| 释义 |
thymine|ˈθaɪmɪn|
Also thymin.
[f. thymic a.1 + -ine5.]
1. Chem. A colourless crystalline alloxur base, C5H6N2O2, obtained by the action of dilute sulphuric acid on thymic acid (thymic a.1 2).
1894Jrnl. Chem. Soc. LXVI. i. 156 Thymic acid..on heating with sulphuric acid.., thymin..is formed. This substance has neither basic nor acidic properties; it..is deposited from water in quadratic and hexagonal crystals. 1898Schäfer's Text Bk. Physiol. I. 66. 1900 Jrnl. Chem. Soc. LXXVIII. i. 319 Thymin was originally described by Kossel as one of the decomposition products of the nucleic acid of the thymus gland. It has since been obtained from nucleic acid from other sources. 1903Amer. Chem. Jrnl. XXIX. 481 On boiling this mercapto derivative with hydrochloric acid we obtained thymine. 1954New Biol. XVI. 15 In desoxyribose nucleic acid the purine is either adenine or guanine, the pyrimidine either cytosine or thymine. 1976Sci. Amer. Jan. 64/3 The DNA molecule consists of two long chains of nucleotides wound in a double helix... Each nucleotide consists of a deoxyribose sugar, a phosphate group and one of four nitrogenous bases: adenine, guanine, thymine or cytosine.
2. Biochem. = thymopoietin.
1968G. Goldstein in Lancet 20 July 122/1 ‘Thymin’..seems an appropriate name for this substance, which not only is present in normal thymus but also appears to be secreted normally and to have an effect in physiological concentrations on neuromuscular transmission. 1974[see thymopoietin].
Hence thyminic |θaɪˈmɪnɪk|, a. Chem. in thyminic acid, a synonym of thymic acid (thymic a.1 2).
1898J. A. Mandel tr. Hammarsten's Physiol. Chem. 100 From adenylic acid and..other nucleic acids Kossel and Neumann have prepared an acid called by them thyminic acid. |