| 单词 | phytol |
| 释义 | phytolphy·tolP0279900 (fī′tôl′, -tŏl′)phytol(ˈfaɪtɒl)Phytolphytol[′fī‚tȯl]PhytolC20H40O, an acyclic monounsaturated diterpene alcohol. Phytol is a colorless liquid with a boiling point of 204°C (at 10 mm of mercury); it is optically active inasmuch as it contains three asymmetric carbon atoms. It is widely distributed in nature as a constituent of chlorophyll molecules in green plants and red algae, of vitamin E (α-tocopherol) and other tocopherols, and of vitamin K1 (phylloquinone). Phytol may be obtained through the acid hydrolysis of chlorophylls (R. Willstätter, 1907) and through the action of the enzyme chlorophyllase on chlorophylls. A stereospecific synthesis of phytol was effected in 1959 by British chemists. In plant cells, the compound is synthesized from mevalonic acid. The biological role of phytol consists in rendering more lipophilic the porphyrin and quinoid structures that participate in electron transfer within the cell. It is assumed that phytol residues in the photosynthetic units (quantasomes) of the chloroplasts are perpendicular to the plane of the porphyrin pigment and that the residues “adhere” to the insulating lipid layer that divides the monomolecular layers of chlorophyll (phytol-containing vitamins E and K1 also forming part of the photosynthetic units). Phytol serves as a growth stimulant in lactic acid bacteria. REFERENCESMayo, P. de. Terpenoidy. Moscow, 1963. (Translated from English.) Biokhimiia rastenii. Moscow, 1968. (Translated from English.)E. P. SEREBRIAKOV phytolphy·tol(fī'tol),phy·tol(fī'tol) |
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