cytosine Biochem.
(ˈsaɪtəʊsaɪn, -iːn)
[ad. G. cytosin (A. Kossel and A. Neumann 1894, in Ber. d. Deut. Chem. Ges. XXVII. ii. 2219), f. cyto- + -ose2 + -ine5.]
A crystalline pyrimidine base, C4H5N3O, which is one of the constituents of nucleic acids and occurs in double-stranded DNA paired with the purine base guanine.
| 1894 Jrnl. Chem. Soc. LXVI. i. 631 Hydrolysis of nucleïc acids... Cytosine, C21H30N16O4 + 5H2O, is precipitated. 1954 New Biol. XVI. 15 In desoxyribose nucleic acid the purine is either adenine or guanine, the pyrimidine either cytosine or thymine. 1955 Sci. Amer. Oct. 70/3 DNA is a long-chain molecule constructed from four comparatively simple chemical units: adenine, thymine, guanine and cytosine. 1969 Times 8 Dec. 12/2 One possibility is that the cytosine arabinoside..destroys the normal cells in bone marrow. |