Page 183 - PG 504-theoretical notes-phyto-1-2024-2025..
P. 183

Clinical pharmacy PharmD program                     Third level                          Phytochemistry-1 (PG-504)





                                       Volatile Oils (Essential oils)


              Volatile  oil  is  a  water  immiscible  complex  mixture  of  low  molecular  weight,  volatile
              constituents of different classes of organic compounds including hydrocarbons and oxygenated
              organic compounds. They are termed ethereal or essential oils (represent the essences of the
              plants).

              N.B. Only a few of the volatile oils poss a single component in a high percetange (e.g. volatile
              oil of mustard yeild not less than 93% of allylisothiocyanate).the volatile oils.



              Definitions:

              Volatile  oil  is  a  water  immiscible  complex  mixture  of  low  molecular  weight,  volatile
              constituents of different classes of organic compounds including hydrocarbons and oxygenated
              organic compounds. They are termed ethereal or essential oils (represent the essences of the
              plants).        N.B. Only a few of the volatile oils posses a single component in a high percetange
              (e.g. volatile oil of mustard yeild not less than 93% of allylisothiocyanate).



              Volatile oils are characterized by:

              1- Capable of volatilization.

              2- Can be distilled from their natural sources.

              3- Do not consist of glyceryl esters of fatty acids.
              4- Cannot be saponified with alkalis.

              5- Do not become rancid.

              6- Oxidized and resinify when exposed to light or air.

              7- Do not leave permanent stains on filter paper.

              Fixed Oil: is non volatile glyceryl ester of fatty acid.

              Mineral oil: high molecular weight

              hydrocarbons obtained from petroleum oil (as paraffin oil)











                                                           164
   178   179   180   181   182   183   184   185   186   187   188