| 释义 |
icos-, icosa-, icosi-
repr. Gr. combining forms of εἴκοσι twenty, used in Eng. in several technical terms (see below); also in icosacolic |aɪkəʊsəˈkəʊlɪk| a. Anc. Pros. [Gr. εἰκοσάκωλ-ος, f. κῶλον member, clause, colon], consisting of twenty cola, or members. icosasemic |aɪkəʊsəˈsiːmɪk| a. Anc. Pros. [Gr. σῆµα mark, σηµεῖον mark, mora], consisting of or containing twenty moræ or units of time, i.e. the equivalent of twenty short syllables. icosian |aɪˈkəʊsɪən| a., of or pertaining to twenty.
b. In Chem. (usu. spelt eicos-) denoting the presence in a molecule of twenty atoms of some element (usu. carbon). [App. first so used in G. eikosylen (Lippmann and Hawliczek 1879, in Ber. d. Deut. Chem. Ges. XII. 72).] So ˈeicosane [-ane 2 b], a hydrocarbon, C20H42, of the paraffin (alkane) series, esp. the normal isomer; eicoˈsanic a., in eicosanic acid, = eicosanoic adj.; eicosaˈnoic a., in eicosanoic acid, a saturated fatty acid, C19H39COOH, of which the normal isomer (also called arachidic acid) is a waxy solid present in small amounts in many natural oils and fats; eicosenic |-ˈiːnɪk| a., in eicosenic acid [tr. G. eikosensäure (M. Bodenstein 1894, in Ber. d. Deut. Chem. Ges. XXVIII. 3403)], = eicosenoic adj.; eicoseˈnoic a., in eicosenoic acid, an unsaturated fatty acid, C19H37COOH, of which one isomer, 9-eicosenic acid (gadoleic acid), is a minor constituent of many fish oils and another, 11-eicosenic acid, occurs in the wax of certain plant seeds; eicoˈsoic a., in eicosoic acid, = eicosanoic adj.
1889G. McGowan tr. Bernthsen's Text-bk. Org. Chem. 34 (table) C20H42. Eicosane. 1948A. W. Ralston Fatty Acids xi. 882 The following are the melting and boiling points which have been reported for the higher normal saturated hydrocarbons: nonadecane, C19H40, 32°, —; eicosane, C20H42, 38°, b0·5 148°; [etc.]. 1966Nomencl. Org. Chem. (I.U.P.A.C.) (ed. 2) A. 6 The first four saturated unbranched acyclic hydrocarbons are called methane, ethane, propane and butane. Names of the higher members of this series consist of a numerical prefix and the termination ‘-ane’... Examples:..6 Hexane. 7 Heptane... 20 Eicosane.
1923Chem. Abstr. XVII. 2560 Normal eicosanic acid is found in nature in the oil of Nephelium lappaceum J. as a glyceride. 1953Heilbron & Bunbury Dict. Org. Compounds (rev. ed.) II. 464, n-Eicosanic Acid (Arachidic acid, n-nonadecane-1-carboxylic acid, eicosoic acid, eicosanoic acid).
1924Chem. Abstr. XVIII. 4318/2 (Index), Eicosanoic acid. See Arachidic acid. 1948A. W. Ralston Fatty Acids i. 44 The vegetable oils generally contain less than 1% of eicosanoic acid. Ibid., Coffee bean oil contains 2·11% of eicosanoic acid..and peanut oils from 3 to 4%.
1895Jrnl. Chem. Soc. LXVIII. i. 127 Icosenic acid, C20H38O2, is formed when behenolic acid is heated with fused caustic potash at 250–270°. 1953Heilbron & Bunbury Dict. Org. Compounds (rev. ed.) II. 464 Δ10-Eicosenic Acid (Eicosenoic acid).
1936Jrnl. Chem. Soc. 1755 The fatty matter present in the seeds of Simmondsia californica Nutt...is a mixture of wax-esters, and not glycerides... The chief acid is Δ11:12-eicosenoic. 1951A. W. Johnson et al. in E. H. Rodd Chem. Carbon Compounds Ia. ix. 640, 9-Eicosenoic acid, gadoleic acid, CH3(CH2)9CH:CH(CH2)7COOH is a common component of fish and marine animal oils such as herring and shark liver oil. 1954E. W. Eckey Vegetable Fats & Oils xiv. 435 Investigations made after eicosenoic acid had been isolated from rapeseed oil and shown to exist in substantial proportion in hare's ear mustard oil confirmed the presence of this C20 monoethenoic acid in rapeseed oil and indicated that it occurs generally in oils of the Cruciferae.
1923Chem. Abstr. XVII. 4447/2 (Index), Eicosoic acid (eicosanic acid), n-. 1951I. L. Finar Org. Chem. ix. 144 Some still higher acids are found in waxes: arachidic (eicosoic), C20H40O2 (m.p. 77°), behenic (docosoic), C22H44O2 (m.p. 82°), [etc.]. |