Abnormal propionic-methylmalonic-succinic acid metabolism in vitamin B12 deficiency and its possible relationship to the neurologic syndrome of pernicious anemia.
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A number of N-[(4-aryl)- or (4-methyl)-l-piperazinyl)alkyl]imides of 3-aryl or 3,3-pentamethylenesuccinic acid were synthesized and tested for anticonvulsant activity in the maximum electroshock seizure (MES) and pentylenetetrazole seizure threshold (scMet) tests. Structures of the novel compounds were confirmed by elemental and spectral analyses.
A series of new phenylsuccinimide derivatives substituted in the aromatic ring and/or at the nitrogen atom was synthesized and tested for activity against pentetrazole- and electroshock-induced convulsions.
Research was performed for studying the effect of some organic compounds, considered by many authors as the products ob barley seed metabolism generated after anaerobic seed treatment, on the mycelium of the fungus Ustilago nuda (Jens.) Rostr. The author examined the effectiveness of ethylacohol, acetaldehyde, acetic acid, succinic acid, lactic acid, and hydroquinone in concentrations from 1 M to 10(-6) M, and the effectiveness of extracts from disinfected seeds in doses from 10 g to 0.001 g/l. The effect of the mentioned solutions was examined as exerted on the growth of dicaryotic mycelium and on the growth of the haploid promycelium of the fungus. The dicaryotic mycelium of Ustilago nuda (Jens.) Rostr. was cultivated on potato agar with benzoic acid. The presence of the acid prevents mitosis, and the chlamydospores germinate on the nutritive medium with two fibres having binuclear cells. The haploid promycelium was cultivated on potato agar; chlamydospores germinated with one four-cell fibre, and individual cells are mononuclear and haploid. Only later, a dicarytic mycelium is created in a complex process. In all the substances used, the concentration of 1 M was found to stop further growth of mycelium. The concentration of 10(-1) M of acetic acid and hydroquinone also stopped growth, the same concentration of acetaldehyde, lactic acid, succinic acid, ethylacohol stimulated mycelium growth in comparison with the control. The concentration of 10(-6) M stimulated mycelium growth in a majority of cases. Extracts from disinfected seeds did not influence mycelium growth significantly in all cases in comparison with the control. The results were similar in the two types of mycelium.
gem-Dimethylsuccinic acid and its higher homolog, 2-methyl-2-ethylsuccinic acid (MESA) are highly potent inhibitors of both carboxypeptidase A (CPA) and B. The inhibition constant of MESA for CPA (0.11 microM for the racemic mixture) is remarkable considering the relatively simple structure of the compound. The molecular feature which is crucial for high affinity binding to both carboxypeptidases appears to be the nonpolar gem-dialkyl locus. The structure of the complex between MESA and CPA has been determined by X-ray crystallography to 2.0 A resolution and shows the R enantiomer of the inhibitor to be bound in a generally substrate-like manner. The carboxymethyl group is coordinated to the Zn ion in the active site, and the gem-dialkyl locus corresponds in position to the alpha-carbon of the C-terminal amino acid in a peptide substrate. The methyl group of the inhibitor occupies a cavity in the enzyme which is apparently not filled upon substrate-binding. We postulate that this cavity (the alpha-methyl hole) is designed to allow the proximal Glu-270 residue to undergo a critical movement during catalysis. The hydrophobic nature of the above cavity may play a role in modulating the reactivity of this residue. These results suggest that similar cenophilic(empty-loving) inhibitors may be found for other enzymes.
A high-capacity carboxylic acid-functionalized resin prepared by ring-opening metathesis polymerization based on cross-linked endo,endo-poly(norborn-2-ene-5,6-dicarboxylic acid) was used for the sampling of volatile, airborne amines from polyurethane (PU) foams. Six tertiary amines which represent commonly used promotors for the formation of PUs from diisocyanates and polyols, namely pentamethyldiethylenetriamine, diazabicyclooctane, N-methylmorpholine, N-ethylmorphine, 1,4-dimethylpiperazine and N,N-dimethylethanolamine, were sorbed onto the new resin. The sorption behavior of the new material was investigated in terms of loading capacities, the influence of concentration, flow-rate as well as of the amount of resin. Breakthrough curves were recorded from each single component as well as of mixtures thereof. Finally, the resin was used for the sampling of amines evaporating from PU foams applied in buildings. Further information about time dependent concentration profiles were obtained using a combination of GC-MS and Fourier transform IR spectroscopy.
The synthesis and pharmacological screening of a series of new phenylsuccinimide derivatives are described. Seven compounds of that series elicited a marked anticonvulsant activity. Among the compounds tested, interesting structures were those metasubstituted with bromine, fluorine or trifluoromethyl group. The most interesting drug seems to be the N-morpholinemethyl derivative of mbromophenylsuccinimide, which has a long duration of activity, elicits a very strong antipentetrazole action, and gives good protection against maximal electroshock seizures.
99mTc(V)-DMSA kits developed by the Radiopharmaceutical Division, Bhabha Atomic Research Centre, have been evaluated for potential use in scanning medullary carcinoma of the thyroid and its metastases. There were 15 patients with proved medullary carcinoma and 6 patients with other differentiated thyroid carcinoma. Amongst the 15 patients with medullary carcinoma, 12 (80%) showed positive localisation either in the primary or one or more metastatic sites. None of the six patients with carcinoma other than medullary showed increased concentration of 99mTc(V)-DMSA. Of the 37 known metastatic sites in 15 patients with medullary carcinoma, 24 showed concentration of 99mTc(V)-DMSA (64.9%). In addition, 99mTc(V)-DMSA concentration was seen in 14 sites where no evidence of metastasis was revealed. The incidence of 99mTc(V)-DMSA concentration in soft tissue and bone metastasis was similar.
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Novel hydroxamate inhibitors of tumor necrosis factor converting enzyme (TACE) and matrix metalloproteases (MMPs) have been synthesized via the Claisen-Ireland rearrangement. Aryl residues have been introduced to fill the enzyme's P1' specificity pocket. The best compound inhibits MMPs and TACE with nanomolar potency and inhibits the release of TNFalpha from cells with an IC50 of 48 nM. Oral administration to rats inhibits the LPS-induced plasma TNFalpha levels with an ED50 of 1 mg/kg.
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