five new aromatic poly(amide-imide)s (5a-e) were synthesized by direct polycondensationreaction of n-(4-carboxy phenyl) trimellitimide (3) with five aromatic diamines (4a-e) by usingtriphenyl phosphite in n-methyl-2-pyrrolidone (nmp) and pyridine at solution containingdissolved cacl2. all of the polymers were obtained in quantitative yields with inherentviscosities between 0.29-0.40 dl/g. the r...

The previous discoveries of butyl fenbufen amide analogs with antitumor effects were further examined. The amide analogs with 1, 3, 4 and 8 carbons chains were prepared in 70-80% yield. Fenbufen had no cytotoxic effects at concentrations ranging from 10 to 100 μM. Methyl fenbufen amide had significant cytotoxic effects at a concentration of 100 μM. As the length of the alkyl amide side chain in...

Attractive interactions between two carboxamide groups in a "stacked" geometry are explored under isolated molecule conditions. Infrared spectra of single conformations of a small gamma-peptide, Ac-gamma(2)-hPhe-NHMe, reveal the presence of a conformation in which the two amide planes are approximately parallel with the amide dipoles in an antialigned orientation. This stacked conformation is e...

We demonstrate how multimode 2D IR spectroscopy of the protein amide I' and II' vibrations can be used to distinguish protein secondary structure. Polarization-dependent amide I'-II' 2D IR experiments on poly-l-lysine in the beta-sheet, alpha-helix, and random coil conformations show that a combination of amide I' and II' diagonal and cross peaks can effectively distinguish between secondary st...

a classical theory is developed which calculates the momentum transfer rate constant between an ion and a non-polar molecule. the model takes into consideration the effect of diffraction outside the capture limit on the rate constants. the theory is used to calculate momentum transfer rate constant for cl- with trans-dichloroethylene and para-difluorobenzene. theoretical results are compared to...

A bicyclo[2.2.2]octane derivative containing both a tertiary amide and a methyl ester (1) was shown crystallographically to adopt a conformation in which the amide is in the cis configuration, which is sterically disfavored, but electronically favored. The steric strain induces a significant torsion (15.91) of the amide, thereby greatly increasing the solvolytic lability of the amide to the ext...

The widely expressed dipeptidyl peptidase-4 enzyme rapidly cleaves the gut hormone glucagon-like peptide-1 [GLP-1(7-36)amide] at the N terminus to generate GLP-1(9-36)amide. Both intact GLP-1(7-36)amide and GLP-1(9-36)amide exert cardioprotective actions in rodent hearts; however, the mechanisms underlying the actions of GLP-1(9-36)amide remain poorly understood. We used mass spectrometry of co...