I.r. difference spectroscopy combined with 13C and 18O double-isotope substitution was used to examine the ester acyl carbonyl stretching vibration of hydrocinnamoyl-chymotrypsin. A single acyl carbonyl stretching band was observed at 1731 cm-1. This contrasts with previous i.r. and resonance Raman spectroscopic studies of a number of trans-3-arylacryloyl-chymotrypsins which showed two acyl car...

The nature of bonding and aromaticity of Ti(3)(CO)(3), a mill-shaped metal-carbonyl complex, is studied carefully. A unique bonding mechanism between metal and carbonyl groups is found in this species. Ti(3)(CO)(3) is an example of a metal-carbonyl complex with prominent metal to carbonyl donation. Moreover, it is proven that not only is Ti(3)(CO)(3) not an antiaromatic complex but also it is t...

A dysregulation of the redox homoeostasis has been reported in various neoplastic disorders. Malondialdehyde/4-hydroxy-2,3-nonenal (MDA/HNE) and protein carbonyl groups represent in vivo indexes of lipid peroxidation and protein oxidation, respectively, suitable to investigate radical-mediated physio-pathological conditions. We evaluated MDA/HNE and protein carbonyl groups in sera of untreated ...

The alkynyl bond of the title compound, C(14)H(19)NO, has a length of 1.170 (5) Å. The amide function shows a trans conformation with respect to the carbonyl group characterized by the torsion angle O-C-N-H of -176 (2)°. There is an inter-molecular N-H⋯O hydrogen bond between the amide function and the carbonyl group. In addition, weak inter-molecular hydrogen bonds stabilize the crystal struct...

When the hydrate reverts to starting materials, either of its two oxygen atoms must leave: one came from the water and one from the carbonyl group, so 50% of the time the oxygen atom that belonged to the carbonyl group will be lost. Usually, this is of no consequence, but it can be useful. For example, in 1968 some chemists studying the reactions that take place inside mass spectrometers needed...

Reactive carbonyl species generated by the oxidation of polyunsaturated fatty acids and sugars are highly reactive due to their electrophilic nature, and are able to easily react with the nucleophilic sites of proteins as well as DNA causing cellular dysfunction. Levels of reactive carbonyl species and their reaction products have been reported to be elevated in various chronic diseases, includ...

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 ...