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The amino acid betaine derived from glycine." []

5-Aminopentanoic acid (or 5-aminovalerate) is a lysine degradation product. It can be produced both endogenously or through bacterial catabolism of lysine. 5-aminovalerate is formed via the following multi-step reaction: L-lysine leads to cadverine leads to L-piperideine leads 5-aminovalerate (PMID:405455). In other words it is a metabolite of cadaverine which is formed via the intermediate, 1-piperideine (PMID:6436440). Cadaverine is a foul-smelling diamine compound produced by protein hydrolysis during putrefaction of animal tissue. High levels of 5-aminovalerate in biofluids may indicate bacterial overgrowth or endogenous tissue necrosis. In most cases endogenous 5-aminovalerate is thought to be primarily a microbial metabolite produced by the gut or oral microflora, although it can be produced endogenously. 5-aminovalerate is a normal metabolite present in human saliva, with a tendency to elevated concentration in patients with chronic periodontitis. Bacterial contamination and decomposition of salivary proteins is primarily responsible for elevated salivary levels (PMID 3481959). Beyond being a general waste product, 5-aminovalerate is also believed to act as a methylene homologue of gamma-aminobutyric acid (GABA) and functions as a weak GABA agonist (PMID:4031870). It is also known as an antifibrinolytic amino acid analog and so it functions as a weak inhibitor of the blood clotting pathway (PMID:6703712). 5- aminovalerate is an in vivo substrate of 4-aminobutyrate:2-oxoglutarate aminotransferase (PMID:4031870). It can be found in Corynebacterium (PMID:27717386).

Isoamyl nitrite (IAN) has been used as antianginal agents for more than 100 years. It is now established that IAN cause direct vasorelaxation through vascular generation of NO and relaxation via a cyclic guanosine monophosphate-dependent process. (PMID: 8996213). IAN is a member of the family of volatile organic nitrites that exert vasodilatory effects and have recently exhibited a considerable potential for inhalation abuse. (PMID: 9829558). All nitrovasodilators act intracellularly by a common molecular mechanism. This is characterized by the release of nitric oxide (NO). This process basically depends on the presence of oxygen as electron acceptor from the sydnonimine molecule. Organic nitrites (such as IAN) require the interaction with a mercapto group to form a S-nitrosothiol intermediate, from which finally NO radicals are liberated. In the presence of thiol compounds organic nitrites (e.g., IAN) and nitrosothiols may act as intermediary products of NO generation. (PMID: 1683227).

4-amino-pentanoic acid

Indole is an aromatic heterocyclic organic compound. It has a bicyclic structure, consisting of a six-membered benzene ring fused to a five-membered nitrogen-containing pyrrole ring. The participation of the nitrogen lone electron pair in the aromatic ring means that indole is not a base, and it does not behave like a simple amine. Indole is a microbial metabolite and it can be produced by bacteria as a degradation product of the amino acid tryptophan. It occurs naturally in human feces and has an intense fecal smell. At very low concentrations, however, indole has a flowery smell and is a constituent of many flower scents (such as orange blossoms) and perfumes. As a volatile organic compound, indole has been identified as a fecal biomarker of Clostridium difficile infection (PMID: 30986230). Natural jasmine oil, used in the perfume industry, contains around 2.5% of indole. Indole also occurs in coal tar. Indole has been found to be produced in a number of bacterial genera including Alcaligenes, Aspergillus, Escherichia, and Pseudomonas (PMID: 23194589, 2310183, 9680309). Indole plays a role in bacterial biofilm formation, bacterial motility, bacterial virulence, plasmid stability, and antibiotic resistance. It also functions as an intercellular signalling molecule (PMID: 26115989). Recently, it was determined that the bacterial membrane-bound histidine sensor kinase (HK) known as CpxA acts as a bacterial indole sensor to facilitate signalling (PMID: 31164470). It has been found that decreased indole concentrations in the gut promote bacterial pathogenesis, while increased levels of indole in the gut decrease bacterial virulence gene expression (PMID: 31164470). As a result, enteric pathogens sense a gradient of indole concentrations in the gut to migrate to different niches and successfully establish an infection.

A morpholine N-oxide resulting from the oxidation of the amino group of N-methylmorpholine." []

Major species at pH 7.3. Published in DOI:10.1039/C6CY01625A" []

Benzeneacetonitrile is found in garden cress. Benzeneacetonitrile is isolated from oil of garden cress (Lepidium sativum) and other plant oils.

2-Aminoacetophenone is found in cereals and cereal products. 2-Aminoacetophenone is a component of tortilla aroma and of other corn flour product

Betaine (CAS: 107-43-7), also known as N,N,N-trimethylglycine, was named after its discovery in sugar beet (Beta vulgaris) in the 19th century. It is a small N-trimethylated amino acid, existing in zwitterionic form at neutral pH. It is now often called glycine betaine to distinguish it from other betaines that are widely distributed in microorganisms, plants, and animals. Many naturally occurring betaines serve as organic osmolytes, substances synthesized or taken up from the environment by cells for protection against osmotic stress, drought, high salinity, or high temperature. Intracellular accumulation of betaines permits water retention in cells, thus protecting from the effects of dehydration (Wikipedia). Betaine functions as a methyl donor in that it carries and donates methyl functional groups to facilitate necessary chemical processes. In particular, it methylates homocysteine to methionine, also producing N,N-dimethylglycine. The donation of methyl groups is important to proper liver function, cellular replication, and detoxification reactions. Betaine also plays a role in the manufacture of carnitine and serves to protect the kidneys from damage. Betaine comes from either the diet or by the oxidation of choline. Betaine insufficiency is associated with metabolic syndrome, lipid disorders, and diabetes, and may have a role in vascular and other diseases (PMID: 20346934). Betaine is important in development, from the pre-implantation embryo to infancy. Betaine is also widely regarded as an anti-oxidant. Betaine has been shown to have an inhibitory effect on NO release in activated microglial cells and may be an effective therapeutic component to control neurological disorders (PMID: 22801281). As a drug, betaine hydrochloride has been used as a source of hydrochloric acid in the treatment of hypochlorhydria. Betaine has also been used in the treatment of liver disorders, for hyperkalemia, for homocystinuria, and for gastrointestinal disturbances (Martindale, The Extra Pharmacopoeia, 30th Ed, p1341).

1-Amino-4-ethynylbenzene http://www.sigmaaldrich.com/catalog/search/ProductDetail/FLUKA/46039

2H-isoindole is an isoindole and a polycyclic heteroarene. It is a tautomer of a 1H-isoindole. Benzopyrroles with the nitrogen at the number two carbon, in contrast to INDOLES which have the nitrogen adjacent to the six-membered ring.

A quinolone that is 1,2-dihydroquinoline substituted by an oxo group at position 2." []

This compound is a reactant in the pathways: nicotine degradation II and nicotine degradation III, where it is converted into 4-(3-pyridyl)-butanoate. This is one of the hypothesized intermediate reactions of nicotine being converted to 3-pyridylacetate. (BioCyc) This compound is likely associated with nicotine accumulation disorders.

3-Indolehydracrylic acid belongs to the family of Indolyl Carboxylic Acids and Derivatives. These are compounds containing a carboxylic acid chain (of at least 2 carbon atoms) linked to an indole ring.

Homomethionine (CAS: 6094-76-4) belongs to the class of organic compounds known as alpha-amino acids. These are amino acids in which the amino group is attached to the carbon atom immediately adjacent to the carboxylate group (alpha carbon). Homomethionine is possibly neutral. Homomethionine has been detected, but not quantified in, several different foods, such as lima beans, red huckleberries, catjang pea, Chinese chestnuts, and pepper (C. annuum). This could make homomethionine a potential biomarker for the consumption of these foods. Homomethionine is found in brassicas and is isolated from cabbage and horseradish.

Erythro-4-hydroxy-L-glutamate(1-) is also known as (2S,4R)-2-ammonio-4-Hydroxypentanedioate. Erythro-4-hydroxy-L-glutamate(1-) is considered to be soluble (in water) and acidic

L-N-Carboxymethylserine is found in green vegetables. L-N-Carboxymethylserine is isolated from asparagus (Asparagus officinalis) shoot

Aminoethoxyacetic acid is a metabolite of linezolid. Linezolid is a synthetic antibiotic used for the treatment of serious infections caused by Gram-positive bacteria that are resistant to several other antibiotics. A member of the oxazolidinone class of drugs, linezolid is active against most Gram-positive bacteria that cause disease, including streptococci, vancomycin-resistant enterococci (VRE), and methicillin-resistant Staphylococcus aureus (MRSA). (Wikipedia)