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Dipeptides
A dipeptide is an organic compound derived from two amino acids. The constituent amino acids can be the same or different. When different, two isomers of the dipeptide are possible, depending on the sequence. Several dipeptides are physiologically important, and some are both physiologically and commercially significant. A well known dipeptide is aspartame, an artificial sweetener. Dipeptides are white solids. Many are far more water-soluble than the parent amino acids. For example, the dipeptide Ala-Gln has the solubility of 586 g/L more than 10x the solubility of Gln (35 g/L). Dipeptides also can exhibit different stabilities, e.g. with respect to hydrolysis. Gln does not withstand sterilization procedures, whereas this dipeptide does. Because dipeptides are prone to hydrolysis, the high solubility is exploited in infusions, i.e. to provide nutrition. Examples Commercial value About six dipeptides are of commercial interest. *Aspartame (''N''-L-α-aspartyl-L-phenylal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenortide
The xenortides (A-D) are a class of linear peptides isolated from the bacterium ''Xenorhabdus nematophila'',{{Cite journal, last=Lang, first=Gerhard, last2=Kalvelage, first2=Tim, last3=Peters, first3=Arne, last4=Wiese, first4=Jutta, last5=Imhoff, first5=Johannes F., date=2008-06-01, title=Linear and Cyclic Peptides from the Entomopathogenic Bacterium Xenorhabdus nematophilus, journal=Journal of Natural Products, volume=71, issue=6, pages=1074–1077, doi=10.1021/np800053n, pmid=18491867, issn=0163-3864 a symbiont of the entomopathogenic nematode ''Steinernema carpocapsae''. This class of compounds is known for their insect virulence and cytotoxicity, cytotoxic biological activities. The tryptamide containing compounds (xenortides B and D) show higher biological activity than the phenylethylamides (xenortides A and C). The most biologically active compound was found to be xenortide B with a potency of less than 1.6 μM activity against ''Trypanosoma brucei rhodesiense'' (sleeping sic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carnosine
Carnosine (''beta''-alanyl-L-histidine) is a dipeptide molecule, made up of the amino acids beta-alanine and histidine. It is highly concentrated in muscle and brain tissues. Carnosine was discovered by Russian chemist Vladimir Gulevich. Carnosine is naturally produced by the body in the liver from beta-alanine and histidine. Like carnitine, carnosine is composed of the root word ''carn'', meaning "flesh", alluding to its prevalence in meat. There are no plant-based sources of carnosine. Carnosine is readily available as a synthetic nutritional supplement. Carnosine can chelate divalent metal ions. Carnosine is also considered a geroprotectant. Products containing carnosine are also used in topical preparations to reduce wrinkles on the skin. Carnosine may increase the Hayflick limit in human fibroblasts, it also appears to reduce the rate of telomere shortening. This could potentially promote the growth of certain cancers that thrive due to telomere preservation. Biosyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ala-Gln
Alanyl-glutamine is a chemical compound which in the form L-alanyl-L-glutamine is used in dietary supplementation, in parenteral nutrition, and in cell culture. It is a dipeptide consisting of alanine and glutamine. Dietary supplement As a dietary supplement, alanyl-glutamine protects the gastrointestinal tract. The protective effect reduces bacterial translocation, thus reducing the risk of infections and infection-related problems such as diarrhea, dehydration, malabsorption, and electrolyte imbalance. Parenteral nutrition At room temperature with 1 atmosphere of pressure, L-alanyl-L-glutamine has a solubility of about 586 g/L, which is more than 10 times glutamine's solubility (35 g/L). Also, glutamine does not withstand sterilization procedures, whereas alanyl-glutamine does. Alanyl-glutamine's high solubility makes it valuable in parenteral nutrition. Cell culture In cell culture, L-alanyl-L-glutamine is sometimes used as a replacement for L-glutamine because this d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcarnosine
''N''-Acetylcarnosine (NAC) (not to be confused with N-Acetylcysteine, which is also abbreviated "NAC") is a naturally occurring compound chemically related to the dipeptide carnosine. The NAC molecular structure is identical to carnosine with the exception that it carries an additional acetyl group. The acetylation makes NAC more resistant to degradation by carnosinase, an enzyme that breaks down carnosine to its constituent amino acids, beta-alanine and histidine. Actions Carnosine and metabolic derivatives of carnosine, including NAC, are found in a variety of tissues but particularly muscle tissue. These compounds have varying degrees of activity as free radical scavengers. It has been suggested that NAC is particularly active against lipid peroxidation in the different parts of the lens in the eye. It is an ingredient in eye drops that are marketed as a dietary supplement (not a drug) and have been promoted for the prevention and treatment of cataracts. There is scant evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anserine
Anserine (β-alanyl-''3''-methylhistidine) is a dipeptide containing β-alanine and 3-methylhistidine. Anserine is a derivative of carnosine, which has been methylated. Anserine has biological activities similar to those of carnosine, including buffering activity, antioxidant properties, metal ion chelation, and anti-aggregation effects. Both anserine and carnosine chelate copper. Because of its methylation, anserine is more stable in serum and resistant to degradation than carnosine. Compared with carnosine, anserine have a higher antioxidant capacity. Anserine can be found in the skeletal muscle and brain of mammals and birds. Anserine is also found in human kidney. The pKa of the imidazole ring of histidine, when contained in anserine, is 7.04. Biosynthesis Anserine can be synthesized through methylation of carnosine, by carnosine N-methyltransferase (''CARNMT1''). Anti-inflammatory effects High concentration of anserine reduced interstitial inflammation and allevia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyotorphin
Kyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. It was first isolated from bovine brain, by Japanese scientists in 1979. Kyotorphin was named for the site of its discovery, Kyoto, Japan and because of its morphine- (or endorphin-) like analgesic activity. Kyotorphin has an analgesic effect, but it does not interact with the opioid receptors. Instead, it acts by releasing met-enkephalin and stabilizing it from degradation. It may also possess properties of neuromediator/ neuromodulator. It has been shown that kyotorphin is present in the human cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless Extracellular fluid#Transcellular fluid, transcellular body fluid found within the meninges, meningeal tissue that surrounds the vertebrate brain and spinal cord, and in the ventricular system, ven ... and that its concentration is lower in patients with persistent pain. References {{Opioidergics Dipepti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartame
Aspartame is an artificial non-saccharide sweetener commonly used as a sugar substitute in foods and beverages. 200 times sweeter than sucrose, it is a methyl ester of the aspartic acid/phenylalanine dipeptide with brand names NutraSweet, Equal, and Canderel. Discovered in 1965, aspartame was approved by the US Food and Drug Administration (FDA) in 1974 and re-approved in 1981 after its initial approval was briefly revoked. Aspartame is one of the most studied food additives in the human food supply. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption at the normal acceptable daily intake limit. Uses Aspartame is about 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces roughly the same energy per gram when metabolized as sucrose does, , the quantity of aspartame needed to produce the same sweetness is so small that its caloric contribution is negligible. The sweet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycylglycine
Glycylglycine is the dipeptide of glycine, making it the simplest peptide. The compound was first synthesized by Emil Fischer and Ernest Fourneau in 1901 by boiling 2,5-diketopiperazine 2,5-Diketopiperazine is an organic compound with the formula (NHCH2C(O))2. The compound features a six-membered ring containing two amide functional group, groups at opposite positions in the ring. It was first compound containing a peptide bo ... (glycine anhydride) with hydrochloric acid. Shaking with alkali and other synthesis methods have been reported. Because of its low toxicity, it is useful as a buffer for biological systems with effective ranges between pH 2.5–3.8 and 7.5–8.9; however, it is only moderately stable for storage once dissolved. It is used in the synthesis of more complex peptides. Glycylglycine has also been reported to be helpful in solubilizing recombinant proteins in ''E. coli''. Using different concentrations of the glycylglycine improvement in protein solubil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspartame
Aspartame is an artificial non-saccharide sweetener commonly used as a sugar substitute in foods and beverages. 200 times sweeter than sucrose, it is a methyl ester of the aspartic acid/phenylalanine dipeptide with brand names NutraSweet, Equal, and Canderel. Discovered in 1965, aspartame was approved by the US Food and Drug Administration (FDA) in 1974 and re-approved in 1981 after its initial approval was briefly revoked. Aspartame is one of the most studied food additives in the human food supply. Reviews by over 100 governmental regulatory bodies found the ingredient safe for consumption at the normal acceptable daily intake limit. Uses Aspartame is about 180 to 200 times sweeter than sucrose (table sugar). Due to this property, even though aspartame produces roughly the same energy per gram when metabolized as sucrose does, , the quantity of aspartame needed to produce the same sweetness is so small that its caloric contribution is negligible. The sweet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Sponge
Sponges or sea sponges are primarily marine invertebrates of the animal phylum Porifera (; meaning 'pore bearer'), a basal clade and a sister taxon of the diploblasts. They are sessile filter feeders that are bound to the seabed, and are one of the most ancient members of macrobenthos, with many historical species being important reef-building organisms. Sponges are multicellular organisms consisting of jelly-like mesohyl sandwiched between two thin layers of cells, and usually have tube-like bodies full of pores and channels that allow water to circulate through them. They have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. They do not have complex nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes, usually via flagella movements of the so-called "collar cells". Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
