564-00-1Relevant articles and documents
Chiroptical properties of 2,2’-bioxirane
Daugey,De Rycke,Brotin,Buffeteau
, p. 342 - 350 (2018/01/15)
The two enantiomers of 2,2′-bioxirane were synthesized, and their chiroptical properties were thoroughly investigated in various solvents by polarimetry, vibrational circular dichroism (VCD), and Raman optical activity (ROA). Density functional theory (DFT) calculations at the B3LYP/aug-cc-pVTZ level revealed the presence of three conformers (G+, G?, and cis) with Gibbs populations of 51, 44, and 5% for the isolated molecule, respectively. The population ratios of the two main conformers were modified for solvents exhibiting higher dielectric constants (G? form decreases whereas G+ form increases). The behavior of the specific optical rotation values with the different solvents was correctly reproduced by time-dependent DFT calculations using the polarizable continuum model (PCM), except for the benzene for which explicit solvent model should be necessary. Finally, VCD and ROA spectra were perfectly reproduced by the DFT/PCM calculations for the Boltzmann-averaged G+ and G? conformers.
METHOD FOR REPROCESSING MIXTURES CONTAINING BIS-EPOXIDE
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Page/Page column 11-13, (2008/06/13)
The invention relates to a method for reprocessing mixtures containing (a) one or several bis-epoxides of general formula (I), wherein R1 and R2 are identical or different and are selected among hydrogen and C1-C3 alkyl, (b) one or several organic solvents, (c) water, and (d) other optional compounds. The inventive method is characterized in that the mixture is subjected to an at least two-stage distillation process, at least one bis-epoxide (a) being converted into the gas phase in at least one stage.
Interstrand and intrastrand DNA-DNA cross-linking by 1,2,3,4-diepoxybutane: Role of stereochemistry
Park, Soobong,Anderson, Christopher,Loeber, Rachel,Seetharaman, Mahadevan,Jones, Roger,Tretyakova, Natalia
, p. 14355 - 14365 (2007/10/03)
1,2,3,4-Diepoxybutane (DEB) is a bifunctional electrophile capable of forming DNA-DNA and DNA-protein cross-links. DNA alkylation by DEB produces N7-(2′-hydroxy-3′,4′-epoxybut-1′-yl)-guanine monoadducts, which can then form 1,4-bis-(guan-7-yl)-2,3-butanediol (bis-N7G-BD) lesions. All three optical isomers of DEB are produced metabolically from 1,3-butadiene, but S,S-DEB is the most cytotoxic and genotoxic. In the present work, interstrand and intrastrand DNA-DNA cross-linking by individual DEB stereoisomers was investigated by PAGE, mass spectrometry, and stable isotope labeling. S,S-, R,R-, and meso-diepoxides were synthesized from L-dimethyl-2,3-O-isopropylidene-tartrate, D-dimethyl-2,3-O-isopropylidene- tartrate, and meso-erythritol, respectively. Total numbers of bis-N7G-BD lesions (intrastrand and interstrand) in calf thymus DNA treated separately with S,S-, R,R-, or meso-DEB (0.01-0.5 mM) were similar as determined by capillary HPLC-ESI+-MS/MS of DNA hydrolysates. However, denaturing PAGE has revealed that S,S-DEB produced the highest number of interchain cross-links in 5′-GGC-3′/3′-CCG-5′ sequences. Intrastrand adduct formation by DEB was investigated by a novel methodology based on stable isotope labeling HPLC-ESI+-MS/MS. Meso DEB treatment of DNA duplexes containing 5′-[1,7, NH2-15N3,2- 13C-G]GC-3′/3′-CCG-5′ and 5′-GGC-3′/ 3′-CC[15N3,2-13C-G]-5′ trinucleotides gave rise to comparable numbers of 1,2-intrastrand and 1,3-interstrand bis-N7G-BD cross-links, while S,S DEB produced few intrastrand lesions. R,R-DEB treated DNA contained mostly 1,3-interstrand bis-N7G-BD, along with smaller amounts of 1,2-interstrand and 1,2-intrastrand adducts. The effects of DEB stereochemistry on its ability to form DNA-DNA cross-links may be rationalized by the spatial relationships between the epoxy alcohol side chains in stereoisomeric N7-(2′-hydroxy-3′,4′-epoxybut-1′-yl)- guanine adducts and their DNA environment. Different cross-linking specificities of DEB stereoisomers provide a likely structural basis for their distinct biological activities.
