scholarly journals Changes in Amino Acid Profiles and Bioactive Compounds of Thai Silk Cocoons as Affected by Water Extraction

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2033
Author(s):  
Chuleeporn Bungthong ◽  
Sirithon Siriamornpun

Silk proteins have many advantageous components including proteins and pigments. The proteins—sericin and fibroin—have been widely studied for medical applications due to their good physiochemical properties and biological activities. Various strains of cocoon display different compositions such as amino-acid profiles and levels of antioxidant activity. Therefore, the objectives of this study were to find a suitable silk protein extraction method to obtain products with chemical and biological properties suitable as functional foods in two strains of Bombyx mori silk cocoon (Nangsew strains; yellow cocoon) and Samia ricini silk cocoon (Eri strains; white cocoon) extracted by water at 100 °C for 2, 4, 6 and 8 h. The results showed that Nangsew strains extracted for 6 h contained the highest amounts of protein, amino acids, total phenolics (TPC) and total flavonoids (TFC), plus DPPH radical-scavenging activity, ABTS radical scavenging capacity, and ferric reducing antioxidant power (FRAP), anti-glycation, α-amylase and α-glucosidase inhibition. The longer extraction time produced higher concentrations of amino acids, contributing to sweet and umami tastes in both silk strains. It seemed that the bitterness decreased as the extraction time increased, resulting in improvements in the sweetness and umami of silk-protein extracts.

2020 ◽  
Vol 10 (2) ◽  
pp. 145-152 ◽  
Author(s):  
Imane Rihab Mami ◽  
Rania Belabbes ◽  
Mohammed El Amine Dib ◽  
Boufeldja Tabti ◽  
Jean Costa ◽  
...  

Background: Carthamus caeruleus belongs to the Asteraceae family. The roots are traditionally used as healing agents. They help to heal burns and treat skin diseases. They are also used against joint inflammation and are very effective against diseases such as irritable bowel syndrome for cancer patients. Objectives: The purpose of this work was i) to study the chemical composition of i) the essential oil and hydrosol extract of Carthamus caeruleus, ii) to isolate the major component of both extracts and iii) to evaluate their antioxidant, antifungal and insecticidal activities. Methods: The essential oil and hydrosol extract obtained from the roots were studied by GC and GC/MS. The antioxidant activities were performed using two different methods i) Radical scavenging activity (DPPH) and ii) the Ferric-Reducing Antioxidant Power (FRAP), using BHT as a positive control. Whereas, the antifungal activity of the essential oil and Carlina oxide was investigated against plant fungi. The fumigation toxicity of C. caeruleus essential oil besides Carlina oxide was evaluated against adults of Bactrocera oleae better known as the olive fly. Results: The essential oil and hydrosol extract were mainly represented by acetylenic compounds such as carline oxide and 13-methoxy carline oxide. Carlina oxide was isolated and identified by 1H and 13C NMR spectroscopic means. The results showed that Carlina oxide presented interesting antioxidant and antifungal properties, while C. caeruleus root essential oil had better insecticidal activity. Furthermore, Carlina oxide has demonstrated promising in vivo antifungal activity to control infection of apples by Penicillium expansum. Conclusion: Carlina oxide can be used as a natural food preservative and alternative to chemical fungicides to protect stored apple against Penicillium expansum.


2020 ◽  
Vol 42 (1) ◽  
pp. 109-109
Author(s):  
Hao Zang Hao Zang ◽  
Qian Xu Qian Xu ◽  
Luyun Zhang Luyun Zhang ◽  
Guangqing Xia Guangqing Xia ◽  
Jiaming Sun and Junyi Zhu Jiaming Sun and Junyi Zhu

A series of hydroxytyrosol (HT) derivatives were synthesized by modification of alcohol hydroxyl group of HT, twenty-five target compounds were obtained and characterized by NMR and HRMS. The antioxidant activities of those compounds were evaluated in three different assays. Except 3e and 3y, all other compounds demonstrated significant 2,2and#39;-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical cation scavenging activity ranging from IC50 3.4 to 24.4 μM, which were more potent than L-ascorbic acid (IC50=24.8 μM). Compounds 3b-3d, 3f-3k, 3m-3x were better than Trolox (18.3 M). Moreover, the ferric reducing antioxidant power (FRAP) of all compounds were discovered to be more potent than L-ascorbic acid (40.7 mmol/g), except 3e, all other compounds (141.5-202.1 mmol/g) were better than Trolox (94.7 mmol/g). Compounds 3a-3d, 3f-3j, 3l-3m, 3o, 3q, 3t, 3v-3y exhibited more potent hydroxyl radical scavenging activity (IC50=245.1-475.1 M) than L-ascorbic acid (554.4 M) and Trolox (500.4 M). Compounds 3q, 3t and 3y exhibited more potent -Glucosidase inhibition activity (39.1-52.4 M) than Acarbose (60.9 M). Compounds 3a, 3d, 3f-3m, 3s-3t, 3v-3y showed some acetylcholinesterase inhibition activities, compounds 3a, 3d, 3f-3j, 3l-3m, 3o-3p, 3s-3t, 3w showed some butyrylcholinesterase inhibition activities.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5337 ◽  
Author(s):  
Chanikan Sonklin ◽  
Natta Laohakunjit ◽  
Orapin Kerdchoechuen

Background Bioactive peptides can prevent damage associated with oxidative stress in humans when consumed regularly. Recently, peptides have attracted immense interest because of their beneficial functional properties, safety and little or no side effects when used at high concentration. Most antioxidant peptides are small in size, less than 1 kDa, and contains a high proportion of hydrophobic amino acid. Particularly, tyrosine, leucine, alanine, isoleucine, valine, lysine, phenyalanine, cysteine, methionine and histidine in peptide chain exhibited high antioxidant activity. Mungbean meal protein (MMP) is highly abundant in hydrophobic amino acids. It indicated that MMP might be a good source of antioxidants. Therefore, the objectives were to optimize the conditions used to generate mungbean meal protein hydrolysate (MMPH) with antioxidant activity from bromelain and to investigate the antioxidant activities of different molecular weight (MW) peptide fraction. Methods Response Surface Methodology (RSM) was used for screening of the optimal conditions to produce MMPH. After that MMPH was fractionated using ultrafiltration membranes with different MW distributions. Crude-MMPH and four fractions were investigated for five antioxidant activities: 2,2,1-diphenyl-1-picrylhydrazyl (DPPH), hydroxyl, superoxide, ferric reducing antioxidant power (FRAP) and metal ion chelation activity. Results The optimal condition to produce the MMPH was 15% (w/w) of bromelain and hydrolysis time for 12 h which showed the greatest DPPH and ABTS radical scavenging activity. After mungbean protein from optimal condition was separated based on different molecular weight, the DPPH radical scavenging activity was the highest for the F4 (less than 1 kDa) peptide fraction. Metal ion chelating activity was generally weak, except for the F4 that had a value of 43.94% at a protein concentration of 5 mg/mL. The F4 also exhibited high hydroxyl and superoxide activities (54 and 65.1%), but moderate activity for ferric reducing antioxidant power (0.102 mmole Fe2+/g protein) compared to other peptide fractions and crude-MMPH. Molecular weight and amino acid were the main factors that determined the antioxidant activities of these peptide fractions. Results indicated that F4 had strong antioxidant potentials. Discussion The lowest MW fraction (less than 1 kDa) contributed to the highest DPPH, superoxide, hydroxyl and metal chelation activity because influence of low MW and high content of hydrophobic amino acid in peptide chain. Results from this study indicated that MMPH peptides donate protons to free radicals because they had significantly high DPPH value compared to superoxide, hydroxyl and FRAP, which reactions were electron donation. Moreover, MMPH peptides had the ability to inhibit transition metal ions because of highly abundant glutamic acid and aspartic acid in peptide chain.


2014 ◽  
Vol 31 (4) ◽  
pp. 245-252 ◽  
Author(s):  
Jovana Veljković ◽  
Jelena Brcanović ◽  
Aleksandra Pavlović ◽  
Snežana Mitić ◽  
Biljana Kaličanin ◽  
...  

Summary While there is a large number of scientific papers reporting chemical composition and biological activities of Aronia melanocarpa, there is a lack information regarding the commercially available bagged tea. In order to supply new information on the antioxidant activity of the Aronia melanocarpa tea infusions, the aim of this study was to evaluate individual phenolic compounds which could be responsible for antioxidant activities of these beverages. Selected anthocyanins (cyanidin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin- 3-O-arabinoside, and cyanidin-3-O-xyloside), gallic acid, caffeic acid, rutin, morin, and protocatechuic acid were simultaneously detected from commercially available tea infusions using a High Performance Liquid Chromatographic (HPLC) method. The antioxidant activity was measured using five in vitro spectrophotometric methods: 1,1-diphenyl- 2-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline- 6-sulphonic acid) radical cation scavenging activity (ABTS), ferric reducing-antioxidant power (FRAP) and reduction power (RP)Fe(III) to Fe(II). Obtained results showed that anthocyanins, predominantly of cyanidin-3-O-galactoside, are the major class of polyphenolic compounds in tea infusions. Among phenolic acids the most abundant is caffeic acid. A significant correlation between DPPH and ABTS and FRAP and RP suggested that antioxidant components in these beverages were capable scavenging free radicals and reducing oxidants. Generally, these beverages had relatively high antioxidant capacities and could be important dietary sources of antioxidant phenolics for the prevention of diseases caused by oxidative stress.


2011 ◽  
Vol 365 ◽  
pp. 169-179 ◽  
Author(s):  
Yao Wang Li ◽  
Bo Li

Some radical scavenging peptides by ORAC method from different hydrolysates were used for the quantitative structure-activity relationships (QSAR) research. Partial least-squares regression analysis (PLSR) was treated as the method to build the model with 17 kinds of amino acid descriptors. In order to translate the sequence to the same length, two-terminal position numbering (TTPN) was applied. Two of amino acid descriptors VSHE and VSW were selected for their excellent performance (R2, Q2, and RMSEcwith VHSE and VSW descriptor are 0.995, 0.630, 0.318 and 0.966, 0.543, 0.181 respectively). VHSE has the definite physicochemical meanings and easy to understand while VSW has good predictive ability (Rand RMSEpwith VHSE and VSW are 0.404, 2.633 and 0.635, 2.298 respectively). It is believed that the position No.2 amino acid from N-terminal (N2) have more importance than others in sequence, and most of electronic properties are negative to activity while all the steric properties are positive to activity as well as the hydrophobic properties. The suitable amino acids in sequence are as follow: G, R, K, W, Y, N, E, H, and Q are suitable for N2position which illustrated the importance of acidic amino acids in peptide sequence for radical scavenging activity.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 679
Author(s):  
Seyadeh Narges Mazloomi ◽  
Alireza Sadeghi Mahoonak ◽  
Leticia Mora ◽  
Mohammad Ghorbani ◽  
Gholamreza Houshmand ◽  
...  

Recently, the use of bioactive compounds in improving human health has received more attention. The aim of the present study was to hydrolyze orange seed proteins using pepsin enzyme to obtain bioactive peptides as well as to study the stability of such activity after simulated gastrointestinal digestion conditions. The method was optimized using different enzyme concentrations from 1% to 3%, hydrolysis times between 2 and 5 h, and an optimal temperature of 33 °C. Biological activities including α-glucosidase inhibition, α-amylase inhibition, Angiotensin I-Converting Enzyme (ACEI) inhibition, ferric reducing antioxidant power, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were evaluated. According to the results, a significant higher value of the biological activity (p < 0.05) was observed using an enzyme ratio of 0.03 E/S and hydrolysis time of 3.5 h. After size-exclusion chromatography separation, fractions 45–49 and 50–54 showed the highest biological roles such as antioxidant, ACEI inhibitory, and hypoglycemic. Fractions with the highest biological activity were purified using RP-HPLC and analyzed using nano-liquid chromatography and mass spectrometry. The results obtained after simulated gastrointestinal digestion indicated that peptide fractions obtained after chromatographic separation significantly maintain their activity.


Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 746
Author(s):  
Claudia Valverde Malaver ◽  
Ana Colmenares Dulcey ◽  
Carlos Rial ◽  
Rosa Varela ◽  
José Molinillo ◽  
...  

A bio-guided study of leaf extracts allowed the isolation of two new macrobicyclic hydrolysable tannins, namely merianin A (1) and merianin B (2), and oct-1-en-3-yl β-xylopyranosyl-(1”-6’)-β-glucopyranoside (3) from Meriania hernandoi, in addition to 11 known compounds reported for the first time in the Meriania genus. The structures were elucidated by spectroscopic analyses including one- and two-dimensional NMR techniques and mass spectrometry. The bioactivities of the compounds were determined by measuring the DPPH radical scavenging activity and by carrying out antioxidant power assays (FRAP), etiolated wheat coleoptile assays and phytotoxicity assays on the standard target species Lycopersicum esculentum W. (tomato). Compounds 1 and 2 exhibited the best free radical scavenging activities, with FRS50 values of 2.0 and 1.9 µM, respectively.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1205
Author(s):  
Adesola A. Adeleke ◽  
Sizwe J. Zamisa ◽  
Md. Shahidul Islam ◽  
Kolawole Olofinsan ◽  
Veronica F. Salau ◽  
...  

A series of fifteen silver (I) quinoline complexes Q1–Q15 have been synthesized and studied for their biological activities. Q1–Q15 were synthesized from the reactions of quinolinyl Schiff base derivatives L1–L5 (obtained by condensing 2-quinolinecarboxaldehyde with various aniline derivatives) with AgNO3, AgClO4 and AgCF3SO3. Q1–Q15 were characterized by various spectroscopic techniques and the structures of [Ag(L1)2]NO3Q1, [Ag(L1)2]ClO4Q6, [Ag(L2)2]ClO4Q7, [Ag(L2)2]CF3SO3Q12 and [Ag(L4)2]CF3SO3Q14 were unequivocally determined by single crystal X-ray diffraction analysis. In vitro antimicrobial tests against Gram-positive and Gram-negative bacteria revealed the influence of structure and anion on the complexes′ moderate to excellent antibacterial activity. In vitro antioxidant activities of the complexes showed their good radical scavenging activity in ferric reducing antioxidant power (FRAP). Complexes with the fluorine substituent or the thiophene or benzothiazole moieties are more potent with IC50 between 0.95 and 2.22 mg/mL than the standard used, ascorbic acid (2.68 mg/mL). The compounds showed a strong binding affinity with calf thymus-DNA via an intercalation mode and protein through a static quenching mechanism. Cytotoxicity activity was examined against three carcinoma cell lines (HELA, MDA-MB231, and SHSY5Y). [Ag(L2)2]ClO4Q7 with a benzothiazole moiety and [Ag(L4)2]ClO4Q9 with a methyl substituent had excellent cytotoxicity against HELA cells.


Author(s):  
Wilart Pompimon ◽  
Wipanoot Baison ◽  
Angkhana Chuajedton ◽  
Phansuang Udomputtimekakul ◽  
Punchavee Sombutsiri ◽  
...  

Introduction: Triphala, a herbal medicine which is a product from Chae Son, Lampang, Thailand, is an unequal-proportional mixture of fruits of three herbs, Phyllanthus emblica, Terminalia chebula, and Terminalia bellirica (2:1:1). Materials and Methods: The contemporary study concentrated on extracts detection and comparative analysis between various annual year (A.D.2017/2018) activities in hexane, ethyl acetate, and methanolic extracts of Triphala. The determination of antioxidant was using by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The broth dilution and agar well diffusion assay were determined antibacterial. Results: Results exposed the valuable biological activity extracts from ethyl acetate and methanol solvents of T. chebula and T. bellirica, which strength is accountable for biological activities. Extracts displayed acceptable radical-scavenging activity analogous with ascorbic acid. The methanol extract of T. bellirica (0.0013 mg/mL), ethyl acetate extract of P. emblica (0.0009 mg/mL), in A.D. 2017 and the ethyl acetate extract of P. emblica (0.0090 mg/mL), the methanol extract of Triphala (0.0176 mg/mL) in 2018, were exhibited higher antioxidant activity. Also, extracts indicated hopeful antibacterial potential against tested strain comparable to chloramphenicol. Conclusion: The results in A.D. 2017 showed that inhibition zone of P. emblica in ethyl acetate extract; S. aureas (8.67 mm), E. aerogenes (8.67 mm), E. coli (EPEC) (7.67 mm), P. mirabilis (7.73 mm) , S. typhimurium (8.33 mm), S. flexneri (8.33 mm) and V. cholera (7.33 mm) together with P. emblica methanol extract; S. aureas (6.67 mm), E. aerogenes (7.76 mm.)  and V. cholera (4.0 mm). Therefore, it could be concluded that Triphala may be a talented candidate in pharmaceutical and future medicine.


2016 ◽  
Vol 77 (3) ◽  
pp. 632-641 ◽  
Author(s):  
C. G. Pereira ◽  
L. Custódio ◽  
M. J. Rodrigues ◽  
N. R. Neng ◽  
J. M. F. Nogueira ◽  
...  

Abstract The halophyte species Plantago coronopus has several described ethnomedicinal uses, but few reported biological activities. This work carried out for the first time a comparative analysis of P. coronopus organs in terms of phenolic composition and antioxidant activity of organic and water extracts from roots, leaves and flowers. The leaves contents in selected nutrients, namely amino acids and minerals, are also described. Roots (ethyl acetate and methanol extracts) had the highest radical scavenging activity (RSA) towards 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, while leaves (hexane extract) had higher RSA on nitric oxide radical and iron chelating ability. High performance liquid chromatography (HPLC) analysis identified eighteen phenolics from which salicylic acid and epicatechin are here firstly described in Plantago species. Leaves had mineral levels similar to those of most vegetables, proving to be a good source for elements like calcium, sodium, iron and magnesium, and also for several of the essential amino acids justifying it use as food. Our results, especially those regarding the phenolics composition, can explain the main traditional uses given to this plantain and, altogether, emphasize the potential of P. coronopus as a source of bioactive molecules particularly useful for the prevention of oxidative stress-related diseases.


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