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Quinoxalines
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. Synthesis They can be formed by condensing ''ortho''-diamines with 1,2-diketones. The parent substance of the group, quinoxaline, results when glyoxal is condensed with 1,2-diaminobenzene. Substituted derivatives arise when α-ketonic acids, α-chlorketones, α-aldehyde alcohols and α-ketone alcohols are used in place of diketones. Quinoxaline and its analogues may also be formed by reduction of amino acids substituted 1,5-difluoro-2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Varenicline
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). Common side effects include nausea, insomnia, abnormal dreams, headache, and nasopharyngitis ( inflammation of the nose and throat). Despite these potential adverse effects, varenicline has proven efficacy in helping individuals quit smoking. It is estimated that approximately one in eleven smokers who use varenicline successfully remain abstinent from tobacco at six months. It is on the World Health Organization's List of Essential Medicines. The medication is available as a generic medication. In the United Stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbadox
Carbadox is a veterinary drug that combats infection in swine, particularly swine dysentery. Indications Carbadox is indicated for control of swine dysentery (vibrionic dysentery, bloody scours, or hemorrhagic dysentery); control of bacterial swine enteritis (salmonellosis or necrotic enteritis caused by ''Salmonella enterica''); aid in the prevention of migration and establishment of large roundworm (''Ascaris suum'') infections; aid in the prevention of establishment of nodular worm ('' Oesophagostomum'') infections. Safety In animal models, carbadox has been shown to be carcinogenic and to induce birth defects. The Food and Drug Administration's Center for Veterinary Medicine has questioned the safety in light of its possible carcinogenicity. Regulation Carbadox is approved in the United States only for use in swine and may not be used within 42 days of slaughter or used in pregnant animals. In 2016, the United States Food and Drug Administration moved to ban its use in por ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinomycin
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). Biosynthesis Echinomycin is a bis-intercalator peptide and is biosynthesized by a unique nonribosomal peptide synthetase (NRPS). Echinomycin is isolated from various bacteria such as ''Streptomyces'' ''lasalienis''. It belongs to a family of quinoxaline antibiotics. There is great interest in this group of compounds because they have very potent antibacterial, anticancer, and antiviral activities. The biosynthesis of echinomycin starts with molecule QC. L-tryptophan is the precursor for QC and its biosynthesis parallels the first stage of nikkomycin biosynthesis. After QC is biosynthesized, the adenylation domain-containing Ecm1 acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
