Nicotine is an alkaloid found in Solonacae families, mainly in tobacco, flywheels and, in smaller quantities, in tomatoes, potatoes, eggplants, and green peppers. Nicotine alkaloids are also present in coca leaves, nicotine ranges from 0.3 to 5% of the dry weight of tobacco. Biosynthesis of nicotine occurs in the roots, and accumulation in the leaves. Nicotine is very strong neuro- and cardiotoxin, especially acting on insects, so previously used as an insecticide, now use its derivatives, such as imidacloprid.
Origin of the name
The name nicotine derives from the Latin name Nicotiana tabacum, which in turn was invented in honor of Jean Nico, the French ambassador to Portugal, who in 1560 sent a little tobacco to Catherine the Medici, recommending it as a remedy for migraine.
History of discovery
Nicotine has been known in its unclean form for a long time. The first mention of "tobacco oil" belongs to the French alchemist Jacques Gauri, who studied plants brought from America. His Instruction sur l'herbe petum (1572) proposes a way to distill tobacco leaves to produce "tobacco oil". Nicotine was used in the 17th-17th centuries as an external remedy for skin diseases. A detailed description of the production of nicotine from tobacco leaves is found in the book "Traité de la Chimie" (Chemistry Guide, 1660) by another French chemist, Nicolas Lefebvre. As an illustration of the principle of separation of substances, and because of its medical significance, it describes in detail what is essentially a water vapor distillation process. As a result of this process, evaporating water carries away nicotine with it and two layers of water and organic water are formed in the receiving flask. The organic layer was separated, cleaned and used to control asthma, spleen inflammation, and epilepsy. In 1809, the French chemist and analyst Louis Nicolas Vauklén published a work on the careful analysis of virgin tobacco. As part of this work, Voklen was able to identify a fairly pure sample of nicotine, as well as apple acid, which is associated with nicotine in tobacco.
Despite his excellent analytical work, Volken is not considered a discoverer of nicotine because he did not recognize the alkaloid in nicotine, believing that its main properties are related to the admixture of ammonia, while the alkaloids themselves are the basis. Nicotine was discovered by German chemists Christian Wilhelm Posselt and Carl Ludwig Raymann. In 1828, they presented a work dedicated to the active start of tobacco. Posselt's and Raymann's research was criticized because many chemists refused to believe that the alkaloid could be a liquid, but a special commission checked and confirmed the results. In 1843, Louis Melsen found an empirical nicotine formula, and in 1893, Adolf Piner presented the structural nicotine formula. To confirm the structure of this substance required synthesis: it was implemented by Ame Pictet in 1904. In a series of articles, Pictet published not only the method of obtaining synthetic nicotine, identical to natural nicotine but also two products of its oxidation - nicotine, and dihydronycotylin. Unfortunately, some of the synthesis stages took place under very harsh conditions, which could lead to doubts about the value of Pictet synthesis as a method of structure confirmation. However, a later synthesis (1928), carried out under mild conditions, confirmed the correctness of the established formula. The first synthesis of optically active (S)-nicotine was carried out in 1982. The source material was optically active substituted pyrrolidine, and the pyridine cycle was created by the input of the synthesis.
Nicotine and schizophrenia
Patients diagnosed with schizophrenia have an increased smoking habit. There are a number of hypotheses regarding the reasons for this addiction, explaining it both in terms of resistance to symptoms of the disorder and in terms of resistance to the negative effects of antipsychotics. One hypothesis is that nicotine itself causes schizophrenia.
According to one study, injections of nicotine in mice reduce the concentration of the DNMT1 DNA-methylation enzyme and increase the expression of GABA-producing GAD67 enzyme in the prefrontal cortex of rodents. It suggests that cigarette addiction in patients can be partially explained by the ability of nicotine to eliminate the negative epigenetic effects of increased levels of DNMT1. However, it is not clear whether schizophrenia leads to an imbalance of DNMT1 and GAD67, which requires correction, as studies of the brain of patients are carried out postmortem, and antipsychotics taken by them change many parameters, including GABAKERGIC.