Nicotine, C 10 H
14 N 2 , is a highly toxic, pale yellow alkaloid produced in tobacco plants in
response to leaf damage. Nicotine is synthesized in
the roots of tobacco plants in response to hormones released by damaged tissue,
and it is then carried to the leaves, where it is stored in concentrations of
between 2 percent and 8 percent by weight. Nicotine is used commercially as an insecticide (it is one of
the few poisons to which insects have not become resistant). Tobacco smoke
contains nicotine, believed to be the active (and addictive) ingredient.
Mayan peoples of South America
used tobacco for recreational and ceremonial, as well as medicinal, purposes.
Mayan sculptures depict high-ranking persons smoking cigars and priests blowing
tobacco smoke over human sacrifices. By the time of the arrival of Christopher
Columbus in the New World, tobacco use had spread throughout both North America
and South America. Early accounts by European explorers describe Native
Americans carrying glowing sticks from which they inhaled, and many pipes are
found among Native American artifacts. Tobacco was often chewed by Native
Americans; the juice was dropped into eyes to improve night vision and applied
to skin as an agent having antiseptic properties.
The men who accompanied
Columbus encountered many users of tobacco, but early European explorers showed
little interest in the plant until they acquired an awareness that it might be
used to treat diseases. Europeans at first
forbade tobacco use, but tobacco gradually gained a reputation among court
physicians as a medicine. For many Europeans, tobacco was suddenly a valuable
New World commodity.
Nicotine is the active
ingredient of tobacco. Nicotine is soluble in water and in nonpolar solvents. It can be absorbed
by the body from smoke that has been taken into the lungs, or through the skin.
It rapidly crosses the blood-brain barrier, appearing in brain tissue minutes after
its absorption into capillaries lining the alveoli of the lungs. The presence
of nicotine in the body stimulates nicotinic-cholinergic receptors of the nervous system,
resulting in increased attention span, increased heart rate and blood pressure,
and increases in the concentrations of some hormones. Habitual users have a
feeling of well-being after intake of nicotine, ascribed to the increased
concentrations of dopamine in the brain. The
increased metabolic rate
that is associated with nicotine use may be what is in back of the common
belief that it is easier to lose weight when using nicotine.
Nicotinic-cholinergic receptors
that are part of the autonomic nervous system may be stimulated at low
concentrations of nicotine, but blocked at higher concentrations. The repeated
use of nicotine-containing products (which includes chewing tobacco, chewing
nicotine-containing gum, or the use of therapeutic patches that
release nicotine for skin absorption) promotes the formation of (new)
nicotinic-cholinergic receptors. The tolerance and eventual addiction that go
along with repeated use may result in increased craving for nicotine.
Many environmentally hazardous
substances, such as asbestos and radon, are
much more hazardous when they become mixed with cigarette smoke, probably
because the particulate matter in smoke in the atmosphere may adsorb these
dangerous substances and carry them into the alveoli of lungs. Many cancers may
be caused by substances or materials associated with nicotine use, such as
tobacco smoke or the tobacco plant itself (as in chewing tobacco). Nicotine
itself, although not known to cause cancer directly, causes proliferation of
both healthy and neoplastic cells, and may further the development of cancer by
stimulating angiogenesis (the growth
of new blood vessels) and thus providing cancerous tissues with increased blood
supplies. The effect of nicotine on cell growth is especially strong in tissue
environments having low concentrations of carbon dioxide, for example, in
damaged lungs; thus, the effect would be greater in persons whose breathing was
already impaired. Nicotine's stimulation of cell growth may account for the
observation that atherosclerotic
plaques (which are intracellular accumulations of lipids ) grow more rapidly in the presence of
this alkaloid substance. This
effect may actually become the basis of medical treatments intended to improve
blood flow to tissues damaged by atherosclerosis.
Single exposure to nicotine in
quantities as small as 50 mg (0.0018 oz) may result in vomiting and seizures; the
average cigarette yields about 3 mg(0.00011 oz). As nicotine can be absorbed
through skin, accidental exposures in persons working with nicotine-containing pesticide preparations may
be fatal. Extracts of chewing tobacco are effective insecticides; commercial insecticide products
contain much higher amounts of nicotine than products intended for human
consumption.
Biosynthesis
Of Nicotine
Levels of nicotine ON TOBACCO
Nicotine in tobacco as a central nervous system
stimulant, tobacco as a major component in cigarettes is a stimulant of the
central nervous system. Tobacco made up of thousands of components, wherein the
main component consists of nicotine, tar and carbon monoxide. Nicotine quickly
enter the brain so a person smokes. Levels of nicotine that is inhaled to be
capable of causing death if the levels are over 30 mg. Each cigarette contains
nicotine average 0.1-1.2 mg nicotine. Of these, the levels of nicotine in the
blood circulation is 25%, but a small amount is able to reach the brain within
15 seconds Tar is not a single substance, composed of hundreds of chemicals
dark and sticky, and classified as a poison maker of cancer. Often, many do not
include the tobacco tar and nicotine in cigarette packaging production. For
example, Sampoerna A Mild is claimed as a cigarette lighter, has a level of 1.5
mg tar per stem. Carbon monoxide is a poison that expel oxygen from binding to
hemoglobin in red blood grains. CO bonds with hemoglobin (COHb) will make HB
can not break the bonds CO and consequently function as an oxygen-carrying
hemoglobin decreased function and this causes the heart work more.
Nicotine as a substance most widely associated with
addiction to cigarettes received by the nicotinic acetylcholine
receptor-adrenergic pathway that then to make smokers feel more calm, pleasure,
stimulate the dopaminergic system, and feel the power of thought more
brilliant. While in the adrenergic pathway, this substance will turn on the
adrenergic system that secrete the neurotransmitter serotonin. Increased
incidence of serotonin is what causes the stimulation of pleasure to find
another cigarette. The process is no different from burning cigarettes
different from the process of burning other solid materials. Cigarettes are
made from dried tobacco leaves, paper, flavorings substances that can be formed
by the elements carbon (C), the element hydrogen (H), the element oxygen (O),
the elements Nitrogen (N), the element sulfur (S) and elements Another small
amounts. Cigarette
overall chemistry can be formulated as CvHwOtNySzSi. This will cause dangerous
reactions cigarettes for health include:
a) Reaction
cigarette with oxygen to form compounds such as CO2, H2O, NOx, SOx, and CO.
This reaction is called combustion reactions that occur at high temperatures
are above 800 degrees Celsius which occurs at the end of a cigarette or surface
in contact with air.
The process of burning cigarettes can be explained by chemical reactions CvHwOtNySzSi + + O2 combustion to CO2 above 800 C + + NOx SOx + SiO2 (ash).
The process of burning cigarettes can be explained by chemical reactions CvHwOtNySzSi + + O2 combustion to CO2 above 800 C + + NOx SOx + SiO2 (ash).
b) The
reaction solution to the chemical structure of chemical compounds cigarette
chemicals. The reaction is due to the high heating and absence of oxygen in
this reaction. This reaction known as pyrolysis reaction. Pyrolysis occurs at
lower combustion than 800 degrees Celsius (about 400-800 degrees Celsius).
Characteristic of the pyrolysis reaction is the formation of thousands of
chemical compounds that are complex. This process can be explained by the
chemical reaction combustion CvHwOtNySzSi + 400-800 C into other chemical
compounds (3000 complex molecules). Although the pyrolysis reaction is not
dominant in the process of smoking, but many belonging to the compounds produced
toxic compounds that have the ability to diffuse in the blood. Pyrolysis
reaction is a reaction that is the most dangerous in the process of smoking.
Actually this can be burnt pyrolysis products when the product through high
temperature and sufficient oxygen, which did not occur in this process because
of the inhaled smoke and gas products in the area of 400-800 degrees Celsius
temperatures flow directly toward the mouth of the temperature around 37
degrees Celsius.
c) The
reaction of the evaporation of water vapor and nicotine. The reaction takes
place at a temperature of 100-400 degrees Celsius where the nicotine is
vaporized at this temperature region no chance with a high temperature and does
not undergo combustion process. Terkondensasinya nicotine vapor in the gas
depends on the temperature, the concentration of nicotine vapor in the gas and
the geometry of the channels through which the gas. If the temperature is less
than 100 degrees Celsius, the nicotine is condensing, so that before the gas enters
the mouth, nicotine condensation has occurred and the gas enters the lungs
still contain these substances, which in the lungs, nicotine will experience
condensation back.