4.1.4.1 Comprising of C and H only: They essentially consist of hydrocarbon present in the natural products.
Examples:
(a) β-Myrcene: It is an unsaturated acyclic hydrocarbon found in oil of bay, verbena, hop and others.
(b) Ocimene: It is also an unsaturated acyclic hydrocarbon found in the essential oil distilled from the fresh leaves of Ocimum basilicum L. and from the fruits of Evodia rutaecarpa (Juss.) Hook & Thoms. It exists in two modifications and forms. The cis- and trans-refers to the stereochemistry at the double-bond between C-3 and C-4.
(c) p-Cymene (Dolcymene): It is an aromatic hydrocarbon and occurs in a number of essential oils e.g., sage, lemon, thyme, nutmeg, coriander, origanum, cinnamon.
(d) Limonene (Syn: Cinene, Cajeputene, Kautschin): It is an alicyclic hydrocarbon and further classified into monocyclic terpene. It occurs in various ethereal oils particularly in oils of lemon, orange, caraway, dill and bergamot.
(e) α-Pinene: It is also an alicyclic hydrocarbon and further classified into bicyclic monoterpene d-α-pinene obtained from Port Oxford Cedar Wood Oil (Chamaecyparls lawsorliana Parl.). l- α-Pinene obtained from Mandarin Peel Oil (Citrus reticulata Blando).
REFERENCES
Ashutosh Kar (2003), Pharmacognosy and Pharmaco biotechnology, 2nd Edition
‘Handbook of Medicinal Herbs’ (2001), J.A. Duke, CRC-Press, London, 1st Edn.
William Charles Evans (2002), Trease and Evans Pharmacognosy 15th Edition by: Trease, Bailliere Tindall; Evans.
Ramstad (1956), E., ‘Modern Pharmacognosy’, McGraw Hill, London.
