Potentiometric differentiated titration of the components of nucleic acids and their derivatives. VII. Acidimetric determination of some N-acyl-2′-deoxyribonucleosides and their 5′-tritylated derivatives

The conditions have been investigated for the potentiometric titration of N-acyl-2′-deoxyribonucleotides and of trityl carbinol derivatives and their two-component mixtures with a nitromethane solution of perchloric acid. The influence of water, acetone, chloroform, and acetic acid on the conditions for the acidimetric analysis of tri-p-methyltrityl carbinol, p-monomethoxytrityl carbinol, and di-p-methoxy trityl carbinol in nitromethane have been shown. Procedures have been developed for the quantitative determination of N6-benzoyl-5′-di-p-methoxytrityl-2′-deoxyriboadenosine, the 5′-tri-p-methyltrityl and 5′-p-monomethoxytrityl derivatives of N4-benzoyl-2′-deoxyribocytidine, of N6-benzoyl-2′-deoxyriboadenosine, and of N2-isobutyryl-2′-deoxyriboguanosine by differentiated potentiometric titration. For the determination of the 5′-di-p-methoxy derivatives of N4-benzoyl-2′-deoxyribocytidine and of N6-benozyl-2′-deoxyriboadenosine a procedure is proposed which includes the use of two parallel titrations. Methods have been developed for the use of milligram amounts of substance.