The relatively large amounts of pseudouridine in that fraction of the ribonucleic acid concerned with the transfer of activated amino acids to ribosomes for peptide bond formation (l-4) suggests that this unusual base may play an essential role in this reaction, and that a specific mechanism exists for its incorporation into interribonucleotide linkage. To obtain information on the nature of th...

Wehave undertaken a detailed investigation of the adsorption, desorption and thermal processing of the astrobiologically significant isomers glycolaldehyde, acetic acid andmethyl formate. Here, we present the results of laboratory infrared and temperature programmed desorption (TPD) studies of the three isomers from model interstellar ices adsorbed on a carbonaceous dust grain analogue surface....

Endogenous phosphatidylcholine in biological membranes exists as isomers with acyl moieties at the sn-1 or sn-2 positions of the glycerol backbone. However, detailed biochemical information on these positional isomers is not generally available. This study is the first report on the separation and identification of positional isomers of endogenous phosphatidylcholine using reversed-phase LC-ESI...

Laser spectroscopy and ion mobility spectrometry are combined to provide structural and photochemical information on photoisomerizing molecules in the gas phase. The strategy exploits the fact that an ion packet propelled through buffer gas by an electric field separates spatially and temporally into its constituent isomers because of small differences in their collision cross sections. Isomers...

The phases of 1,2,3,4-tetrahydro-2,3-naphthalenediol (or 2,3-tetralindiol) and of 1,2-cyclohexanediol have been investigated. The structure of a very stable 1:1 compound (or co-crystal) of the cis and trans isomers of 2,3-tetralindiol, the existence of which has been known for nearly a century, has finally been determined. No evidence of any analogous compound between the cis and trans isomers ...

Aryl-cobalamins are a new class of organometallic structural mimics vitamin B12 designed as potential ‘antivitamins B12’. Here, the first cationic aryl-cobinamides described, which were synthesized using newly developed diaryl-iodonium method. The obtained pairs coordination isomers, stereo-structure was unambiguously assigned based on homo- and heteronuclear NMR spectra. availability isomers w...

The synthesis of two isomers of nn-b-fluoromalic acid has been reported in a previous publication from this laboratory (1). On the basis of elementary analysis and equivalent weights, the two isomers were undoubtedly the threo and erythro isomers of nn-fi-fluoromalic acid. However, at that time it was not possible to make a definite assignment of stereochemical configuration to the two isomers....

Santilli (J. Catal. 99, 335–341, 1986) has presented experimental data for sorption of hexane isomers, n-hexane (n-C6), 3-methylpentane (3MP), and 2,2-dimethylbutane (22DMB), in various zeolites. The experimental data on the loadings of the isomers at various temperatures using silicalite are particularly intriguing; 3MP and 22DMB are both seen to exhibit maxima in the sorption loadings with in...

the aim of this study is investigating the transport mechanism of ibuprofen chiral isomers inside singlewall carbon nano tube (swcnt) using mathematical modeling. to achieve this goal, molecular dynamicssimulation has been performed to evaluate the interactions of ibuprofen isomers with swcnt in an aqueoussolution. results show that both chiral forms of ibuprofen molecules enter and remain insi...

BACKGROUND Ropivacaine is believed to have a lower incidence of clinical cardiac side effects than bupivacaine. The aim of this study was to compare the direct cardiac effects of the optically pure S(-)-ropivacaine isomer and its nonclinically used R(+)-isomer with both optically pure bupivacaine isomers in isolated hearts. The hypothesis was that differences in direct cardiac effects are disti...