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N-Nitrosonornicotine
''N''-Nitrosonornicotine (NNN) is a tobacco-specific nitrosamine produced during the curing and processing of tobacco. Toxicity It has been classified as a List of IARC Group 1 carcinogens, Group 1 carcinogen. Although no adequate studies of the relationship between exposure to NNN and human cancer have been reported, there is sufficient evidence that NNN causes cancer in experimental animals. Sources NNN is found in a variety of tobacco products including smokeless tobacco like chewing tobacco and snuff (tobacco), snuff, cigarettes, and cigars. It is present in smoke from cigars and cigarettes, in the saliva of people who chew betel, betel quid with tobacco, and in the saliva of oral-snuff and e-cigarette users. NNN is produced by the nitrosation of nornicotine during the curing, aging, processing, and smoking of tobacco. Roughly half of the NNN originates in the unburnt tobacco, with the remainder being formed during burning. NNN can be produced in the acidic environment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nornicotine
Nornicotine is an alkaloid found in various plants including ''Nicotiana'', the tobacco plant. It is chemically similar to nicotine, but does not contain a methyl group. It is a precursor to the carcinogen N-Nitrosonornicotine, ''N''-nitrosonornicotine that is produced during the curing and processing of tobacco. Nornicotine can react in human saliva to form N-Nitrosonornicotine, N-nitrosonornicotine, a known type 1 carcinogen. Synthesis There are several routes for the synthesis of nornicotine. One route is the demethylation of nicotine, which can be accomplished by reaction with silver oxide. \mathrm Another route is the partial reduction of 3-myosmine, which can be accomplished by standard catalytic hydrogenation conditions using palladium as a catalyst or with sodium borohydride.. This reaction gives the racemic product. \mathrm Pharmacology Nornicotine possess high affinity for alpha-6 and alpha-7 subunits of nAChRs. It also inhibits DAT in striatum via nAChR and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
N-Nitrosonornicotine
''N''-Nitrosonornicotine (NNN) is a tobacco-specific nitrosamine produced during the curing and processing of tobacco. Toxicity It has been classified as a List of IARC Group 1 carcinogens, Group 1 carcinogen. Although no adequate studies of the relationship between exposure to NNN and human cancer have been reported, there is sufficient evidence that NNN causes cancer in experimental animals. Sources NNN is found in a variety of tobacco products including smokeless tobacco like chewing tobacco and snuff (tobacco), snuff, cigarettes, and cigars. It is present in smoke from cigars and cigarettes, in the saliva of people who chew betel, betel quid with tobacco, and in the saliva of oral-snuff and e-cigarette users. NNN is produced by the nitrosation of nornicotine during the curing, aging, processing, and smoking of tobacco. Roughly half of the NNN originates in the unburnt tobacco, with the remainder being formed during burning. NNN can be produced in the acidic environment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NNN Mechanism Of Action
NNN may refer to: Arts and entertainment * '' Neal 'n' Nikki'', a 2005 Indian movie directed by Arjun Sablok and starring Uday Chopra and Tanisha * NNN, the production code for the 1972 ''Doctor Who'' serial '' The Mutants'' Companies and organizations * National Numeracy Network (NNN), a professional organization that promotes numeracy in the United States * NNN Reit, a real estate investment trust in the United States * Norsk Naerings- og Nytelsesmiddelarbeiderforbund, the Norwegian Union of Food, Beverage and Allied Workers News * NAM News Network, a news network set up by non-aligned countries * Newspaper National Network, a marketing partnership of the top 25 newspaper companies in America and the Newspaper Association of America * Nippon News Network, the Japanese television news network * '' Norddeutsche Neueste Nachrichten'', a German newspaper * Nine News Now, an Australian news bulletin * National Nine Network, former name of the Nine Network * National Nine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosamines
Nitrosamines (or more formally ''N''-nitrosamines) are organic compounds produced by industrial processes. The chemical structure is , where R is usually an alkyl group. Nitrosamines have a nitroso group () that are "probable human carcinogens", bonded to a deprotonated amine. Most nitrosamines are carcinogenic in animals. A 2006 systematic review supports a "positive association between nitrite and nitrosamine intake and gastric cancer, between meat and processed meat intake and gastric cancer and oesophageal cancer, and between preserved fish, vegetable and smoked food intake and gastric cancer, but is not conclusive". Chemistry The organic chemistry of nitrosamines is well developed with regard to their syntheses, their structures, and their reactions. They usually are produced by the reaction of nitrous acid () and secondary amines, although other nitrosyl sources (e.g. , , Alkyl nitrite, RONO) have the same effect: : The nitrous acid usually arises from protonation of a nit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco-specific Nitrosamine
Tobacco-specific nitrosamines (TSNAs) comprise one of the most important groups of carcinogens in tobacco products, particularly cigarettes (traditional and electronic) and fermented dipping snuff. Background These nitrosamine carcinogens are formed from nicotine and related compounds by a nitrosation reaction that occurs during the curing and processing of tobacco. Essentially the plant's natural alkaloids combine with nitrate forming the nitrosamines. They are called tobacco-specific nitrosamines because they are found only in tobacco products, and possibly in some other nicotine-containing products. The tobacco-specific nitrosamines are present in cigarette smoke and to a lesser degree in "smokeless" tobacco products such as dipping tobacco and chewing tobacco; additional information has shown that trace amounts of NNN and NNK have been detected in e-cigarettes. They are present in trace amounts in snus. They are important carcinogens in cigarette smoke, along with combu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smokeless Tobacco
Smokeless tobacco is a tobacco product that is used by means other than smoking. Their use involves chewing, sniffing, or placing the product between gum and the cheek or lip. Smokeless tobacco products are produced in various forms, such as chewing tobacco, snuff, snus, and dissolvable tobacco products. Smokeless tobacco is widely used in South Asia and this accounts for about 80% of global consumption. All smokeless tobacco products contain nicotine and are therefore highly addictive. Quitting smokeless tobacco use is as challenging as smoking cessation. Using smokeless tobacco can cause various harmful effects such as dental disease, oral cancer, oesophagus cancer, and pancreas cancer, coronary heart disease, as well as negative reproductive effects including stillbirth, premature birth and low birth weight. Smokeless tobacco poses a lower health risk than traditional combusted products. However it is not a healthy alternative to cigarette smoking. The level of risk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of IARC Group 1 Carcinogens
IARC group 1 Carcinogens are substances, chemical mixtures, and exposure circumstances which have been classified as carcinogenic to humans by the International Agency for Research on Cancer (IARC). This category is used when there is sufficient evidence of carcinogenicity in humans. Exceptionally, an agent ( chemical mixture) may be placed in this category when evidence of carcinogenicity in humans is less than sufficient, but when there is sufficient evidence of carcinogenicity in experimental animals and strong evidence in exposed humans that the agent (mixture) acts through a relevant mechanism of carcinogenicity. This list focuses on the hazard linked to the agents. This means that while carcinogens are capable of causing cancer, it does not take their risk into account, which is the probability of causing a cancer, given the level of exposure to this carcinogen. The list is up to date as of January 2024. Agents Infectious conditions Viruses *Human immunodeficiency viru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer
Cancer is a group of diseases involving Cell growth#Disorders, abnormal cell growth with the potential to Invasion (cancer), invade or Metastasis, spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible Signs and symptoms of cancer, signs and symptoms include a lump, abnormal bleeding, prolonged cough, unexplained weight loss, and a change in defecation, bowel movements. While these symptoms may indicate cancer, they can also have other causes. List of cancer types, Over 100 types of cancers affect humans. Tobacco use is the cause of about 22% of cancer deaths. Another 10% are due to obesity, poor Diet (nutrition), diet, sedentary lifestyle, lack of physical activity or Alcohol abuse, excessive alcohol consumption. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. infectious causes of cancer, Infection with specific viruses, bacteria and parasites is an environmental factor cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Median Lethal Dose
In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of higher toxicity. The term LD50 is generally attributed to John William Trevan. The test was created by J. W. Trevan in 1927. The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug botox without animal tests. Conventions The LD50 is usually expr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrous Acid
Nitrous acid (molecular formula ) is a weak and monoprotic acid known only in solution, in the gas phase, and in the form of nitrite () salts. It was discovered by Carl Wilhelm Scheele, who called it " phlogisticated acid of niter". Nitrous acid is used to make diazonium salts from amines. The resulting diazonium salts are reagents in azo coupling reactions to give azo dyes. Structure In the gas phase, the planar nitrous acid molecule can adopt both a ''syn'' and an ''anti'' form. The ''anti'' form predominates at room temperature, and IR measurements indicate it is more stable by around 2.3 kJ/mol. p. 462. Image:Trans-nitrous-acid-2D-dimensions.png , Dimensions of the ''anti'' form(from the microwave spectrum) Image:Trans-nitrous-acid-3D-balls.png , Model of the ''anti'' form Image:Cis-nitrous-acid-3D-balls.png , ''syn'' form Preparation and decomposition Free, gaseous nitrous acid is unstable, rapidly disproportionating to nitric oxides: :2 HNO2 → NO2 + ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosonium
The nitrosonium ion is , in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. It can be viewed as nitric oxide with one electron removed. This ion is usually obtained as the following salts: , ( nitrosylsulfuric acid, more descriptively written ) and . The and salts are slightly soluble in acetonitrile . NOBF4 can be purified by sublimation at 200–250 °C and . Synthesis and spectroscopy is isoelectronic with CO, and . It arises via protonation of nitrous acid: :HONO + H+ NO+ + H2O In its infrared spectrum of its salts, νNO is a strong peak in the range 2150-2400 cm−1. Chemical properties Hydrolysis reacts readily with water to form nitrous acid: : For this reason, nitrosonium compounds must be protected from water or even moist air. With base, the reaction generates nitrite: : As a diazotizing agent reacts with aryl amines, , to give diazonium salts, . The resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
