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nitrofurantoin
A urinary anti-infective agent effective against most gram-positive and gram-negative organisms. Although sulfonamides and antibiotics are usually the agents of choice for urinary tract infections, nitrofurantoin is widely used for prophylaxis and long-term suppression.
nitrofurazone
A topical anti-infective agent effective against gram-negative and gram-positive bacteria. It is used for superficial WOUNDS AND INJURIES and skin infections. Nitrofurazone has also been administered orally in the treatment of TRYPANOSOMIASIS.
nitrogen
An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
nitrogen compounds
Inorganic compounds that contain nitrogen as an integral part of the molecule.
nitrogen dioxide
Nitrogen oxide (NO2). A highly poisonous gas. Exposure produces inflammation of lungs that may only cause slight pain or pass unnoticed, but resulting edema several days later may cause death. (From Merck, 11th ed) It is a major atmospheric pollutant that is able to absorb UV light that does not reach the earth's surfa...
nitrogen isotopes
Stable nitrogen atoms that have the same atomic number as the element nitrogen but differ in atomic weight. N-15 is a stable nitrogen isotope.
nitrogen mustard compounds
A group of alkylating agents derived from mustard gas, with the sulfur replaced by nitrogen. They were formerly used as toxicants and vesicants, but now function as antineoplastic agents. These compounds are also powerful mutagens, teratogens, immunosuppressants, and carcinogens.
nitrogen oxides
Inorganic oxides that contain nitrogen.
nitrogen radioisotopes
Unstable isotopes of nitrogen that decay or disintegrate emitting radiation. N atoms with atomic weights 12, 13, 16, 17, and 18 are radioactive nitrogen isotopes.
nitroglycerin
A volatile vasodilator which relieves ANGINA PECTORIS by stimulating GUANYLATE CYCLASE and lowering cytosolic calcium. It is also sometimes used for TOCOLYSIS and explosives.
nitrohydroxyiodophenylacetate
Also called 4-hydroxy-3-iodo-5-nitrophenylacetate. A haptenic determinant that can be radiolabeled and used as salts and derivatives for investigations of immunogenic specificity studies.
nitroimidazoles
IMIDAZOLES having a nitro moiety.
nitromifene
A non-steroidal estrogen antagonist (as the 1:1 citrate) most commonly used as a research tool in animal studies.
nitroparaffins
Alkanes having one or more nitro (NO2) groups attached to carbon atoms.
nitrophenols
PHENOLS carrying nitro group substituents.
nitrophenylgalactosides
Includes ortho-, meta-, and para-nitrophenylgalactosides.
nitroprusside
A powerful vasodilator used in emergencies to lower blood pressure or to improve cardiac function. It is also an indicator for free sulfhydryl groups in proteins.
nitroquinolines
Quinolines substituted in any position by one or more nitro groups.
nitrosamines
A class of compounds that contain a -NH2 and a -NO radical. Many members of this group have carcinogenic and mutagenic properties.
nitroso compounds
Organic compounds containing the nitroso (-N=O) group attached to an organic moiety.
nitrosoguanidines
Nitrosylated derivatives of guanidine. They are used as MUTAGENS in MOLECULAR BIOLOGY research.
nitrosomethylurethane
An alkylating carcinogen that produces gastrointestinal and probably lung and nervous system tumors.
nitrosourea compounds
A class of compounds in which the core molecule is R-NO, where R is UREA.
nitrous acid
Nitrous acid (HNO2). A weak acid that exists only in solution. It can form water-soluble nitrites and stable esters. (From Merck Index, 11th ed)
nitrous oxide
Nitrogen oxide (N2O). A colorless, odorless gas that is used as an anesthetic and analgesic. High concentrations cause a narcotic effect and may replace oxygen, causing death by asphyxia. It is also used as a food aerosol in the preparation of whipping cream.
nitrovin
An antibacterial growth promoter used in animal feeds.
nitroxinil
Proposed anthelmintic for fasciola and liver fluke infestations.
nizatidine
A histamine H2 receptor antagonist with low toxicity that inhibits gastric acid secretion. The drug is used for the treatment of duodenal ulcers.
nk cell lectin-like receptor subfamily a
An inhibitory subclass of NK cell lectin-like receptors that interacts with CLASS I MAJOR HISTOCOMPATIBILITY ANTIGENS and prevents the activation of NK CELLS.
n-methyl-3,4-methylenedioxyamphetamine
An N-substituted amphetamine analog. It is a widely abused drug classified as a hallucinogen and causes marked, long-lasting changes in brain serotonergic systems. It is commonly referred to as MDMA or ecstasy.
n-methylaspartate
An amino acid that, as the D-isomer, is the defining agonist for the NMDA receptor subtype of glutamate receptors (RECEPTORS, NMDA).
n-methylscopolamine
A muscarinic antagonist used to study binding characteristics of muscarinic cholinergic receptors.
n,n-dimethyltryptamine
An N-methylated indoleamine derivative and serotonergic hallucinogen which occurs naturally and ubiquitously in several plant species including Psychotria veridis. It also occurs in trace amounts in mammalian brain, blood, and urine, and is known to act as an agonist or antagonist of certain SEROTONIN RECEPTORS.
n-nitrosopyrrolidine
Carcinogenic nitrosamine that may be formed from preservatives in meats during their preparation or in the liver during metabolism.
nobelium
A man-made radioactive element of the actinide metal series. It has the atomic symbol No, and atomic number 102.
noble gases
Elements that constitute group 18 (formerly the zero group) of the periodic table. They are gases that generally do not react chemically.
nociceptin
A pronociceptive peptide that acts as a specific endogenous agonist to the NOCICEPTIN RECEPTOR.
nocodazole
Nocodazole is an antineoplastic agent which exerts its effect by depolymerizing microtubules.
nodal protein
The founding member of the nodal signaling ligand family of proteins. Nodal protein was originally discovered in the region of the mouse embryo primitive streak referred to as HENSEN'S NODE. It is expressed asymmetrically on the left side in chordates and plays a critical role in the genesis of left-right asymmetry dur...
nodal signaling ligands
Members of the transforming growth factor superfamily that play a role in pattern formation and differentiation during the pregastrulation and GASTRULATION stages of chordate development. Several nodal signaling ligands are specifically involved in the genesis of left-right asymmetry during development. The protein gro...
nogalamycin
An anthrocycline from a Streptomyces nogalater variant. It is a cytolytic antineoplastic that inhibits DNA-dependent RNA synthesis by binding to DNA.
nomifensine
An isoquinoline derivative that prevents dopamine reuptake into synaptosomes. The maleate was formerly used in the treatment of depression. It was withdrawn worldwide in 1986 due to the risk of acute hemolytic anemia with intravascular hemolysis resulting from its use. In some cases, renal failure also developed. (From...
nonachlazine
Coronary vasodilator with a novel mechanism of action; proposed as antianginal agent.
nonmuscle myosin type iia
A nonmuscle isoform of myosin type II found predominantly in platelets, lymphocytes, neutrophils and brush border enterocytes.
nonmuscle myosin type iib
A nonmuscle isoform of myosin type II found predominantly in neuronal tissue.
non-nutritive sweeteners
Chemical additives, such as aspartame, saccharin, and sucralose, that give a sweet taste to foods without contributing significant calories or promoting tooth decay. They are generally much sweeter than sucrose.
nonoxynol
Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Nonoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide, formulated primarily as a component of vaginal foams and cream...
nonsteroidal anti-androgens
Nonsteroidal agents which block the action or downregulate the synthesis of ANDROGENS.
nootropic agents
Drugs used to specifically facilitate learning or memory, particularly to prevent the cognitive deficits associated with dementias. These drugs act by a variety of mechanisms.
norandrostanes
Androstanes in which ring contractions have occurred or which are lacking carbon-18. Compounds with any degree of unsaturation are included. Androstanes which are lacking carbon-19 are ESTRANES.
norbornanes
Compounds that include or are derivatives of norbornane(bicyclo[2.2.1]heptane).
nordazepam
An intermediate in the metabolism of DIAZEPAM to OXAZEPAM. It may have actions similar to those of diazepam.
nordefrin
A norepinephrine derivative used as a vasoconstrictor agent.
norepinephrine
Precursor of epinephrine that is secreted by the ADRENAL MEDULLA and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the LOCUS CERULEUS. It is also found in p...
norethandrolone
A synthetic hormone with anabolic and androgenic properties and moderate progestational activity.
norethindrone
A synthetic progestational hormone with actions similar to those of PROGESTERONE but functioning as a more potent inhibitor of ovulation. It has weak estrogenic and androgenic properties. The hormone has been used in treating amenorrhea, functional uterine bleeding, endometriosis, and for CONTRACEPTION.
norethindrone acetate
Acetate ester of norethindrone that is used as a long-term contraceptive (CONTRACEPTIVE AGENTS).
norethynodrel
A synthetic progestational hormone with actions and uses similar to those of PROGESTERONE. It has been used in the treatment of functional uterine bleeding and ENDOMETRIOSIS. As a contraceptive (CONTRACEPTIVE AGENTS), it has usually been administered in combination with MESTRANOL.
norfenfluramine
A FENFLURAMINE analog that inhibits serotonin uptake and may provoke release of serotonin. It is used as an appetite depressant and an experimental tool in animal studies.
norfloxacin
A synthetic fluoroquinolone (FLUOROQUINOLONES) with broad-spectrum antibacterial activity against most gram-negative and gram-positive bacteria. Norfloxacin inhibits bacterial DNA GYRASE.
norgestrel
A synthetic progestational agent with actions similar to those of PROGESTERONE. This racemic or (+-)-form has about half the potency of the levo form (LEVONORGESTREL). Norgestrel is used as a contraceptive, ovulation inhibitor, and for the control of menstrual disorders and endometriosis.
norgestrienone
A synthetic steroid with progestational and contraceptive activities.
norisoprenoids
Thirteen-carbon butene cyclohexene degradation products formed by the cleavage of CAROTENOIDS. They contribute to the flavor of some FRUIT. Ionone should not be confused with the similarly named ionol.
norleucine
An unnatural amino acid that is used experimentally to study protein structure and function. It is structurally similar to METHIONINE, however it does not contain SULFUR.
normetanephrine
A methylated metabolite of norepinephrine that is excreted in the urine and found in certain tissues. It is a marker for tumors.
norpregnadienes
Pregnadienes which have undergone ring contractions or are lacking carbon-18 or carbon-19.
norpregnanes
Pregnanes which have undergone ring contractions or are lacking carbon-18 or carbon-19. Unsaturation in the steroid ring system is not included.
norpregnatrienes
Pregnatrienes which have undergone ring contractions or are lacking carbon-18 or carbon-19.
norpregnenes
Pregnenes with one double bond or more than three double bonds which have undergone ring contractions or are lacking carbon-18 or carbon-19..
norprogesterones
Progesterones which have undergone ring contraction or which are lacking carbon 18 or 19.
norsteroids
Steroids which have undergone contraction in ring size or reduction in side chains.
nortriptyline
A metabolite of AMITRIPTYLINE that is also used as an antidepressive agent. Nortriptyline is used in major depression, dysthymia, and atypical depressions.
nortropanes
Derivatives of 8-azabicyclo[3.2.1]octane.
noscapine
A naturally occurring opium alkaloid that is a centrally acting antitussive agent.
novobiocin
An antibiotic compound derived from Streptomyces niveus. It has a chemical structure similar to coumarin. Novobiocin binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p189)
noxae
Agents capable of exerting a harmful effect on the body.
noxythiolin
Local antibacterial that probably acts by releasing formaldehyde in aqueous solutions. It is used for THERAPEUTIC IRRIGATION of infected body cavities - bladder, peritoneum, etc. and as a spray for burns.
n-substituted glycines
AMINO ACIDS composed of GLYCINE substituted at the nitrogen rather than the usual carbon position, resulting in the loss of HYDROGEN BONDING donors. Polymers of these compounds are called PEPTOIDS.
nucleic acid-based vaccines
Vaccines formulated with nucleic acids specific for a target antigen. They are designed to induce antibody production against the target by host.
nucleic acid probes
Nucleic acid which complements a specific mRNA or DNA molecule, or fragment thereof; used for hybridization studies in order to identify microorganisms and for genetic studies.
nucleic acids, nucleotides, and nucleosides
Complex compounds of high molecular weight occurring in living cells. These are basically of two types, ribonucleic (RNA) and deoxyribonucleic (DNA) acids, both of which consist of nucleotides (nucleoside phosphates linked together by phosphate bridges).
nucleic acid synthesis inhibitors
Compounds that inhibit cell production of DNA or RNA.
nucleoside q
A modified nucleoside which is present in the first position of the anticodon of tRNA-tyrosine, tRNA-histidine, tRNA-asparagine and tRNA-aspartic acid of many organisms. It is believed to play a role in the regulatory function of tRNA. Nucleoside Q can be further modified to nucleoside Q*, which has a mannose or galact...
nucleosides
Purine or pyrimidine bases attached to a ribose or deoxyribose. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
nucleotides
The monomeric units from which DNA or RNA polymers are constructed. They consist of a purine or pyrimidine base, a pentose sugar, and a phosphate group. (From King & Stansfield, A Dictionary of Genetics, 4th ed)
nutritive sweeteners
Any agent that adds not only sweet taste but some energy value to food. They include natural sugars such as SUCROSE; FRUCTOSE; and GALACTOSE; and certain SUGAR ALCOHOLS.
nylidrin
A beta-adrenergic agonist. Nylidrin causes peripheral vasodilation, a positive inotropic effect, and increased gastric volume of gastric juice. It is used in the treatment of peripheral vascular disorders and premature labor.
nylons
Polymers where the main polymer chain comprises recurring amide groups. These compounds are generally formed from combinations of diamines, diacids, and amino acids and yield fibers, sheeting, or extruded forms used in textiles, gels, filters, sutures, contact lenses, and other biomaterials.
nystatin
Macrolide antifungal antibiotic complex produced by Streptomyces noursei, S. aureus, and other Streptomyces species. The biologically active components of the complex are nystatin A1, A2, and A3.
o-acetyl-adp-ribose
An acetyl ester of ADENOSINE DIPHOSPHATE RIBOSE formed during NAD-dependent deacetylation of proteins by SIRTUINS. The acetate group resides on the ribose ring where nicotinamide was cleaved from NAD during the reaction. Several isomers of O-acetyl-ADP-ribose have been isolated from the reaction.
o-aminoazotoluene
An azo dye with carcinogenic properties.
o antigens
The lipopolysaccharide-protein somatic antigens, usually from gram-negative bacteria, important in the serological classification of enteric bacilli. The O-specific chains determine the specificity of the O antigens of a given serotype. O antigens are the immunodominant part of the lipopolysaccharide molecule in the in...
obidoxime chloride
Cholinesterase reactivator occurring in two interchangeable isomeric forms, syn and anti.
o-(chloroacetylcarbamoyl)fumagillol
Semisynthetic analog of fumagillin (a cyclohexane-sesquiterpene antibiotic isolated from ASPERGILLUS FUMIGATUS) that inhibits angiogenesis.
o-chlorobenzylidenemalonitrile
A riot control agent which causes temporary irritation of the eyes and the mucosal surface of the respiratory tract. It is a more potent irritant than OMEGA-CHLOROACETOPHENONE, but less incapacitating.
ochratoxins
Isocoumarins found in ASPERGILLUS OCHRACEUS and other FUNGI. Ochratoxin contaminated FOOD has been responsible for cases of FOODBORNE DISEASES.
octanes
Eight-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.
octanols
Isomeric forms and derivatives of octanol (C8H17OH).
octopamine
An alpha-adrenergic sympathomimetic amine, biosynthesized from tyramine in the CNS and platelets and also in invertebrate nervous systems. It is used to treat hypotension and as a cardiotonic. The natural D(-) form is more potent than the L(+) form in producing cardiovascular adrenergic responses. It is also a neurotra...
octoxynol
Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.