All articles starting with H
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Hydrow, Inc.
Hydrow, Inc., legally Crew By True Rowing, Inc., is a Boston-based connected fitness company whose Hydrow rowing machine streams live and on-demand workouts and had over 200,000 users by 2022.
Hydrox
Hydrox is the original creme-filled chocolate sandwich cookie, launched in 1908 by Sunshine Biscuits, four years before Oreo. Discontinued by Keebler in 1999, it was revived by Leaf Brands in 2015 with a kosher, vegan-certified formula.
Hydroxamic acid
A hydroxamic acid, or hydroxamate, is an N-hydroxy amide that strongly chelates metal ions, making it a major pharmacophore in medicinal chemistry and an iron-binding group of bacterial siderophores.
Hydroxide
Hydroxide, also called the hydroxide anion or OH⁻ ion, is the diatomic anion that is the conjugate base of water; its compounds include sodium hydroxide, hydroxide minerals, and layered double hydroxides.
Hydroxide anomaly
The hydroxide anomaly is the anomalously high mobility of the hydroxide ion in water, explained by structural diffusion, though it still moves slower than hydronium.
Hydroxocobalamin
Hydroxocobalamin (Cyanokit, Cobalin-H, Neo-Cytamen) is a manufactured vitamin B12 (cobalamin) form given by injection for B12 deficiency and, at 5 g IV, as a cyanide-poisoning antidote; preferred in the UK over cyanocobalamin for longer retention.
Hydroxy group
The hydroxy group, also called the OH or alcohol group, is the –OH functional group made of oxygen bonded to hydrogen; compounds with it on a saturated carbon are alcohols.
Hydroxyacetone
Hydroxyacetone, also called acetol, is the simplest hydroxy ketone, a colorless liquid that forms in the atmosphere from isoprene oxidation, occurs in human metabolism, and appears in e-cigarette aerosols.
Hydroxyamphetamine
Hydroxyamphetamine (4-hydroxyamphetamine, Paredrine, Paremyd with tropicamide) is an indirect sympathomimetic amine that releases norepinephrine to dilate the pupil and localize Horner's syndrome lesions; now largely superseded by apraclonidine.
Hydroxyapatite
Hydroxyapatite, also known as calcium hydroxyapatite or hydroxylapatite, is a calcium phosphate mineral with formula Ca10(PO4)6(OH)2 that forms most of human bone and tooth enamel.
Hydroxycamptothecin
Hydroxycamptothecin (10-hydroxycamptothecin, HCPT, 10-羟基喜树碱), a topoisomerase I-inhibiting alkaloid from Camptotheca acuminata, about 30 times more active than camptothecin but limited by lactone instability and poor water solubility.
Hydroxycarbamide
Hydroxycarbamide (hydroxyurea), a ribonucleotide reductase inhibitor synthesized in 1869, FDA-approved 1967 as an antineoplastic and 1998 for sickle cell anemia; raises HbF, reduces pain crises, mainstay disease-modifying SCD drug.
Hydroxychloroquine
Hydroxychloroquine (Plaquenil, HCQ), a 4-aminoquinoline DMARD derived from chloroquine and quinine, treats rheumatoid arthritis, lupus, skin conditions, and malaria; large trials found no COVID-19 benefit, and retinopathy is the main long-term risk.
Hydroxycitric acid
Hydroxycitric acid (HCA), or hydroxycitrate, is a tricarboxylic acid and the principal acid of Garcinia cambogia fruit rinds, used in weight-loss supplements with at best a small, questionable effect.
Hydroxycut
Hydroxycut, also sold as Hydroxycut Advanced and Hydroxycut Hardcore, is an Iovate/MuscleTech weight loss supplement brand recalled in 2009 after 23 FDA-reported liver injury cases and one death, with reformulated products still on sale.
Hydroxyethylthiazole kinase
Hydroxyethylthiazole kinase (ThiM, EC 2.7.1.50), encoded by thiM, is a ribokinase-family trimeric enzyme that phosphorylates 4-methyl-5-beta-hydroxyethylthiazole with ATP and Mg2+ as the key salvage step of bacterial, archaeal, and plant thiamine biosynthesis.
Hydroxykynureninuria
Hydroxykynureninuria, also known as xanthurenic aciduria or kynureninase deficiency, is a very rare inherited disorder of tryptophan metabolism with large urinary losses of xanthurenic acid, kynurenine, and 3-hydroxykynurenine.
Hydroxyl number
The hydroxyl number, also called hydroxyl value or OH value, gives the hydroxyl content of a substance in mg KOH per gram and is the key polyol specification.
Hydroxyl radical
The hydroxyl radical, also known as the OH radical, is a highly reactive diatomic molecule, HO, best known as the atmosphere's primary cleansing oxidant of methane, carbon monoxide, and pollutants.
Hydroxyl radical footprinting
Hydroxyl radical footprinting is a structural probing method in which hydroxyl radicals cleave nucleic acid backbones or oxidize protein side chains, mapping binding sites, folding, and conformational change in solution.
Hydroxylamine
Hydroxylamine (NH2OH, also called oxammonium) is an inorganic compound of ammonia bearing a hydroxy group, a white solid that is thermally unstable and used mainly to make caprolactam for nylon.
Hydroxylamine reductase
Hydroxylamine reductase (EC 1.7.99.1), the activity annotated to hybrid cluster protein (HCP, prismane protein), reduces NH2OH to NH3 and H2O via a hybrid [4Fe-2S-2O] cluster; its physiological relevance is debated.
Hydroxylamine reductase/Ni-containing CO dehydrogenase
IPR004137, Hydroxylamine reductase/Ni-containing CO dehydrogenase (HCP/CODH), is an InterPro protein family uniting hybrid cluster proteins (prismane protein) and anaerobic nickel CO dehydrogenases sharing a prismane-like scaffold and related Fe-S-O/Ni-Fe clusters.
Hydroxylation
Hydroxylation: adding a hydroxyl group to a compound where none existed before; carried out biologically by P450 monooxygenases via radical rebound, and in collagen by ascorbate-dependent prolyl and lysyl hydroxylases.
Hydroxylysine
Hydroxylysine (5-hydroxylysine) is an amino acid formed by hydroxylation of lysine residues in proteins, best known as a component of collagen, the structural protein of connective tissue.
Hydroxymethylfurfural production
Hydroxymethylfurfural production is the manufacture of 5-hydroxymethylfurfural (HMF), a bio-based platform chemical made by acid-catalyzed dehydration of sugars such as fructose; no large-scale commercial plant was running as of 2020.
Hydroxymethylglutaryl-CoA synthase
Hydroxymethylglutaryl-CoA synthase (HMG-CoA synthase, EC 2.3.3.10) is an enzyme condensing acetyl-CoA and acetoacetyl-CoA into HMG-CoA; cytosolic HMGCS1 serves cholesterol synthesis, mitochondrial HMGCS2 controls ketogenesis, and HMGCS2 deficiency is a rare ketogenesis disorder.
Hydroxynorketamine
Hydroxynorketamine (HNK) is a hydroxylated metabolite of ketamine, formed in the body after ketamine administration. Twelve stereoisomers exist; the (2R,6R) form is studied as a rapid-acting antidepressant without dissociation.
Hydroxyphenyl salicylamide
Hydroxyphenyl salicylamide (N-(4-hydroxyphenyl)salicylamide, oxaphenamide, osalmid; CAS 526-18-1) is a salicylanilide fungicide, EU ID 134, not approved in the EU since the 2002/2076/EC decision, with a 0.01 mg/kg default MRL.
Hydroxyprogesterone caproate
Hydroxyprogesterone caproate (17-OHPC; Delalutin, Makena, Proluton Depot) is a synthetic long-acting progestin ester given weekly by intramuscular injection. FDA approved it in 2011 to prevent recurrent preterm birth and withdrew that approval in April 2023; the EU suspended it in 2024.