nicotine

Nicotine

 Nicotine belongs to a class of alkaloids contained in the family Solanaceae. Nicotine is found in large quantities in tobacco plants, were found in small quantities in tomatoes, potatoes and eggplant. Nicotine, along with cocaine can also be found on the leaves of the coca plant. Nicotine levels ranged between 0.6 - 3.0% of the dry weight of tobacco, with biosynthesis process occurs in roots and accumulate in tobacco leaves. Nicotine occurs from the biosynthesis of N in roots and accumulate on the leaves. The function is as a chemical nicotine antiherbivora and that it contains a neurotoxin that is very sensitive to the insect, so that nicotine is used as an insecticide in the past.
Nicotine (β-pyridil-α-N-methyl pyrrolidine) is a specific organic compounds contained in tobacco leaves. If inhaled compounds will cause psychological stimulus for smokers and makes it addictive. All this is happening is the high quality tobacco generally contain nicotine and high aromatisnya compounds. Environmental factors that influence the levels of nicotine such as soil type, altitude, density of plant populations, fertilizer and land type. Tobacco grown in heavy soils nicotine yield is lower than that grown in clay. Tobacco nicotine levels tend to increase when grown in higher areas. The more plant population per acre lower nicotine levels, and the higher dose of nitrogen fertilizer higher nicotine levels. Levels of nicotine tobacco grown in the paddy field is lower than on land tegal.
LD50 toxicities in doses of 40-60 mg of nicotine on (0.5-1 mg / kg) can be a lethal dose for an adult human. At low concentrations of about 1 mg, nicotine gives a stimulant in the mammalian brain neurons to release dophamine, a neurotransmitter that makes us feel better. Besides, it also releases glutamate to be related to the brain's memory and convey the message that it will get the great taste of smoke. This is the beginning of dependence on nicotine through smoking.
The pharmacology of nicotine plays a role in accelerating heart rate, strengthens every heartbeat and lowers oxygen consumption by the heart muscle. In terms of fisiodinamik, nicotine effect euphoria, increase alertness, and gives the sensation of relaxation and tranquility.

The biosynthetic pathway of nicotine involves a coupling reaction between the two cyclic structures that compose nicotine. Metabolic studies show that the pyridine ring of nicotine is derived from nicotinic acid while the pyrrolidone is derived from N-methyl-Δ¹-pyrrollidium cation. Biosynthesis of the two component structures proceeds via two independent syntheses, the NAD pathway for nicotinic acid and the tropane pathway for N-methyl-Δ¹-pyrrollidium cation.

The NAD pathway in the genus nicotiana begins with the oxidation of aspartic acid into α-imino succinate by aspartate oxidase (AO). This is followed by a condensation with glyceraldehyde-3-phosphate and a cyclization catalyzed by quinolinate synthase (QS) to give quinolinic acid. Quinolinic acid then reacts with phosphoriboxyl pyrophosphate catalyzed by quinolinic acid phosphoribosyl transferase (QPT) to form nicotinic acid mononucleotide (NaMN). The reaction now proceeds via the NAD salvage cycle to produce nicotinic acid via the conversion of nicotinamide by the enzyme nicotinamidase.

The N-methyl-Δ¹-pyrrollidium cation used in the synthesis of nicotine is an intermediate in the synthesis of tropane-derived alkaloids. Biosynthesis begins with decarboxylation of ornithine by ornithine decarboxylase (ODC) to produce putrescine. Putrescine is then converted into N-methyl putrescine via methylation by SAM catalyzed by putrescine N-methyltransferase (PMT). N-methylputrescine then undergoes deamination into 4-methylaminobutanal by the N-methylputrescine oxidase (MPO) enzyme, 4-methylaminobutanal then spontaneously cyclize into N-methyl-Δ¹-pyrrollidium cation.