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Oxidative stress is linked to several invasive diseases which causes significant clinical and economic impact, therefore, there is a need to develop new antioxidants. The natural products could play an important role in overcoming the current need. In the present work, the antioxidant bioassay-guided fractionation of the ethanolic extract of Inula viscosa leaves (Asteraceae) was performed using DPPH and ABTS assays affording three known compounds, which were successfully characterized as ilicic acid (1), taxifolin (2) and quercetin (3) based on 1D, 2D NMR. Compounds 2 and 3 were identified as the most active, displaying similar or higher potency against ABTS (value 41.27 for quercetin and 142.58 for taxifolin) and similar activity against DPPH (value 41.27 for quercetin and 142.58 for taxifolin) than the well-known reference, ascorbic acid (value 65.36 for quercetin and 58.43 for taxifolin) but less potency than the standard gallic acid. The discussion of SAR of the antioxidant potential revealed that the type of natural product is crucial for the activity and the substitution pattern on the flavonoid skeleton modulate the antioxidant profile. Our findings show that I. viscosa leaves may be a natural source of antioxidants and once again the role of flavonoids health benefits is more strongly endorsed., (Copyright © 2021 The Author(s). Published by Elsevier Inc. All rights reserved.)

We synthesized eleven new amiridine-piperazine hybrids 5a-j and 7 as potential multifunctional agents for Alzheimer's disease (AD) treatment by reacting N-chloroacetylamiridine with piperazines. The compounds displayed mixed-type reversible inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). Conjugates were moderate inhibitors of equine and human BChE with negligible fluctuation in anti-BChE activity, whereas anti-AChE activity was substantially dependent on N4-substitution of the piperazine ring. Compounds with para-substituted aromatic moieties (5g, 5h, and bis-amiridine 7) had the highest anti-AChE activity in the low micromolar range. Top-ranked compound 5h, N-(2,3,5,6,7,8-hexahydro-1H-cyclopenta[b]quinolin-9-yl)-2-[4-(4-nitro-phenyl)-piperazin-1-yl]-acetamide, had an IC 50 for AChE = 1.83 ± 0.03 μM (K i  = 1.50 ± 0.12 and αK i  = 2.58 ± 0.23 μM). The conjugates possessed low activity against carboxylesterase, indicating a likely absence of unwanted drug-drug interactions in clinical use. In agreement with analysis of inhibition kinetics and molecular modeling studies, the lead compounds were found to bind effectively to the peripheral anionic site of AChE and displace propidium, indicating their potential to block AChE-induced β-amyloid aggregation. Similar propidium displacement activity was first shown for amiridine. Two compounds, 5c (R = cyclohexyl) and 5e (R = 2-MeO-Ph), exhibited appreciable antioxidant capability with Trolox equivalent antioxidant capacity values of 0.47 ± 0.03 and 0.39 ± 0.02, respectively. Molecular docking and molecular dynamics simulations provided insights into the structure-activity relationships for AChE and BChE inhibition, including the observation that inhibitory potencies and computed pK a values of hybrids were generally lower than those of the parent molecules. Predicted ADMET and physicochemical properties of conjugates indicated good CNS bioavailability and safety parameters comparable to those of amiridine and therefore acceptable for potential lead compounds at the early stages of anti-AD drug development., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The bioactive peptides and trace element selenium (Se) both have good antioxidant activity. However, whether combined Se and bioactive peptides have more excellent antioxidant activity remain unknown. The aim of this study is to prepare a Se-rich peptide fraction containing both Se and peptides from Se-rich yeast protein hydrolysate and investigated its antioxidant activity and effect on ultraviolet B (UVB) radiation-induced skin oxidative damage. The peptide fractions with different molecular weight (MW) and Se content were obtained by enzymatically hydrolyzing normal or Se-rich yeast proteins followed by a filtration process. In vitro free radical scavenging and lipid peroxidation inhibition assays showed that Se-rich peptides fraction with lower MW of <1 kDa (sSeP) had the highest antioxidant activity compared with Se-rich peptide fractions with higher MW of <3 kDa or normal peptide fractions. Oral administration of sSeP significantly decreased the level of malonaldehyde (MDA) in liver and serum, and increased the activity of glutathione peroxidase (GPx) in liver and serum in normal mice. When topically applied on the dorsal skin of mice, sSeP effectively alleviate UVB radiation-induced skin damage and oxidative stress by increasing GPx and catalase activities and glutathione content in skin or serum. Furthermore, sSeP showed a protective effect against H 2 O 2 -induced cytotoxicity in cultured human epidermal keratinocytes (HaCaT) cells probably by increasing aquaporin-3 expression and attenuating the phosphorylation of p38 MAPK. Overall, the results showed that Se-rich yeast peptide fraction containing Se and bioactive peptides could be a promising antioxidant nutrient used as food additive to enhance the body's antioxidant ability or as cosmeceutical product to minimize the skin oxidative damage., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Antioxidants have been the subject of intense research interest due to their numerous health benefits. In this work, a series of new conjugates of hydroxytyrosol and coumarin were synthesized and evaluated for their free radical scavenging, toxicity and antioxidant mechanism in vitro. The all target compounds 14a-t exhibited better radical scavenging activity than BHT, hydroxytyrosol, and coumarin in both DPPH radical and ABTS + radical cation scavenging assays. The structure-activity relationships study indicated that the number and position of hydroxyl groups on the coumarin ring were vital to a good antioxidant capacity. Furthermore, the most promising compound 14q showed less toxicity in hemolysis assay and weaker antiproliferative effects than BHT against normal WI-38 and GES cells, and enhanced viability of H 2 O 2 -induced HepG2 cells. Additionally, 14q decreased the apoptotic percentage of HepG2 cells, reduced the ROS produce and LDH release, and improved GSH and SOD levels in H 2 O 2 -treated HepG2 cells. Lastly, 14q exhibited more stability than hydroxytyrosol in methanol solution. These results revealed that conjugations of hydroxytyrosol and coumarin show better antioxidant capacity, and are the efficacious approach to finding novel potential antioxidant., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Thirty benzofuran-2-yl(phenyl)methanones 1-30 were synthesized and characterized their structures by spectroscopic techniques. Substituted phenacyl bromide and different derivatives of 2-hydroxy-benzaldehyde treated in the presence of anhydrous K 2 CO 3 in acetonitrile at room temperature to afford the desired benzofurans 1-30. All compounds were screened for their in vitro α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. Results revealed that para substituted compounds were found to be more active than the others with IC 50 values ranges for α-amylase inhibition (IC 50  = 18.04-48.33 µM), DPPH (IC 50  = 16.04-32.33 µM) and ABTS (IC 50  = 16.99-33.01 µM) radical scavenging activities. Activities results were compared with the standards acarbose (IC 50  = 16.08 ± 0.07 µM) for α-amylase, ascorbic acid (IC 50  = 15.08 ± 0.03 and 15.09 ± 0.17 µM) for DPPH and ABTS radical scavenging activities, respectively. Kinetic studies predicted that all compounds followed non-competitive mechanism of inhibition. Molecular docking results showed good protein-ligand interactions profile against the corresponding target. To the best of our knowledge, out of thirty molecules, ten compounds 18-20, 22, and 25-30 were structurally new., (Copyright © 2020 Elsevier Inc. All rights reserved.)

In this work, the synthesis method and applications of nanocomposite polymer stabilized silver nanoparticles (AgNPs) are reported. 3-Aminophenyl boronic acid (3APBA) was used as a reductant of silver nitrate which acted as an oxidant for the polymerization of 3APBA through in situ chemical oxidative polymerization to poly(3-aminophenyl boronic acid) or PABA. The formation of PABA in the reaction mixture led to particle agglomeration owing to PABA poor solubility. However, in the presence of hydrophilic poly(vinyl alcohol) (PVA), PABA binds to the free hydroxyl group of PVA to form a composite polymer (PABA-PVA), which perfectly stabilized the formed AgNPs. Succinctly, PVA acted as a solubilizer and stabilizer for (PABA-PVA)AgNPs synthesis. Synthesis was optimized and sharp absorption peaks at 290 nm and 426 nm were observed, attributing to the π-π* transition of the benzenoid ring of PABA and the characteristic absorption spectrum of AgNPs, respectively. (PABA-PVA)AgNPs was characterized using UV-vis, TEM, FESEM, EDX, XRD, FTIR, TGA/DTG, DLS and zeta potential analysis. In addition, the antibacterial, antioxidant and metal chelating capacities of (PABA-PVA)AgNPs were evaluated. The (PABA-PVA)AgNPs exhibited significant antibacterial activity against Escherichia coli and Listeria monocytogenes, and good antioxidant and metal chelating properties of (PABA-PVA)AgNPs, thus validating its attractive biological applications., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Multi-targeted anticancer drugs are in focus as a promising research topic. A new series of benzothiazoles hybridized with pyrimidine moiety was designed and synthesized using the lead compound 4a. Various chemical modifications on the pyrimidine ring of 4a at four different positions were done in a trial to get new multi-targeted anticancer agents. The structures of the newly synthesized compounds were established on their elemental analyses and spectral data. All final synthesized derivatives were submitted to the National Cancer Institute (NCI), USA, to be screened for their in vitro anticancer activity. Further evaluation for the cytotoxic activity of the most active compounds was performed using the MTT assay method. Compounds 4d, 8d, 8h, 8i and 17 were then selected for examining their in vitro enzyme inhibitory activities against EGFR, HER2 and TS enzymes using lapatinib and 5FU as standards. Furthermore, cell cycle analysis and apoptosis induction detection were also evaluated. Finally, molecular docking studies were carried out for compounds 4d, 8d, 8h, 8i and 17 to interpret their observed enzymatic activities based on the ligand-protein interactions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The Scrophularia genus is a rich source of phenylethanoid glycosides, with diverse biological activities including anti-diabetic properties. This study investigated anti-type 2 diabetic potential and active component of Scrophularia flava Grau. A new phenylethanoid glycoside was isolated from aerial parts of the plant and identified as 2-(4-hydroxy-3-methoxyphenyl) ethyl 6-deoxy-3-O-[(2E)-3-(3 hydroxy-4-methoxyphenyl) prop-2-enoyl]-α-rhamnopyranosyl-(1 → 3)-[α-rhamnopyranosyl-(1 → 6)]-4-O-[(2E)-3-(4-hydroxy-3-methoxyphenyl) prop-2-enoyl]-β-glucopyranoside. It was named flavaioside. The structure of flavaioside was identified based on 1 H NMR, 13 C NMR, DEPT-HSQC, COSY, HMBC, NOESY and LC-ESI-MS-MS. Total methanol extract, fractions (A-F) and specific main phenylethanoid glycoside (flavaioside), were assessed for inhibitory effects against the α-glucosidase enzyme (in vitro anti-type 2 diabetic assay). The antioxidant activities of methanol extracts, all fractions and isolated flavaioside were identified based on 2, 2'-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging activity, 2, 2'-azino-bis (3-ethylbenzothiazoline)-6-sulphonic acid radical cation (ABTS + ) scavenging activity, phosphomolybdenum method, and metal chelating activity. In comparison to the other fractions, the best antioxidant result was observed in fraction E and its main compound, flavaioside, in DPPH (IC 50  = 4.26, 2.57 µg/mL) and ABTS + (EC 50  = 55.45, 6.34 µg/mL) scavenging activities. Flavaioside showed significantly stronger activities than α-tocopherol and ascorbic acid in DPPH and ABTS + assays. Furthermore, flavaioside showed a potent inhibitory activity on the α-glucosidase enzyme which was comparable with the known anti-type 2 diabetic drug, acarbose (91.85%, and 92.87%, respectively). Fraction E and flavaioside showed α-glucosidase inhibitory activities with IC 50 values, 65.05 and 6.50 µg/mL. The plant and its isolated flavaioside can possess acceptable anti-type 2 diabetic potential and anti-oxidant activity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Nitroxides and nitroxide-containing nanoparticles (RNP) are excellent antioxidants. However, they have relatively high reduction potentials, which make them behave like oxidants or show little activity in some antioxidant assays. We found that stable nitroxyl radicals (TEMPO and 4-amino-TEMPO) has low reactivity in the test of scavenging of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) radical (ABTS • ). As a result, supplementation of blood plasma with nitroxides may decrease its total antioxidant capacity assayed with ABTS • . Nitroxides oxidize Fe 2+ and in this way interfere with the ferric-Xylenol Orange assay of peroxides. Nitroxides as well as RNP directly oxidize glutathione and fluorogenic probes used for estimation of reactive oxygen species (ROS) (dihydro-2'7'-dichlorofluorescein diacetate, dihydroethidine and dihydrorhodamine 123) and thus produce artefacts in assays of glutathione and ROS in cell-free and cellular systems. These results point to the necessity of careful interpretation of antioxidant assays concerning nitroxides and RNP or performed in their presence., Competing Interests: Declaration of competing interest All authors declare that they have no conflicts of interest with respect to the research, authorship, and/or publication of this article., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The functional gelatin/curcumin composite film was prepared using an emulsifier, sodium dodecyl sulfate (SDS). The composite films were characterized using field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR). The FE-SEM test results showed that curcumin was evenly distributed in the gelatin polymer matrix to form a flexible composite film with a smooth surface. The addition of 1.5 % of curcumin improved the UV blocking effect by more than 99 % at a loss of 5.7 % of transparency compared to neat gelatin films. The addition of curcumin (up to 1 wt%) significantly improved mechanical and water vapor barrier properties. Also, the gelatin/curcumin composite films exhibited remarkable antimicrobial activity against foodborne pathogenic bacteria, E. coli and L. monocytogenes, and showed strong antioxidant activity comparable to ascorbic acid. Antibacterial and antioxidant gelatin/curcumin composite films with improved UV protection, water vapor barrier and mechanical properties have high potential in active food packaging applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)

In this paper, polysaccharides from the seeds of three species of genus Glycyrrhiza were extracted to investigate the physicochemical properties, structural characteristics and antioxidant activities. The polysaccharides were composed of xylose, mannose, galactose, and glucose with different molar ratio. Fourier transform infrared spectroscopy showed the presence of key functional groups of polysaccharides whereas scanning electron microscopy analysis revealed the characteristic morphology of different polysaccharides, and thermogravimetric analysis exhibited good thermal stability of all samples. The antioxidant activities of polysaccharides were evaluated in vitro. All the three polysaccharides demonstrated strong reducing power, as well as scavenging activity against DPPH, ABTS, and hydroxyl free radicals. Antioxidant assays indicated that all the polysaccharides have obvious antioxidant activities and possess a potential development and application value in food, cosmetics as well as pharmaceutical industries., (Copyright © 2019 Elsevier B.V. All rights reserved.)

We synthesized conjugates of tacrine with 1,2,4-thiadiazole derivatives linked by two different spacers, pentylaminopropene (compounds 4) and pentylaminopropane (compounds 5), as potential drugs for the treatment of Alzheimer's disease (AD). The conjugates effectively inhibited cholinesterases with a predominant effect on butyrylcholinesterase (BChE). They were also effective at displacing propidium from the peripheral anionic site (PAS) of acetylcholinesterase (AChE), suggesting that they could block AChE-induced β-amyloid aggregation. In addition, the compounds exhibited high radical-scavenging capacity. Conjugates 5 had higher anti-BChE activity and greater anti-aggregant potential as well relatively lower potency against carboxylesterase than compounds 4. Quantum-mechanical (QM) characterization agreed with NMR data to identify the most stable forms of conjugates for docking studies, which showed that the compounds bind to both CAS and PAS of AChE consistent with mixed reversible inhibition. Conjugates 4 were more potent radical scavengers, in agreement with HOMO localization in the enamine-thiadiazole system. Computational studies showed that all of the conjugates were expected to have good intestinal absorption, whereas conjugates 4 and 5 were predicted to have medium and high blood-brain barrier permeability, respectively. All conjugates were predicted to have medium cardiac toxicity risks. Overall, the results indicated that the conjugates are promising candidates for further development and optimization as multifunctional therapeutic agents for the treatment of AD., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Diabetes is one of the metabolic disorders in the world. It is the prime reason of mortality and morbidity owing to hyperglycemia which is link with numerus obstacles. Artemisia argyi is commonly used as an ingredient in healthy foods as well as an herbal medicine in Asian countries. The present research aims to evaluate the hypoglycemic effects of A. argyi and reveal its the potentially active constituents. The chemical composition was identified by HPLC-DAD-Q-TOF-MS, and fractionation was performed by extraction. The fractions were assessed by the blood glucose level, oral glucose tolerance and small intestinal α-glucosidase inhibitory tests, and an analysis of the total phenolic content (TPC), antioxidant and α-glucosidase inhibitory activities. In our efforts to characterize the compounds responsible for hypoglycemic effect, bioactivity-guided fraction of the MeOH extract and chemical investigation of its active EtOAc fraction led to the successful identification of caffeoylquinic acids, which were elucidated by molecular docking, using the crystal structure of S. cerevisiae isomaltase (PD code: 3AXI). In summary, this bio-guided search revealed that caffeoylquinic acids from A. argyi as potential active constituents displayed with hypoglycemic activity, which provided a basis for further study of pharmacological activity., (Copyright © 2019 Elsevier Inc. All rights reserved.)

A series of (hetero)arylethenesulfonyl fluorides (1-58) were synthesized and screened for their in vitro antioxidant (DPPH, ABTS and DMPD methods) and anti-inflammatory activities. The results revealed that compounds 4, 15, 16, 24, 25, 26, 38, 39, 40, and 54 exhibited excellent antioxidant activity using all the three performed antioxidant methods, which were superior to the standard antioxidants ascorbic acid and gallic acid. Compounds 6-9, 11, 18, 19, 21, 22, 30, 39, 40, 44, 45, 48-50, 54, 55 and 57 displayed promising anti-inflammatory activity, which were better than the reference drug indomethacin. Preliminary structure-activity relationship (SAR) revealed that compounds containing electron donating (OH and OCH 3 ) groups on the phenyl ring possessed excellent antioxidant properties while compounds containing electron-withdrawing (Cl, NO 2 , F and Br) groups on the phenyl ring were found to be most potent anti-inflammatory agents. The presence of SO 2 F group played a crucial role in increases both antioxidant and anti-inflammatory activities., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In this paper, a series of novel bromophenol derivatives were synthesized and evaluated for their acetylcholinesterase and α-glycosidase enzymes inhibition properties and antioxidant activity. Diarylmethanones were synthesized and their bromination was carried out. During bromination, some compounds gave new bromophenols via regioselective O-demethylation. Demethylation of brominated diarylmethanones was also performed with BBr 3 to give novel bromophenols. In addition, we examines the antioxidant capacity of novel bromophenol derivatives using several in vitro bioanalytical methodologies such as 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS⋅ + ) and 1,1-diphenyl-2-picryl-hydrazyl free radical (DPPH) radical scavenging activity, Fe 3+ and Cu 2+ reducing activities and ferrous (Fe 2+ ) ions chelating activities. Also, novel bromophenols and methoxylated bromophenols derivatives were tested against acetylcholinesterase and α-glycosidase, which associated with some metabolic diseases. The novel bromophenols showed Ki values in range of 8.94 ± 0.73-59.45 ± 14.97 nM against AChE and 4.31 ± 1.93-44.14 ± 2.19 nM against α-glycosidase., (Copyright © 2019 Elsevier Inc. All rights reserved.)

In this research, the antioxidant property of thymosin alpha-1 (Thα1) peptide was investigated through various antioxidant methods. Thα1 showed 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (IC 50  = 20 µM) and its 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging reached 45.33% at 80 µM (IC 50  = 85 µM). In addition, hydroxyl and superoxide radical scavenging of Thα1 peptide exhibited a concentration-depended manner. The IC 50 values of hydroxyl and superoxide radical scavenging were estimated to be 82 µM and 20 µM, respectively. The effect of Thα1 on eliminating superoxide radicals was higher (62.23%) than other antioxidant assays. Moreover, the antioxidant activity of Thα1 peptide was evaluated by measuring cellular reactive oxygen species (ROS). Results indicated that Thα1 decreased the generation of ROS level in 1321 N1 human neural asterocytoma cells. The inhibitory effect of Thα1 on angiotensin-converting enzyme (ACE) was determined. The kinetic parameters (K m and V max ) and the inhibition pattern were examined. Based on the Lineweaver-Burk plot, Thα1 displayed a mixed inhibition pattern. The IC 50 and K i values of Thα1 were 0.8 µM and 3.33 µM, respectively. Molecular modeling suggested that Thα1 binds to ACE-domains with higher affinity binding to N-domain with the binding energy of -22.87 kcal/mol. Molecular docking indicated that Thα1 interacted with ACE enzyme (N- and C-domains) due to electrostatic, hydrophobic, and hydrogen forces. Our findings suggested that Thα1 possess a multifunctional peptide with dual antioxidant and ACE-inhibitory properties. Further researches are needed to investigate the antioxidant and anti-hypertensive effect of Thα1 both in vitro and in vivo., (Copyright © 2019 Elsevier Inc. All rights reserved.)

An efficient and convenient Meglumine catalyzed procedure for the synthesis of bis(indolyl) methanes at ambient temperature under aqueous conditions in high yields. The catalytic reaction proceeds very smoothly. Clean reaction, ease of product isolation/purification, easily available reactants, metal free and environmentally friendly reaction conditions are the notable advantages of the present methodology. All the entitled compounds were characterized by IR, 1 H, 13 C NMR, mass spectra and evaluated for their antioxidant (DPPH, H 2 O 2 and NO scavenging methods). They exhibited potent in vitro antioxidant activity dose-dependently. The binding interactions and molecular docking studies for entitled compounds were studied against 3MNG protein. 4d exhibited marked binding affinity with excellent docking score of -7.6 K.cal/mol and emerged as a lead compound., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Stem of Vigna angularis (Willd.) Ohwi & H. Ohashi (VAS) is a main byproduct with considerable bioactivities. In present study, a bioassay-guided phytochemical investigation was used and led to the isolation of 16 compounds including one new compound (1) and one compound (2) isolated from nature source firstly along with 14 known compounds (3-16). The structures of isolates were identified by NMR and HR-ESI-MS data. The ability of antioxidant and α-glucosidase inhibition of the compounds were measured in vitro. Most of the ingredients shown strong ABTS radical scavenging activity (IC 50  = 4.21-14.93 μM) and α-glucosidase inhibitory activity (IC 50  = 0.05-34.14 μM). Enzyme kinetic analysis and molecular docking of compounds 1 and 2 were conducted. Compounds 1 and 2 were competitive inhibitor for α-glucosidase, with the inhibition kinetic constant value of 1.03 and 1.06 μM, respectively. The potent α-glucosidase inhibitory ability of compounds 1 and 2 resulted from firm binding with the active site of α-glucosidase., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Two series of sulfonylpiperazines linked [1,3]dioxolo[4,5-g]chromenones were synthesized featuring phenyl (7a-k) and chalcone (12a-k) bridge representing flavones or homoisoflavonoids core. New molecules are synthesized utilizing aldol condensation to inspect as antioxidants against DPPH and ABTS + and antiproliferative agents toward selected human cancer cell lines. Cytotoxicity of new compounds was confirmed using SRB assay against non-cancer MDCK cell line. The results concluded that both individual structures of 7 and 12 were vital for modulating pharmacological potencies and presence of different electron withdrawing and electron donating functional group(s) on the phenylsulfonyl entity yielded varied biological effects. Substituent h (OCF 3 ) and j, k (OCH 3 ) were found to play a crucial role scavenging DPPH and ABTS + as well as inhibiting cancer cell lines SK-OV-3 and HT-29. Moreover, molecules bearing halogen atom(s) such as substituent b-g expressed excellent inhibitory potential against HeLa and A-549 cancerous cell lines. Bioassay data displayed some interesting structure-activity relationships which are discussed in this paper. The results justified that tested derivatives are promising antioxidants and cytotoxic agents and warrant further structural optimization and bioassay studies. Spectroscopic techniques such as FT-IR, 1 H NMR, 13 C NMR and elemental analysis (CHN) were carried out to confirm the final structures., (Copyright © 2019. Published by Elsevier Inc.)

A group of N-benzylpiperidine-3/4-carbohydrazide-hydrazones were designed, synthesized and evaluated for acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) activities, Aβ 42 self-aggregation inhibitory potentials, and antioxidant capacities, in vitro. All of the compounds displayed eeAChE and huAChE inhibitory activity in a range of IC 50  = 5.68-11.35 µM and IC 50  = 8.80-74.40 µM, respectively and most of the compounds exhibited good to moderate inhibitory activity on BuChE enzyme. Kinetic analysis and molecular modeling studies were also performed for the most potent compounds (1g and 1j). Not only the molecular modeling studies but also the kinetic analysis suggested that these compounds might be able to interact with the catalytic active site (CAS) and the peripheral anionic site (PAS) of the enzymes. In the light of the results, compound 1g and compound 1j may be suggested as lead compounds for multifunctional therapy of AD., (Copyright © 2018 Elsevier Inc. All rights reserved.)

To contribute towards effective exploitation and utilization of natural antioxidants, response surface methodology (RSM) was employed to optimize the medium composition for the production of exopolysaccharides from the medicinal mushroom Ganoderma lingzhi (GLEPS). An optimal medium for GLEPS production was gave through Plackett-Burman design, path of steepest ascent, and Box-Behnken design as follows: glucose (59.62 g/L), yeast extract (10.03 g/L), CaCO 3 (0.2 g/L), thiamine (45.13 mg/L), KH 2 PO 4 (1.0 g/L), peptone (1.5 g/L), Tween 80 (10.26 mL/L), ZnSO 4 (0.3 g/L), mannitol (1.5 g/L), MgSO 4 (0.5 g/L), and aspartate (8.86 g/L). The GLEPS yield obtained was 3.57 ± 0.21 g/L-3.16-fold higher than that produced in basal medium alone. The resulting GLEPS rich in uronic acid, d-mannose, l-rhamnose, and d-glucose, was a heteropolysaccharide with high-molecular weights (475,000 kDa and 21.6 kDa, 87.97%). It was demonstrated that the GLEPS with higher carbohydrate and uronic acid contents exhibited strong in vitro antioxidant activities via radical scavenging, reductive capacity, and chelation of transition metal catalysis. These findings indicated that RSM is an efficient tool to predict the composition of culture medium required for maximizing GLEPS yield, and GLEPS had potent antioxidant activities and could be explored as a novel natural antioxidant in functional food or medicine., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Dihydropyridines (DHPs) obtained from Hantzsch multicomponent reactions are an important pharmaceutical class of compounds marketed as antihypertensive (e.g., nifedipine, nitrendipine, and amlodipine) drugs. This study synthesized new symmetrical and unsymmetrical long-chain fatty DHPs using multicomponent reactions under metal-free conditions with sulfamic acid as a catalyst. The DHPs were tested for antioxidant activity using three different methods. The insertion of a long chain into the DHP core contributed to antioxidant potential, and compounds derived from nitro aldehydes have better antioxidant potential than the antihypertensive drug nifedipine. In addition, fatty analogs to nifedipine derived from palmitic and oleic chains showed similar antioxidant activity to the common standards butylated hydroxytoluene and vitamin E. These results showed that our new synthesized products may find novel applications as antioxidant additives or for tools for use in drug discovery., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The genus Silene is renowned in Turkey for its traditional use as food and medicine. Currently, there are 138 species of Silene in Turkey, amongst which have been several studies for possible pharmacological potential and application in food industry. However, there is currently a paucity of data on Silene salsuginea Hub.-Mor. This study endeavours to access its antioxidant, enzyme inhibitory, and anti-inflammatory properties. Besides, reversed-phase high-performance liquid chromatography-diode array detector (RP-HPLC-DAD) was used to detect phenolic compounds, and molecular docking was performed to provide new insights for tested enzymes and phenolics. High amounts of apigenin (534 μg/g extract), ferulic acid (452 μg/g extract), p-coumaric acid (408 μg/g extract), and quercetin (336 μg/g extract) were detected in the methanol extract while rutin (506 μg/g extract) was most abundant in the aqueous extract. As for their biological properties, the methanol extract exhibited the best antioxidant effect in the DPPH and CUPRAC assays, and also the highest inhibition against tyrosinase. The aqueous extract was the least active enzyme inhibitor but showed the highest antioxidant efficacy in the ABTS, FRAP, and metal chelating assays. At a concentration of 15.6 μg/mL, the methanol extract resulted in a moderate decrease (25.1%) of NO production in lipopolysaccharide-stimulated cells. Among the phenolic compounds, epicatechin, (+)-catechin, and kaempferol showed the highest binding affinity towards the studied enzymes in silico. It can be concluded that extracts of S. salsuginea are a potential source of functional food ingredients but need further analytical experiments to explore its complexity of chemical compounds and pharmacological properties as well as using in vivo toxicity models to establish its maximum tolerated dose., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A novel polysaccharide named Sorghum Water-Soluble Polysaccharide (SWSP) was purified from Sorghum bicolor (L.) seeds. It was structurally characterized by high performance liquid chromatography (HPLC), thin layer chromatography (TLC), Fourier transform-infrared spectroscopy analysis (FT-IR), X-ray diffraction (XRD) and mass spectroscopy (MS). HPLC and TLC showed that SWSP is a glucose polymer. The FT-IR spectrum proved the polysaccharide characteristic band of SWSP. XRD and microscopy analyses revealed that SWSP is a semi-crystalline polymer. Functional properties of SWSP were determined based on Water Holding Capacity (WHC), Oil Holding Capacity (OHC) and emulsification properties. SWSP showed good WHC and OHC, recorded at 3.01±0.03 and 1.02±0.03g/g, respectively and exhibited excellent emulsion properties even after 168h (61.5±0.02%). The effect of SWSP on oxidative stability of sausage during storage up to 12days at 4°C was investigated. Results showed a high rate (P<0.05) of oxymyoglobin and low lipid oxidation. The antioxidant activities of SWSP were also studied in vitro. Results demonstrated that the polysaccharides exhibited interesting 1,1-diphenyl-2-picrylhydrazyl (DPPH), ABTS radical scavenging, and ß-carotene bleaching inhibition activities. Overall, this natural polysaccharide was proved to enhance the oxidation stability of sausages, since it can efficiently substitute synthetic antioxidants in meat industry., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Lectins are proteins able to interact specifically and reversibly with carbohydrates. They are present in all living beings, particularly in legume seeds, which have many biological functions. The aim of this study was to isolate, characterize and verify antioxidant, anti-hemolytic, antitumor and gastroprotective activities in a lectin present in seeds of Phaseolus lunatus L. var. cascavel (PLUN). The isolation of lectin was performed by size exclusion chromatography on Sephadex G-100, which was isolated from a protein capable of agglutinating only human erythrocytes type A, being this the only inhibited haemagglutination n-acetyl-d-galactosamine. Its weight was estimated by PAGE is 128kDa. The lectin is thermostable up to 80°C and is active between pH 2-11. As 8M urea was able to denature the lectin. PLUN is a glycoprotein consisting of 2% carbohydrate and has antioxidant action with ascorbic acid equivalent antioxidant capacity (μMAA/g) of 418.20, 326 and 82.9 for total antioxidant activity, ABTS radical capture and capture of DPPH radical, respectively. The lectin has antitumor activity against melanoma derived cells at doses of 100 and 50mg/ml, reducing up to 83% tumor cells, and gastroprotective action, reducing up to 63% damaged area of ​​the stomach induced by ethanol., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Purification, preliminary characterization and bioactivity of polysaccharides from Grateloupia livida (GL) were investigated. Three water-soluble sulfated polysaccharide fractions (GLP-1, GLP-2 and GLP-3) were isolated and purified from the edible and medicinal red seaweed, Grateloupia livida (Harv.) Yamada by DEAE Sepharose CL-6B and Sephadex G-100 column chromatography, and chemical characterization was performed by HPGPC, GC-MS, FT-IR and SEM. In addition, anticoagulant activities were determined by activated partial thromboplastin time (APTT), thrombin time (TT) and prothrombin time (PT) using normal human plasma in vitro. The antioxidant activities against DPPH and ABTS + radicals were evaluated and compared. The molecular weights of GLP-1, GLP-2 and GLP-3 were 39.5, 60.4 and 3.36kDa, respectively. Monosaccharide analysis revealed that three polysaccharide fractions were homopolysaccharides and comprised of galactose only. Anticoagulant assays indicated that crude GLP, and purified GLP-1 and GLP-2 effectively prolonged APTT and TT, but not PT. All polysaccharide fractions exhibited significant in vitro antioxidant activities in a dose-dependent manner. GLP-2 showed consistently better anticoagulant and antioxidant activities compared with GLP, GLP-1 and GLP-3. These results demonstrate that sulfated polysaccharides isolated from Grateloupia livida can serve as readily available alternative natural sources of anticoagulant and antioxidant agents., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A water-soluble polysaccharide named as CSP-2 was isolated and purified from Chaenomeles speciosa by DEAE-Sepharose and Sephadex G-100 column chromatography. CSP-2 was composed of galactose (Gal), rhamnose (Rha), glucose (Glc) and xylose (Xyl) with a relative molar ratio of 3.8:1.6:1.2:0.4. The average molecular weight of CSP-2 was estimated to be about 4.6×10 4 Da. The in vitro antioxidant assay showed that CSP-2 exhibited remarkable antioxidant activities to scavenge the DPPH radical, superoxide radical, hydroxyl radical and ABTS radical and significant cytoprotective effects on H 2 O 2 -induced PC12 cells injury in a concentration-dependent manner. Overall, CSP-2 may be useful as a naturally potential antioxidant agent for application in food and medicinal fields., (Copyright © 2016 Elsevier B.V. All rights reserved.)

From the reaction of Cu(II) with the non-steroidal anti-inflammatory drug ketoprofen (Hketo), complex [Cu 2 (keto) 4 (H 2 O) 2 ] was isolated, while the presence of a N,N'-donor heterocyclic ligand 2,2'-bipyridylamine (bipyam), 1,10-phenanthroline (phen) or 2,2'-bipyridine (bipy) led to the formation of complexes of the formula [Cu(keto) 2 (N,N'-donor)(H 2 O)]. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structure of [Cu(keto) 2 (bipyam)(H 2 O)] was determined by X-ray crystallography. The ability of ketoprofen and its complexes to scavenge 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals was evaluated; the complexes were more active scavengers than free Hketo. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the binding constant of the compounds to the albumins were calculated. Diverse techniques including UV spectroscopy, cyclic voltammetry and viscosity measurements as well as fluorescence emission spectroscopy for the competitive studies of the compounds with ethidium bromide, were employed in our attempt to examine the interaction of the compounds with calf-thymus DNA; as a conclusion, intercalation is the most possible mode of binding., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The reaction of NiCl 2 with the non-steroidal anti-inflammatory drug diflunisal (Hdifl) resulted in the formation of complex [Ni(difl-O) 2 (MeOH) 4 ], 1. The co-existence of a N,N'-donor heterocyclic ligand 2,2'-dipyridylketone oxime (Hpko), 1,10-phenanthroline (phen), 2,2'-bipyridine (bipy) and 2,2'-bipyridylamine (bipyam) led to the formation of complexes [Ni(difl-O) 2 (Hpko-N,N') 2 ], 2, [Ni(difl) 2 (phen)(MeOH) 2 ], 3, [Ni(difl) 2 (bipy)(MeOH) 2 ], 4 and [Ni(difl-O,O') 2 (bipyam)], 5, respectively. The complexes were characterized by physicochemical and spectroscopic techniques and the crystal structures of complexes 1 and 2 were determined by X-ray crystallography. The ability of the complexes to scavenge in vitro 1,1-diphenyl-picrylhydrazyl, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) and hydroxyl radicals was investigated; the complexes were more active scavengers than free Hdifl. The interaction of the complexes with serum albumins was investigated by fluorescence emission spectroscopy and the binding constants of the compounds to the albumins were calculated. UV spectroscopy, cyclic voltammetry and viscosity measurements as well as fluorescence emission spectroscopy for the competitive studies of the complexes with ethidium bromide were employed so as to monitor the interaction of the compounds with calf-thymus DNA and revealed intercalation as the most possible mode of binding., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Pramipexole is a dopaminergic agonist used in Parkinson's disease treatment. It is thought to exert its therapeutic and side effects through actions on dopamine D3 receptors. In a recent study, we found that at doses occupying D3 but not D2 receptors pramipexole reduced locomotion and operant responding for primary and conditioned reinforcement. These effects, however, were not blocked by a D3 receptor antagonist and were present in D3 knockout mice, suggesting non-D3 receptor mechanisms. Among the next highest affinity binding sites of pramipexole are adrenergic α2 receptors. Here we explored α2 receptor involvement in the behavioural effects of pramipexole. We found that the α2 antagonist atipamezole, which was itself behaviourally silent, counteracted pramipexole's reduction of locomotion, but not operant responding for water or a conditioned reinforcer. The resulting behavioural profile was similar to that of a higher dose of pramipexole, leading to the hypothesize that atipamezole mediates its behavioural effects by increasing pramipexole effective dose. In support of this hypothesis, we found that atipamezole increased pramipexole concentration in blood plasma. This is not likely due to an effect on drug metabolism since pramipexole is not known to undergo metabolic transformation. Future work should examine two alternative hypotheses; that pramipexole plasma concentration is elevated as the result of 1) competition with atipamezole for renal excretion, or 2) atipamezole blockade of peripheral α2 binding sites, thereby preventing pramipexole distribution to α2-rich tissues. The suggestion of adrenergic effects of pramipexole is important in light of recent interest in adrenergic pathophysiology in Parkinson's disease., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Garcinia hombroniana (seashore mangosteen) in Malaysia is used to treat itching and as a protective medicine after child birth. This study was aimed to investigate the bioactive chemical constituents of the bark of G. hombroniana. Ethyl acetate and dichloromethane extracts of G. hombroniana yielded two new (1, 9) and thirteen known compounds which were characterized by the spectral techniques of NMR, UV, IR and EI/ESI-MS, and identified as; 2,3',4,5'-tetrahydroxy-6-methoxybenzophenone(1), 2,3',4,4'-tetrahydroxy-6-methoxybenzophenone (2), 2,3',4,6-tetrahydroxybenzophenone (3), 1,3,6,7-tetrahydroxyxanthone (4), 3,3',4',5,7-pentahydroxyflavone (5),3,3',5,5',7-pentahydroxyflavanone (6), 3,3',4',5,5',7-hexahydroxyflavone (7), 4',5,7-trihydroxyflavanone-7-rutinoside (8), 18(13→17)-abeo-3β-acetoxy-9α,13β-lanost-24E-en-26-oic acid (9), garcihombronane B (10), garcihombronane D (11), friedelan-3-one (12), lupeol (13), stigmasterol (14) and stigmasterol glucoside (15). In the in vitro cytotoxicity against MCF-7, DBTRG, U2OS and PC-3 cell lines, compounds 1 and 9 displayed good cytotoxic effects against DBTRG cancer cell lines. Compounds 1-8 were also found to possess significant antioxidant activities. Owing to these properties, this study can be further extended to explore more significant bioactive components of this plant., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The aim of this study was to investigate the impact of inhibition of p53 in X-irradiated human peripheral blood lymphocytes (HPBL) in the G0 phase of the cell cycle in the presence or absence of pifithrin-alpha (PFT-alpha), a specific inhibitor of p53, on repair of DNA damage or induced apoptosis. Lymphocyte (HPBL) cultures were X-irradiated with 3 Gy in the absence or presence of PFT-alpha. In order to distinguish the effects of PFT-alpha either on DNA repair or on apoptosis, PFT-alpha was added to the cultures employing different protocols namely, a) "continuous treatment", where PFT-alpha was added four hours before X-irradiation and left until the end of the experiment, b) "pre-treatment", where PFT-alpha was added four hours before X-irradiation and removed by washing the cells with phosphate buffered saline (PBS) four hours after irradiation and c) "post-treatment", where PFT-alpha was added four hours after irradiation and left in the medium until the harvest. At various times after irradiation of lymphocytes, Single Cell Gel Electrophoresis was performed to detect DNA damage in individual cells. Apoptosis and chromosomal aberrations were quantified at later sampling times following irradiation. The results presented here strengthen the known role of p53 protein in priming apoptotic cell death in HPBL following X-irradiation. Furthermore, our data suggest that the inhibition of p53 by PFT-alpha affects the repair kinetics of X-ray induced DNA lesions leading to mis-repair events and consequently to an enhancement of cytogenetic damage in HPBL., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)