Measurement of Pyrimidine (6-4) Photoproducts in DNA by a Mild Acidic Hydrolysis-HPLC Fluorescence Detection Assay
摘要:
Pyrimidine (6-4) pyrimidone photoproducts constitute one of the major classes of DNA lesions induced by far-UV irradiation. However, their biological role remains difficult to assess partly because of the lack of a specific and sensitive assay for monitoring their formation in DNA. Here is presented a measurement method based on the release of the (6-4) base adducts from DNA followed by an HPLC separation associated with a sensitive and specific fluorescence detection. The quantitative and mechanistic aspects of the chemical hydrolysis, based on the use of hydrogen fluoride stabilized in pyridine, were investigated, using dinucleoside monophosphate (6-4) photoproducts as model compounds. The final hydrolysis products were isolated and characterized by UV, fluorescence, mass, and H-1 NMR spectroscopies. Application of the assay to far-UV irradiated calf thymus DNA provided information on the sequence effect on the rate of formation of three of the four possible bipyrimidine (6-4) photoproducts.
Thermolytic 4-Methylthio-1-butyl Group for Phosphate/Thiophosphate Protection in Solid-Phase Synthesis of DNA Oligonucleotides
作者:Jacek Cieślak、Andrzej Grajkowski、Victor Livengood、Serge L. Beaucage
DOI:10.1021/jo035861f
日期:2004.4.1
phosphate/thiophosphate protectinggroup for DNA oligonucleotides has been investigated for its potential application to a “heat-driven” process for either oligonucleotidesynthesis on diagnostic microarrays or, oppositely, to the large-scale preparation of therapeutic oligonucleotides. The preparation of phosphoramidites 10a−d is straightforward, and the incorporation of these amidites into oligonucleotides via solid-phase
An efficient oxidizing reagent for the synthesis of mixed backbone oligonucleotides via the h-Phosphonate approach
作者:Nikhil U Mohe、Kamlesh J Padiya、Manikrao M Salunkhe
DOI:10.1016/s0968-0896(02)00615-6
日期:2003.4
diesters to the corresponding phosphates. The system is found to be inert to the phosphoramidate (P-N) and the phosphorothioate (P-S) linkages and has successfully been applied to the solid phase synthesis of mixed-backbone oligonucleotides (MBOs).
Thermolytic Properties of 3-(2-Pyridyl)-1-propyl and 2-[<i>N</i>-Methyl-<i>N</i>-(2-pyridyl)]aminoethyl Phosphate/Thiophosphate Protecting Groups in Solid-Phase Synthesis of Oligodeoxyribonucleotides
作者:Jacek Cieślak、Serge L. Beaucage
DOI:10.1021/jo0354490
日期:2003.12.1
thermolytic phosphate/thiophosphate protecting groups has been investigated. Specifically, 2-pyridinepropanol and 2-[N-methyl-N-(2-pyridyl)]aminoethanol were incorporated into deoxyribonucleoside phosphoramidites 7a-d and 9, which were found as efficient as 2-cyanoethyl deoxyribonucleoside phosphoramidites in solid-phase oligonucleotide synthesis. Whereas the removal of 3-(2-pyridyl)-1-propyl phosphate/thiophosphate
Synthesis of Bis(deoxyribonucleoside) Phosphoromorpholidate Derivatives for Oligodeoxyribonucleotide Preparation by Use of a Selective Phosphitylating Reagent
5′-O-protected deoxyribonucleoside phosphorobisamidite with the second deoxyribonucleoside (coupling), and c) a nonaqueous oxidation with t-BuOOH (oxidation). In the coupling step, the 5′-O-protected deoxyribonucleoside phosphorobisamidite was selectively reacted with 5′-OH group of the second deoxyribonucleoside, and therefore, a protection of hydroxyl groups of the second deoxyribonucleoside is not necessary
Efficient Inhibition of Photo[2 + 2]cycloaddition of Thymidilyl(3‘−5‘)thymidine and Promotion of Photosplitting of the <i>cis-syn</i>-Cyclobutane Thymine Dimer by Dimeric Zinc(II)−Cyclen Complexes Containing <i>m</i>- and <i>p</i>-Xylyl Spacers
作者:Shin Aoki、Chizuyo Sugimura、Eiichi Kimura
DOI:10.1021/ja981788c
日期:1998.10.1
Monomeric and dimeric zinc(II) complexes of cyclen (cyclen = 1,4,7,10-tetraazacyclododecane) inhibited the photo[2 + 2]cycloaddition of thymidilyl(3‘−5‘)thymidine (d(TpT)) at neutral pH in aqueoussolution for a novel mechanism. Comparison of the initial rates and the product yields of the photodimerization of d(TpT) (in Tris buffer at pH 7.6 with I = 0.10 (NaNO3)) at 3−5 °C by high-pressure mercury