Reaction Process: Reactome:R-ATH-2162123
Synthesis of Prostaglandins (PG) and Thromboxanes (TX) related metabolites
find 11 related metabolites which is associated with chemical reaction(pathway) Synthesis of Prostaglandins (PG) and Thromboxanes (TX)
H+ + TPNH + prostaglandin D2 ⟶ 11epi-PGF2a + TPN
Prostaglandin E2
The naturally occurring prostaglandin E2 (PGE2) is known in medicine as dinoprostone, and it is the most common and most biologically active of the mammalian prostaglandins. It has important effects during labour and also stimulates osteoblasts to release factors which stimulate bone resorption by osteoclasts (a type of bone cell that removes bone tissue by removing the bones mineralized matrix). PGE2 is also the prostaglandin that ultimately induces fever. PGE2 has been shown to increase vasodilation and cAMP production, enhance the effects of bradykinin and histamine, and induce uterine contractions and platelet aggregation. PGE2 is also responsible for maintaining the open passageway of the fetal ductus arteriosus, decreasing T-cell proliferation and lymphocyte migration, and activating the secretion of IL-1α and IL-2. PGE2 exhibits both pro- and anti-inflammatory effects, particularly on dendritic cells (DC). Depending on the nature of maturation signals, PGE2 has different and sometimes opposite effects on DC biology. PGE2 exerts an inhibitory action, reducing the maturation of DC and their ability to present antigen. PGE2 has also been shown to stimulate DC and promote IL-12 production when given in combination with TNF-alpha. PGE2 is an environmentally bioactive substance. Its action is prolonged and sustained by other factors especially IL-10. It modulates the activities of professional DC by acting on their differentiation, maturation, and their ability to secrete cytokines. PGE2 is a potent inducer of IL-10 in bone marrow-derived DC (BM-DC). PGE2-induced IL-10 is a key regulator of the BM-DC pro-inflammatory phenotype (PMID:16978535). Prostaglandins are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent and are able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis through receptor-mediated G-protein linked signalling pathways. Dinoprostone is a naturally occurring prostaglandin E2 (PGE2) and the most common and most biologically active of the mammalian prostaglandins. It has important effects in labour and also stimulates osteoblasts to release factors which stimulate bone resorption by osteoclasts (a type of bone cell that removes bone tissue by removing the bones mineralized matrix). PGE2 has been shown to increase vasodilation and cAMP production, to enhance the effects of bradykinin and histamine, induction of uterine contractions and of platelet aggregation. PGE2 is also responsible for maintaining the open passageway of the fetal ductus arteriosus; decreasing T-cell proliferation and lymphocyte migration and activating the secretion of IL-1α and IL-2. PGE2 exhibits both pro- and anti-inflammatory effects, particularly on dendritic cells (DC). Depending on the nature of maturation signals, PGE2 has different and sometimes opposite effects on DC biology. PGE2 exerts an inhibitory action, reducing the maturation of DC and their ability to present antigen. PGE2 has also been shown to stimulate DC and promote IL-12 production when given in combination with TNF-alpha. PGE2 is an environmentally bioactive substance. Its action is prolonged and sustained by other factors especially IL-10. It modulates the activities of professional DC by acting on their differentiation, maturation and their ability to secrete cytokines. PGE2 is a potent inducer of IL-10 in bone marrow-derived DC (BM-DC), and PGE2-induced IL-10 is a key regulator of the BM-DC pro-inflammatory phenotype. (PMID: 16978535) G - Genito urinary system and sex hormones > G02 - Other gynecologicals > G02A - Uterotonics > G02AD - Prostaglandins Chemical was purchased from CAY14010, (Lot 0410966-34); Diagnostic ions: 351.8, 333.1, 271.1, 188.9 D012102 - Reproductive Control Agents > D010120 - Oxytocics C78568 - Prostaglandin Analogue Prostaglandin E2 (PGE2) is a hormone-like substance that participate in a wide range of body functions such as the contraction and relaxation of smooth muscle, the dilation and constriction of blood vessels, control of blood pressure, and modulation of inflammation.
Nicotinamide adenine dinucleotide phosphate
NADPH is the reduced form of NADP+, and NADP+ is the oxidized form of NADPH. Nicotinamide adenine dinucleotide phosphate (NADP) is a coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled with a pyrophosphate linkage to 5-phosphate adenosine 2,5-bisphosphate. NADP serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). NADP is formed through the addition of a phosphate group to the 2 position of the adenosyl nucleotide through an ester linkage (Dorland, 27th ed). This extra phosphate is added by the enzyme NAD+ kinase and removed via NADP+ phosphatase. NADP is also known as TPN (triphosphopyridine nucleotide) and it is an important cofactor used in anabolic reactions in all forms of cellular life. Examples include the Calvin cycle, cholesterol synthesis, fatty acid elongation, and nucleic acid synthesis (Wikipedia). Nicotinamide adenine dinucleotide phosphate. A coenzyme composed of ribosylnicotinamide 5-phosphate (NMN) coupled by pyrophosphate linkage to the 5-phosphate adenosine 2,5-bisphosphate. It serves as an electron carrier in a number of reactions, being alternately oxidized (NADP+) and reduced (NADPH). (Dorland, 27th ed.) [HMDB]. NADPH is found in many foods, some of which are american pokeweed, rice, ginseng, and ostrich fern. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
Prostaglandin F2alpha
Prostaglandin F2a (PGF2) is one of the earliest discovered and most common prostaglandins. It is actively biosynthesized in various organs of mammals and exhibits a variety of biological activities, including contraction of pulmonary arteries. It is used in medicine to induce labor and as an abortifacient. PGF2a binds to the Prostaglandin F2 receptor (PTGFR) which is a member of the G-protein coupled receptor family. PGF2-alpha mediates luteolysis. Luteolysis is the structural and functional degradation of the corpus luteum (CL) that occurs at the end of the luteal phase of both the estrous and menstrual cycles in the absence of pregnancy. PGF2 may also be involved in modulating intraocular pressure and smooth muscle contraction in the uterus and gastrointestinal tract sphincters. PGF2 is mainly synthesized directly from PGH2 by PGH2 9,11-endoperoxide reductase. A small amount of PGF2 is also produced from PGE2 by PGE2 9-ketoreductase. A PGF2 epimer has been reported to exhibit various biological activities, and its levels are increased in bronchoalveolar lavage fluid, plasma, and urine in patients with mastocytosis and bronchial asthma. PGF2 is synthesized from PGD2 by PGD2 11-ketoreductase. (PMID: 16475787). Prostaglandins are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. Prostaglandin F2a (PGF2) is one of the earliest discovered and most common prostaglandins. It is actively biosynthesized in various organs of mammals and exhibits a variety of biological activities, including contraction of pulmonary arteries. It is used in medicine to induce labor and as an abortifacient. PGF2a binds to the Prostaglandin F2 receptor (PTGFR) which is a member of the G-protein coupled receptor family. PGF2-alpha mediates luteolysis. Luteolysis is the structural and functional degradation of the corpus luteum (CL) that occurs at the end of the luteal phase of both the estrous and menstrual cycles in the absence of pregnancy. PGF2 may also be involved in modulating intraocular pressure and smooth muscle contraction in the uterus and gastrointestinal tract sphincters. PGF2 is mainly synthesized directly from PGH2 by PGH2 9,11-endoperoxide reductase. A small amount of PGF2 is also produced from PGE2 by PGE2 9-ketoreductase. A PGF2 epimer has been reported to exhibit various biological activities, and its levels are increased in bronchoalveolar lavage fluid, plasma, and urine in patients with mastocytosis and bronchial asthma. PGF2 is synthesized from PGD2 by PGD2 11-ketoreductase. (PMID: 16475787) G - Genito urinary system and sex hormones > G02 - Other gynecologicals > G02A - Uterotonics > G02AD - Prostaglandins Chemical was purchased from CAY16010 (Lot 171332-126); Diagnostic ions: 353.2, 309.2, 281.1, 253.0, 193.1 D012102 - Reproductive Control Agents > D000019 - Abortifacient Agents D012102 - Reproductive Control Agents > D010120 - Oxytocics C78568 - Prostaglandin Analogue KEIO_ID P066 Dinoprost (Prostaglandin F2α) is an orally active, potent prostaglandin F (PGF) receptor (FP receptor) agonist. Dinoprost is a luteolytic hormone produced locally in the endometrial luminal epithelium and corpus luteum (CL). Dinoprost plays a key role in the onset and progression of labour[1][2].
Prostaglandin D2
Prostaglandin D2 (or PGD2) is a prostaglandin that is actively produced in various organs such as the brain, spleen, thymus, bone marrow, uterus, ovary, oviduct, testis, prostate and epididymis, and is involved in many physiological events. PGD2 binds to the prostaglandin D2 receptor (PTGDR) which is a G-protein-coupled receptor. Its activity is mainly mediated by G-S proteins that stimulate adenylate cyclase resulting in an elevation of intracellular cAMP and Ca2+. PGD2 promotes sleep; regulates body temperature, olfactory function, hormone release, and nociception in the central nervous system; prevents platelet aggregation; and induces vasodilation and bronchoconstriction. PGD2 is also released from mast cells as an allergic and inflammatory mediator. Prostaglandin H2 is an unstable intermediate formed from PGG2 by the action of cyclooxygenase (COX) in the arachidonate cascade. In mammalian systems, it is efficiently converted into more stable arachidonate metabolites, such as PGD2, PGE2, PGF2a by the action of three groups of enzymes, PGD synthases (PGDS), PGE synthases and PGF synthases, respectively. PGDS catalyzes the isomerization of PGH2 to PGD2. Two types of PGD2 synthase are known. Lipocalin-type PGD synthase is present in cerebrospinal fluid, seminal plasma and may play an important role in male reproduction. Another PGD synthase, hematopoietic PGD synthase is present in the spleen, fallopian tube, endometrial gland cells, extravillous trophoblasts and villous trophoblasts, and perhaps plays an important role in female reproduction. Recent studies demonstrate that PGD2 is probably involved in multiple aspects of inflammation through its dual receptor systems, DP and CRTH2. (PMID:12148545)Prostaglandins are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. Prostaglandin D2 (or PGD2) is a prostaglandin that is actively produced in various organs such as the brain, spleen, thymus, bone marrow, uterus, ovary, oviduct, testis, prostate and epididymis, and is involved in many physiological events. PGD2 binds to the prostaglandin D2 receptor (PTGDR) which is a G-protein-coupled receptor. Its activity is mainly mediated by G-S proteins that stimulate adenylate cyclase resulting in an elevation of intracellular cAMP and Ca2+. PGD2 promotes sleep; regulates body temperature, olfactory function, hormone release, and nociception in the central nervous system; prevents platelet aggregation; and induces vasodilation and bronchoconstriction. PGD2 is also released from mast cells as an allergic and inflammatory mediator. Chemical was purchased from CAY 12010, (Lot 0436713-1); Diagnostic ions: 351.1, 333.0, 271.3, 233.1, 189.1
NADP+
[C21H29N7O17P3]+ (744.0832754)
[Spectral] NADP+ (exact mass = 743.07545) and NAD+ (exact mass = 663.10912) were not completely separated on HPLC under the present analytical conditions as described in AC$XXX. Additionally some of the peaks in this data contains dimers and other unidentified ions. COVID info from COVID-19 Disease Map Corona-virus Coronavirus SARS-CoV-2 COVID-19 SARS-CoV COVID19 SARS2 SARS
12-HHTrE
12(S)-HHTrE is an unusual product of the cyclooxygenase (COX) pathway and one of the primary arachidonic acid metabolites of the human platelet.1 It is biosynthesized by thromboxane (TX) synthesis from prostaglandin H2 (PGH2) concurrently with TXA2. The biological role of 12(S)-HHTrE is uncertain. It is avidly oxidized to 12-oxoHTrE by porcine 15-hydroxy PGDH. [HMDB] 12(S)-HHTrE is an unusual product of the cyclooxygenase (COX) pathway and one of the primary arachidonic acid metabolites of the human platelet.1 It is biosynthesized by thromboxane (TX) synthesis from prostaglandin H2 (PGH2) concurrently with TXA2. The biological role of 12(S)-HHTrE is uncertain. It is avidly oxidized to 12-oxoHTrE by porcine 15-hydroxy PGDH.
Prostaglandin H2
Prostaglandin H2 (PGH2) is the first intermediate in the biosynthesis of all prostaglandins. Prostaglandins are synthesized from arachidonic acid by the enzyme COX-1 and COX-2, which are also called PGH synthase 1 and 2. These enzymes generate a reactive intermediate PGH2 which has a reasonably long half-life (90-100 s) but is highly lipophilic. PGH2 is converted into the biologically active prostaglandins by prostaglandin isomerases, yielding PGE2, PGD2, and PGF2, or by thromboxane synthase to make TXA2 or by prostacyclin synthase to make PGI2. Most nonsteroidal anti-inflammatory drugs such as aspirin and indomethacin inhibit both PGH synthase 1 and 2. A key feature for eicosanoid transcellular biosynthesis is the export of PGH2 or LTA4 from the donor cell as well as the uptake of these reactive intermediates by the acceptor cell. Very little is known about either process despite the demonstrated importance of both events. In cells, PGH2 rearranges nonenzymatically to LGs even in the presence of enzymes that use PGH2 as a substrate. When platelets form thromboxane A2 (TXA2) from endogenous arachidonic acid (AA), PGH2 reaches concentrations very similar to those of TXA2 and high enough to produce strong platelet activation. Therefore, platelet activation by TXA2 appears to go along with an activation by PGH2. The agonism of PGH2 is limited by the formation of inhibitory prostaglandins, especially PGD2 at higher concentrations. That is why thromboxane synthase inhibitors in PRP and at a physiological HSA concentration do not augment platelet activation (PMID: 2798452, 15650407, 16968946). Prostaglandins are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent and are able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis through receptor-mediated G-protein linked signalling pathways. Prostaglandin h2, also known as pgh2 or 9s,11r-epidioxy-15s-hydroxy-5z,13e-prostadienoate, is a member of the class of compounds known as prostaglandins and related compounds. Prostaglandins and related compounds are unsaturated carboxylic acids consisting of a 20 carbon skeleton that also contains a five member ring, and are based upon the fatty acid arachidonic acid. Thus, prostaglandin h2 is considered to be an eicosanoid lipid molecule. Prostaglandin h2 is practically insoluble (in water) and a weakly acidic compound (based on its pKa). Prostaglandin h2 can be found in a number of food items such as gooseberry, evergreen huckleberry, quince, and capers, which makes prostaglandin h2 a potential biomarker for the consumption of these food products. Prostaglandin h2 can be found primarily in human platelet tissue. In humans, prostaglandin h2 is involved in several metabolic pathways, some of which include magnesium salicylate action pathway, ketorolac action pathway, trisalicylate-choline action pathway, and salicylate-sodium action pathway. Prostaglandin h2 is also involved in a couple of metabolic disorders, which include leukotriene C4 synthesis deficiency and tiaprofenic acid action pathway. Prostaglandin h2 is acted upon by: Prostacyclin synthase to create prostacyclin Thromboxane-A synthase to create thromboxane A2 and 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) (see 12-Hydroxyheptadecatrienoic acid) Prostaglandin D2 synthase to create prostaglandin D2 Prostaglandin E synthase to create prostaglandin E2 Prostaglandin h2 rearranges non-enzymatically to: A mixture of 12-(S)-hydroxy-5Z,8E,10E-heptadecatrienoic acid (HHT) and 12-(S)-hydroxy-5Z,8Z,10E-heptadecatrienoic acid (see 12-Hydroxyheptadecatrienoic acid) Use of Prostaglandin H2: regulating the constriction and dilation of blood vessels stimulating platelet aggregation Effects of Aspirin on Prostaglandin H2: Aspirin has been hypothesized to block the conversion of arachidonic acid to Prostaglandin . D009676 - Noxae > D016877 - Oxidants > D010545 - Peroxides
Thromboxane A2
A thromboxane which is produced by activated platelets and has prothrombotic properties: it stimulates activation of new platelets as well as increases platelet aggregation.
Malondialdehyde
Malondialdehyde (MDA) is the dialdehyde of malonic acid and a biomarker of oxidative damage to lipids caused by smoking. Oxidized lipids are able to produce MDA as a decomposition product. The mechanism is thought to involve formation of prostaglandin-like endoperoxides from polyunsaturated fatty acids with two or more double bonds. An alternative mechanism is based on successive hydroperoxide formation and β-cleavage of polyunsaturated fatty acids. MDA is then directly formed by β-scission of a 3-hydroperoxyaldehyde or by reaction between acrolein and hydroxyl radicals. While oxidation of polyunsaturated fatty acids is the major source of MDA in vivo, other minor sources exists such as byproducts of free radical generation by ionizing radiation and of the biosynthesis of prostaglandins. Aldehydes are generally reactive species capable of forming adducts and complexes in biological systems and MDA is no exception although the main species at physiological pH is the enolate ion which is of relative low reactivity. Consistent evidence is available for the reaction between MDA and cellular macromolecules such as proteins, RNA and DNA. MDA reacts with DNA to form adducts to deoxyguanosine and deoxyadenosine which may be mutagenic and these can be quantified in several human tissues. Oxidative stress is an imbalance between oxidants and antioxidants on a cellular or individual level. Oxidative damage is one result of such an imbalance and includes oxidative modification of cellular macromolecules, induction of cell death by apoptosis or necrosis, as well as structural tissue damage. Chemically speaking, oxidants are compounds capable of oxidizing target molecules. This can take place in three ways: abstraction of hydrogen, abstraction of electrons or addition of oxygen. All cells living under aerobic conditions are continuously exposed to a large numbers of oxidants derived from various endogenous and exogenous sources. The endogenous sources of oxidants are several and include the respiratory chain in the mitochondria, immune reactions, enzymes such as xanthine oxidase and nitric oxide synthase and transition metal mediated oxidation. Various exogenous sources of ROS also contribute directly or indirectly to the total oxidant load. These include effects of ionizing and non-ionizing radiation, air pollution and natural toxic gases such as ozone, and chemicals and toxins including oxidizing disinfectants. A poor diet containing inadequate amounts of nutrients may also indirectly result in oxidative stress by impairing cellular defense mechanisms. The cellular macromolecules, in particular lipids, proteins and DNA, are natural targets of oxidation. Oxidants are capable of initiating lipid oxidation by abstraction of an allylic proton from a polyunsaturated fatty acid. This process, by multiple stages leading to the formation of lipid hydroperoxides, is a known contributor to the development of atherosclerosis. (PMID: 17336279). MDA has been identified as a uremic toxin according to the European Uremic Toxin Working Group (PMID: 22626821). It is used as an indicator of fatty acid and lipid peroxidation, and oxidative changes in foods
11b-PGF2a
11b-PGF2a is an intermediate metabolite in the arachadonic acid metabolic pathway. 11b-PGF2 is irreversibly produced from prostaglandin D2 via the enzyme prostaglandin-F synthase [EC:1.1.1.188].(KEGG)Prostaglandins are eicosanoids. The eicosanoids consist of the prostaglandins (PGs), thromboxanes (TXs), leukotrienes (LTs), and lipoxins (LXs). The PGs and TXs are collectively identified as prostanoids. Prostaglandins were originally shown to be synthesized in the prostate gland, thromboxanes from platelets (thrombocytes), and leukotrienes from leukocytes, hence the derivation of their names. All mammalian cells except erythrocytes synthesize eicosanoids. These molecules are extremely potent, able to cause profound physiological effects at very dilute concentrations. All eicosanoids function locally at the site of synthesis, through receptor-mediated G-protein linked signalling pathways. D012102 - Reproductive Control Agents > D000019 - Abortifacient Agents D012102 - Reproductive Control Agents > D010120 - Oxytocics
Hydrogen Ion
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])