All articles starting with P

Phenoxy herbicide

Phenoxy herbicides are a family of synthetic auxin weed killers built on a phenoxyacetic acid backbone, selectively killing broadleaf plants while sparing grasses; 2,4-D was first synthesized in 1941.

Oct 22, 2026

Phenoxy-dioxetane chemiluminescent probes

Phenoxy-dioxetane chemiluminescent probes are synthetic molecules built on a phenoxy-substituted 1,2-dioxetane ring that emit light through chemical decomposition once a target enzyme removes the phenol's protective group.

Phenoxybenzamine

Phenoxybenzamine, sold as Dibenzyline, is a long-acting, irreversible alpha-adrenergic receptor blocker used to control hypertension and sweating in pheochromocytoma and to prepare patients before tumor removal surgery.

Phenoxymethylpenicillin

Phenoxymethylpenicillin, or penicillin V, is an acid-stable, narrow-spectrum oral β-lactam antibiotic developed at Lilly from phenoxyacetic acid and made oral by Brandl at Biochemie in 1952; used for streptococcal and respiratory infections.

Phenoxypropazine

Phenoxypropazine (fenoxypropazine, Drazine) is a hydrazine-class, non-selective irreversible MAOI antidepressant marketed by Smith & Nephew from 1961 and withdrawn in 1966 for hepatotoxicity.

Phenprocoumon

Phenprocoumon, sold in Germany as Marcumar since 1953, is a long-acting coumarin oral anticoagulant that inhibits vitamin K epoxide reductase and is used to prevent and treat thrombosis and embolism.

Phensuximide

Phensuximide (Milontin), also called N-methyl-2-phenylsuccinimide, is a succinimide anticonvulsant developed by Parke-Davis in the 1950s for absence (petit mal) seizures; weakly effective, rarely used, and no longer sold in the US.

Phentermine

Phentermine, also known as Adipex-P, is a Schedule IV sympathomimetic amine appetite suppressant approved by the FDA in 1959 for short-term obesity treatment; combined with topiramate (Qsymia) it is among the most effective weight-loss drugs.

Phenthoate

Phenthoate (Cidial, Elsan, OMS 1075), CAS 2597-03-7, is an organophosphorus insecticide and acaricide for citrus and rice that inhibits cholinesterase; its acute toxicity rises sharply with trimethyl phosphate impurities, and it is not EU-approved.

Phentolamine

Phentolamine is a reversible, non-selective alpha-1 and alpha-2 blocker sold in the United States since 1952 as Regitine, once used for hypertension and now mainly for pheochromocytoma surgery.

Phenyl aminosalicylate

Phenyl aminosalicylate (fenamisal, CAS 133-11-9) is the phenyl ester prodrug of para-aminosalicylic acid, a tuberculostatic antituberculosis drug marketed from 1959 as Pheny-Pas-Tebamin and later discontinued.

Phenyl glycidyl ether

Phenyl glycidyl ether, also called glycidyl phenyl ether or 1,2-epoxy-3-phenoxypropane, is a colorless liquid used mainly as a reactive diluent in epoxy resins and regulated as a potential occupational carcinogen.

Phenyl group

The phenyl group, also known as the phenyl ring, is the monovalent fragment C₆H₅–, formed by removing one hydrogen atom from benzene so the ring can bond to a molecule.

Phenyl isocyanate

Phenyl isocyanate, also called isocyanatobenzene, is the simplest aromatic isocyanate, a very toxic colorless liquid used as a reagent and as a model compound in urethane chemistry.

Phenylacetaldehyde

Phenylacetaldehyde, also called 2-phenylethanal or hyacinthin, is an aromatic aldehyde with a sweet, honey-like odor found in foods, wine, honey, and floral scents, used in flavorings and perfumery.

Phenylacetic acid

Phenylacetic acid (PAA) is a white crystalline carboxylic acid with a sweet, honey-like odor that occurs in plants and bacteria and serves as a natural auxin and penicillin G precursor.

Phenylacetone

Phenylacetone, also called phenyl-2-propanone or benzyl methyl ketone, is a colorless liquid ketone and amphetamine metabolite, best known as an illicit precursor controlled by the DEA.

Phenylacetylene

Phenylacetylene (ethynylbenzene) is the simplest aryl alkyne, a colorless liquid building block in organic synthesis, best known as the standard terminal alkyne substrate in Sonogashira cross-coupling.

Phenylacetylglutamine

Phenylacetylglutamine (PAGln), C13H16N2O4, is a gut-microbiota-derived metabolite formed when bacteria convert dietary phenylalanine to phenylacetic acid, conjugated with glutamine in human liver; a uremic toxin linked to cardiovascular disease, thrombosis, and senescence.

Phenylalanine

Phenylalanine is an essential amino acid converted to tyrosine by phenylalanine hydroxylase (BH4-dependent); its deficiency causes phenylketonuria (PKU), and aspartame contains it, requiring PKU warning labels.

Phenylalanine ammonia-lyase

Phenylalanine ammonia-lyase (PAL, EC 4.3.1.24), a homotetrameric MIO-dependent lyase deaminating L-phenylalanine to trans-cinnamic acid and ammonia; found in plants, fungi, yeasts, and bacteria but not animals; basis of pegvaliase PKU therapy.

Phenylalanine and tyrosine metabolism

Phenylalanine and tyrosine metabolism is the pathway by which phenylalanine is converted to tyrosine and degraded to fumarate and acetoacetate; its best-known disorder is phenylketonuria.

Phenylalanine hydroxylase

Phenylalanine hydroxylase (PAH, EC 1.14.16.1), also phenylalanine 4-monooxygenase: a non-heme iron, BH4-dependent homotetrameric enzyme converting phenylalanine to tyrosine; its deficiency causes phenylketonuria.

Phenylalanine metabolism

Phenylalanine metabolism: human disposal of the essential amino acid L-phenylalanine, mainly via PAH and BH4 hydroxylation to tyrosine in liver and kidney; alternative transamination to phenylpyruvate underlies phenylketonuria.

Phenylalanyl-tRNA synthetase

Phenylalanyl-tRNA synthetase (PheRS), EC 6.1.1.20, a class II aminoacyl-tRNA synthetase charging tRNA^Phe with phenylalanine; exists as bacterial and cytosolic (αβ)2 heterotetramers and a monomeric mitochondrial form; edits mischarged Tyr-tRNA^Phe in its β-subunit B3/B4 domain.