strategies were developed to obtain isonucleosides 2a and 2b. Starting from the known compound 4, an extension of one carbon unit at sugar 6-terminal was achieved by Wittigreaction and Stannyl-desulfonylation reaction. After oxidation of the double bond, the isonucleosides with elongated side chain 2a and 2b were synthesized. For the synthesis of isonucleosides containing different bases, an epoxide
incorporated into a DNA single strand and siRNA. It was found that isonucleoside 5 modified oligonucleotides can form stable double helical structures with their complementary DNA and RNA and the stability towards nuclease and ability to activate RNase H are more promising compared with the unmodified, natural analogues. In siRNA, passenger strand modified with isonucleoside (5a/b) at 3′ or 5′ terminal
Synthesis and Structural Characterization of Homochiral Homo-Oligomers of cis-γ-Methoxy-Substituted cis- and trans-Furanoid-β-Amino Acids
作者:Awadut G. Giri、Ganesh F. Jogdand、Pattuparampil R. Rajamohanan、Sunil K. Pandey、Chepuri V. Ramana
DOI:10.1002/ejoc.201101424
日期:2012.5
Herein we describe the synthesis of cis-/trans-3-aminotetrahydrofuran-2-carboxylic acids (cis-/trans-FAA) having a γ-methoxy group cis to the amine. The homo-oligomers of these two diastereomeric FAAs have been prepared. Preliminary investigation of their solution secondary structures revealed that they are the same as the homo-oligomers of the parent cis-/trans-FAA with the methoxy group only being
Carbapenem antibiotic compounds of the general formula :
wherein the moiety
is a 4, 5 or 6 membered mono, di- or tri- substituted oxygen or sulfur containing ring ; wherein Z is oxygen, sulfur, sulfoxide and sulfone, pharmaceutical compositions thereof useful for the treatment of bacterial infections, processes for preparing the compounds and new intermediates useful in the process.
通式为...的碳青霉烯类抗生素化合物
其中分子
其中 Z 是氧、硫、亚砜和砜;用于治疗细菌感染的药物组合物;制备该化合物的工艺以及在该工艺中有用的新中间体。
Studies on the synthesis and biological activities of 4′-(R)-hydroxy-5′-(S)-hydroxymethyl-tetrahydrofuranyl purines and pyrimidines
A series of 4'-(R)-hydroxy-5'-(S)-hydroxymethyl-tetrahydrofuranyl purines and pyrimidines were synthesized by the reaction of 3,4-epoxy-5-(S,trans)-dimethoxymethyl-tetrahydrofuran and nucleobases under the catalysis of potassium tert-butoxide and 18-crown-6. Compounds 6a, 6c and 7b have shown significant inhibition on the growth of HL-60 cells. The phosphotriester and phosphodiester of isonucleoside 8a-d were synthesized and cytotoxic activities were reported. The conformation of isonucleosides in solution was studied by H-1 NMR. Copyright (C) 1996 Elsevier Science Ltd