4. Myrrh
Synonyms Gum Myrrh, Myrrha.
Biological Source Myrrh is an oleo-gum-oresin obtained from the stem and branches of Commiphora obyssinica (Berg) Engler or from other species of Commiphora belonging to family Burseraceae.
Preparation The plants usually exude yellow coloured resin after proper incisions are made in the bark of a tree. It gradually hardens and becomes dark or reddish-brown in appearance. The mass is collected by the native tribals of Somalia for trading.
Characteristic Features Myrrh normally occurs either in the form of isolated irregular, rounded tears of 2.5 cm in diameter or as masses duly formed by the agglomeration of these tears. The tears are dull, rough and reddish-brown in appearance. It has a strong aromatic odour and possesses an acrid, bitter taste.
Chemical Constituents Myrrh contains volatile oil (7-17%), resin (20-25%), gum (57-61%), and bitter principle (3 to 4%). The volatile oil consists of eugenol, m-cresol and cuminaldehyde.
The resin is found to consist of a mixture of α-, β-, and γ-commiphoric acids (resin acids). Besides, it also contains two phenolic resins α- and β-heerabomyrrholic acids which are ether insoluble.
The oleo-gum-resin yields alcohol-soluble extract not less than 30%. It also contains phenolic compound such as: pyrocatechin and protocatechuic acid. The crude alcohol-insoluble fraction i.e., ‘gum, comprises of protein (18%) and carbohydrate (64%) made up of arabinose, galactose and glucuronic acid. However, the gum is found to be associated with an oxidase enzyme.
Chemical Tests
1. Myrrh when triturated with water produces an yellow-emulsion.
2. When myrrh (0.1 g) is triturated with 0.5 g of pure washed sand (SiO2) in the presence of ether, filtered and evaporated on an electric water-bath, it forms a thin film of violet colour on being exposed to bromine vapours in a closed dessicator.
Uses
1. It is used chiefly in perfumes and incense.
2. It is frequently employed as an antiseptic and stimulant.
3. Myrrh acts as an astringent to the mucous membrane and hence it find its application in oral hygiene formulations, such as: gargles, mouth-washes.
4. It is also used as a carminative.
