Novel stereoselective incorporation and hydrolysis of long-chain amino-acid substrates by vesicular membrane systems which include tri- or tetra-peptide catalysts

Chitin oligosaccharides (COs) hold high promise as organic fertilizers in the ongoing agro-ecological transition. Short- and long-chain COs can contribute to the establishment of symbiotic associations between plants and microorganisms, facilitating the uptake of soil nutrients by host plants. Long-chain COs trigger plant innate immunity. A fine investigation of these different signaling pathways requires improving the access to high-purity COs. Here, we used the response surface methodology to optimize the production of COs by enzymatic hydrolysis of water-soluble chitin (WSC) with hen egg-white lysozyme. The influence of WSC concentration, its acetylation degree, and the reaction time course were modelled using a Box–Behnken design. Under optimized conditions, water-soluble COs up to the nonasaccharide were formed in 51% yield and purified to homogeneity. This straightforward approach opens new avenues to determine the complex roles of COs in plants.

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Novel Amino Acid Derivatives of Quinolines as Potential Antibacterial and Fluorophore Agents

Scientia Pharmaceutica ◽

10.3390/scipharm88040057 ◽

2020 ◽

Vol 88 (4) ◽

pp. 57

Author(s):

Oussama Moussaoui ◽

Rajendra Bhadane ◽

Riham Sghyar ◽

El Mestafa El Hadrami ◽

Soukaina El Amrani ◽

...

Keyword(s):

Amino Acid ◽

Methyl Esters ◽

Amino Acid Derivatives ◽

Bacterial Strains ◽

Fluorescent Properties ◽

Topoisomerase Iv ◽

Microdilution Method ◽

Hydrolysis Of ◽

Derivatives Of

A new series of amino acid derivatives of quinolines was synthesized through the hydrolysis of amino acid methyl esters of quinoline carboxamides with alkali hydroxide. The compounds were purified on silica gel by column chromatography and further characterized by TLC, NMR and ESI-TOF mass spectrometry. All compounds were screened for in vitro antimicrobial activity against different bacterial strains using the microdilution method. Most of the synthesized amino acid-quinolines show more potent or equipotent inhibitory action against the tested bacteria than their correspond esters. In addition, many of them exhibit fluorescent properties and could possibly be utilized as fluorophores. Molecular docking and simulation studies of the compounds at putative bacterial target enzymes suggest that the antimicrobial potency of these synthesized analogues could be due to enzyme inhibition via their favorable binding at the fluoroquinolone binding site at the GyrA subunit of DNA gyrase and/or the ParC subunit of topoisomerase-IV.

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THE HYDROLYSIS OF MONOPHOSPHOINOSITIDE BY EXTRACTS OF BRAIN

Canadian Journal of Biochemistry ◽

10.1139/o67-095 ◽

1967 ◽

Vol 45 (6) ◽

pp. 853-861 ◽

Cited By ~ 60

Author(s):

W. Thompson

Keyword(s):

Fatty Acids ◽

Enzyme Activity ◽

Calcium Ions ◽

Brain Extract ◽

Monovalent Cations ◽

High Concentration ◽

Diffusible Factor ◽

Hydrolysis Of ◽

The Brain ◽

Long Chain

The hydrolysis of monophosphoinositide by soluble extracts from rat brain is described. Diglyceride and inositol monophosphate are liberated along with a small amount of free fatty acids. Hydrolysis of the lipid is optimal at pH 5.4 in acetate buffer. The reaction is stimulated by calcium ions or by high concentration of monovalent cations and, to a less extent, by long-chain cationic amphipathic compounds. Enzyme activity is lost on dialysis of the brain extract and can be restored by diffusible factor(s). Some differences in the conditions for hydrolysis of mono- and tri-phosphoinositides are noted.

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