suggested that the RNA content of yeast products should be chemically reduced if these products are to be consumed in high amounts as a source of protein (50 grams or more per day). However, such processing is expensive, and as of today (2008), it seems that commonly available Brewer’s yeast products are not RNA-reduced. Consumption of moderate amounts of yeast (5 grams per day) should provide enough uridine for improved health, while minimizing possible side effects such as increased uric acid production.

Uridine is a molecule (known as a nucleoside) that is formed when uracil is attached to a ribose ring (also known as a ribofuranose) via a ?-N1-glycosidic bond.

If uracil is attached to a deoxyribose ring, it is known as a deoxyuridine.

Harvard researchers report that supplementation in rats with a combination of uridine and EPA/DHA omega-3 fatty acids has antidepressant activity equivalent to that of commonly prescribed antidepressant medications, such as Prozac and other SSRIs. [1]

Iododeoxyuridine is a radiosensitizer and increases the amount of DNA damage received from ionizing radiation.

Azidothymidine (AZT) - used in the treatment of HIV infection. AZT inhibits the process of reverse transcription, a critical step in the viral life cycle.

Tritiated thymidine is commonly used in cell proliferation assays. The thymidine is incorporated into dividing cells and the level of this incorporation, measured using a liquid scintillation counter, is proportional to the amount of cell proliferation.

Bromodeoxyuridine (BrdU) is another thymidine analog that is often used for the detection of proliferating cells in living tissues.

In its composition, deoxythymidine is deoxyribose (a pentose sugar) joined to the pyrimidine base thymine.

Deoxythymidine can be phosphorylated with one, two or three phosphoric acid groups, creating respectively dTMP, dTDP or dTTP ((deoxy)thymidine mono- di- or triphosphate).

It exists in solid form as small white crystals or white crystalline powder, has a molecular weight of 242.229 u, and has a melting point of 185 °C. The stability of deoxythymidine under standard temperature and pressure (STP) is very high.

Deoxythymidine is non-toxic and as part of one of the four nucleotides in DNA it is a naturally occurring compound that exists in all living organisms and DNA viruses. RNA has uridine (uracil joined to ribose) instead. Uracil is chemically very similar to thymine, the latter being 5-methyluracil. Since thymine nucleotides are precursors of DNA, not RNA, the prefix “deoxy” is often left out, i.e., deoxythymidine is often just called thymidine.

Thymidine (more precisely called deoxythymidine; can also be labelled deoxyribosylthymine, and thymine deoxyriboside) is a chemical compound, more precisely a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. In cell biology it is used to synchronize the cells in S phase.

Before the boom in thymidine use caused by the need for thymidine for the production of the antiretroviral drug azidothymidine (AZT), much of the world’s thymidine production came from herring sperm.[1]

Queuosine is a modified nucleoside that is present in certain tRNAs in bacteria and eukaryotes.[1][2] Originally identified in E. coli, queuosine was found to occupy the first anticodon position of tRNAs for histidine, aspartic acid, asparagine and tyrosine.[3] The first anticodon position pairs with the third “wobble” position in codons, and queuosine improves accuracy of translation.[4][5][6] Synthesis of queuosine begins with GTP. In bacteria, two classes of riboswitch are known to regulate genes that are involved in the synthesis or transport of pre-queuosine1, a precursor to queuosine: PreQ1-I riboswitches and PreQ1-II riboswitches.

Pseudouridine (abbreviated ?) is the C-glycoside isomer of the nucleoside uridine, and it is the most prevalent of the over one hundred different modified nucleosides found in RNA.[1] ? is found in all species and in all classes of RNA including mRNA.[2][3] ? is formed by enzymes called ? synthases, which post-transcriptionally isomerize specific uridine residues in RNA in a process termed pseudouridylation.[4]

Recent studies suggest it may offer protection from radiation.[5]

Orotidine is a nucleoside formed by attaching orotic acid to a ribose ring via a ?-N1-glycosidic bond. It is found in bacteria, fungi and plants. It was first isolated in 1951 from the fungus Neurospora by A. Michael Michelson, William Drell, and Herschel K. Mitchell.[1] In humans, orotidine occurs as its 5′-phosphate (orotidylic acid), which is an intermediate in pyrimidine nucleotide biosynthesis (cytidine and uridine) that are found in nucleic acids. Orotidine itself is not a component of nucleic acid. Large amounts of orotidine are excreted in the urine of cancer patients treated with 6-azauridine

An NTP binding site is a type of binding site found in nucleoside monophosphate (NMP) kinases, N can be adenosine or guanosine. A P-loop is one of the structural motifs common for nucleoside triphosphate (NTP) binding sites, it interacts with the bound nucleotide’s phosphoryl groups. For the binding site to be able to bind a nucleotide, the nucleotide must be complex bound to Mg2+ og Mn2+. Nucleotide binding will cause conformational changes in the protein because the P-loop will bend.

In its composition, 5-methyluridine is ribose (a pentose sugar) joined to a pyrimidine base and is similar to cytidine, uridine, 2-deoxyuridine, 2-deoxyguanosine, and 2-deoxy-5-methyluridine.

It exists in solid form as small white crystals or white crystalline powder, has a molecular weight of 258.23 u, and has a melting point of 185 °C. The stability of 5-methyluridine under standard temperature and pressure (STP) is very high.