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891.
A synthetic strategy for branched ribonucleotides, which have recently been discovered, was described. A fully protected adenosine unit (5) having the tris (4,5-dichlorophthalimido)trityl (CPTr), bis(anilino)phosphoryl (BAP), and bis(phenylthio)phosphoryl (BPTP) groups as the 5'-, 2'-, and 3'-hydroxyl protecting groups, respectively, was synthesized from adenosine by a five-step reaction involving a new method for the 2'-O-phosphorylation by the use of hexaethylphosphorous triamide. The selective deprotection of appropriate protecting groups from 5 followed by stepwise condensation with two different ribonucleoside derivatives (7 and 10) gave a protected branched ribonucleotide (11) via a 3'-phosphorylated 2'-5' dinucleotide (8). Deprotection of 11 and 8 gave a branched trinucleotide (12) and 3'-phosphorylated dinucleotide (13). 相似文献
892.
Oligoribonucleotides were obtained without contamination of 2'-5' linked regioisomers by means of polymer support when Thp group was employed as 2'-hydroxyl protecting group. 相似文献
893.
894.
K Kohno S Nishiyama T Kamimura M Sekine T Hata I Kumagai K Miura 《Nucleic acids symposium series》1985,(16):233-236
In other to examine the binding ability of the 5'-terminal part of eukaryotic mRNA to 80S ribosome, several kinds of oligoribonucleotides, pA-U-G, m7G5'pppA-U-G, m7G5'pppG-U, m7G5'pppA-U-G-A-C-C, were synthesized chemically. The binding experiments of oligonucleotides to 80S ribosome showed that the capped structure as well as AUG are essential for ribosome binding, and the efficiency is enhanced by the 5'-leader sequence if it would include complementary sequence to the 3'-terminal part of 18S rRNA. 相似文献
895.
896.
A 3',5'-unprotected 2'-O-bis(tert-butoxy)-phosphinyl-6-N-benzoyladenosine derivative was prepared as a key intermediate for the synthesis of branched RNAs, and used for construction of building units from which chain elongation in any of 2'-, 3'-, and 5'-directions would be possible. From this synthetic intermediate, 2'-phosphorylated ApC dimer was also synthesized. 相似文献
897.
Masatomo Kimura Shun-ichi Udagawa Akinobu Shoji Hikaru Kume Masaki Imori Takao Satou Shigeo Hashimoto 《Mycopathologia》1990,111(1):47-53
A female patient with systemic lupus erythematosus (SLE) developed pulmonary aspergillosis with staphylococcal pneumonia and hepatic candidiasis.Aspergillus terreus, which is a rare causative organism of pulmonary aspergilosis, was identified from a pulmonary lesion by culture. The aleurioconidium production, a characeristic of the genusAspergillus sect.terrei, was demonstrated on short and irregular hyphal features in tissue sections. This report is the first of a combined case of pulmonary aspergillosis due toA. terreus with infections caused by other microorganisms. 相似文献