scholarly journals Production of a Thermostable Chitosanase from Shrimp Heads via Paenibacillus mucilaginosus TKU032 Conversion and its Application in the Preparation of Bioactive Chitosan Oligosaccharides

Marine Drugs ◽  
2019 ◽  
Vol 17 (4) ◽  
pp. 217 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Anh Dzung Nguyen ◽  
San-Lang Wang
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Radical Scavenging ◽  
Chitosan Oligosaccharide ◽  
Chitosan Oligosaccharides ◽  
Potential Applications ◽  
Shrimp Heads ◽  
Fraction I

Chitosanase has attracted great attention due to its potential applications in medicine, agriculture, and nutraceuticals. In this study, P. mucilaginosus TKU032, a bacterial strain isolated from Taiwanese soil, exhibited the highest chitosanase activity (0.53 U/mL) on medium containing shrimp heads as the sole carbon and nitrogen (C/N) source. Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, a chitosanase isolated from P. mucilaginosus TKU032 cultured on shrimp head medium was determined at approximately 59 kDa. The characterized chitosanase showed interesting properties with optimal temperature and thermal stability up to 70 °C. Three chitosan oligosaccharide (COS) fractions were isolated from hydrolyzed colloidal chitosan that was catalyzed by TKU032 chitosanase. Of these, fraction I showed the highest α-glucosidase inhibitor (aGI) activity (65.86% at 20 mg/mL); its inhibitory mechanism followed the mixed noncompetitive inhibition model. Fractions II and III exhibited strong 2,2-diphenyl1-picrylhydrazyl (DPPH) radical scavenging activity (79.00% at 12 mg/mL and 73.29% at 16 mg/mL, respectively). In summary, the COS fractions obtained by hydrolyzing colloidal chitosan with TKU032 chitosanase may have potential use in medical or nutraceutical fields due to their aGI and antioxidant activities.

scholarly journals Bioprocessing of Squid Pens Waste into Chitosanase by Paenibacillus sp. TKU047 and Its Application in Low-Molecular Weight Chitosan Oligosaccharides Production

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1163 ◽  
Author(s):  
Chien Thang Doan ◽  
Thi Ngoc Tran ◽  
Van Bon Nguyen ◽  
Trung Dung Tran ◽  
Anh Dzung Nguyen ◽  
...  
Keyword(s):  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Radical Scavenging ◽  
Maximum Activity ◽  
Degree Of Polymerization ◽  
Chitosan Oligosaccharide ◽  
Scavenging Activity ◽  
Paenibacillus Sp

Chitosan oligosaccharide (COS) has become of great interest in recent years because of its worthy biological activities. This study aims to produce COS using the enzymatic method, and investigates Paenibacillus sp. TKU047, a chitinolytic-producing strain, in terms of its chitosanase productivity on several chitinous material-containing mediums from fishery process wastes. The highest amount of chitosanase was produced on the medium using 2% (w/v) squid pens powder (0.60 U/mL) as the single carbon and nitrogen (C/N) source. The molecular mass of TKU047 chitosanase, which could be the smallest one among chitinases/chitosanases from the Paenibacillus genus, was approximately 23 kDa according to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method. TKU047 chitosanase possessed the highest activity at 60 °C, pH 7, and toward chitosan solution with a higher degree of deacetylation (DDA) value. Additionally, the hydrolysis products of 98% DDA chitosan catalyzed by TKU047 chitosanase showed the degree of polymerization (DP) ranging from 2 to 9, suggesting that it was an endo-type activity chitosanase. The free radical scavenging activity of the obtained chitosan oligosaccharide (COS) was determined. The result showed that COS produced with Paenibacillus sp. TKU047 chitosanase expressed a higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity than that from the commercial COSs with maximum activity and IC50 values of 81.20% and 1.02 mg/mL; 18.63% and 15.37 mg/mL; and 15.96% and 15.16 mg/mL, respectively. As such, Paenibacillus sp. TKU047 may have potential use in converting squid pens waste to produce chitosanase as an enzyme for bio-activity COS preparation.

scholarly journals Structure and Antioxidant Activity of Soy Protein Isolate-Dextran Conjugates Obtained by TiO2Photocatalysis

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Bei Jin ◽  
Xiaosong Zhou ◽  
Bing Li ◽  
Caiyan Chen ◽  
Xiaosa Zhang ◽  
...  
Keyword(s):  
Soy Protein ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Soy Protein Isolate ◽  
Sodium Dodecyl ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Protein Isolate ◽  
Random Coil

The aim of this study was to investigate the structural characteristics and antioxidant activities of soy protein isolate- (SPI-) dextran conjugates obtained by TiO2photocatalysis treatment. Results revealed that the UV-vis absorption and the fluorescence intensity increased as the photocatalytic power increased (P<0.05). Higher photocatalytic power could promote the extent of glycation and the formation of high molecular weight SPI-dextran conjugates, which were evidenced by free amino group content and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The Fourier transform infrared (FT-IR) spectra suggested that the amide I, II, and III bands of SPI were altered by the glycation induced by TiO2photocatalysis. Moreover, significant changes of secondary structure occurred in SPI-dextran conjugates. Theα-helix,β-sheet,β-turns, and random coil were changed from approximately 10.6%, 37.9%, 12.9%, and 38.6% to 3.8%, 10.4%, 17.7%, and 68.8%, respectively, after treatment at photocatalytic power of 1000 W. In addition, SPI-dextran conjugates obtained by TiO2photocatalysis treatment exhibited high hydroxyl radical scavenging activity and possessed increased reducing power. All data indicated that TiO2photocatalysis was an efficient method for promoting protein-polysaccharide copolymerisation.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

scholarly journals Antioxidant and UV-radiation absorption activity of aaptamine derivatives – Potential application for natural organic sunscreens

2021 ◽  
Author(s):  
Thi Le Anh Nguyen ◽  
Thi Hoai Nam Doan ◽  
Dinh Hieu Truong ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
...  
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Chelating Activity ◽  
Radical Adduct ◽  
Potential Applications

Antioxidant and UV absorption activities of three marine product originated - aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (<b>C1</b>), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (<b>C2</b>), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (<b>C3</b>) were theoretically studied by density functional theory (DFT). Direct antioxidant activities of C1–C3 were firstly evaluated via their intrinsic thermochemical properties and radical scavenging activity of the potential antioxidants with the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1 (kapp, 7.13x10<sup>6</sup> M-1 s-1) while RAF is more dominant with C2 (k<sub>app</sub>, 1.40x10<sup>5</sup> M-1 s-1) and C3 (kapp, 2.90x10<sup>5</sup> M-1 s-1). Antioxidant activity of aaptamine derivatives can be classified as <b>C1 </b>> <b>C3 </b>> <b>C2</b>. Indirect antioxidant properties based on Cu(I) and Cu(II) ions chelating activity were also investigated in aqueous phase. All three studied compounds show spontaneous and favorable Cu(I) ion chelating activity with DG0 being -15.4, -13.7, and -15.7 kcal.mol-1, whereas DG0 for Cu(II) chelation are -10.4, -10.8, and -2.2 kcal.mol-1 for C1, C2 and C3, respectively. In addition, all compounds show UVA and UVB absorption; in which the excitations are determined mostly as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient.<br>

scholarly journals Wet milling of buckwheat cultivars and some quality properties of the fractions

2021 ◽  
pp. 108201322110113
Author(s):  
Ayşenur Arslan ◽  
Claudia Monika Haros ◽  
Erkan Yalçın ◽  
Ahmet Güneş
Keyword(s):  
Phenolic Compound ◽  
Dietary Fibre ◽  
Radical Scavenging Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Radical Scavenging ◽  
Trolox Equivalent Antioxidant Capacity ◽  
Total Phenolic ◽  
Wet Milling ◽  
Total Recovery

The hulled buckwheat cultivars ( Aktaş cv. and Güneş cv.) were wet-milled, and then some chemical, yields, colour, functional properties, phenolic compound, antioxidant activity, and pasting, thermal and retrogradation properties of starches were investigated and compared with the wholegrain buckwheat flour (with hull) and buckwheat groat flour (without hull) of the same cultivars. Sodium dodecyl sulphate polyacrylamide gel electrophoresis patterns of flours and protein fractions were examined under reducing and non-reducing conditions. The hull, germ+dietary fibre, protein and starch fractions were collected. The total recovery for Aktaş cv. and Güneş cv. cultivars were 98.1% and 96.1%; total starch yields were 51.6% and 49.7%; pasting temperatures of the starches were found as 83.7 and 85.7°C; and final viscosities of starches were determined as 3.5 and 3.4 Pa·s, respectively. The resistant starch contents of starch fractions of Aktaş cv. ve Güneş cv. were found as 3.28% and 3.62%, respectively. The highest total phenolic compound contents were detected with dimethyl sulphoxide extraction in the germ+dietary fibre fractions. The highest 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and trolox equivalent antioxidant capacity were found in the hull fraction (as 81.7%) and germ+dietary fibre fraction (as 11.8 mmol/kg) of Aktaş cv. cultivar.

scholarly journals Radical-Scavenging and UV-Radiation Absorption Activities of Aaptamine Derivatives: DFT and TD-DFT Studies

2021 ◽  
Author(s):  
Thi Hoai Nam Doan ◽  
Thi Le Anh Nguyen ◽  
Nguyen Thi Ai Nhung ◽  
Duong Tuan Quang ◽  
Duy Quang Dao
Keyword(s):  
Density Functional ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Hydrogen Atom Transfer ◽  
Radiation Absorption ◽  
Functional Theory ◽  
Radical Adduct ◽  
Td Dft ◽  
Potential Applications

Antioxidant and UV absorption activities of three aaptamine derivatives including piperidine[3,2-b]demethyl(oxy)aaptamine (C1), 9-amino-2-ethoxy-8-methoxy-3H-benzo[de][1,6]naphthyridine-3-one (C2), and 2-(sec-butyl)-7,8-dimethoxybenzo[de]imidazo[4,5,1-ij][1,6]-naphthyridin-10(9H)-one (C3) were theoretically studied by density functional theory (DFT). Optimized geometries of C1C3 and theirs intrinsic thermochemical properties such as bond dissociation energy, proton affinity, and ionization potential were calculated at DFT/M05-2X/6-311++G(d,p) level of theory in vacuo and in water. The results show that C1C3 exhibited similar potent antioxidant activities, which are comparable to well-known antioxidants such as Trolox or cembrene. The radical scavenging activity of the antioxidants were then investigated by evaluation the Gibbs free energy (ΔrG0) of the reaction between C1C3 and the HOO●/HO● radicals via four mechanisms, including: hydrogen atom transfer (HAT), single electron transfer (SET), proton loss (PL) and radical adduct formation (RAF). Kinetic calculation reveals that HOO● scavenging in water is occurred via HAT mechanism with C1@C19 while RAF is more dominant with C2 and C3. Antioxidant activity of aaptamine derivatives can be classified as C1 > C3 > C2. In addition, all compounds are active in UV-Vis absorption; the excitations of which are determined as π-π* transition. Overall, the results suggest the potential applications of the aaptamines in pharmaceutics and cosmetics, i.e. as sunscreen and antioxidant ingredient<br>

Composition of essential oil and antioxidant activity of Khat (Catha edulis Forsk), Ethiopia

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Gas Chromatography ◽  
Essential Oils ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Free Radical Scavenging ◽  
Gas Chromatography Mass Spectrometry ◽  
Bahir Dar ◽  
Dpph Radical ◽  
Catha Edulis

In this study, we determined the chemical composition and antioxidant activities of the essential oils from two different varieties of khat (Catha edulis Forsk) cultivated in Ethiopia. The essential oils were extracted by hydrodistillation using the Clevenger type apparatus, identifications of compounds were made by gas chromatography and gas chromatography-mass spectrometry (GC-MS). Seventy seven different compounds were identified from essential oils of the two different khat cultivars. The essential oils in the samples from Bahir Dar and Wendo were composed of 50 and 34 compounds, respectively. The major compound identified in khat essentials oils include: limonene, 1-phenyl-1,2-propanedione, 1-hydroxy,1-phenyl-2-propanone, camphor, (sulfurous acid)-2-propylundecyl ester, hexadecane, O-mentha-1(7), 8-dien-3-ol, heptadecane, 10-methylnonadecane, (phthalic acid)-isobutyl octadecyl ester, and tritetracontane. The antioxidant and free radical scavenging activity of the oils were assessed by means of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay. The scavenging activities of the oils were 23.5-23.6 μg AAE/kg of fresh khat sample.

Antioxidant activity of cookiessupplemented with sugarbeet dietary fiber

2011 ◽  
pp. 151-157 ◽  
Author(s):  
Marijana B. Saka ◽  
Julianna F. Gyura ◽  
Aleksandra Mišan ◽  
Zita I. Šereš ◽  
Biljana S. Pajin ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Shelf Life ◽  
Dietary Fiber ◽  
Wheat Flour ◽  
Room Temperature ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Functional Characteristics

The antioxidant activity of cookies prepared by the addition of sugarbeet dietary fibers was investigated in order to estimate their influence on functional characteristics and shelf-life of cookies. Treated fiber (TF) was obtained from sugarbeet by extraction with sulfurous acid (75 °C at pH = 5.7during 60 min) and treatment with hydrogen peroxide (20 g/LH2O2 at pH = 11 during 24 h). The fiber obtained was dried (80 °C), ground and sieved. TF was investigated in comparison with commercially available Fibrex®. The cookies were prepared by the addition of 0, 7, 9 and 11% of sugarbeet dietary fiber as a substitute for wheat flour in the formulation of cookies. The antioxidant properties of cookies were tested every 7 days using a DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity test during 6 weeks of storage at room temperature (23 ± 1 ºC). The obtained results indicated that substitution of wheat flour with Fibrex® in the formulation of cookies upgraded the antioxidant activity, i.e. the functional characteristics of Fibrex®-enriched cookies and could prolong their shelf-life. In contrast, TF did not increase the antioxidant activity of TF-enriched cookies. The better antioxidant activities of Fibrex®-enriched cookies could be attributed to the presence of ferulic acid.

Chemical variability and antioxidant activities of the essential oils of the aerial parts of Ammoides verticillata and the roots of Carthamus caeruleus and their synergistic effect in combination

2020 ◽  
Vol 23 ◽  
Author(s):  
Imane Rihab Mami ◽  
Noria Merad-Boussalah ◽  
Mohammed El Amine Dib ◽  
Boufeldja Tabti ◽  
Jean Costa ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Natural Food ◽  
Chemical Compositions ◽  
Chemical Variability ◽  
Ammoides Verticillata

Aim and Objective: Oxidative stress is implicated in the development and progression of many disease. Some of appropriate actions that could be initiated to taken to resolve the problem of these diseases are search for new antioxidant substances isolated from plants. The aims of this study were to study the intraspecies variations of A. verticillata and C. caeruleus essential oils from 8 locations using statistical analysis, the in vitro antioxidant properties of collective essential oils and in combinations. Materials and Methods: The essential oils were analyzed by GC and GC-MS. The intraspecies variations of the essential oil compositions were discussed using principal component analysis (PCA) and cluster analysis (CA). The antioxidant properties were evaluated DPPH-radical scavenging activity and β-carotene bleaching test. Results: The main components of Ammoides verticillata collective essential oil (Coll EO) were thymol (30.5%), carvacrol (23.2%), p-cymene (13.1%), limonene (12.5%) and terpinene-4-ol (12.3%). While roots of Carthamus caeruleus essential oil were dominated by carline oxide (86.2%). The chemical variability allowed the discrimination of two main Groups for both Coll EOs. A direct correlation between the altitudes, climate and the chemical compositions was evidenced. Ammoides verticulata and Carthamus caeruleus Coll Eos showed good antioxidant activity. In binary mixture, the interaction both Coll Eos and between oils rich of thymol and/or carvacrol with carlina oxide produced the best synergistic effects, compared to individual essential oils and the synthetic antioxidant (BHT). Conclusion: Ammoides verticillata and Carthamus caeruleus essential oil blends can be used as a natural food preservative and alternative to chemical antioxidants.

Green Synthesis, Characterization, DPPH and Ferrous Ion-chelating (FIC) Activity of Tetrakis-Schiff’s Bases of Terephthalaldehyde

2019 ◽  
Vol 16 (3) ◽  
pp. 249-255
Author(s):  
Momin Khan ◽  
Umar Ali ◽  
Anis Ur Rahman ◽  
Muhammad Ibrahim ◽  
Abdul Hameed ◽  
...  
Keyword(s):  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Aromatic Aldehydes ◽  
Ferrous Ion ◽  
Future Research ◽  
Scavenging Activity ◽  
Schiff’S Bases ◽  
Schiff's Bases ◽  
Antioxidant Agents

Background: The role of small molecules as antioxidants to prevent the oxidation of other molecules and inhibit them from radical formation is the area of much interest to cure disease especially cancer. Moreover, the antioxidants play important role as stabilizers to prevent oxidation of fuels and lubricants. </P><P> Methods: In the present study, fifteen tetrakis-Schiff’s bases derivatives (1-15) were synthesized and screened for their antioxidant activities. Compounds 1-15 were synthesized by continuous stirring of reaction mixture of 1,4-bis (hydrazonomethyl)benzene (1 mmol) with various substituted aromatic aldehydes (2 mmol) in distilled water using acetic acid as catalyst at room temperature for 2-10 min. </P><P> Results: Our present study showed that all compounds are better ferrous ion-chelating agents except compound 1,4-bis((E)-((E)-(3,4-dimethoxybenzylidene)hydrazono)methyl)benzene (6) (IC50 = 329.26 &#177; 4.75 &#181;M) which has slightly low activity than the standard EDTA (IC50 = 318.40 &#177; 5.53 μM). In addition, DPPH radical scavenging activity of eleven compounds showed higher activity than the standard. However, remaining four compounds showed comparable radical scavenging activity to the standard DPPH (IC50 = 257.77 &#177; 4.60 &#181;M). </P><P> Conclusion: The series of fifteen Schiff’s bases (1-15) were synthesized and evaluated as antioxidants. From both assays, it has been demonstrated that most of the tetrakis-Schiff’s bases have potential to serve as leads for the development of antioxidant agents for future research.

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