1740-57-4Relevant articles and documents
Extended structures controlled by intramolecular and intermolecular hydrogen bonding: A case study with pyridine-2,6-dicarboxamide, 1,3-benzenedicarboxamide and N,N'-dimethyl-2,6-pyridinedicarboxamide
Marlin,Olmstead,Mascharak
, p. 211 - 223 (2000)
The small organic molecule pyridine-2,6-dicarboxamide, although known in the literature for some time, exhibits interesting and previously unexplored intermolecular and intramolecular hydrogen bonding both in solid state and in solution. With the aid of X-ray crystallography and variable-temperature NMR spectroscopy, we here demonstrate the presence of a very strong hydrogen bonding network for this molecule both in condensed state and solution. Furthermore, a novel extended hydrogen bonding graph-set has been derived for this molecule in crystalline state. Comparison of pyridine-2,6-dicarboxamide with 1,3-benzenedicarboxamide, where the intramolecular hydrogen bonding to the pyridine ring in the former has been removed, yields a different intermolecular hydrogen bonded structure in the solid state. A new graph-set has been determined for the extended structure of 1,3-benzenedicarboxamide in the solid state. In solution, 1,3-benzenedicarboxamide is shown to maintain a hydrogen bonding pattern that is weaker than that observed with pyridine-2,6-dicarboxamide. Replacement of one hydrogen on each carboxamide nitrogen of pyridine-2,6-dicarboxamide by a methyl group also alters the extended structure to a significant extent. In N,N'-dimethyl-2,6-pyridinedicarboxamide, the three-dimensional hydrogen bonding pattern observed with pyridine-2,6-dicarboxamide all but collapses to one-dimensional chains. (C) 2000 Elsevier Science B.V.
Preparation method of M-phenylenediamine
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Paragraph 0006; 0016; 0017; 0019; 0020; 0022; 0023; 0025, (2021/02/10)
The invention belongs to the technical field of petrochemical organic synthesis, and particularly relates to a preparation method of m-phenylenediamine. According to the invention, m-phthalonitrile isused as a reaction raw material, and m-phenylenediamine is prepared through two steps of reactions of catalytic hydrolysis amidation and Hofmann degradation. According to the method, the key technical problems that in the process of producing m-phenylenediamine through benzene nitration and hydrogenation in a traditional process, due to the fact that dangerous processes of nitration and hydrogenation are involved, potential safety hazards in the production process are large, and the environment is polluted are solved, nitration and hydrogenation reactions are not involved in the process, thereaction temperature is low, reaction is mild, control is easy, the yield reaches 80% or above, and product purity reaches 95% or above.
NADP-dependent glutamate dehydrogenases in a dimorphic zygomycete Benjaminiella poitrasii: Purification, characterization and their evaluation as an antifungal drug target
Deshpande, Mukund V.,Kulkarni, Anand M.,Pathan, Ejaj K.,Prasanna, Nallaballe V. L.,Ramana, Chepuri V.
, (2020/08/21)
Background: It has been reported that the genes coding for NADP-dependent glutamate dehydrogenases (NADP-GDHs) showed a cause-effect relationship with Yeast-Hypha (Y[sbnd]H) reversible transition in a zygomycete Benjaminiella poitrasii. As Y[sbnd]H transition is significant in human pathogenic fungi for their survival and proliferation in the host, the NADP-GDHs can be explored as antifungal drug targets. Methods: The yeast-form specific BpNADPGDH I and hyphal-form specific BpNADPGDH II of B. poitrasii were purified by heterologous expression in E. coli BL-21 cells and characterized. The structural analogs of L-glutamate, dimethyl esters of isophthalic acid (DMIP) and its derivatives were designed, synthesized and screened for inhibition of NADP-GDH activity as well as Y[sbnd]H transition in B. poitrasii, and also in human pathogenic Candida albicans strains. Results: The BpNADPGDH I and BpNADPGDH II were found to be homo-hexameric proteins with native molecular mass of 282 kDa and 298 kDa, respectively and subunit molecular weights of 47 kDa and 49 kDa, respectively. Besides the distinct kinetic properties, BpNADPGDH I and BpNADPGDH II were found to be regulated by cAMP-dependent- and Calmodulin (CaM) dependent- protein kinases, respectively. The DMIP compounds showed a more pronounced effect on H-form specific BpNADPGDH II and inhibited Y[sbnd]H transition as well as growth in B. poitrasii and C. albicans strains. Conclusion: The present study will be useful to design and develop antifungal drugs against dimorphic human pathogens using glutamate dehydrogenase as a target. Significance: Glutamate dehydrogenases can be explored as a target against human pathogenic fungi.