Complexes of molybdenum(V) and molybdenum(IV) with dithiocarbamates derived from α-amino acids. Reaction kinetics in organic solvents

Polyhedron ◽  
1993 ◽  
Vol 12 (23) ◽  
pp. 2791-2799 ◽  
Author(s):  
Benigno Macias ◽  
Julio J. Criado ◽  
Maria V. Villa ◽  
Licesio J. Rodriguez ◽  
Manuel Castillo
Keyword(s):  
Amino Acids ◽  
Reaction Kinetics ◽  
Organic Solvents

Stereoselectivity of montmorillonite in the adsorption and deamination of some amino acids

Clay Minerals ◽  
1992 ◽  
Vol 27 (1) ◽  
pp. 109-118 ◽  
Author(s):  
B. Siffert ◽  
A. Naidja
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Reaction Kinetics ◽  
Clay Mineral ◽  
Room Temperature ◽  
Optical Isomers ◽  
Racemic Mixtures ◽  
Deamination Reaction

AbstractOptical isomers deamination of L- and D-glutamic and aspartic amino acids and of their DL racemic mixtures has been achieved in the presence of Na-montmorillonite at pH = 6 and room temperature. The adsorption curves showed that the enantiomer adsorbed depends on the type of amino acid. Nevertheless, deamination reaction kinetics brought about a stereoselectivity of the clay mineral for the L-isomer and implicitly showed an unquestionable “structural chirality character” of the clay mineral.

Dicyclohexylurea derivatives of amino acids as dye absorbent organogels and anion sensors

2019 ◽  
Vol 17 (11) ◽  
pp. 3026-3039 ◽  
Author(s):  
Karabi Roy ◽  
Suvankar Ghosh ◽  
Monikha Chetia ◽  
Priyadarshi Satpati ◽  
Sunanda Chatterjee
Keyword(s):  
Amino Acids ◽  
Organic Solvents ◽  
Large Range ◽  
Anion Sensors ◽  
Derivatives Of

Dicyclohexyl urea (DCU) derivatives of amino acids Fmoc-Phe-DCU (M1), Fmoc-Phg-DCU (M2) and Fmoc-Gaba-DCU (M3) have been shown to form phase selective, thermoreversible and mechanically robust gels in a large range of organic solvents. Organogels act as dye adsorbants and M1–M3 act as selective anion sensors for F−, OH− and OAc−.

Kinetics of polymeric substrate (dextrin or peptone) removal by activated sludge: hydrolysis of polymers to monomers is the rate-determining step

1997 ◽  
Vol 36 (12) ◽  
pp. 159-167 ◽  
Author(s):  
Yuu Ubukata
Keyword(s):  
Amino Acids ◽  
Activated Sludge ◽  
Reaction Kinetics ◽  
Removal Rate ◽  
Order Reaction ◽  
First Order Reaction ◽  
Municipal Sewage ◽  
First Order ◽  
Rate Determining Step ◽  
Hydrolysis Of

Most of the organic compounds in primary effluent are polymers such as proteins and polysaccharides. However the bacteria present in activated sludge (AS) can only directly take up monomers such as amino acids and glucose which are produced from polymers by hydrolysis. Therefore, it is assumed that the hydrolysis of polymers to monomers by the bacteria is the rate-determining step in polymer removal. In this study, AS was acclimated to dextrin or peptone, and polymers (dextrin or peptone) and monomers (glucose or a mixture of free amino acids) were used as substrates for kinetic tests. The removal of monomers and polymers by the AS followed zero- and pseudo first-order reaction kinetics, respectively. The removal rate of monomers was higher than that of polymers, and the oxygen uptake rate of the AS during monomer removal was higher than that during polymer removal. One of the important differences between the polymers and monomers used in this study is whether glycosidic linkages or peptide bonds exist in the material. It was therefore verified that the hydrolysis of polymers to monomers by AS was the rate-determining step in polymer removal. The removal of polymers apparently followed first-order reaction kinetics at high F/M ratios, but nth-order reaction kinetics at low F/M ratios (n>1), which are commonly used in municipal sewage treatment.

scholarly journals Gene Expression and Molecular Characterization of a Xylanase from Chicken Cecum Metagenome

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Hind AL-Darkazali ◽  
Vithaya Meevootisom ◽  
Duangnate Isarangkul ◽  
Suthep Wiyakrutta
Keyword(s):  
Amino Acids ◽  
Organic Solvents ◽  
Signal Peptide ◽  
Animal Feed ◽  
Feed Additives ◽  
Peptide Sequence ◽  
Calculated Molecular Mass ◽  
Signal Peptide Sequence ◽  
Putative Signal Peptide ◽  
Chicken Cecum

A xylanase genexynAMG1with a 1,116-bp open reading frame, encoding an endo-β-1,4-xylanase, was cloned from a chicken cecum metagenome. The translatedXynAMG1protein consisted of 372 amino acids including a putative signal peptide of 23 amino acids. The calculated molecular mass of the matureXynAMG1was 40,013 Da, with a theoretical pI value of 5.76. The amino acid sequence ofXynAMG1showed 59% identity to endo-β-1,4-xylanase fromPrevotella bryantiiandPrevotella ruminicolaand 58% identity to that fromPrevotella copri.XynAMG1has two conserved motifs, DVVNE and TEXD, containing two active site glutamates and an invariant asparagine, characteristic of GH10 family xylanase. ThexynAMG1gene without signal peptide sequence was cloned and fused with thioredoxin protein (Trx.Tag) in pET-32a plasmid and overexpressed inEscherichia coliTuner™(DE3)pLysS. The purified matureXynAMG1was highly salt-tolerant and stable and displayed higher than 96% of its catalytic activity in the reaction containing 1 to 4 M NaCl. It was only slightly affected by common organic solvents added in aqueous solution to up to 5 M. This chicken cecum metagenome-derived xylanase has potential applications in animal feed additives and industrial enzymatic processes requiring exposure to high concentrations of salt and organic solvents.

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