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 Phytochemical contents and antioxidant activities of fern, Asplenium ceterach L. in different altitudes

2019 ◽  
Vol 48 (2) ◽  
pp. 315-320
Author(s):  
Asuman Karadeniz Pekgöz ◽  
Ilker Çinbilgel
Keyword(s):  
High Performance ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Ecological Factors ◽  
Total Phenolic ◽  
Plant Chemical ◽  
Dpph Radical Scavenging ◽  
Phytochemical Contents ◽  
Different Altitudes

Phytochemical contents and antioxidant activities of fern (Asplenium ceterach L.) distributed in different altitudes (22 stations) were compared and the relationships between altitude and plant chemical contents were studied. The highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity was found in 22nd station (IC50 = 47.91 μg/ml) and the highest total phenolic content was found in 9th station (110.62 μgGAE/ml) whereas the maximum total flavonoid content was found in 20th station (232.67 μgCE/ml). High performance liquid chromatography (HPLC) analysis indicates that the maximum pterosin b (0.235 μg/ml), catechin (2.756 μg/ml) and quercetin (0.207 μg/ml) values were found in 21th station whereas the maximum chlorogenic acid (17.718 μg/ml) was obtained in 9th and caffeic acid (6,598 μg/ml) in 13th stations. It was observed that altitude is not potent alone, but it can be a factor in the occurrence of other ecological factors like soil properties, water, humidity, light and temperature.

scholarly journals Different Extraction Solvents and Sample Preparation Methods Affect the Antioxidant Activities and Total Phenol Contents of Theobroma Cacao Powder (P01-016-19)

2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
Hyoeun Yoo ◽  
Hyun-Sook Kim
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Methanol Solution ◽  
Total Phenol ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Freeze Dried ◽  
Dpph Radical Scavenging

Abstract Objectives Cacao(Theobroma cacao) has been widely consumed since more than 4000 years ago which was regarded as sacred food. Cacao has been considered as a strong antioxidant due to its abundant phenolic and especially flavonoid contents. In this experiment, different extraction solvents and methods were used to analyze whether these factors affect the antioxidant activities and phytochemical compounds of cacao powder extracts. Methods Four different cacao extract samples were examined to identify their anti-oxidative activities; raw cacao powder extracted in 70% methanol solution(RM), raw cacao powder extracted in 80% ethanol solution(RE), freeze dried cacao powder extracted in 70% methanol solution(FM), freeze dried cacao powder extracted in 80% ethanol solution(FE). Total phenolic compound content was calculated based on gallic acid standard curve and total flavonoid content was calculated based on the standard curve of quercetin. ABTS scavenging activity was experimented with ABTS reagent diluted by PBS(pH7.4) to make the O.D. value 0.7 ± 0.02 at 734 nm before using 2.5 mM ABTS. The DPPH radical scavenging activity was assessed by 1 mM DPPH methanol solution. Results The contents of total phenol compounds were 45.4 mg GAE/g(RM), 37.3 mg GAE/g(RE), 50.6 mg GAE/g(FM), and 52.7 mg GAE/g(FE). The contents of total flavonoid compounds were 34.3 mg QE/g(RM), 29.7 mg QE/g(RE), 85.1 mg QE/g(FM), and 89.7 mg QE/g(FE). FM group showed the highest ABTS radical scavenging activity which is a marker of antioxidant activity but the other sample groups represented almost as high ABTS radical scavenging activity as FM group. RM group showed the highest DPPH radical scavenging activity which is also a marker of antioxidant activity. Conclusions The results show that different extract solvents and sample preparation methods affect DPPH radical scavenging activity, total phenol and flavonoid contents of cacao powder extracts. Therefore, appropriate methods should be applied according to the purpose of the study. Funding Sources Department of Food and Nutrition, Sookmyung Women's University, Republic of Korea.

scholarly journals ANTIOXIDANT ACTIVITIES OF FRACTIONS FROM ETHYL ACETATE EXTRACTS OF GARCINIA FRUTICOSA LAUTERB. LEAVES

2018 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Riza Shabrina ◽  
Berna Elya ◽  
Arikadia Noviani
Keyword(s):  
Antioxidant Activity ◽  
Ethyl Acetate ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Group Identification ◽  
Radical Scavenging ◽  
Dpph Radical ◽  
Frap Assay ◽  
Antioxidant Power ◽  
Dpph Radical Scavenging

Objective: This study aimed to fractionate the antioxidant activity of the ethyl acetate leaf extract and to characterize the most active fractionsaccording to compound groups.Methods: The ethyl acetate extract was fractionated with column chromatography using a gradient elution system. Fractions were first screenedqualitatively for antioxidant activity before active fractions were quantified with respect to in vitro antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and the ferric-reducing antioxidant power (FRAP) assay. The compound groups were identifiedfollowing separation by thin-layer chromatography.Results: Fraction 11 exhibited the greatest DPPH radical-scavenging activity, with an IC50 value of 6.58 μg/mL, while the fraction with the greatestantioxidant activity according to the FRAP assay was fraction 10, with a ferric ion equivalent antioxidant activity value of 1015.34 μmol/g.Conclusion: Compound group identification revealed that Fractions 10 and 11 contained flavonoids, with two common to both fractions, whilefraction 10 also contained one specific flavonoid.

STUDY OF ANTIBACTERIAL AND ANTIOXIDANT ACTIVITIES OF SAXICOLOUS LICHEN $ \textit{XANTHOPARMELIA STENOPHYLLA} $

2020 ◽  
Vol 54 (2 (252)) ◽  
pp. 132-137
Author(s):  
A.G. Simonyan ◽  
R.R. Sargsyan ◽  
H.H. Panosyan ◽  
A.H. Trchounian
Keyword(s):  
Methanol Extract ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Gram Positive Bacteria ◽  
Acetone Extracts ◽  
Dpph Radical Scavenging

Antibacterial and antioxidant activities of different extracts of saxicolous lichen Xanthoparmelia stenophylla sampled from Norashen, Gegharkunik Province of Armenia were studied. Methanol, ethanol and acetone extracts of lichen thalli were demonstrated to have activity against only tested gram-positive bacteria. Methanol extract of the lichen showed the highest amount of DPPH radical scavenging activity (~68%). Our studies did not reveal any significant antibacterial and antioxidant activities of aqueous extract.

Chemical Composition of Essential Oil and Antioxidant Activities of Curcuma petiolata Roxb. Rhizomes

2012 ◽  
Vol 506 ◽  
pp. 393-396 ◽  
Author(s):  
A. Thakam ◽  
N. Saewan
Keyword(s):  
Ascorbic Acid ◽  
Essential Oil ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Etoac Extract ◽  
Dpph Radical Scavenging

Pulverized rhizome of Curcuma peliolata on hydrodistillation, afforded light yellow essential oil in the yield of 0.13% v/w. The chemical constituent of the essential oil was determined by GC-MS. Nine compounds representing 95.34 % of the total oil were identified. The major compounds of the oil were 2-methyl-5-pentanol, 1H-pyrrol-1-amine,2-(4-methoxyphenyl)-n,n,5-trimethyl, and curcumol. The distillated aqueous was extracted with dicloromethane (DCM), ethyl acetate (EtOAc), and n-butanol. The DPPH radical scavenging and reducing power of the extracts were investigated. Curcumin and ascorbic acid were used as standard references. The DPPH radical scavenging activity was decrease in order: curcumin ascorbic acid EtOAc extract > DCM extract > n-butanol extract > aqueous extract. The EtOAc extract showed significantly highest inhibition of the radical scavenging activity with IC50 0.092 ± 0.001 mg/mL (curcumin and ascorbic acid (IC50 0.012 and 0.013 mg/mL, respectively (P<0.05)). While, the DCM extract showed highest reducing power with IC50 = 0.271 mg/mL which lower than that of standard curcumin (IC50 = 0.013 mg/mL) and ascorbic acid (IC50 = 0.002 mg/mL).Introduction

scholarly journals Comparison of Depolymerization of Chitosan into Chitooligosaccharides from the Shrimp Shell Waste of Parapeneopsis Stylifera by Non-Specific Enzymes

2021 ◽  
Author(s):  
V. Renuka ◽  
Chandragiri Nagaraja Rao Ravishankar ◽  
Elavarasan Krishnamoorthy ◽  
Abubacker Aliyamveetil Zynudheen
Keyword(s):  
Thermal Behavior ◽  
Antioxidant Activities ◽  
Proteolytic Enzymes ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Structural Difference ◽  
Dpph Radical ◽  
Dpph Radical Scavenging

Abstract Two different non-specific proteolytic enzymes (papain and pepsin) and two carbohydrase enzymes (α-amylase and β-amylase) were used for the depolymerization of chitosan to produce chitooligosaccharides (COS). The COS produced using papain, pepsin, α-amylase and β-amylase were characterized for physico-chemical, structural, thermal and antioxidant activities. Chitooligosaccharides produced using pepsin enzyme had higher solubility compared to other three COS. Structural variation of chitosan and their oligosaccharides were studied by FTIR analysis and it revealed the existence of various structural difference among the oligosaccharides and chitosan. Thermal behavior of chitosan and oligosaccharides were examined using DSC analysis, and it exhibits difference in the glass transition temperature among the four oligosaccharides and native chitosan. Anti-oxidant analysis such as DPPH radical scavenging activity and reducing power revealed the antioxidant ability of chitooligosaccharides. Among the four COS, pepsin-COS had the highest DPPH radical scavenging and reducing power activity. According to the patterns of molecular weight reduction, antioxidant properties, thermal behavior properties, four enzymes α- amylase, β-amylase, pepsin and papain found suitable for hydrolyzing chitosan into chitooligosaccharide. As it is superior to chitosan, chitooligosaccharide can be utilized in food industry as bio-preservatives to enhance the quality, safety and shelf life of the products.

scholarly journals Antioxidant activity of some natural essential oils in Vietnam: Comparison between QSAR simulation and experimental study

2020 ◽  
Vol 129 (1D) ◽  
Author(s):  
Tran Thi Ai My ◽  
Le Trung Hieu ◽  
Nguyen Thi Thanh Hai ◽  
Ton Nu My Phuong ◽  
Huynh Thi Phuong Loan ◽  
...  
Keyword(s):  
Essential Oils ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Qsar Model ◽  
Piper Betle ◽  
Scavenging Activity ◽  
Dpph Radical ◽  
Ageratum Conyzoides ◽  
Dpph Radical Scavenging

Antioxidant activities of essential oils from leaves of Piper betle L. (T) and Cleistocalyx operculatus L. (V), and aerial parts of Ageratum conyzoides L. (H) natively grown in Thua Thien Hue province of Vietnam were investigated.Quantitative structure–activity relationship (QSAR) model was constructed from the 27 compounds including 4-hydroxy-chromene-2H-one and its derivatives. DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity was applied to estimate the antioxidant property of these essential oils through IC50 (mg/mL) values. QSAR model is used to predict the radical scavenging activity IC50 mg/mL of T, V, and H. The results indicate that there is a good agreement between the experimental data and the predicted values using the QSAR model. The three essential oils display the DPPH radical scavenging activities with the IC50 values being in the order of T > H > V of 3.71 mg/mL,596.44 mg/mL and 637.03 mg/mL, respectively. The essential oil of T exhibits the strong DPPH radical scavenging activity that is close to the reference compound ascorbic acid (IC50 value of 3.03 mg /mL).

scholarly journals Callus formation, phenolics content and related antioxidant activities in tissue culture of a medicinal plant colocynth (Citrullus colocynthis)

2021 ◽  
Vol 10 (2) ◽  
pp. 79-94
Author(s):  
Farouk K. El-Baz ◽  
Amal A. Mohamed ◽  
Sami I. Ali
Keyword(s):  
Total Phenolics ◽  
Antioxidant Activities ◽  
Callus Formation ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Callus Cultures ◽  
Scavenging Activity ◽  
Dpph Radical Scavenging Activity ◽  
Dpph Radical Scavenging

Callus cultures from stems, leaves and roots of colocynth were initiated on MS media supplemented with various combinations of 2,4 dichlorophenoxyacetic acid (2,4-D) with kinetin (KIN) and benzyladenine (BA) with α-naphthaleneacetic acid (NAA). The highest percentage of callus formation frequency (98.9%) was obtained from stem explants grown on MS media supplemented with (1.0 mg/L) 2,4-D + (1.0 mg/L) KIN. The total phenolics and flavonoid content of the colocynth callus cultures were measured. The results showed that the MS medium supplemented with 6.0 mg/L 2,4-D + 2.0 mg/L KIN (MD3) gave the highest content of total phenolics (19.2 mg/100g d.w.) in leaf-derived calli. The highest content of flavonoids (47.3 mg/100g d.w.) was obtained in stem derived calli grown on the same medium (MD3). Antioxidant activities of extracts were determined using different assays, including DPPH radical scavenging activity, hydrogen peroxide (H2O2) scavenging activity and ferric reducing power. Leaf-derived calli cultured on MS medium + 2.0 mg/L 2,4-D + 1.0 mg/L KIN (MD1) showed the highest DPPH radical scavenging activity (85.3%). The highest percentage of H2O2 scavenging activity (61.4%) was detected in leaf explant-derived calli growing on MD1. The leaf-derived calli growing on (MD3) gave the highest ferric reducing power (22.3 μg/g d.w.), compared to the activities of stems, leaves and roots of in vitro grown seedlings (3.28, 12.9 and 2.85 μg/g d.w.), which were used as controls. On the basis of the current findings, we conclude that MS media supplemented with different combinations of 2,4-D and KIN yields higher phenolics, flavonoids contents and antioxidant activities than MS media supplemented with BA and NAA.

scholarly journals Effects of Solvents on Total Phenolic Content and Antioxidant Activity of Ginger Extracts

2020 ◽  
Author(s):  
Dessie Ezez ◽  
Molla Tefera
Keyword(s):  
Total Phenolic Content ◽  
Phenolic Content ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Acetone Extract ◽  
Total Phenolic ◽  
Dpph Radical ◽  
Dpph Radical Scavenging Activity ◽  
Dpph Radical Scavenging

Abstract Ginger (Zingiber officinale) is a popular spice which used for the treatment of different gastrointestinal and inflammatory discomfort. In the present study, the total phenolic content (TPC) and antioxidant activity of ginger extract using four solvents (ethanol, methanol, acetone and ethyl acetate) were determined. Among the four solvents, methanol extract showed that the maximum phenolic (1183.813 mg GAE/100 g at Ayikel and 1022.409 mg GAE/100 g at Mandura) and the least were found in acetone extract (748.865 mg GAE/100 g at Ayikel and 690.152 mg GAE/100 g at Mandura). In addition, the highest DPPH radical scavenging activity (84.868% at Ayikel and 82.883% at Mandura) was observed in methanol. However, acetone showed the least DPPH radical scavenging activity (73.864% at Ayikel and 70.597% at Mandura). Antioxidant activities of ginger extracts were also expressed as IC50 values and acetone extract has maximum IC50 value (0.654 and 0.812 mg/mL) followed by ethyl acetate and ethanol, while the lowest for methanol extracts (0.481 and 0.525 mg/mL). The result of this study showed that extraction solvents significantly affected the total phenolic content and antioxidant activities of ginger. Thus, ginger can be regarded as promising candidates for natural sources of antioxidants with high value of phenolic contents.

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