Yacon (Smallanthus sonchifolius Poepp. & Endl.) as a Novel Source of Health Promoting Compounds: Antioxidant Activity, Phytochemicals and Sugar Content in Flesh, Peel, and Whole Tubers of Seven Cultivars.

The aim of this study was to evaluate the quality characteristics of seven yacon (Smallanthus sonchifolius Poepp. and Endl.) cultivars (Cajamarca, Cusco, Early White, Late Red, Morado, New Zealand and Quinault) cultivated in the southwest of Germany. The following phyto/chemical traits were investigated in different yacon tuber parts (flesh, peel, and whole tubers): total dry matter, sugar content (fructose, glucose, and sucrose content), total phenolic content (TPC), total flavonoid content (TFC), 2,20-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, and Ferric reducing antioxidant power (FRAP). The results indicated a significant interaction between cultivar and tuber part on all of the examined traits (p < 0.0001). Of flesh and whole tuber, cv. Late Red, cv. Morado, and cv. Cajamarca had the highest TPC, TFC, DPPH radical scavenging activity, and FRAP. They also had relatively higher total sugar content. Cv. New Zealand had the lowest amount of sugars, TPC, TFC, DPPH radical scavenging activity, and FRAP, but the highest ABTS radical scavenging activity content in its flesh and whole tuber. Moreover, the results indicated that the peel of yacon tubers contained considerably high amounts of phytochemicals while possessing low sugar contents. Overall, this study provides a broad insight into the phyto/chemical content of yacon tubers from different cultivars, which can be used for further breeding programs, and the selection of proper cultivars for specific food product development.

Abalone visceral peptides containing Cys and Tyr exhibit strong in vitro antioxidant activity and cytoprotective effects against oxidative damage.

The in vitro antioxidation and cytoprotection of abalone visceral peptides against oxidative damage were investigated. Results show that the DPPH· scavenging activities of the 16 chemically synthesized peptides were significantly and positively correlated with their reducing power. Their scavenging activities against ABTS·+ were positively correlated with their ability to inhibit linoleic acid oxidation. Only Cys containing peptides exhibited good DPPH· scavenging activity, while only Tyr containing peptides showed significant ABTS·+ scavenging activity. In the cytoprotection assay, all four representative peptides significantly increased the viability of H2O2-damaged LO2 cells and the activities of GSH-Px, CAT, and SOD, and all decreased MDA levels and LDH leakage, in which the Cys-containing peptides were more effective at increasing the activities of antioxidant enzymes, while the Tyr-containing peptides were more effective at decreasing MDA levels and LDH leakage. Abalone visceral peptides containing both Cys and Tyr exhibit strong in vitro and cellular antioxidation.

Synthesis and in vitro assessment of anticholinesterase and antioxidant properties of triazineamide derivatives.

Aim: Cholinesterase inhibitors and radical scavengers have been recognized as powerful symptomatic anti-Alzheimer's disease agents. Hence, the present study aimed to develop new triazineamides as potent anticholinesterase and antioxidant agents. Methods: Triazineamide (7a-i) derivatives were synthesized using cyanuric chloride via nucleophilic substitution followed by condensation. Ellman assay, 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging assay and molecular docking studies with Autodock 4.2.3 program were conducted. Results: Triazineamide 7c was assessed as a potent, selective and mixed-type dual inhibitor of acetylcholinesterase, with and IC50 of 5.306 ± 0.002 µM, by binding simultaneously with the catalytic active and peripheral anionic sites of acetylcholinesterase, and it had strong 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) radical scavenging abilities. Conclusion: These results suggest that triazineamides may be of interest to establish a structural basis for new anti-Alzheimer's disease agents.

Enhancing antioxidant and antimicrobial activity of carnosic acid in rosemary (Rosmarinus officinalis L.) extract by complexation with cyclic glucans.

Of all the active compounds in rosemary extract, carnosic acid (CaA) has the most potent antimicrobial and antioxidant activity; however, its low solubility limits its applications. We developed complexing systems using cycloamylose (CA), branched dextrin (BD), and ß-cyclodextrin (ßCD) to improve the solubility of CaA and compared it to the use of maltodextrin (MD). The complexes formed with CA, BD, ßCD, and MD improved the water solubility of CaA by as much as 2.8-fold, 2.1-fold, 1.75-fold, and 2.06-fold, respectively. The antioxidant capacity of CaA in aqueous solutions was also enhanced in the complexes due to the increased water solubility. Interestingly, the antimicrobial activity was improved more dramatically upon complexation with CA (7.27-fold) compared to the improvement when complexed with BD (4.82-fold), ßCD (2.87-fold), and MD (3.83-fold). This may be due to the improvement of the antimicrobial potential of the functional groups of CaA by complexation with flexible cyclic glucans.

Radical scavenging activities of Tyr-, Trp-, Cys- and Met-Gly and their protective effects against AAPH-induced oxidative damage in human erythrocytes.

Radical scavenging activities of Tyr-, Trp-, Cys- and Met-Gly and their protective effects against AAPH-induced oxidative damage in erythrocytes were evaluated in this study. This damage includes hemolysis, oxidation of hemoglobin, formation of MDA and the depletion of glutathione (GSH) and catalase (CAT). Results showed that Tyr- and Trp-Gly could quench the radicals effectively in ABTS and ORAC assays with TE (Trolox equivalent) values of more than 1.0 µmol TE/µmol, followed by Cys- and Met-Gly. All these dipeptides could protect erythrocytes against AAPH-induced hemolysis in a dose-dependent manner. They could also significantly (p<0.05) retard the oxidation of hemoglobin and depletion of GSH in erythrocytes. The protective effects of these dipeptides decreased in the following order: Trp-Gly>Tyr-Gly>Met-Gly>Cys-Gly, which were consistent with their peroxyl radical scavenging activities. It suggested that these dipeptides might protect erythrocytes against AAPH-induced oxidative damage, mainly by acting as the direct radical scavengers.

Optimisation of extraction of bioactive compounds from Feronia limonia (wood apple) fruit using response surface methodology (RSM).

In this study, the extraction conditions for the maximum recovery of polyphenols with high antioxidant activity were optimised by response surface methodology (RSM) in Feronia limonia fruit. The independent variables were viz. concentration of ethanol (X1: 30-70%), incubation temperature (X2: 37-60%) and solvent-to-solid ratio (X3: 20-40%). ANOVA results showed that concentration of ethanol and temperature affected the total polyphenol content (TPC, Y1), DPPH (Y2) and ABTS (Y3) radical scavenging activities significantly (p<0.05) whereas solvent-to-solid ratio was found to be insignificant. A second-order polynomial model satisfactorily fitted the experimental data with the R(2) values of 0.966, 0.946 and 0.955, respectively for the responses Y1, Y2 and Y3 (p<0.0001), implying a good agreement between the predicted and experimental values. The optimal conditions for the highest yield of TPC (7.21±1.4 g GAE/g) with >80% radical scavenging activities were derived at X1=62.7%, X1=49.7 °C and X3=39.4 mL/g.

Pitfalls of using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay to assess the radical scavenging activity of peptides: Its susceptibility to interference and low reactivity towards peptides.

DPPH assay is widely used to evaluate the radical scavenging activities of peptides. Effects of pH and buffers on the stability of DPPH• and its reduced product (DPPHH) in the ethanol-buffer solution were investigated in this study and the reactivity of DPPH• towards several dipeptides was compared to that of 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) and the peroxyl radicals in oxygen radical absorbance capacity (ORAC) assay. Results showed that the deprotonation of DPPHH under basic condition could interfere with the spectrophotometric measurement at 515-525nm. It was suggested that the reaction mixture be maintained at a final pH range of 5.0-6.5 in 1:1 ethanol-acetate/citrate buffer medium when evaluating the activities of peptides. Additionally, among tested dipeptides, only Cys-containing dipeptides displayed DPPH• scavenging activity with 0.14-0.28µmol TE (Trolox equivalent)/µmol, while Tyr/Trp-containing dipeptides with high reactivity towards ABTS•+ and peroxyl radicals were inert to DPPH• with TE values less than 0.02.

Evaluation of Physiological Activities of the Citron (Citrus junos Sieb. ex TANAKA) Seed Extracts.

Citron seed extracts (CSEs) were made using distilled water (CSEW), ethanol (CSEE), and n-hexane (CSEH), to measure the total polyphenol contents, DPPH and ABTS radical scavenging activities, and anti-complementary activity. The total polyphenol content was observed the highest in CSEE (188.71 µg/mL), and occurred in the following order: CSEE>CSEW (141.11 µg/mL)>CSEH (26.19 µg/mL) at 10 mg/mL. CSEE (63.56%) and CSEW (56.61%) showed significantly higher DPPH radical scavenging activities when compared with CSEH (28.57%). ABTS radical scavenging activities of CSEE (45.53%) and CSEW (40.02%) were also observed to be higher, whereas CSEH did not show ABTS radical scavenging activity. Anti-complementary activity of CSEE (26.85%) showed a greater activity than that of CSEW (7.84%) at 1,000 µg/mL. Limonin and nomilin contents had the highest values (1.882% and 2.089%) in CSEE, and with 0.327% and 0.139% in CSEW; however, CSEH showed relatively very low values at 0.061% and 0.026%, respectively. Among the CSEs tested, CSEE as a by-product from citron may provide an important source of dietary antioxidant compounds with rich polyphenol and limonoid contents, and immunopotentiating activity, including the complement activation factor.

Study on Antioxidant Activity of Different Concentrations of Alcohol Extracts from Paeonia Rockii Pollen / 中国中医药信息杂志

Objective To evaluate the antioxidant activity of different concentrations of alcohol extracts from Paeonia Rockii pollen.Methods The antioxidant activity of different concentrations of alcohol extracts from Paeonia Rockii pollen was evaluated by cupric reducing power method, DPPH radical scavenging activity method and ABTS radical scavenging activity method.Results The amounts of antioxidant activity of gallic acid of anhydrous ethanol extract, 75％ alcohol extract, 50％ alcohol extract, 25％ alcohol extract, and water extract from Paeonia Rockii pollen were 26.00, 28.33, 28.90, 14.98, and 9.24 mg/g, respectively. The sequence of the ability of scavenging DPPH free radical and ABTS radical was Vc > 50％ alcohol extract > 75％ alcohol extract > anhydrous ethanol extract > 25％ alcohol extract > water extract.Conclusion The different concentrations of alcohol extracts from Paeonia Rockii pollen has relatively strong antioxidant activity, especially for 50％ alcohol extract and 75％ alcohol extract.