Quinoxalines

Varenicline, sold under the brand names Chantix and Champix among others, is a medication used for smoking cessation and for the treatment of dry eye syndrome. It is a nicotinic acetylcholine receptor partial agonist. When activated, this receptor leads to the release of dopamine in the nucleus accumbens, the brain's reward center, thereby reducing cravings and withdrawal symptoms with smoking cessation, although less pronounced than a full agonist (e.g. nicotine).

A quinoxaline, also called a benzopyrazine, in organic chemistry, is a heterocyclic compound containing a ring complex made up of a benzene ring and a pyrazine ring. It is isomeric with other naphthyridines including quinazoline, phthalazine and cinnoline. It is a colorless oil that melts just above room temperature. Although quinoxaline itself is mainly of academic interest, quinoxaline derivatives are used as dyes, pharmaceuticals (such as varenicline), and antibiotics such as olaquindox, carbadox, echinomycin, levomycin and actinoleutin.

Brimonidine is an α2 agonist medication used to treat open-angle glaucoma, ocular hypertension, and rosacea. In rosacea it improves the redness. It is used as eye drops or applied to the skin. It is also available in the fixed-dose combination medication brimonidine/timolol along with timolol maleate.

Carbadox is a veterinary drug that combats infection in swine, particularly swine dysentery.

NBQX (2,3-dioxo-6-nitro-7-sulfamoyl-benzo[f]quinoxaline) is an antagonist of the AMPA receptor.

DNQX (6,7-dinitroquinoxaline-2,3-dione) is a competitive antagonist at AMPA and kainate receptors, two ionotropic glutamate receptor (iGluR) subfamilies. It is used in a variety of molecular biology subfields, notably neurophysiology, to assist researchers in determining the properties of various types of ion channels and their potential applications in medicine.

CNQX or cyanquixaline (6-cyano-7-nitroquinoxaline-2,3-dione) is a competitive AMPA/kainate receptor antagonist. Its chemical formula is C9H4N4O4. CNQX is often used in the retina to block the responses of OFF-bipolar cells for electrophysiology recordings.

thumb|Proposed enzymatic reaction mechanism for the biotransformation of 1 to 2. Echinomycin is a peptide antibiotic. It is a dimer of two peptides creating a cyclic structure. It contains a bicyclic aromatic chromophore that is attached to the dimerized cyclic peptide core and a thioacetal bridge. It intercalates into DNA at two specific sites, thereby blocking the binding of hypoxia inducible factor 1 alpha (HIF1alpha).

Glecaprevir (INN,) is a hepatitis C virus (HCV) nonstructural (NS) protein 3/4A protease inhibitor that was identified jointly by AbbVie and Enanta Pharmaceuticals. It is being developed as a treatment of chronic hepatitis C infection in co-formulation with an HCV NS5A inhibitor pibrentasvir. Together they demonstrated potent antiviral activity against major HCV genotypes and high barriers to resistance in vitro.

Quinalphos is an organothiophosphate chemical chiefly used as a pesticide. It is a reddish-brown liquid. The chemical formula is C12H15N2O3PS, and IUPAC name O,O-diethyl O-quinoxalin-2-yl phosphorothioate. Ranked 'moderately hazardous' in World Health Organization's (WHO) acute hazard ranking, use of quinalphos, classified as a yellow label (highly toxic) pesticide in India, is widely used in the following crops: wheat, rice, coffee, sugarcane, and cotton.

Sulfaquinoxaline (IUPAC name: '4-Amino-N-2-quinoxalinylbenzenesulfonamide') is a veterinary medicine which can be given to cattle and sheep to treat coccidiosis.

Erdafitinib, sold under the brand name Balversa, is an anti-cancer medication. It is a small molecule inhibitor of fibroblast growth factor receptor (FGFR) used for the treatment of cancer. FGFRs are a subset of tyrosine kinases which are unregulated in some tumors and influence tumor cell differentiation, proliferation, angiogenesis, and cell survival. Astex Pharmaceuticals discovered the drug and licensed it to Janssen Pharmaceuticals for further development.

SRT-1720 is an experimental drug that was studied by Sirtris Pharmaceuticals intended as a small-molecule activator of the sirtuin subtype SIRT1. The compound has been studied in animals, but safety and efficacy in humans have not been established.

CX-516 is an ampakine and nootropic that acts as an AMPA receptor positive allosteric modulator and had been undergoing development by a collaboration between Cortex, Shire, and Servier. It was studied as a potential treatment for Alzheimer's disease under the brand name Ampalex, and was also being examined as a treatment for ADHD.