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— The total mixed proteins (excluding proteolipids) were isolated from cat cerebral cortex and subjected to acid and enzymic hydrolyses. Analyses on the hydrolysates were carried out by specific enzymic procedures to determine the glutamyl, glutaminyl, aspartyl and asparaginyl composition. The content of total glutamyl and total aspartyl residues was the same in all types of protein samples, with average values of 78 and 58 /miol/100 mg of protein, respectively. In biopsy samples approximately 45 per cent of each total was in the amide form. Preparation of slices of cerebral cortex for incubation was associated with deamidation in situ of 16 per cent of the protein-bound glutaminyl residues. The extent of deamidation was not increased by incubation or by prolonged hypoxia and was unaffected by prior anaesthesia or by incubation of slices with 10 mM-NH4Cl or 40 mM-malonate. Slices prepared from animals intoxicated with methionine sulphoximine exhibited no deamidation. No deamidation was observed for slices of subcortical white matter, liver, kidney, testis or diaphragm of the cat. Cortical proteins from other species appeared to behave similarly to those of the cat. The 5-4 μmol of NH3 released/g of fresh cortex could account for about 85 per cent of the endogenous free ammonia regularly encountered in such slices. Hence the labile fraction of protein-bound glutaminyl amide groups represents, as previously suspected, a major source of endogenous cerebral NH3. Proteins isolated from cerebral cortical slices incubated with L-[U-14C]glutamic acid or L-[U-14C]glutamine contained 105 (±0.095) per cent of the total 14C metabolized. The ratios (x 100) of protein to free pool specific radioactivities (c.p.m.μmol) of glutamic acid and of glutamine were in the range 0-22 to 0-42, or of the same order as previously reported for other amino acids. Comparable results were obtained with proteins isolated from cerebral cortical slices incubated with 10 mM-15NH4Cl or L-[amide-15N]glutamine or both. In the amide N of protein-bound glutaminyl residues the atoms per cent excess 15N ranged from 007 to 0-42. This degree of labelling could be accounted for completely by the turnover of the entire glutaminyl moiety, as indicated by the 14C studies. Simultaneous analyses of free pool NH3 and glutamine suggested that transfer of glutamine from medium to slice involves deamidation as it is taken up and reamidation after entry.

The amide groups of poly(N-methyl laurolactam), poly(N-ethyl laurolactam) and poly(N-benzyl laurolactam) were shown by PMR and CMR to acquire both the anti and syn conformations in CDCl3 at 30°C. At 80°C, the PMR signals of the two conformations collapsed to one signal, at an intermediate chemical shift. The anti - syn PMR and/or CMR signals were displayed by carbon nuclei and protons of all the groups which are directly bonded to the amide moieties in the three polymers. The magnetic non-equivalence of the carbon nuclei and protons of a number of other groups which are not directly linked to the amide functions was also demonstrated.

The structure of poly(N-methyl laurolactam) has been studied in the solid state and in solution. In oriented, annealed monofilaments, the chain exhibits a distorted extended planar zigzag conformation. Upon orientation, an increase in crystallinity and a slight shift of the large d spacing in the diffraction pattern to a higher value is observed. In the crystalline regions of the polymer, the amide groups are proposed to have the anti conformation, whereas the amorphous regions may consist of both the syn and anti forms. Differential scanning calorimetry and thermal mechanical analysis showed multiple melting endotherms which probably result from partial melting and reorganization of small, imperfect crystallites. In solution, nuclear magnetic resonance spectroscopy showed the presence of a conformational equilibrium of the syn and anti amide groups in the polymer chains. The effect of thermal and mechanical treatments on certain infrared group frequencies of the amide moieties was studied and correlated with other pertinent analytical data.

An investigation of Grignard reaction of N-(N', N'-dialkylaminomethyl) amides (N-Mannich base) revealed that the phthalimide and succinimide derivatives underwent nucleophilic attack by Grignard reagent resulting in substitution of the amide residue with alkyls of Grignard reagent, to give tertiary amines in fair yields. These reactions have provided an practical means for preparation of tertiary amines from secondary amines through the N-Mannich bases. In these reactions it was also found that, when more than one molar equivalent amount of Grignard reagent was used, attacks to the amide moieties intially formed proceeded to give phthalimidine derivatives and γ-ketoamide respectively in the case of using N-(N', N'-dialkylaminomethyl) phthalimide and N-(N', N'-dialkylaminomethyl) succinimide. For identities of a series of the γ-ketoamides obtained discussions of their spectral data are also described.

Feeding dieldrin at 5 or 25 ppm for 7 or 14 days to white mice decreased the toxicity of Bidrin [dimethyl phosphate, ester with cis-3-hydroxy-N,N-dimethylcrotonamide] and phosphamidon [dimethyl phosphate, ester with 2-chloro-N,N-diethyl-3-hydroxycrotonamide], both vinyl phosphates with substituted amide moieties; increased the toxicity of dimethoate [O,O-dimethyl S-(N-methylcarbamoylmethyl) phosphorodithioate] about 2-fold; and slightly decreased the toxicity of malathion [diethylmercaptosuccinate, S-ester with O,O-dimethyl phosphorodithioate]. Feeding DDT at 25 or 100 ppm had no significant effect on the toxicity of phosphamidon, although the toxicities of Bidrin and malathion were slightly decreased, and the toxicity of dimethoate was slightly increased. Dieldrin, therefore, has a more pronounced effect than DDT on the toxicity of the organophosphorus compounds used.