Conversion of Dihydroflavonols to Flavonols with Enzyme Extracts from Flower Buds of Matthiola incana R. Br.

1984 ◽  
Vol 39 (7-8) ◽  
pp. 714-719 ◽  
Author(s):  
R. Spribille ◽  
G. Forkmann
Keyword(s):  
Enzyme Activity ◽  
Flower Development ◽  
Rapid Decline ◽  
Soluble Enzyme ◽  
Flower Buds ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Matthiola Incana ◽  
Substantial Correlation

Abstract Soluble enzyme preparations from flower buds of Matthiola incana catalysed the conversion of dihydrokaempferol to kaempferol and of dihydroquercetin to quercetin. The reaction required 2-oxoglutarate, ascorbate and Fe2+ as cofactors and had a pH-optimum at about 7.0. Highest enzyme activity was already present in the youngest buds followed by a rapid decline during bud and flower development. Furthermore, a substantial correlation was observed between the enzyme activity for flavonol formation and the flavonol content of the buds and flowers.

Genetic and Biochemical Studies on the Conversion of Dihydroflavonols to Flavonols in Flowers of Petunia hybrida

1986 ◽  
Vol 41 (1-2) ◽  
pp. 179-186 ◽  
Author(s):  
G. Forkmann ◽  
P. de Vlaming ◽  
R. Spribille ◽  
H. Wiering ◽  
A. W. Schram
Keyword(s):  
Enzyme Activity ◽  
Petunia Hybrida ◽  
Soluble Enzyme ◽  
Flower Buds ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Biochemical Studies ◽  
High Enzyme ◽  
Substantial Correlation ◽  
High Enzyme Activity

Abstract Soluble enzyme preparations from flower buds of Petunia hybrida catalyzed the conversion of dihydroflavonols to flavonols. Dihydrokaempferol and dihydroquercetin were readily converted to the respective flavonols, whereas dihydromyricetin was a poor substrate. The reaction required 2-oxoglutarate, ascorbate and Fe2+ as cofactors and had a pH optimum at about 6.5. In the presence of the dominant allele Fl, high enzyme activity for flavonol formation was found, whereas in enzyme preparations from flower buds of recessive genotypes (fl/fl) only low enzyme activity could be observed. A substantial correlation was found between enzyme activity for flavonol formation and the flavonol content of buds and flowers during development.

scholarly journals Pre-fermentative treatment of a model wine with aim to serve as a functional food with decreased alcohol content

2017 ◽  
Vol 63 (01) ◽  
pp. 47-53
Author(s):  
Irina Mladenoska ◽  
Verica Petkova ◽  
Tatjana Kadifkova Panovska
Keyword(s):  
Enzyme Activity ◽  
Gluconic Acid ◽  
Functional Food ◽  
Ph Value ◽  
Enzymatic Reaction ◽  
Alginate Beads ◽  
High Concentration ◽  
Ph Optimum ◽  
Enzyme Preparations ◽  
Initial Ph

The effect of substrate concentration on the enzyme activity in the reaction of glucose conversion into gluconic acid was investigated by using three different enzyme preparations in media with two different glucose concentrations. The media were simulating the conditions in the must, thus named as minimal model must, and were composed form combination of several organic acids and glucose. Those media were having initial pH of 3.5 that is a very unfavorable for glucose oxidase activity having a pH optimum at the pH value of 5.5. Among the three preparations used, the bakery additive, Alphamalt Gloxy 5080, was the most active in the medium with glucose concentration of 10 g/L, showing conversion of more than 70% for the period of 24 h, while the same enzyme preparation in the medium with 100 g/L glucose converted only about 7% of glucose. The pH value of the medium at the beginning and at the end of the enzymatic reaction was a good indicator of the enzyme activity. It seems that for the conversion of glucose in higher concentration, enzymatic preparation in high concentration should also be used. The preliminary attempt of immobilization of two preparations of glucose oxidases in alginate beads was also performed and a successful immobilization procedure for utilization in food industry was preliminarily developed. Keywords: glucose oxidases, enzymatic pretreatment, glucose, gluconic acid, model wine, functional food

Oxidation of Flavanones to Flavones with Flower Extracts of Antirrhinum majus (Snapdragon)

1981 ◽  
Vol 36 (9-10) ◽  
pp. 737-741 ◽  
Author(s):  
G. Stotz ◽  
G. Forkmann
Keyword(s):  
Enzyme Activity ◽  
Microsomal Fraction ◽  
Antirrhinum Majus ◽  
Microsomal Enzyme ◽  
Ph Optimum ◽  
Enzyme Preparations

Abstract Enzyme preparations from flowers of Antirrhinum majus catalysed the oxidation of naringenin to apigenin and of eriodictyol to luteolin. Enzyme activity was found to be localized in the microsomal fraction. The reaction required NADPH as cofactor and had a pH optimum of about 7.0. The NADPH-dependent microsomal enzyme activity was also present in flower extracts of other flavone-producing plants, whereas flower extracts of plants which lack flavones were found to lack also this enzyme activity.

Genetic Control of Chalcone Synthase Activity in Flowers of Matthiola incana R.Br

1981 ◽  
Vol 36 (7-8) ◽  
pp. 619-624 ◽  
Author(s):  
R. Spribille ◽  
G. Forkmann
Keyword(s):  
Enzyme Activity ◽  
Genetic Control ◽  
Chalcone Synthase ◽  
Condensation Reaction ◽  
Chalcone Isomerase ◽  
Wild Type ◽  
Enzyme Preparations ◽  
Matthiola Incana ◽  
Anthocyanin Pathway ◽  
Malonyl Coa

Abstract Chalcone synthase activity was demonstrated in enzyme preparations from flowers of defined genotypes of Matthiola incana (stock). The product formed from 4-coumaroyl-CoA and malonyl-CoA was naringenin and not the isomeric chalcone, because chalcone isomerase was also present in the reaction mixture. Chalcone synthase activity could be detected only in flower extracts of genotypes with wild-type alleles at the locus f Thus, the interruption of the anthocyanin pathway in white flowering lines with recessive alleles (ff) of this gene is clearly due to a lack of this enzyme activity. Independent on the genetic state of the locus b which controls the formation of pelargonidin or cyanidin, respectively, in the flowers, 4-coumaroyl-CoA was the only suitable substrate for the condensation reaction.

UDP-Glucose: Anthocyanidin/FIavonol 3-O-Glucosyltransferase in Enzyme Preparation from Flower Extracts of Genetically Defined Lines of Matthiola incana R. Br.

1986 ◽  
Vol 41 (7-8) ◽  
pp. 699-706 ◽  
Author(s):  
M. Teusch ◽  
G. Forkmann ◽  
W. Seyffert
Keyword(s):  
Enzyme Activity ◽  
Structural Gene ◽  
Enzyme Preparation ◽  
Reaction Rate ◽  
Flower Colour ◽  
Hydroxyl Group ◽  
Anthocyanin Synthesis ◽  
Ph Optimum ◽  
Matthiola Incana ◽  
Highly Active

Abstract In flower extracts of Matthiola incana an enzyme catalyzing the transfer of glucose from UDP- glucose to the hydroxyl group at 3-position of anthocyanidins and flavonols was demonstrated. The pH-optimum of this reaction is at pH 8.5 for pelargonidin and pH 9.5 for quercetin as substrate. The reaction is inhibited by both substrates above 10 nmol per assay. The enzyme is highly active, within 30 sec 3 nmol of 3-glucosides were formed. At 30 °C the enzyme is stable for hours and at -20 °C months. Besides UDP-glucose, TDP-glucose is a suitable glucosyl-donor, but with a reduced (70%) reaction rate. Enzyme activity is clearly inhibited by Fe2+ and Cu2+ ions, and by diethylpyrocarbonate. Acyanic or pale coloured mutants of several genes interfering with anthocyanin synthesis after dihydroflavonol formation show a more or less drastically reduced enzyme activity (5-40%). But none of these genes can be regarded as the structural gene for the 3-glucosyltransferase. The influence of these genes on enzyme activity and flower colour is dis­cussed.

Anthocyanin Biosynthesis in Flowers of Matthiola incana Flavanone 3-and Flavonoid 3′-Hydroxylases

1980 ◽  
Vol 35 (9-10) ◽  
pp. 691-695 ◽  
Author(s):  
G. Forkmann ◽  
W. Heller ◽  
H. Grisebach
Keyword(s):  
Microsomal Fraction ◽  
Anthocyanin Biosynthesis ◽  
Wild Type Allele ◽  
Soluble Enzyme ◽  
Wild Type ◽  
Hydroxylase Activity ◽  
Enzyme Preparations ◽  
Type Allele ◽  
Matthiola Incana

Abstract Enzyme preparations from flowers of defined genotypes of Matthiola incana contain two dif­ ferent hydroxylases for hydroxylation of naringenin in the 3-and 3′-position, respectively. The 3-hydroxylase is a soluble enzyme and requires as cofactors 2-oxoglutarate, Fe2+ and ascorbate. Besides naringenin eriodictyol is a substrate for the 3-hydroxylase. The 3′-hydroxylase is localized in the microsomal fraction and requires NADPH as cofactor. Naringenin and dihydro-kaempferol but not 4-coumarate or 4-coumaroyl-CoA are substrates for this enzyme. 3′-Hydroxylase activity is present only in genetic lines of M. incana with the wild-type allele b+.

scholarly journals Preparation of immobilized baker's-yeast glucose 6-phosphate dehydrogenase attached to modified sepharose and sephadex and a comparison of the properties of these preparations with those of the soluble enzyme

1976 ◽  
Vol 157 (2) ◽  
pp. 289-294 ◽  
Author(s):  
M A Goheer ◽  
B J Gould ◽  
D V Parke
Keyword(s):  
Immobilized Enzyme ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Soluble Enzyme ◽  
Ph Optimum ◽  
Yeast Saccharomyces Cerevisiae ◽  
Enzyme Preparations ◽  
Ph Range ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Sepharose 4B

1. Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate-NADP+ oxidoreductase, EC 1.1.1.49) from baker's yeast (Saccharomyces cerevisiae) was immobilized on CNBr-activated Sepharose 4B with retention of about 3% of enzyme activity. This uncharged preparation was stable for up to 4 months when stored in borate buffer, pH7.6, at 4 degrees C. 2. Stable enzyme preparations with negative or positive overall charge were made by adding valine or ethylenediamine to the CNBr-activated Sepharose 4B 30min after addition of the enzyme. 3. These three immobilized enzyme preparations retained 40-60% of their activity after 15 min at 50 degrees C. The soluble enzyme is inactivated by these conditions. 4. The soluble enzyme lost 45 and 100% of its activity on incubation for 3h at pH6 and 10 respectively. The three immobilized-enzyme preparations were completely stable over this entire pH range. 5. The pH optimum of the positively and negatively charged immobilized-enzyme preparations were about 8 and 9 respectively. The soluble enzyme and the uncharged immobilized enzyme had an optimum pH at about 8.5 6. Glucose 6-phosphate dehydrogenase immobilized on CNBr-activated Sephadex G-25 was unstable, as was enzyme attached to CNBr-activated Sepharose 4B to which glycine, asparitic acid, valine or ethylenediamine was added at the same time as the enzyme.

FERMENTATIVE HYDROLYTIC PREPARATION METHODS OF CEREAL WORT FOR ALCOHOL FERMENTATION

1970 ◽  
pp. 52-56
Author(s):  
Е. M. Serba ◽  
М. B. Overchenko ◽  
L. V. Rimareva ◽  
N. I. Ignatova ◽  
А. E. Orekhova ◽  
...  
Keyword(s):  
Alcoholic Fermentation ◽  
Raw Materials ◽  
Alcohol Concentration ◽  
Activity Level ◽  
Optimal Dosage ◽  
Main Role ◽  
Alcohol Fermentation ◽  
Ph Optimum ◽  
Amylolytic Enzyme ◽  
Enzyme Preparations

In the production of alcohol in the preparation of grain raw materials for fermentation, the main role is given to enzyme preparations of amylolytic action, which are key enzymes that catalyze the hydrolysis of starch. Amylolytic enzyme preparations with a different composition of enzymes and their level of activity, a mechanism of biocatalytic effect on starch, and a range of thermal and pH optimum are widely represented on the Russian market. The development of optimal conditions for the preparation of grain wort, the rational selection and dosage of concentrated enzyme preparations, the properties of which correspond to the parameters of the technological process, will ensure the effective preparation of starch for fermentation, and increase the profitability of alcohol production. The aim of this work was to study the influence of enzyme preparations of amylolytic action and the conditions of their use on the efficiency of the process of alcoholic fermentation and the yield of the final product, ethanol. The effect of various dosages of enzyme preparations of glucoamylase action, with a different ratio of the main enzyme glucoamylase and minor enzyme α-amylase, as well as methods for preparing wheat wort on the process of alcoholic fermentation, was studied. It was found that the enzyme preparation, the source of glucoamylase, in which α-amylase was present in a ratio of 15: 1 (in terms of activity level), turned out to be more effective in fermenting prepared wheat wort: its optimal dosage was 8 units. GLS / g starch. The presence of a sufficient amount of α-amylase in this preparation compensated for the dosage of thermostable α-amylase. The alcohol concentration in the mash was 10.2% vol., The alcohol yield was 67.9 cm3 / 100 g of starch. When glucoamylase with a lower ratio of the main and minor enzyme (75: 1) was used at the saccharification stage, an increase in the wort fermentation depth was observed with an increase in the concentration of glucoamylase to 9-10 units of GLS / g and α-amylase to 0.5 units. AC / g. It was also found that an increase in the duration of enzymatic-hydrolytic preparation of the wort had a positive effect on the fermentation process, the alcohol concentration in the mash increased to 10.2 vol.%. It was shown that the introduction of proteases into the wort helps to reduce the viscosity of grain wort, enriching it with assimilable yeast amino acids, which leads to an increase in the yield of alcohol. It has been confirmed that the synergy of the action of enzymes of amylolytic and proteolytic effects on polymers of grain raw materials allows to increase the efficiency of their conversion to ethanol. The conditions of enzymatic-hydrolytic processing of grain raw materials for fermentation are developed. The use of the digestion stage did not significantly affect the fermentation results of wheat wort.

scholarly journals Interaction of soluble glucosyl- and mannosyl-transferase enzyme activities in the synthesis of a glucomannan

1972 ◽  
Vol 129 (3) ◽  
pp. 645-655 ◽  
Author(s):  
J. S. Heller ◽  
C. L. Villemez
Keyword(s):  
Enzyme Activity ◽  
Enzyme Activities ◽  
Enzyme Preparation ◽  
The Other ◽  
Acceptor Molecule ◽  
Soluble Enzyme ◽  
Phaseolus Aureus ◽  
Polymeric Product ◽  
Sugar Nucleotide ◽  
Solubilized Enzyme

A neutral-detergent-solubilized-enzyme preparation derived from Phaseolus aureus hypocotyls contains two types of glycosyltransferase activity. One, mannosyltransferase enzyme activity, utilizes GDP-α-d-mannose as the sugar nucleotide substrate. The other, glucosyltransferase enzyme activity, utilizes GDP-α-d-glucose as the sugar nucleotide substrate. The soluble enzyme preparation catalyses the formation of what appears to be a homopolysaccharide when either sugar nucleotide is the only substrate present. A β-(1→4)-linked mannan is the only polymeric product when only GDP-α-d-mannose is added. A β-(1→4)-linked glucan is the only polymeric product when only GDP-α-d-glucose is added. In the presence of both sugar nucleotides, however, a β-(1→4)-linked glucomannan is formed. There are indications that endogenous sugar donors may be present in the enzyme preparation. There appear to be only two glycosyltransferases in the enzyme preparation, each catalysing the transfer of a different sugar to the same type of acceptor molecule. The glucosyltransferase requires the continual production of mannose-containing acceptor molecules for maintenance of enzyme activity, and is thereby dependent upon the activity of the mannosyltransferase. The mannosyltransferase, on the other hand, does not require the continual production of glucose-containing acceptors for maintenance of enzyme activity, but is severely inhibited by GDP-α-P-glucose. These properties promote the synthesis of β-(1→4)-linked glucomannan rather than β-(1→4)-linked glucan plus β-(1→4)-linked mannan when both sugar nucleotide substrates are present.

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