5. Turpentine
Synonyms Gum turpentine;
Gum thus.
Biological Source Turpentine
is the oleoresin obtained from pinus palustris Miller and
from other species of Pinus, belonging to the natural order Pinaceae.
Preparation Turpentine is
usually collected from the slash pine i.e., Pinus elliottii Engelmann
var. eliotti, and Pinus palustris Miller, which grow in abundance in the
Northern Florida, Georgia, and North and South Carolina. However, the yield of turpentine
exclusively depends on the treatment and the size of the tree. If proper
skill and expertise are practiced the pine trees may yield turpentine for 15 to
20 years at a stretch.
The oleoresin is
normally secreted in the ducts that are situated almost beneath the cambium in the
sapwood. In spring the bark is neatly cut from the tree with the help of a
long-handled cutting knife known as the “bark-hack”. After the removal
of the chipped bark, the freshly exposed surface is quickly sprayed with a
solution of 50% (w/w) sulphuric acid.* The flowing oleoresin is guided
by galvanized metal gutters right into the various containers tied close to the
tree-trunk. The thickliquid thus collected is removed as turpentine by
pot-still distillation periodically.
Characteristic Features The
gum turpentine is an yellowish, opaque, sticky mass having a characteristic
odour and taste. It is almost insoluble in water, but soluble in ether,
ethanol, chloroform and glacial acetic acid.
Chemical Constituents The
gum-turpentine when subjected to steam-distillation yields 15 to 30% of
a volatile oil known in the trade as “turpentine oil”. It contains
mainly the terpenes, such as: dextro- and laevo-α-pinene,
β-pinene and camphene.
Uses
1. It is employed externally as
a counterirritant.
2. It is also used as a
rubefacient.
3. It is used as a constituent
of stimulating ointments.
4. It is employed industrially
as an insecticide.
5. It is used as a solvent for
waxes.
6. It is utilized extensively
in the production of synthetic comphor.
7. It is used in making various
types of polishes, such as: shoe polish, furniture polish and stove polish.
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* Acid treatment collapses the thin-walled
parenchymal cells which line the resin ducts. Thus, the duct channels get enlarged
thereby allowing a faster uninterrupted flow of oleoresin and minimising the
chances of hardened secretions blocking the outlets.
Source:Pharmacognosy And Pharmacobiotechnology By Ashutosh Kar
Source:Pharmacognosy And Pharmacobiotechnology By Ashutosh Kar
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