Styrene 7,8-oxide, which reacts preferentially at the N-7 position of guanine, yielded two pairs of diastereomers 7-(1'-hydroxy-2'-phenylethyl)-dGMP (the alpha-isomer) and 7-(2-hydroxy-2-phenylethyl)-dGMP (the beta-isomer) on reaction with deoxyguanosine-3'-monophosphate (3'-dGMP). The alpha- and beta-isomers were formed in the ratio 32:68. T4 polynucleotide kinase preferentially mediated label...

two possible isomers of some 1,3-diaryl-h-benzo[f]chromene have been studied using density functional theory. structures of e1 and e2 isomers were optimized at the b3lyp and mp2 levels with different basis sets. the total electronic energies show that e2 isomer is about 3-5 kcal/mol more stable than e1 isomer and this energy difference is attributed to the planarity of heterocyclic ring and mor...

A systematic and detailed analysis of adsorption and diffusion properties of xylene isomers over Beta zeolites with different mesoporosity was conducted. Adsorption isotherms of xylene isomers over microporous and mesoporous Beta zeolites through gravimetric methods were applied to investigate the impact of mesopores inside Beta zeolites on the adsorption properties of xylene isomers in the pre...

the incidence of pre-lingual hearing loss (hl) is about 1 in 1000 neonates. more than 60% of cases are inherited. non-syndromic hl (nshl) is extremely heterogeneous: more than 130 loci have been identified so far. the most common form of nshl is the autosomal recessive form (arnshl). in this study, a cohort of 36 big arnshl pedigrees with 4 or more patients from 7 provinces of iran was investig...

The hydrolysis of several phenylacetylamino compounds was studied using a purified preparation of E. coli penicillin acylase. The L-isomers of phenylacetyl amino acids were cleaved much faster than the D-isomers. The same observations was made for some phenylacetylamino beta-lactams. When the beta-lactam ring is incorporated in a penam or cephem ring system, the D-isomers were hydrolysed somewh...

We have considered combinatorial and group theoretical analysis of three recently synthesized isomers of C60H36. We have obtained the generating functions for nuclear spin species of the protons and C nuclei, and special cases of those functions yield the NMR spectral patterns. Our NMR results for three isomers with C1, C3 and T symmetries agree with experiment. We have also predicted the ESR h...

In present study, the density functional theory (DFT-B3LYP) method with SVP basis set was used for optimizing and studying the electronic structural properties of cis and trans isomers of bis-(5-nitro-2H-tetrazolato-N2) tetraammine cobalt (III) perchlorate (BNCP) as powerful explosives at 298.15 K temperature and 1 atmosphere pressure. And also, Natural Bond Orbital (NBO) population analysis an...

Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were performed with a glassy carbon electrode (GCE) modified with polyglutamic acid (PGA) on the three dihydroxybenzene isomers, catechol (CT), hydroquinone (HQ), and resorcinol (RS). At bare GCE, these isomers exhibited voltammograms with highly overlapped redox peaks that impeded their simultaneous detection in binary and ternar...

UNLABELLED The aim of this study was to investigate whether D-amino acid isomers of O-(11)C-methyl tyrosine ((11)C-CMT) and O-(18)F-fluoromethyl tyrosine ((18)F-FMT) were better than the corresponding L-isomers as tumor- detecting agents with PET in comparison with the difference between L- and D-methyl-(11)C-methionine ((11)C-MET). METHODS L- and D-(11)C-MET, (11)C-CMT, and (18)F-FMT were in...