| 释义 |
dehydro- before a vowel also dehydr-. Chem.|diːˈhaɪdrəʊ|
A prefix used in forming the names of some organic compounds, denoting (a) the loss of one atom of hydrogen (or freq. two), (b) the loss of a molecule of water (= anhydro-); as dehydrotriacetonamine; deˌhydroaˈscorbic acid, an oxidation product, C6H6O6, of ascorbic acid; deˌhydrochoˈlesterol [ad. G. dehydro-cholesteryl (A. Windaus et al. 1935, in Ann. Chem. DXX. 106)], the provitamin, C27H44O, of vitamin D3, naturally formed in human and animal skin under the influence of sunlight.
1877H. Watts Fownes' Man. Chem. (ed. 12) II. 264 Triacetonamine, C9H17NO...Dehydrotriacetonamine, C9H15N. 1933Nature 3 June 800/2 We found that by the action of a copper acetate solution upon ascorbic acid, a dehydroascorbic acid is formed. 1935Chem. Abstr. XXIX. 7995 (title) 7-Dehydrocholesterol. Ibid., 7-Hydrocholesterol..with BzCl in C5H5N gives a dibenzoate... Heating..gives 58% of the benzoate..of 7-dehydrocholesterol. 1946Nature 3 Aug. 169/1 The preparation from cholesterol (I) of 7-dehydrocholesterol (III), which on irradiation gave a highly antirachitic product (vitamin D3). 1959New Biol. XXIX. 35 Dehydroascorbic acid, the oxidized form of vitamin C, is reported as having been obtained..from seawater. 1962H. Heath in A. Pirie Lens Metabolism Rel. Cataract 365 Present evidence would seem to indicate that it [sc. ascorbic acid] is actively secreted [by the ciliary body] in the nonionized, oxidized form, dehydroascorbic acid. 1965Nomencl. Org. Chem. (I.U.P.A.C.) C. 42 Loss of two hydrogen atoms from a compound designated by a trivial name is denoted by a prefix ‘didehydro-’... In common usage ‘dehydro-’ is often used in place of ‘didehydro-’. For example the above compound [sc. 7, 8-didehydrocholesterol] is often termed dehydrocholesterol. 1968R. S. Cahn Introd. Chem. Nomencl. (ed. 3) iii. 44 Removal of atoms is indicated in a few cases, e.g., dehydro (loss of 2H), anhydro (loss of H2O). |