Reaction Process: BioCyc:META_PWY-7683

Hydroxylamine

H3NO (33.0214628)

Hydroxylamine is a reactive chemical with formula NH2OH. It can be considered a hybrid of ammonia and water due to parallels it shares with each. At room temperature pure NH2OH is ordinarily a white, unstable crystalline, hygroscopic compound; Hydroxylamine is a reactive chemical with formula NH2OH. It can be considered a hybrid of ammonia and water due to parallels it shares with each. At room temperature pure NH2OH is ordinarily a white, unstable crystalline, hygroscopic compound; however it is almost always encountered as an aqueous solution.; NH2OH is an intermediate in biological nitrification. The oxidation of NH3 is mediated by hydroxylamine oxidoreductase (HAO).; however it is almost always encountered as an aqueous solution.; A colorless inorganic compound (HONH2) used in organic synthesis and as a reducing agent, due to its ability to donate nitric oxide.; Hydroxylamine may explode on heating. It is an irritant to the respiratory tract, skin, eyes, and other mucous membranes. It may be absorbed through the skin, is harmful if swallowed, and is a possible mutagen.; NH2OH is an intermediate in the biological nitrification. The oxidation of NH3 is mediated by HAO (hydroxylamine oxidoreductase). Hydroxylamine is found in gram bean and mung bean. Hydroxylamine is a reactive chemical with formula NH2OH. It can be considered a hybrid of ammonia and water due to parallels it shares with each. At room temperature pure NH2OH is ordinarily a white, unstable crystalline, hygroscopic compound; however it is almost always encountered as an aqueous solution. A colorless inorganic compound (HONH2) used in organic synthesis and as a reducing agent, due to its ability to donate nitric oxide. Hydroxylamine may explode on heating. It is an irritant to the respiratory tract, skin, eyes, and other mucous membranes. It may be absorbed through the skin, is harmful if swallowed, and is a possible mutagen. NH2OH is an intermediate in the biological nitrification. The oxidation of NH3 is mediated by HAO (hydroxylamine oxidoreductase).

Nitric oxide

NO (29.997989)

The biologically active molecule nitric oxide (NO) is a simple, membrane-permeable gas with unique chemistry. It is formed by the conversion of L-arginine to L-citrulline, with the release of NO. The enzymatic oxidation of L-arginine to L-citrulline takes place in the presence of oxygen and NADPH using flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), heme, thiol, and tetrahydrobiopterin as cofactors. The enzyme responsible for the generation of NO is nitric oxide synthase (E.C. 1.7.99.7; NOS). Three NOS isoforms have been described and shown to be encoded on three distinct genes: neuronal NOS (nNOS, NOS type I), inducible NOS (NOS type II), and endothelial NOS (eNOS, NOS type III). Two of them are constitutively expressed and dependent on the presence of calcium ions and calmodulin to function (nNOS and eNOS), while iNOS is considered non-constitutive and calcium-independent. However, experience has shown that constitutive expression of nNOS and eNOS is not as rigid as previously thought (i.e. either present or absent), but can be dynamically controlled during development and in response to injury. Functionally, NO may act as a hormone, neurotransmitter, paracrine messenger, mediator, cytoprotective molecule, and cytotoxic molecule. NO has multiple cellular molecular targets. It influences the activity of transcription factors, modulates upstream signaling cascades, mRNA stability and translation, and processes the primary gene products. In the brain, many processes are linked to NO. NO activates its receptor, soluble guanylate cyclase by binding to it. The stimulation of this enzyme leads to increased synthesis of the second messenger, cGMP, which in turn activates cGMP-dependent kinases in target cells. NO exerts a strong influence on glutamatergic neurotransmission by directly interacting with the N-methyl-D-aspartate (NMDA) receptor. Neuronal NOS is connected to NMDA receptors (see below) and sharply increases NO production following activation of this receptor. Thus, the level of endogenously produced NO around NMDA synapses reflects the activity of glutamate-mediated neurotransmission. However, there is recent evidence showing that non-NMDA glutamate receptors (i.e. AMPA and type I metabotropic receptors) also contribute to NO generation. Besides its influence on glutamate, NO is known to have effects on the storage, uptake and/or release of most other neurotransmitters in the CNS (acetylcholine, dopamine, noradrenaline, GABA, taurine, and glycine) as well as of certain neuropeptides. Finally, since NO is a highly diffusible molecule, it may reach extrasynaptic receptors at target cell membranes that are some distance away from the place of NO synthesis. NO is thus capable of mediating both synaptic and nonsynaptic communication processes. NO is a potent vasodilator (a major endogenous regulator of vascular tone), and an important endothelium-dependent relaxing factor. NO is synthesized by NO synthases (NOS) and NOS are inhibited by asymmetrical dimethylarginine (ADMA). ADMA is metabolized by dimethylarginine dimethylaminohydrolase (DDAH) and excreted in the kidneys. Lower ADMA levels in pregnant women compared to non-pregnant controls suggest that ADMA has a role in vascular dilatation and blood pressure changes. Several studies show an increase in ADMA levels in pregnancies complicated with preeclampsia. Elevated ADMA levels in preeclampsia are seen before clinical symptoms have developed; these findings suggest that ADMA has a role in the pathogenesis of preeclampsia. In some pulmonary hypertensive states such as ARDS, the production of endogenous NO may be impaired. Nitric oxide inhalation selectively dilates the pulmonary circulation. Significant systemic vasodilation does not occur because NO is inactivated by rapidly binding to hemoglobin. In an injured lung with pulmonary hypertension, inhaled NO produces local vasodilation of well-ventilated lung units and may "steal" blood flow away from unventil... D002317 - Cardiovascular Agents > D014665 - Vasodilator Agents > D045462 - Endothelium-Dependent Relaxing Factors D019141 - Respiratory System Agents > D018927 - Anti-Asthmatic Agents > D001993 - Bronchodilator Agents D018373 - Peripheral Nervous System Agents > D001337 - Autonomic Agents D018377 - Neurotransmitter Agents > D064426 - Gasotransmitters D000975 - Antioxidants > D016166 - Free Radical Scavengers D020011 - Protective Agents > D000975 - Antioxidants R - Respiratory system

Hydroxide

HO- (17.0027396)

In chemistry, hydroxide is the most common name for the diatomic anion OH, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known. Hydroxide ion is a kind of ligand. It donates one pair of electrons, behaving as a Lewis base. Examples include the aluminate ion [Al(OH)4]- and aurate ion [Au(OH)4]-. [HMDB] In chemistry, hydroxide is the most common name for the diatomic anion OH, consisting of oxygen and hydrogen atoms, usually derived from the dissociation of a base. It is one of the simplest diatomic ions known. Hydroxide ion is a kind of ligand. It donates one pair of electrons, behaving as a Lewis base. Examples include the aluminate ion [Al(OH)4]- and aurate ion [Au(OH)4]-.

Ammonium

H4N+ (18.0343724)

Ammonium, also known as ammonium(1+) or nh4+, is a member of the class of compounds known as homogeneous other non-metal compounds. Homogeneous other non-metal compounds are inorganic non-metallic compounds in which the largest atom belongs to the class of other nonmetals. Ammonium can be found in a number of food items such as irish moss, sago palm, sorghum, and malabar spinach, which makes ammonium a potential biomarker for the consumption of these food products. Ammonium can be found primarily in blood and sweat. Ammonium exists in all living species, ranging from bacteria to humans. In humans, ammonium is involved in the the oncogenic action of 2-hydroxyglutarate. Ammonium is also involved in a couple of metabolic disorders, which include the oncogenic action of d-2-hydroxyglutarate in hydroxygluaricaciduria and the oncogenic action of l-2-hydroxyglutarate in hydroxygluaricaciduria. Moreover, ammonium is found to be associated with n-acetylglutamate synthetase deficiency. The ammonium cation is a positively charged polyatomic ion with the chemical formula NH+ 4. It is formed by the protonation of ammonia (NH3). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR+ 4), where one or more hydrogen atoms are replaced by organic groups (indicated by R) . Ammonium is an important source of nitrogen for many plant species, especially those growing on hypoxic soils. However, it is also toxic to most crop species and is rarely applied as a sole nitrogen source. The ammonium (more obscurely: aminium) cation is a positively charged polyatomic cation with the chemical formula NH4+. It is formed by the protonation of ammonia (NH3). Ammonium is also a general name for positively charged or protonated substituted amines and quaternary ammonium cations (NR4+), where one or more hydrogen atoms are replaced by organic radical groups (indicated by R). Ammonium is found to be associated with N-acetylglutamate synthetase deficiency, which is an inborn error of metabolism.

Hydrogen Ion

H+ (1.0078246)

Hydrogen ion, also known as proton or h+, is a member of the class of compounds known as other non-metal hydrides. Other non-metal hydrides are inorganic compounds in which the heaviest atom bonded to a hydrogen atom is belongs to the class of other non-metals. Hydrogen ion can be found in a number of food items such as lowbush blueberry, groundcherry, parsley, and tarragon, which makes hydrogen ion a potential biomarker for the consumption of these food products. Hydrogen ion exists in all living organisms, ranging from bacteria to humans. In humans, hydrogen ion is involved in several metabolic pathways, some of which include cardiolipin biosynthesis cl(i-13:0/a-25:0/a-21:0/i-15:0), cardiolipin biosynthesis cl(a-13:0/a-17:0/i-13:0/a-25:0), cardiolipin biosynthesis cl(i-12:0/i-13:0/a-17:0/a-15:0), and cardiolipin biosynthesis CL(16:1(9Z)/22:5(4Z,7Z,10Z,13Z,16Z)/18:1(11Z)/22:5(7Z,10Z,13Z,16Z,19Z)). Hydrogen ion is also involved in several metabolic disorders, some of which include de novo triacylglycerol biosynthesis TG(20:3(8Z,11Z,14Z)/22:6(4Z,7Z,10Z,13Z,16Z,19Z)/22:5(7Z,10Z,13Z,16Z,19Z)), de novo triacylglycerol biosynthesis TG(18:2(9Z,12Z)/20:0/20:4(5Z,8Z,11Z,14Z)), de novo triacylglycerol biosynthesis TG(18:4(6Z,9Z,12Z,15Z)/18:3(9Z,12Z,15Z)/18:4(6Z,9Z,12Z,15Z)), and de novo triacylglycerol biosynthesis TG(24:0/20:5(5Z,8Z,11Z,14Z,17Z)/24:0). A hydrogen ion is created when a hydrogen atom loses or gains an electron. A positively charged hydrogen ion (or proton) can readily combine with other particles and therefore is only seen isolated when it is in a gaseous state or a nearly particle-free space. Due to its extremely high charge density of approximately 2×1010 times that of a sodium ion, the bare hydrogen ion cannot exist freely in solution as it readily hydrates, i.e., bonds quickly. The hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions . Hydrogen ion is recommended by IUPAC as a general term for all ions of hydrogen and its isotopes. Depending on the charge of the ion, two different classes can be distinguished: positively charged ions and negatively charged ions. Under aqueous conditions found in biochemistry, hydrogen ions exist as the hydrated form hydronium, H3O+, but these are often still referred to as hydrogen ions or even protons by biochemists. [Wikipedia])

Nitrite Ion

NO2- (45.992904)