The crystal and molecular structure of thymidine

Abstract

The crystal structure of thymidine (CIoN2OsH14) has been determined from data collected on a Hilger and Watts linear diffractometer and a Wooster four-circle diffractometer. Thymidine is orthorhombic, space group P2~2121, with the following cell dimensions: a= 4.860_ 0.005, b = 13.91 _+ 0.01 and c= 16.32 +_ 0.01/~. The structure was solved by a Patterson interpretation method and the positional and thermal parameters were refined by the method of least-squares. The carbon, nitrogen and oxygen atom thermal parameters were refined anisotropically. The final R value for the 1230 observed reflexions is 0.066 and the average standard deviations in the bond lengths and angles are about 0.006/~, and 0.4 ° respectively.

Stereochemistry of nucleic acids and their constituents. XIV. Crystal and molecular structure of 2,4-dithiouridine monohydrate

“…The bond angles in the base are quite similar to the values observed in 4-thiouridine (Saenger & Scheit, 1969), thymidine (Young, Tollin & Wilson, 1969) and the other 5-substituted bases such as 5-methyluridine (Hunt & Sabramanian, 1969), 5-fluoro-2'-deoxyuridine (Harris & Maclntyre, 1964) and 5-chlorouridine (Coulter, 1969). The exocyclic angles involving the C-S bond are remarkably close to the values found in the corresponding keto compounds.…”

A kinetic and nuclear magnetic resonance study of methylated pyrimidine nucleosides

“…Because H2' is expected at -3.0 ppm in a sytz 2'-deoxyriboside (31), a preference for the anti conformation is apparent. (dUrd and dThd are anri in the crystal state (32,33); of the methylated derivatives only m4Urd has been crystallized and shown to be tinri.)' In the case of m'dUrd and m'd'rhd, methylation has converted the 2-keto oxygen to a methoxyl whose shielding effects in a s~n pyrimidine have not been evaluated.…”

A conformational study of the adducts of 2′-deoxythymidine and 2,2,6,6-tetramethyl-1,4-piperidone-N-oxyl by 1H and 13C nuclear magnetic resonance

“…Data for H3', H4', H5', and H5" are not given since they show smaller variations. Data are also shown for Hl', H2', and H2" of dT and m6du (6-methyl-2'-deoxyuridine), which prefer the anti and syn conformations, respectively, in the crystal and aqueous solution states (10,29,32,33). A striking feature of the diagram is the similarity, for 6T1 and 6T2 on the one hand and for 6T3 and 6T4 on the other hand, in the data for Hl', H2', and H2", the sugar protons of which are expected to sense most strongly the shielding effects of the TAN and base moieties.…”