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Thymidine 0.001 molar

Nucleosides and nucleotides, 2 X 10-6 molar solution of adenosine, guanosine, cytidine, uridine, thymidine, inosine, adenosine monophosphate, adenosine triphosphate, guanosine monophosphate, uridine monophosphate, thymidine monophosphate, inosine monophosphate. [Pg.648]

Protection of hydroxyl groups.The t-butyldimethylsilyl (TBDMS) group is recommended for the protection of the 5 -primary hydroxyl groups of nucleosides, For example, the reaction of thymidine (1) with r-butyidimethylchlorosilane in DMT containing imidazole (2.5 molar cq., 1,492-494 2,220) gives the ether (2) in 60% yield, o o... [Pg.57]

Until recently, there were two methods for analysis of TP activity spectrophotometry and TFC, both of which were based on the conversion of thymidine to thymine. The spectrophotometric assay is based on the difference in molar-extinction coefficients between thymidine and thymine at alkaline pH. A fixed time-point at 90 min (12) or 16 h (13) has been used. [Pg.112]

Comparison of the uptake of(III.147) and MTXin cultured L1210 cells [45] confirmed that the quinazoline was able to accumulate to a higher level than MTX when the cells were exposed to the same concentration of drug (4 M) for 40 min. Competitive uptake experiments suggested that (III. 147) shares a common active transport mechanism with MTX and folinic acid. As expected, high concentrations of folinic acid (50 juM) fully protected the cells from the effects of (III. 147). At lower folinic acid concentrations, however, there was only partial protection thus, 5 juM folinic acid (a 100-fold molar excess) was fully protected the cells from 0.05 juM (III. 147), whereas 0.5 /tM folinic acid (only a 10-fold excess) did not. Cells were also completely protected from 0.05 juM (III. 147) with 100 pM thymidine and 100/tM hypoxanthine, and greater protection was achieved with 5 /tM folinic and 100 /iM thymidine than with 5 iM folinic acid alone. It was concluded from these results that (III. 147) does not kill cells solely via DHFR inhibition, but rather via concomitant inhibition of DHFR and TS. [Pg.37]

A second example involves a transesterification reaction catalyzed by an antibody generated against a phosphonate diester transition state analogue [11]. The antibody catalyzes the corresponding acyl transfer reaction of thymidine and an alanyl ester with an effective molarity of 3 x 10 m... [Pg.343]

The 3 -isobut5Toylamino-thymidine derivative (117), on the other hand, reacts with 1 equiv of LR in the side chain to form the thioamide (118). Phosphite esters which are used as intermediates in solid-phase synthesis of oligonucleotides are converted into the corresponding phosphorothioates (119). Interestingly, LR can also be used as a potent catalyst for the s)uithesis of nucleosides. Tetramethylglycoluril (120) is readily converted to the monothiono- (121) or the dithionoglycolurU (122) depending on the applied molar amount of LR. ... [Pg.62]

The method was also used to follow Dieckmann cyclization of a resin-bound pimelate ester. In loading of the resin and the subsequent reactions, scintillation counting was used to determine the fate of the radiolabel (Crowley and Rapoport, 1970). In oligonucleotide synthesis on polymer supports, thymidine [( H)methyl] was loaded on the polymer. This aided in determination of molar ratio of the products after cleavage, by a combination of scintillation counting and uv spectrophotometry (Narang et aL, 1977). [Pg.50]

Emura T, Suzuki N, Fujioka A, Ohshimo H, Fukushima M (2005) Potentiation of the antitumor activity of a, a, a-tiifluorothymidine by the co-administration of an inhibitor of thymidine phosphorylase at a suitable molar ratio in vivo. Int J Oncol 27 449-456... [Pg.662]

Reaction of dimer 1 with 5 -DMT-thymidine phosphoramidite, followed by Me2S BH3, results in the formation of trimer 3 (trinucleoside boranophosphate methylester, 3) (see Scheme I) in which both intemu-cleotide linkages are boranophosphate methyl ester groups. This reaction was carried out with equal molar amounts of 1 and DMT-thymidine-phosphoramidite, and the yield of 3 was only 22.4% prior to and 5.2% after HPLC. Yet a large proportion (ca. 66%) of dimer 1 was recovered unreacted. Clearly, the procedure must be optimized to obtain a 99%+ coupling yield before it could be used for practical synthesis of oligonucleotides. In a second experiment performed in an NMR tube, 5 Eq of amidite resulted in >95% conversion. [Pg.235]


See other pages where Thymidine 0.001 molar is mentioned: [Pg.32]    [Pg.33]    [Pg.79]    [Pg.122]    [Pg.182]    [Pg.230]    [Pg.295]    [Pg.180]    [Pg.442]    [Pg.443]    [Pg.443]    [Pg.205]    [Pg.158]   
See also in sourсe #XX -- [ Pg.2 , Pg.417 ]




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