scholarly journals β-amylase-resistant amylose. Effect of urea on the limited hydrolysis of amylose by β-amylase

1976 ◽  
Vol 153 (2) ◽  
pp. 339-342 ◽  
Author(s):  
N B Patil
Keyword(s):  
Active Site ◽  
Chemical Properties ◽  
Inhibitory Effect ◽  
Physical And Chemical Properties ◽  
Urea Treatment ◽  
Conventional Methods ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

Amylose prepared from starch dispersed in 10M-urea, pH6.2, was found to be resistant to the action of β-amylase and phosphorylase, though it was degraded by α-amylase. Amylose isolated by conventional methods was similarly refractory after urea treatment, and was hydrolysed by β-amylase to the extent of 32-35%; it had no inhibitory effect towards β-amylase. The physical and chemical properties of the modified amylose were in general comparable with those of normal amylose with a β-amylolysis limit of 94-98%%. Starch and amylopectin were unaffected by urea treatment, i.e. the presence of amylopectin protected amylose against changes induced in it by urea. It is speculated that urea treatment “freezes” amylose molecules in a conformation that renders non-reducing termini inaccessible to the active site of the exo-enzymes. Such changes may limit the degradative action of β-amylase and phosphorylase.

scholarly journals Polar Head Modified Phospholipids by Phospholipase D-Catalyzed Transformations of Natural Phosphatidylcholine for Targeted Applications: An Overview

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 997
Author(s):  
Chiara Allegretti ◽  
Francesca Denuccio ◽  
Letizia Rossato ◽  
Paola D’Arrigo
Keyword(s):  
Phospholipase D ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Reaction Conditions ◽  
Chemical Methods ◽  
Polar Head ◽  
Transphosphatidylation Reaction ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

This review describes the use of phospholipase D (PLD) to perform the transphosphatidylation of the most common natural phospholipid (PL), phosphatidylcholine (PC) to obtain polar head modified phospholipids with real targeted applications. The introduction of different polar heads with distinctive physical and chemical properties such as charge, polarity and dimensions allows the obtainment of very different PLs, which can be exploited in very diverse fields of application. Moreover, the inclusions of a bioactive moiety in the PL polar head constitutes a powerful tool for the stabilization and administration of active ingredients. The use of this biocatalytic approach allows the preparation of compounds which cannot be easily obtained by classical chemical methods, by using mild and green reaction conditions. PLD is a very versatile enzyme, able to catalyze both the hydrolysis of PC to choline and phosphatidic acid (PA), and the transphosphatidylation reaction in the presence of an appropriate alcohol. The yield of production of the desired product and the ratio with the collateral PA formation is highly dependent on parameters such as the nature and concentration of the alcohol and the enzymatic source. The application of PLD catalyzed transformations for the production of a great number of PLs with important uses in medical, nutraceutical and cosmetic sectors will be discussed in this work.

THE EFFECT OF GLUCOAMYLASE ON VARIOUS TYPES OF STARCH IN THE NATIVE STATE

2020 ◽  
pp. 284-285
Author(s):  
Z. Borodina
Keyword(s):  
Low Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Native State ◽  
Physical And Chemical ◽  
Hydrolysis Of ◽  
And Chemical Properties

Was conducted a study of low-temperature hydrolysis of various types of starch in the native state: corn, corn amylopectin, pea, wheat and rice starches. Were establidhed different susceptibility of starches to the action of the enzyme glucoamylase, changes in the physical and chemical properties of samples after hydrolysis.

scholarly journals Copper: Synthesis Techniques in Nanoscale and Powerful Application as an Antimicrobial Agent

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
B. A. Camacho-Flores ◽  
O. Martínez-Álvarez ◽  
M. C. Arenas-Arrocena ◽  
R. Garcia-Contreras ◽  
L. Argueta-Figueroa ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Inhibitory Effect ◽  
Inorganic Nanoparticles ◽  
Metal Particles ◽  
Gram Negative Bacteria ◽  
Physical And Chemical Properties ◽  
Optimal Parameters ◽  
Composites Materials ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanosized metal particles show specific physical and chemical properties that allow the creation of new composites materials, which are important for multiple applications in biology and medicine such as infections control. Metal nanoparticles, mainly copper, exhibit excellent inhibitory effect on Gram-positive and Gram-negative bacteria; therefore the exploration about the efficient, economical, and friendly environmental technics to synthesize inorganic nanoparticles is imperative. In this work a brief overview of the several methods is made including the comparison of the methods, mainly between sonochemical, microwave, and chemical routes. It allows determining the optimal parameters and technical conditions to synthesize copper nanoparticles with physical and chemical properties suitable for the oral bacterial inhibition.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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