Biomedical subjects

S Maikuma

Publications and source records attributed to S Maikuma.

4 recordsLinked to original sources

PubMed1988

Sequence-defined dimer block synthesis from unprotected nucleoside.

mediates to synthesize the oligodeoxynucleotides have been synthesize otected nucleoside using morpholinophosphorditetrazolide. From these sequence-defined oligodeoxynucleotides were also synthesized. The gen is composed of following steps; a) reaction of 5'-O-protected nucleo orpholinophosphorditetrazolide (phosphitilation), b) reaction of the nucleoside phosphoramidite with the second nucleoside (condensation), ueous oxidation with t-BuOOH (oxidation). RE 1/hlp F2/cmt F3/ext F4/can F5/nxt F6/ins F7/up F8/dwn F9/fin

Indicators and Reagents↗

PubMed1986

An approach to DNA fragment synthesis from unprotected nucleoside.

Oligodeoxynucleotides have been synthesized from unprotected nucleoside by use of morpholinophosphordichloridite as a phosphorylating reagent. This procedure consists of three (in situ) steps; the reaction of 5'-O-protected deoxynucleotide with morpholinophosphordichloridite, the reaction of the resulting on active mononucleotide derivative with the second nucleoside, non-aqueous oxidation, and then removal of amino moiety at phosphate diester linkage.

Base Sequence↗

PubMed1985

A rapid synthesis of a DNA fragment using an unprotected nucleoside and a phosphine derivative.

A rapid synthesis of DNA fragment from unprotected nucleoside and phosphine derivative, morpholinophosphordichloridite, has been studied, demonstrating a d(T-T) and its amino-phosphonate derivative syntheses. A high selectivity of this reagent eliminates the protection of nucleoside hydroxyl groups. The P-N bond in the resulting dinucleoside phosphite can readily be converted to a phosphite triester with alcohol and to the corresponding aminophosphonate by a non-aqueous oxidation with m-chlorobenzoic acid. The P-N bond in the phosphate link is very stable and so provides a protection for the phosphoryl group which has many potential uses. Deprotection can be achieved by a simple treatment with NH2OH.

DNA↗

PubMed1984

A simple and convenient synthesis of 3'-5'- or 2'-5'-linked oligoribonucleotide by polymerization of unprotected ribonucleoside using phosphorus tris-azole.

Oligoribonucleotides have been synthesized directly from unprotected ribonucleosides by a chemical polymerization approach using phosphorus tris-azoles. The procedure involves two steps: (i) the reaction of unprotected ribonucleoside with phosphorus tris-azole and (ii) the in situ oxidation of the resulting phosphite with iodine and water. Several phosphorus tris-azoles were investigated for generating oligoribonucleotide chains. Phosphorus tris-azoles of which azoles are imidazole, 2-methylimidazole, and 2-ethyl-4-methylimidazole were found to be most effective. Uridine, adenosine, and cytidine oligonucleotides were obtained rapidly in high yields without any protection. The inter-ribonucleotidic linkage of the oligomers consists of 3'-5'- and 2'-5'-linkages. The linkage isomers were easily separated by a reverse phase column chromatography. The present approach provides a convenient and potentially useful method for preparing 3'-5'- or 2'-5'-linked oligoribonucleotides.

Animals↗