It is also conceivable that, at lower pH, depurination can occur via protonation of the purine nucleobase at both N1 and N7. The presence of the 2′-OH has a significant effect on the nucleoside’s susceptibility to depurination. For example, guanosine and adenosine are more resistant to depurination compared to deoxyadenosine and deoxyguanosine. Deoxyadenosine itself depurinates 1200 times faster than adenosine (York, 1981).
Interestingly, N-acyl-protected purine nucleosides (particularly deoxyadenosine) are more prone to depurination than unprotected nucleosides. Among N-acyl-protected deoxyadenosines, protection at N6 with α-phenylcinnamoyl, naphthaloyl, 3-methoxy-4-phenoxybenzoyl, 9-fluorenylmethoxycarbonyl (FMOC), and tert-butylphenoxyacetyl …show more content…
Depurination is faster at terminal sites than at internal sites in an oligonucleotide chain (Suzuki et al., 1994). Interestingly, a solution of 15% dichloroacetic acid (DCA) in methylene chloride was ideal as a detritylating reagent that induced minimal depurination compared to the traditionally used 2% DCA/methylene …show more content…
(2009) prepared DNA probes S.55 from nucleosides S.16 incorporating thermolytic protetcing groups, N-arylcarbamoyl and N-(phenylsulphonyl)carbamoyl (psc), onto the amino groups of deoxycytidine, deoxyadenosine, and deoxyguanosine by reacting with corresponding isocynates (Figure X.X.X). Deprotection was carried out by heating under neutral conditions, enabling a new system of molecular switching by simply heating and reprotection with isocynates. Figure X.X.X shows deprotection mechanism under thermal conditions. A combination of thermolytic phosphate and amino protecting groups may lead to oligonucleotides that can be depeotected without any basic
Interestingly, N-acyl-protected purine nucleosides (particularly deoxyadenosine) are more prone to depurination than unprotected nucleosides. Among N-acyl-protected deoxyadenosines, protection at N6 with α-phenylcinnamoyl, naphthaloyl, 3-methoxy-4-phenoxybenzoyl, 9-fluorenylmethoxycarbonyl (FMOC), and tert-butylphenoxyacetyl …show more content…
Depurination is faster at terminal sites than at internal sites in an oligonucleotide chain (Suzuki et al., 1994). Interestingly, a solution of 15% dichloroacetic acid (DCA) in methylene chloride was ideal as a detritylating reagent that induced minimal depurination compared to the traditionally used 2% DCA/methylene …show more content…
(2009) prepared DNA probes S.55 from nucleosides S.16 incorporating thermolytic protetcing groups, N-arylcarbamoyl and N-(phenylsulphonyl)carbamoyl (psc), onto the amino groups of deoxycytidine, deoxyadenosine, and deoxyguanosine by reacting with corresponding isocynates (Figure X.X.X). Deprotection was carried out by heating under neutral conditions, enabling a new system of molecular switching by simply heating and reprotection with isocynates. Figure X.X.X shows deprotection mechanism under thermal conditions. A combination of thermolytic phosphate and amino protecting groups may lead to oligonucleotides that can be depeotected without any basic