A. Nicotine
Synonyms Nicolan; Nicabate; Nicoderm; Nicotell TTS; Nicopatch; Nicotinell; Habitrol; Tabazur.
Biological Sources It is obtained from the dried leaves of Nicotiana tabacum Linn., (Solanaceae) (Virginia Tobacco; Tobacco); sprouts of Asclepias syriaca L. (Asclepiadaceae) (Common Milkweed); dried leaves and roots of Datura metel L. (Solanaceae) (Unmatal, Metel, Hindu Datura); leaves of Duboisia myoporoides R. Br. (Solanaceae) (Corkwood Tree, Pituri); fresh forage of Equisetum arvense L. (Equisetaceae) (Field Horsetail); herbs of Equisetum hyemale L. (Equisetaceae) (Shavegrass, Great Scouring Rush); leaves of Erythroxylum coca Lam., (Erythroxylaceae) (Coca); fruits and leaves of Nicotiana glauca R. Grah. (Solanaceae) (Tree Tobacco); and leaves of Nicotiana rustica Linn. (Solanaceae)–present upto 2-8%.
Chemical Structure
(S)-3-(1-Methyl-2-pyrrolidixyl) pyridine; (C10H14N2).
Preparation Commercial nicotine is entirely a byproduct of the tobacco industry; and the extraction from-N. tabacum has been described in literature.*
Characteristic Features
1. It is a colourless to pale yellow oily liquid, very hygroscopic in nature, and turns brown on exposure to air and light.
2. It has an inherent acrid burning taste.
3. It develops the odour of pyridine.
4. It has a bp745 247°C with partial decomposition; and bp17 123-125°C.
5. It is a steam-volatile product.
6. Its physical parameters are; nD201.5282 ; d420 1.0097 ;[α] D20 - 1690; pK1 (15°) 6.16 and pK2 10.96; and pH of 0.05 M solution 10.2.
7. It readily forms salts with almost any acid; and double salts with many metals and acids.
8. Solubility: It is miscible with water below 60°C; and on mixing nicotine with water the volume contracts. However, it is found to be very soluble in chloroform, ethanol, ether, petroleum ether and kerosene oils.
Identification Tests
1. Nicotine Hydrochloride (C10H14N2.HCl): It is obtained as deliquescent crystals having specific rotation [α] D20 +1040 (p = 10).
2. Nicotine Dihydrochloride (C10H14N2.2HCl): The deliquescent crystals are extremely soluble in water and ethanol.
3. Nicotine Sulphate [(C10H14N2)2.H2SO4] (Synonym: Nicotine neutral sulphate): It is obtained as hexagonal tablets having optical rotation [α] D20 +880 (p = 70); and is soluble in water and ethanol.
4. Nicotine Bitartrate (C10H14N2.2C4H6O6) (Synonym: Nicotine Tartrate): It is obtained as the dihydrate, crystals having mp 90 °C; [α] D20 +260 (C = 10); and is found to be very soluble in ethanol and water.
5. Nicotine Zinc Chloride Double Salt Monohydrate (C10H16Cl4N2Zn-H2O): It is very soluble in water; and sparingly soluble in ether and ethanol.
6. Nicotine Salicylate (C17H20N2O3): (Synonym: Eudermol): It is obtained as hexagonal plates having mp 118°C; [α] D20 +130 (C = 9); and is found to be freely soluble in ethanol and water.
Uses
1. It is used extensively as an insecticide and fumigant.
2. It finds its application as a ‘contact poison’ in the form of soap i.e., as its oleate, laurate and naphthenate salts.
3. It is also used as a ‘stomach poison’ in combination with bentonite.
4. One of its recent applications nicotine is employed as chewable tablets of lozenges for the treatment of smoking withdrawl syndrome.
5. It possesses a unique action on the autonomic ganglia which it first stimulates and subsequently depresses ultimately leading to paralysis.
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* Gattermann, Wieland, ‘Laboratory Methods of Organic Chemistry’ New York, 24th edn., (1937)
