NH-CO-groups

Sophorine was isolated from Sophora alopecuroides (26). The nature of MS decay showed that sophorine is a quinolizidine alkaloid of the lupinine type. The IR spectrum suggests the presence of a franj-quinolizidine moiety (2675-2945 cm ) and an — NH—CO— group (1605 and 1683 cm ). On the basis of chemical shift analysis and signal multiplicity of H- and C-NMR spectra as well as biosynthetic considerations, structure 59 was proposed for sophorine. 

That the electron-withdrawing effect of the carbonyl on imparting acidity to the proton of the -NH-CO-group might be mimicked by a -CH2-CO- group and,... 

This is the chemical reaction of water with another compound, e.g. a protein can be broken down by hydrolysis (H20) into the separate amino acids. Here the water attacks the peptide bonds, —NH-CO— groups. 

For their detection, the papers may be sprayed with reagents commonly used for the detection of keto and aminodeoxy sugars. Those of particular value include the direct Ehrlich reaction, the orcinol-trichloroacetic acid reagent, the chlorine-benzidine reagent for the detection of —NH—CO— groupings, and the Bial reaction as modified by Bohm und Baumeister. The limit of detection with the orcinol-trichloroacetic acid reagent is reported to be 5 ixg. of V-acetylneuraminic acid. For the detection of methoxyneuraminic acid, ninhydrin may also be used. 

The ring carbonyl group is part of a cyclic urea it cannot therefore be regarded as a typical ketone or amide. A cyclic —NH—CO— group and its sulphur analogue are therefore classified as lactam carbonyl and lactam thiocarbonyl, respectively, whatever the size of the ring. Cyclization of lactam (1.5) is classified... 

These polymers contain the —NH.CO— group. Originally the aliphatic polyamides were only utilized as fibres, but in recent years engineering applications of these polymers have been realized. Aromatic polyamides and polyimides as high-performance fibres are also being developed. 

Aliphatic and aryl amides with -CO-NH-NH-CO-group (in solution)... 

The colour is due to the formation of p-dimethylaminobenzylidine urea. Similar colours are given with compounds containing the — NH—CO—grouping, such as biuret. Alkalies and excess of strong acid discharge the colour. Nitrites interfere by forming deep yellow nitro derivatives that are not bleached by alkalies. 

---