UNLABELLED UV resonance Raman spectroscopy (UVRRS) using 244-nm excitation was used to study the impact of aging on human dentin. The intensity of a spectroscopic feature from the peptide bonds in the collagen increases with tissue age, similar to a finding reported previously for human cortical bone. INTRODUCTION The structural changes that lead to compromised mechanical properties with age ...

Amide bond-forming reactions are of tremendous significance in synthetic chemistry. Methodological research has, in the past, focused on efficiency and selectivity, and these have reached impressive levels. However, the unacceptable amounts of waste produced have led the ACS GCI Roundtable to label 'amide bond formation avoiding poor atom economy' as the most pressing target for sustainable syn...

Glucagon-like peptide-1 (GLP-1), which has been extensively applied for treating type 2 diabetes mellitus (T2DM), is an incretin hormone that regulates glucose homeostasis. GLP-1(28-36)amide, a C-terminal nonapeptide (FIAWLVKGRamide) of GLP-1, is a major product derived from the cleavage of GLP-1 by the neutral endopeptidase (NEP). GLP-1(28-36)amide has long been regarded as a metabolically ina...

In the title compound, C11H10BrNO3, two independent mol-ecules (A and B) crystallize in the asymmetric unit. The dihedral angles between the mean planes of the 4-bromo-phenyl ring and amide group are 24.8 (7) in mol-ecule A and 77.1 (6)° in mol-ecule B. The mean plane of the methyl-idene group is further inclined by 75.6 (4) in mol-ecule A and 72.5 (6)° in mol-ecule B from that of the amide gro...

The couplings between all amide fundamentals and their overtones and combination vibrational states are calculated. Combined with the level energies reported previously (Hayashi, T.; Zhuang, W.; Mukamel, S. J. Phys. Chem. A 2005, 109, 9747), we obtain a complete effective vibrational Hamiltonian for the entire amide system. Couplings between neighboring peptide units are obtained using the anha...

The structure and absolute configuration of the title compound, C8H11NO4, which is a known quorum-sensing modulator, have been determined. The mol-ecule exhibits signs of an intra-molecular attractive carbon-yl-carbonyl n→π* inter-action between the amide and lactone ester groups, specifically - a short contact of 2.709 (2) Å between the amide oxygen atom and ester carbon atom, approach of the ...

In the course of a β-site APP-cleaving enzyme 1 (BACE1) inhibitor discovery project an in situ synthesis/screening protocol was employed to prepare 120 triazole-linked reduced amide isostere inhibitors. Among these compounds, four showed modest (single digit micromolar) BACE1 inhibition. Our ligand design was based on a potent reduced amide isostere 1, wherein the P(2) amide moiety was replaced...

Two new samples of poly(amide-imide)/nanocomposites containing bicyclo segment and dibenzalaceton moiety in the main chain were synthesized by a solution intercalation technique. Poly(amide-imide) (PAI) 8 as a source of polymer matrix was synthesized by the direct polycondensation reaction of N,N´-bis(4-carboxyphenyl)bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic diimide 3 with 2,6-bis(4-amino...

We report a new synthetic methodology for poly(ester amide)s by anionic ring-opening copolymerization of N-sulfonyl aziridines and cyclic anhydrides. Phosphazenes organocatalysts have been found to promote highly-active, controlled, selective alternating in the absence any competitive side reaction (zwitterionic mechanism exchange transacylations). Mechanistic studies shown first-order dependen...

A technique is described for measuring the approximate exchange rates of the more labile amide protons in a protein. The technique relies on a comparison of the intensities in 1H-15N correlation spectra recorded with and without presaturation of the water resonance. To distinguish resonance attenuation caused by hydrogen exchange from attenuation caused by cross relaxation, the experiment is re...