Adenine, 9- -, preparation

The mixture from Step 1 (3.0 mmol) was added to a suspension of sodium adenine [prepared from adenine (3.0 mmol) and NaH (3.0 mmol) in 25 ml DMF] and the mixture heated to 80 °C 12 hours. The solvent was removed, the residue adsorbed on 3 g silica gel of a 70 g silica gel column, and the mixture eluted using CH2Cl2/methyl alcohol, gradient 96 4 to 94 6. The cis isomer was isolated in 29.9% yield, mp = 200-203 °C trans isomer, 17.6% yield, mp = 186-189°C. H- and i C-NMR, IR, UV-Vis and EIMS data supplied for both isomers. 

Wei, H., Li, Wang, Y. and Wang, E. (2007) Silver nanopartides coated with adenine preparation, self-assembly and application in surface-enhanced Raman scattering. Nanotechnology, 18(17), 175610/1-175610/5. 

For the investigation of molecular recognition in micelles, adenine derivatives and positively charged (thyminylalkyl)ammonium salts such as shown in Figure 30 were prepared, which were solubilized in sodium dodecyl sulfate (SDS) solutions. Nmr studies have shown that binding occurs in a 1 1 molar ratio in the interior of the micelles as illustrated in Figure 30 (192). 

Himethylformamide [68-12-2] can be produced from the reaction of hydrogen cyanide and methanol. Adenine [73-24-5] can be prepared from hydrogen cyanide in Hquid ammonia. Thioformamide [115-08-2] can be produced from hydrogen cyanide and hydrogen sulfide. 

The pixyl ether is prepared from the xanthenyl chloride in 68-87% yield. This group has been used extensively in the protection of the 5 -OH of nucleosides it is readily cleaved by acidic hydrolysis (80% AcOH, 20°, 8-15 min, 100% yield, or 3% trichloroacetic acid). It can be cleaved under neutral conditions with ZnBrj, thus reducing the extent of the often troublesome depurination of A -6-benzyloxy-adenine residues during deprotection. Conditions which remove the pixyl group also partially cleave the THP group (t,/2 for THP at 2 -OH of ribonucleoside = 560 s in 3% Cl2CHC02H/CH2Cl2). ... 

Nicotinamide adenine dinucleotide phosphate (NADP, TPN) [53-59-8] M 743.4, pK] 1.1 (PO4H2), pK 4.0 (adenine NH ), pKa 6.1 (P04 ). Purified by anion-exchange chromatography in much the same way as for NAD [Dalziel and Dickinson Biochem J 95 311 7965 Biochemical Preparations 11 87 7966]. Finally it is purified by dissolving in H2O and precipitating with 4 volumes of Me2CO and dried in... 

The utility of the Zincke reaction has been extended to the preparation of various NAD and NADH analogs. Holy and co-workers synthesized a series of NAD analogs containing nucleotide bases as a means to study through-space interaction between the pyridinium and base portions. Nicotinamide-derived Zincke salt 8 was used to link with various adenine derivatives via tethers that contained hydroxyl (105 —> 106, Scheme 8.4.35), phosphonate (107—>108, Scheme 8.4.36), and carboxylate "... 

Fig. 33. Stepwise preparative desorption chromatography of phosphoric esters of adenosine on CS-AV-17 cellosorbent 1) adenine, 2) adenosine, 3) adenosine monophosphate, 4) adenosine diphosphate, 5) adenosine triphosphate...

A 12), 0-(thymin-l-yl)ethyldodecyldimethylamrnonium chloride), 25 (T12), j3-(theophyllin-7-yl)ethyldodecylammonium chloride, 26 (TH12), j3-(adenin-9-yl)-ethyloctadecyldimethylammonium chloride (A 18), and /3-(thymin-l-yl)ethylocta-decyldimethylammonium chloride (T18)47. These model compounds were prepared by the Menschutkin reaction of dodecyldimethyl amine or octadecyldimethylamine with chloroethylated bases. 

The samples of l,6-T2-DBpD and l,6-T2-2,3,7,8-Cl4-DBpD are useful in metabolism and mode of action studies. For example, when incubated with rabbit liver microsomes, l,6-T.>-DBpD is extensively metabolized to polar product(s) but only when these preparations are fortified with reduced nicotinamide-adenine dinucleotide phosphate. Under the same conditions l,6-T2-2,3,7,8-Cl4-DBpD is completely resistant to metabolic attack. In some types of studies, a higher specific activity possibly is desirable i.e., >1 Ci/mmole), and this can be achieved, with the methodology already developed, by using larger amounts of tritium gas or working on a larger synthetic scale so that it is not necessary to add unlabeled materials to assist in crystallization steps where a certain minimum amount of compound is necessary. 

Dideoxy-2-fluoro- 3-D-co r/zrc>-pentofuranosyl)adenine (877) was prepared from the 5 -(9-protected precursors (876) by treatment with DAST (CH2CI2 82% yield) or with BU4NF for the corresponding 2 -triflate. The corresponding threo isomer (879) was obtained by deoxygenation at... 

The second B. thuringiensis toxin, the /3-exotoxin has a much broader spectrum encompassing the Lepidoptera, Coleoptera and Diptera. It is an adenine nucleotide, probably an ATP analogue which acts by competitively inhibiting enzymes which catalyse the hydrolysis of ATP and pyrophosphate. This compound, however, is toxic when administered to mammals so that commercial preparations of the B. thuringiensis 5-endotoxin are obtained from strains which do not produce the j8-exotoxin. 

Catalysis by flavoenzymes has been reviewed and various analogues of FAD have been prepared e.g. P -adenosine-P -riboflavin triphosphate and flavin-nicotinamide dinucleotide ) which show little enzymic activity. The kinetic constants of the interaction between nicotinamide-4-methyl-5-acetylimidazole dinucleotide (39) and lactic dehydrogenase suggest the presence of an anionic group near the adenine residue at the coenzyme binding site of the enzyme. ... 

There have been few reports of purine derivatives1 that contain metal-carbon nucleobase binding (75), and those that have been described are often polymetalated (84). Quite recently mononuclear complexes of adenine and guanine have been prepared that contain... 

Seasonal variations in the metabolic fate of adenine nucleotides prelabelled with [8—1-4C] adenine were examined in leaf disks prepared at 1-month intervals, over the course of 1 year, from the shoots of tea plants (Camellia sinensis L. cv. Yabukita) which were growing under natural field conditions by Fujimori et al.33 Incorporation of radioactivity into nucleic acids and catabolites of purine nucleotides was found throughout the experimental period, but incorporation into theobromine and caffeine was found only in the young leaves harvested from April to June. Methy-lation of xanthosine, 7-methylxanthine, and theobromine was catalyzed by gel-filtered leaf extracts from young shoots (April to June), but the reactions could not be detected in extracts from leaves in which no synthesis of caffeine was observed in vivo. By contrast, the activity of 5-phosphoribosyl-1-pyrophosphate synthetase was still found in leaves harvested in July and August. 

MOFs containing nitrogen-donor building blocks were also widely investigated, particularly adenine group which was extensively used due to framework robustness, richness in nitrogen sites, and framework diversity [162]. Song et al. [163] reported the preparation of three new... 

The reaction to Shapiro s criticisms was quick in coming from the Miller group in La Jolla, California (Nelson et al., 2001). These authors argued that cytosine is easier to prepare from cyanoacetaldehyde and urea at low temperatures than theoretically calculated. They also criticized the incorrect interpretation of the data on the hydrolysis of adenine. As was to be expected, the possibility that solutions could have undergone concentration via evaporation (lagoons or beaches) and freezing out at low temperatures (which also leads to concentration of solutions) are defended. 

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