4. Cannabis
Synonyms Indian Hemp; Indian cannabis; Marihuana; Marijuana; Pot; Grass; Weed; Bhang; Ganja; Charas, Hashish.
Biological Source Cannabis consists of the dried flowering tops of pistillate plants of Cannabis sativa L., (C. satira var. indica Auth.), belonging to family: Moraceae.
Preparation After years of intensive and extensive research carried out on the selective cultivation of Cannabis, two of its genetic types have been evolved, namely: (i) Drug Type, and (ii) Hemp Type.
These two distinctly separate genetic types of Cannabis shall be described briefly as stated below:
A. Drug type (Cannabis): It is, in fact, the rich (upto 15%) in the psychoactive constituent (–)-∆9-trans-tetra-hydrocannabinol (∆9-THC) as shown below:
The ∆9-THC is usually concentrated into a resin that is secreted right into the trichomes located on the small leaves (bracts) and bracteoles (i.e., the leaf-like structure which encloses the ovary) of the flowering tops of the female plant. Interestingly, for the specific drug usages either the resin (hashish) is employed or the flowering tops of the female plant (marijiana). Nevertheless, the male plant also generates an equivalent quantity of the active constituents; however, it is not concentrated into a resin but found throughout the entire plant.
B. Hemp Type (Cannapis): It contains surprisingly very little active principal. Cannabidiol is the predominant cannabinoid present in it as given below:
The hemp-type cannabis also possesses the elongated bast* fibers which is very much desired in the manufacture of ropes.
Chemical Constituents The chemical constituents ∆9 THC and cannabidiol present in the drugtype and hemp-type cannabis have already been discussed above. Besides, the resin contains several active constituents, such as: cannabinol, cannin, cannabol, tetrahydrocannabinol, cannabigerol, cannabichromene and ∆8-tetrahydrocannabinol.
It also contains choline, volatile oil and trigonelline. However, the Indian Hemp seeds contain 20% of fixed oil.
Chemical Tests
1. Shake 0.1g of resin with 5 ml petroleum ether (60-80°C) and filter. To 1 ml of the filtrate, add
2 ml of 15% solution of HCl gas in ethanol, when a red colouration appears at the junction of the two layers. However, after shaking, the upper layer becomes colourless while the lower one attains a distinct orange pink colour, which finally vanishes upon addition of water.
2. Extract 1g of resin with methanol, filter and evaporate to complete dryness. Again extract the resulting residue with petroleum ether (60-80°C), filter directly into a separating funnel and extract the ethereal layer successively with 5% (w/v) Na2CO3and 5% (w/w) H2SO4. Wash the ethereal layer with distilled water, decolourise with powdered activated carbon, if necessary, and evaporate the filtrate. Add to the residue a few drops of N/10 alcoholic KOH solution, when a purple colouration is obtained.
Uses It has been used as a sedative in equine colic.
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* Bast: Fibrous material obtained from the pholeum of jute, flax etc., used for making rope, matting etc.,
