scholarly journals Influence of 2,5-dichloro-1,4-benzoquinone on jack bean urease activity. Inhibitory effect, total reducing capacity and DPPH radical scavenging activity.

2011 ◽  
Vol 58 (4) ◽  
Author(s):  
Mirosława Kot ◽  
Zofia Olech
Keyword(s):  
Light Exposure ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Order Rate Constant ◽  
Inhibitory Effect ◽  
Pseudo First Order Reaction ◽  
Experimental Conditions ◽  
Jack Bean ◽  
Direct Modification ◽  
Reducing Capacity

Inhibition of jack bean activity by 2,5-dichloro-1,4-benzoquinone (DCBQ) was studied in phosphate buffer, pH 7.0. It was found that DCBQ acted as a strong, time and concentration dependent inactivator of urease. Under the experimental conditions obeyed the terms of pseudo-first-order reaction, urease was totally inactivated. Application of Wilson-Kitz method proved that the urease-DCBQ interaction followed a simple bimolecular process and the presence of intermediate complex was undetectable. The determined second order rate constant of the inactivation was 0.053 (μM min)(-1). Thiols such as l-cysteine, glutathione and dithiothreitol (DTT) protected urease from inhibition by DCBQ but DCBQ-modified urease did not regain its activity after DTT application. The thiol protective studies indicated an essential role of urease thiol(s) in the inhibition. The irreversibility of the inactivation showed that the process was a result of a direct modification of urease thiol(s) by DCBQ (DCBQ chlorine(s) substitution). The decomposition of DCBQ in aqueous solution at natural light exposure was monitored by visible spectrophotometry, determination of the total reducing capacity (Folin-Ciocalteu method) and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging ability. The DCBQ conversion resulted in a decrease of the inhibition power and was well correlated with the increase of the total reducing capacity and DPPH scavenging ability. These findings were attributed to DCBQ transformation by photolysis and the hydrolysis effect was found to be negligible.

Curcumin-based antioxidant and glycohydrolase inhibitor compounds: Synthesis and in vitro appraisal of the dual activity against diabetes

2020 ◽  
Vol 16 ◽  
Author(s):  
Sajjad Esmaeili ◽  
Nazanin Ghobadi ◽  
Donya Nazari ◽  
Alireza Pourhossein ◽  
Hassan Rasouli ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Enzyme Inhibitor ◽  
Radical Scavenging Activity ◽  
Curcuma Longa ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Inhibitory Effect ◽  
Curcumin Derivatives ◽  
Reducing Power Assay

Background: Curcumin, as the substantial constituent of the turmeric plant (Curcuma longa), plays a significant role in the prevention of various diseases, including diabetes. It possesses ideal structure features as enzyme inhibitor, including a flexible backbone, hydrophobic nature, and several available hydrogen bond (H-bond) donors and acceptors. Objective: The present study aimed at synthesizing several novel curcumin derivatives and further evaluation of these compounds for possible antioxidant and anti-diabetic properties along with inhibitory effect against two carbohydrate-hydrolyzing enzymes, α-amylase and α-glucosidase, as these enzymes are therapeutic targets for attenuation of postprandial hyperglycemia. Methods: Therefore, curcumin-based pyrido[2,3-d]pyrimidine derivatives were synthesized and identified using an instrumental technique like NMR spectroscopy and then screened for antioxidant and enzyme inhibitory potential. Total antioxidant activity, reducing power assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH• ) radical scavenging activity were done to appraisal the antioxidant potential of these compounds in vitro. Results: Compounds L6-L9 showed higher antioxidant activity while L4, L9, L12 and especially L8 exhibited the best selectivity index (lowest α-amylase/α-glucosidase inhibition ratio). Conclusion: These antioxidant inhibitors may be potential anti-diabetic drugs, not only to reduce glycemic index but also to limit the activity of the major reactive oxygen species (ROS) producing pathways.

scholarly journals Chemical and Biological Profile and Allergenicity of Thymus baicalensis Plant of Mongolian Origin

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1905
Author(s):  
Tuya Narangerel ◽  
Michał Sójka ◽  
Radosław Bonikowski ◽  
Konrad Jastrząbek ◽  
Witold Sroczyński ◽  
...  
Keyword(s):  
Unsaturated Fatty Acids ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Antimicrobial Properties ◽  
Volatile Oil ◽  
Inhibitory Effect ◽  
Food Supplement ◽  
Oil Composition ◽  
Polyphenolic Composition ◽  
Health Promoting

Thymus baicalensis is a medicinal plant recognized as a traditional Mongolian therapeutic and health-promoting food supplement. The aim of the study was to check the suitability of the tested plant for supporting the treatment of certain diseases. The following study is the first one to showcase the versatile scope of characteristics of T. baicalensis, including its volatile oil composition, polyphenolic composition, lipid composition, phenolic and flavonoid contents, antioxidant activity, antimicrobial properties and ingestive allergenicity. Myrcene, at 26.15%, was shown to be the most abundant component of the volatile oil. Compounds known as inherent components of the Thymus genus: thymol and carvacrol made up only about 0.24% of the extracted oil. As much as 10.11 g kg−1 of polyphenol compounds were identified as derivatives of luteolin-7-O-glucuronide. The lipid extract was found to be rich in palmitic acid (31.05%), while unsaturated fatty acids were not reported. Spectrophotometric determination of the phenols and flavonoids indicated 7.541 mg of gallic acid g−1 and 4.345 mg of quercitin g−1, respectively. The free radical scavenging activity was determined by the 2,2-difenylo-1-pikrylohydrazyl method at IC50 = 206.97 µg mL−1. The extracts also had a strong inhibitory effect on M. flavus and P. fluorescenes bacteria, as well as S. cerevisiae yeasts. The Bet v 1 and profilin allergens in T. baicalensis were reported at 175.17 ng g−1 and 1.66 ng g−1, respectively.

Synthesis of various β-D-glucopyranosyl and β-D-xylopyranosyl hydroxybenzoates and evaluation of their antioxidant activities

2017 ◽  
Vol 23 (3) ◽  
pp. 213-223 ◽  
Author(s):  
Yasutaka Shimotori ◽  
Masayuki Hoshi ◽  
Yosuke Osawa ◽  
Tetsuo Miyakoshi
Keyword(s):  
Methyl Linoleate ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Inhibitory Effect ◽  
Novozym 435 ◽  
Regioselective Deacetylation ◽  
Hydroxybenzoic Acids ◽  
High Antioxidant Activity ◽  
Dpph Radical Scavenging

AbstractVarious β-D-glucopyranosyl and β-D-xylopyranosyl hydroxybenzoates were efficiently prepared from 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (TAGB) or 2,3,4-tri-O-acetyl-α-D-xylopyranosyl bromide (TAXB), respectively, by amine-promoted glycosylation. Regioselective deacetylation of the resulting acetylated β-D-gluco- and β-D-xylopyranosyl hydroxybenzoates was investigated using Novozym 435 as a lipase catalyst. In the case of β-D-glucopyranosyl hydroxybenzoates, Novozym 435-catalyzed deacetylation is regioselective at C-4 and C-6 positions. On the other hand, β-D-xylopyranosyl hydroxybenzoates are deacetylated only at the C-4 position. Antioxidant activities of free hydroxybenzoic acids and the respective β-D-gluco- and β-D-xylopyranosyl hydroxybenzoates were evaluated by DPPH˙ radical scavenging as well as their inhibitory effect on autoxidation of bulk methyl linoleate. The β-D-xylopyranosyl protocatechoate, as well as quercetin and α-tochopherol, show high antioxidant activity for the radical scavenging activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH˙). In bulk methyl linoleate, the antioxidant activities of β-D-gluco- and β-D-xylopyranosyl protocatechoates are higher than that of α-tocopherol.

scholarly journals Effect of N-Amide Substitution on Antioxidative Activities of Melatonin Derivatives

2020 ◽  
Vol 88 (1) ◽  
pp. 3 ◽  
Author(s):  
Panyada Panyatip ◽  
Nutjaree Pratheepawanit Johns ◽  
Aroonsri Priprem ◽  
Kouichi Nakagawa ◽  
Ploenthip Puthongking
Keyword(s):  
Radical Scavenging Activity ◽  
Parent Compound ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Inhibitory Effect ◽  
Disodium Salt ◽  
Peroxyl Radicals ◽  
Frap Assay ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power

Five N-amide substituted melatonin (MLT) derivatives were synthesized and evaluated for antioxidative activities, and compounds 9–12 showed higher electron spin resonance (ESR) response than MLT. 4-Bromobenzoyl and naphthoyl derivatives (10 and 11) presented stronger hydroxyl radical inhibitory effect than MLT in Fenton reaction. The substitution at the N1-position on the MLT core structure with acetyl (8), benzoyl (9), 4-bromobenzoyl (10), and naphthoyl (11) and N2-substitution with 4-bromobenzoyl (12) decreased the reducing power of the derivatives in ferric reducing antioxidant power (FRAP) assay. Compounds 8–11 also presented lower antioxidant capacity than their parent compound in 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) disodium salt (ABTS) assay; whereas, compound 12 presented radical scavenging activity similarly to MLT. All aryl derivatives (9–12) showed higher ability to quench peroxyl radicals than MLT about three times, especially the benzoylated derivatives (9 and 10) that presented the highest ability in oxygen radical absorbance capacity (ORAC) assay.

scholarly journals Encapsulation of Grapefruit Essential Oil in Emulsion-Based Edible Film Prepared by Plum (Pruni Domesticae Semen) Seed Protein Isolate and Gum Acacia Conjugates

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 784
Author(s):  
Chen Li ◽  
Jiliu Pei ◽  
Xiaohui Xiong ◽  
Feng Xue
Keyword(s):  
Essential Oil ◽  
Seed Protein ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Surface Hydrophobicity ◽  
Inhibitory Effect ◽  
Edible Films ◽  
Continuous Phase ◽  
Protein Isolate ◽  
Gum Acacia

A dry-heated Maillard reaction was used to prepare plum seed protein isolate and gum acacia conjugates. Emulsion-based edible films (EBEF) were prepared by the encapsulation of grapefruit essential oil using conjugates solution as the continuous phase. The conjugates formed from 3 days of dry heating showed a significant improvement in emulsifying properties due to the unfolding of protein, as confirmed by structure analysis. The droplet size, electrical charge, and viscosity of emulsions increased with the increasing essential oil concentration, and all emulsions exhibited ‘gel’-like behavior. The water vapor barrier property, surface hydrophobicity, mechanical properties, and thermal stability of the films were improved as the essential oil content increased in the range of 1–4% due to enhancement in intermolecular interaction and compatibility, as well as a denser microstructure. Furthermore, all films exhibited an inhibitory effect against E. coli, while their radical scavenging activity depended on the release rate from films. The results obtained in this work confirmed that EBEF could be used as a novel food active packaging in the near future.

scholarly journals In Vitro Inhibitory Effect on Carbohydrates Digestion and Antioxidant Potential of Garlic Scape (P06-076-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Dammah Otieno ◽  
Salma Altuwaijri ◽  
Hye Won Kang
Keyword(s):  
Antioxidant Activity ◽  
Digestive Enzymes ◽  
Radical Scavenging Activity ◽  
Health Effect ◽  
Radical Scavenging ◽  
Inhibitory Effect ◽  
Total Phenolic ◽  
Total Antioxidant Activity ◽  
Total Antioxidant

Abstract Objectives Inhibition of carbohydrate absorption from intestine is an efficient way to prevent type 2 diabetes. Some edible plants have shown the potential as anti-diabetic agents by inhibiting carbohydrate-digestive enzymes in intestine. In terms of edible plant's health effect, bioactive compounds’ stability during the process of digestive enzymes has been commonly questioned. Therefore, the objectives of this study were to 1) examine inhibitory effect of garlic scape (GS), the green flower head of garlic on carbohydrate-degrading enzymes and 2) investigate antioxidant activity and total phenolic content (TPC) of GS treated with intestinal digestive enzymes. Methods GS extract (GSE) was prepared with 80% methanol (v/v) by homogenization, sonication, and filtration, and evaporation. α-glucosidase, maltase, glucoamylase, sucrase, α-amylase inhibitory activities were determined by measuring glucose hydrolyzed from nitrophenyl-glucopyranoside, maltose, starch, sucrose, and starch, respectively. To prepare gastrointestinal enzyme-digested GSE, GSE was digested with pepsin and a pancreatin-bile solution. GSE and gastrointestinal enzyme-digested GSE were assessed for TPC using a Folin-Ciocalteu reagent and for total antioxidant and radical scavenging activities by the following methods, phosphomolybdeum, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods, respectively. Results GSE (20 mg/ml) showed 30%, 50%, and 42% inhibition on α-glucosidase, maltase, and glucoamylase enzyme activities, respectively. GSE (50 mg/ml) showed 55.1% DPPH radical and 5782 mg vitamin C equivalent (VCE)/g ABTS radical scavenging activities. Total antioxidant activity of the GSE (1.5 mg/ml) exhibited 2.76 mg VCE/g. Consistent with its antioxidant property, the GSE showed a dose-dependent increase in TPC. Gastrointestinal enzymatic treatment resulted in approximately 46% reduction in DPPH and ABTS radical scavenging activity, total antioxidant activity, and TPC of the GSE. Conclusions Garlic scape has the potential as a natural anti-diabetic agent. Garlic scape keeps beneficial effects after the process of intestinal digestive system. Funding Sources The work was supported by USDA.

Antioxidant Properties of Cashew Apple Wine (CAW)

2011 ◽  
Vol 396-398 ◽  
pp. 1645-1651 ◽  
Author(s):  
Qiu Ping Zhong ◽  
Yong Cheng Li
Keyword(s):  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Free Radical ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Scavenging Activity ◽  
Total Antioxidant Activity ◽  
Total Antioxidant ◽  
Reducing Capacity

In this study, total polyphenols content (TPC) and ascorbic acid content (AAC) in CAW were quantified. Total antioxidant activity, reducing capacity, and free radical scavenging activity of CAW were assayed. The TPC and AAC were 160 mg GAE /100ml and 132 mg/100 ml，respectivity. CAW exhibited effective antioxidant activities in the employed in vitro experiments, including total antioxidant activity, reducing capacity, and free radical scavenging activity, which indicates that phenolic compounds and ascorbic acid may play a key role in the antioxidant function of CAW.

Comparative Effects of Vitamin K2 and Vitamin E on Experimental Arteriosclerosis

1999 ◽  
Vol 69 (1) ◽  
pp. 23-26 ◽  
Author(s):  
Seyama ◽  
Hayashi ◽  
Takegami ◽  
Usami
Keyword(s):  
Vitamin E ◽  
Vitamin K ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Male Rats ◽  
Side Chain ◽  
Scavenging Activity ◽  
Experimental Conditions ◽  
Experimental Arteriosclerosis

The comparative effects of vitamin K2 and vitamin E on aortic calcium (Ca) and inorganic phosphorus (P) levels in the aorta and the elastin fraction (fr.) were investigated in male rats after experimental arteriosclerosis was induced by vitamin D2 with atherogenic diet. Both vitamin K2 (100 mg/kg b.w.) and vitamin E (40 mg/kg b.w.) inhibited the increase of Ca and P in the aorta and the elastin fr. from the arteriosclerotic rats. Vitamin K2 (50 mg/kg b.w.) also suppressed the deposition of Ca and P in the aorta, but there was no change due to vitamin K3 or geranylgeraniol (side chain of vitamin K2) administration. Both vitamin K2 and vitamin E showed lipid radical scavenging activity in the in vitro experiment. However, neither vitamin K3 nor geranylgeraniol exhibited anti-arteriosclerotic or radical scavenging activity under the above experimental conditions. It is suggested that vitamin K2 and vitamin E promoted an antiarteriosclerotic effect by radical scavenging activity. These actions of vitamin K2 are required in the structure of 2-methylnaphthoquinone and its side chain (geranylgeraniol).

Relationship of fruit color and light exposure to lycopene content and antioxidant properties of tomato

2003 ◽  
Vol 83 (4) ◽  
pp. 913-919 ◽  
Author(s):  
S. E. Cox ◽  
C. Stushnoff ◽  
D. A. Sampson
Keyword(s):  
High Performance ◽  
Light Exposure ◽  
Radical Scavenging Activity ◽  
Tomato Fruit ◽  
Antioxidant Properties ◽  
Fruit Size ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Lycopene Content ◽  
Phenolic Concentration

Tomato (Lycopersicon esculentum Mill.), a potent source of antioxidants in the diet, is characterized by remarkable genetic biodiversity, especially in fruit size and color. Horticultural practices and breeding efforts hold the potential to enhance antioxidant content in tomato fruit, but which antioxidants are most important? Lycopene content, total phenolic content, and radical scavenging capacity were examined in yellow, orange, red, and black-fruited tomato cultivars using lyophilized samples. Color was generally an accurate indicator of lycopene content, with a yellow cultivar containing less lycopene than red cultivars, and two of three red cultivars containing more than an orange cultivar. However, black cultivars as a group did not contain more lycopene than red. Tomato fruit harvested green-mature and exposed to 24 h light during ripening at 25°C in a growth cabinet had a higher lycopene concentration than green-mature fruit exposed for 8 h. 2,2'-azino-bis(3-ethylbenz-thiazoline-6-sulfonic acid (ABTS) radical scavenging activity did not vary among different colored cultivars, and was no different in stored (2 yr) or freshly prepared lyophilized samples. Total phenolic concentration was higher in orange, red, and black fruited cultivars than in yellow. Total phenolic concentration was lower in lyophilized powder samples of orange, red, and black cultivar fruit stored for 2 yr at -20°C relative to freshly prepared samples. Neither lycopene nor total phenolic concentration was well correlated to antioxidant capacity. Key words: High performance liquid chromatography, photoperiod

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