TERPENES — hydrocarbons (C 5 H 8 ) n , the molecule to-rykh is constructed of isoprene fragments
By number of isoprene fragments of T. triterpena (6 fragments) and polyterpenes are subdivided into monoterpenes (2 isoprene fragments), sequiterpenes (3 fragments), diterpenes (4 fragments). In medicine as pharmaceuticals apply nek-ry T. — menthol (see), terpin hydrate (see), camphor (see), turpentine (see), vitamin A (see. Retinolum ), vitamin D (see. Calciferols ), vitamin E (see. Tokoferola ), phthiocol (see. Fillokhinona ), and also cineol — the main component of eucalyptus and rosemary oil and ascaridole — a component of henopodiyevy oil. Treat polyterpenes carotinoids (see) and rubbers (see), diterpene phytol is a component of a chlorophyll (see) and Retinolum, a triterpena squalene (see) and lanosterin are predecessors cholesterol (see). T. are a part and other biologically active agents, napr, saponins (see), mono - and sesquicyclic terpenes serve as the main components of specific fragrant essential oils in plants (see).
Monocyclic T. contain a six-membered cycle with methyl and isopro-saw groups in para-situation (see a constitutional formula of I). Bicyclic T. contain one of the carbon skeletons making Karan (II) group, a pinan (III) and camphane (IV).
T., as a rule, not rastvorima in water, represent or the oily liquids possessing a high volatility or solid crystal matters. Aliphatic lowest T. tsiklizutsya easily. All T. are isomerized under the influence of acids, alkalis and temperature. Their chemical properties depend on existence of functional groups and features of a carbon skeleton of a molecule.
In the nature the oxidized T. meet in the form of hydrocarbons (see), alcohols (see), aldehydes (see), ketones (see), laptops (see), oxides and peroxides (see).
T. take from pitch of coniferous plants and essential oils. Turpentine, to-ry represents mix of cyclic terpenes (hl. obr. pinene), receive distillation of pitch-gallipot with water vapor. The remained solid residue (rosin) is widely applied to industrial needs. Turpentine is used as organic solvent (see. Solvents ), and also for synthesis of many organic compounds, including pharmaceuticals. Other T. — menthol (oil of a peppermint), limonene (oil from wild orange and citrus crusts), (Laurus camphora wood) receive carvon (caraway oil), cineol, ascaridole, camphor extraction or distillation of oils from various parts of plants (bark, wood, leaves, flowers and natural latex).
Bibliography: Biogenesis of natural compounds, the lane with English, under the editorship of JI. M. Ginodma-na, M., 1965; Hauptmann 3., Gref Yu. and Reman X. Organic chemistry, the lane with English, M., 1979.
N. V. Prokazova.