Purine structural formulas

Birds excrete nitrogen as uric acid Uric acid is a purine having the molecular formula C5H4N4O3 it has no C—H bonds Write a structural formula for uric acid... 

Chemical Name 2-Amino-1,9-dihvdro-9-[(2-hvdroxvethoxv)methvl] -6H-purin-6-one Common Name Acycloguanosine 9-(2-hvdroxvethoxvmethvl)guanine Structural Formula ... 

Chemical Name 9-/3-D-arabinofuranosyl-9H-purine-6-amine monohydrate Common Name Adenine arablnoside spongoadenosine Structural Formula ... 

Chemical Name 9H-Purin-6-amine, 9-((2-chloro-6-fluorophenyl)methyl)-Common Name Arprinocid Structural Formula ... 

Chemical Name lH-Purine-2,6-dione, 3,7-dihydro-l-hexyl-3,7-dimethyl-Common Name Hexyltheobromine Pentifylline Structural Formula ... 

Fig. 1. Structural formulas and numbering system for the purine nucleobases and nucleosides...

Fig. 7.1 The structural formula of ATP is shown with its main characteristics. The purine part is in blue that is connected in a beta glycosidic bond to the furanose sugar moiety the OH groups are in red as are the three phosphate groups that are attached to the 5 OH group of the ribose...

Chemical Name 3,7-Dihydro-3,7-dimethyl-1-(5-oxohexyl)-1 H-purine-2,6-dione Common Name Oxpentifylline vazofirin Structural Formula g... 

The three pyrimidine bases are uracil, thymine, and cytosine, usually abbreviated U, T, and C. Adenine (A) and guanine (G) are the two purine bases. Adenine, guanine, and cytosine are found in both DNA and RNA, but uracil is ordinarily found only in RNA, and thymine only in DNA. Structural formulas of the five bases are given in I Figure 11.3. 

Classify caffeine and theobromine according to whether each is a pyrimidine or a purine. One of these cannot isomerize to an enolic form two different enols are possible for the other. Explain and write structural formulas for the possible enols. 

Structural formulas of the five most important purine and pyrimidine bases found in DNA and RNA.The hydrogen atom shown in color is lost in the formation of an W-glycoside. 

The monosaccharide component of DNA is 2-deoxy-D-ribose (the 2-deoxy refers to the absence of a hydroxyl group at the 2 position), whereas that of RNA is D-ribose. The glycosidic bond is between C-1 (the anomeric carbon) of ribose or 2-deoxyribose and N-1 of a pyrimidine base or N-9 of a purine base. Figure 20.2 shows the structural formula for uridine, a nucleoside derived from ribose and uracil. 

The use of newer techniques, such as tracer methodology and tissue studies in vitro, has permitted a more direct study of the problem and will form the body of this chapter. The structural formulas of allantoin and the purine compounds that are pertinent to a discussion of purine metabolism, as well as the numbering system of the purine ring, are illustrated in Fig. 1. 

Nucleosides consist of (1) a purine or pyrimidine, which is responsible for the high characteristic ultraviolet absorption (2) a pentose, which is either ribose or desoxyribose. The structural formulas of adenosine (I), guanosine (II), uridine (III), and cytidine (IV) are given below. 

The structural formulas of allantoin and the purine compounds that are pertinent to a discussion of purine metabolism, as well as the numbering system of the purine ring, are illustrated in Fig. 1. 

The structural formulas of the monomeric constituents of nucleic acids are given in Figure 10.11. These are pyrimidine or purine nitrogen-containing bases, two sugars, and phosphate. DNA molecules are made up of the nitrogen-containing bases... 

Figures 2 and 3 show simplified structural formulas of adenine and adenosine complexes, respectively. The structures of the complexes reflect the pronounced tendency of purines to act as bridging ligands. Binding sites of adenine differ with metal ion variation. Evidence from IR, electronic spectra, and magnetic susceptibilities reported previously suggest structures for the complexes vary both with the central metal and the nature of the ligand.

The TJV spectra were measured for practically all the numerous derivatives. Beside the analytical application of these to demonstrate the position of the substituent no detailed interpretation was attempted, however. On the whole, they are similar to the spectra of analogous purine derivatives and also display a similar dependence on Despite the fact that the question of structure with regard to the lactim-lactam (or thiolactim-thiolactam) tautomerism has not been studied in detail, it can be assumed that oxygen and sulfur derivatives, at variance with the conventional way of writing the formulas, possess a lactam or thiolactam structure. This is in agreement with the views on the analogous purine derivatives. 

A detailed analysis of crystal structures in compounds with formula Pt(amine)2 (purine)2 has made clear that H-bond interaction between the amine N-H and the 06 of the purine do occur frequently140,141. ... 

The heteroaromatic betaines, [l,3,4]thiadiazolo[3,2-a]pyrimidine-5,7-diones (753), which are isoconjugate with methylated xanthines, are in the same way as the latter found to be inhibitors of cyclic AMP phosphodiesterase (78JPS1762). The N-/3-D-ribofuranosyl nucleoside (754) inhibits the synthesis of RNA and DNA but not of protein. The primary blockade is in the synthesis of purine nucleotides (79MI42902). RNA synthesis is also inhibited by [l,3,4]thiadiazolo[3,2-a]pyrimidines of structure (755). The activity is attributed to the chemical reactivity at C-2 leading to reactions with an SH or OH group in RNA polymerase (80ABC1923). Compounds with the 7-oxo formula (756) are claimed to be useful as immune enhancers (78GEP2712932). 

The system was first named by Fischer 0899CB435) but the correct ring structure was proposed much earlier <1875LA( 175)243) in a formula for uric acid. In the general literature purine nomenclature has been to a large extent affected by the abundance of trivial names for compounds which were isolated before their structures were known and by variation in description of tautomeric forms. 

Purine derivatives are considered to be prebiotic molecules. Purine as well as adenine (HCN) can be formed from hydrogen cyanide in the presence of ammonia in a prebiotic atmosphere. Similar reaction in the presence of water can lead to other purines. Purine chemistry goes back to the roots of organic chemistry. Uric acid was the first purine isolated from bladder stones by Scheelc in 1776. The correct empirical formula of uric acid was established much later by Liebig and Mitscherlich. The correct structure was suggested by L. Medicus and was shown to be correct by the syntheses ofHorbaezewski. Behrend and Roosen, and unambiguously by E. Fischer. The development of purine chemistry by E. Fischer is a milestone in heterocyclic chemistry. 

---