Variation in DPPH scavenging activity and major volatile oil components of cassumunar ginger, Zingiber montanum (Koenig), in response to water deficit and light intensity

Cassumunar ginger, Zingiber montanum (Koenig) Link ex Dietr. (Zingiberaceae), is called Phlai in Thailand. The current study investigates the levels of antioxidant activity and major volatile oil components in cassumunar ginger exposed to varying water deficits (0, 30, 60, 90 and 120 days before harvest) and light intensities (100%, 50% and 25% sunlight). A 120-day water deficit resulted in high volatile oil content and increased sabinene content, but DPPH scavenging activity was not affected. The quantity of volatile oil in the cassumunar ginger exposed to a 120-day water deficit was almost twice that of both the control and the sample exposed to a 30-day deficit. The highest terpinen-4-ol content was obtained after a 60-day water deficit, and (E)-1-(3′,4′-dimethoxyphenyl) butadiene content tended to decrease with prolonged water deficiency. The antioxidant activities of cassumunar ginger were 52.98%, 41.75% and 42.93% in plants grown at 100%, 50%, and 25% sunlight, respectively. Light intensity of 50% or 25% increased the biomass of cassumunar ginger but decreased the volatile oil content; antioxidant activity was not significantly affected.     

Purification and Antioxidant Property of Antioxidative Oligopeptide from Short-Necked Clam (Ruditapes philippinarum) Hydrolysate In Vitro

Short-necked clam (Ruditapes philippinarum) muscle was hydrolyzed with trypsin, and the antioxidant activities of isolated peptides were investigated. The hydrolysate was fractionated by chromatographic methods using Sephadex G-25 gel filtration and Hypersil BDS C18 reversed phase high performance liquid chromatography (RP-HPLC). The antioxidant activities of the hydrolysate were determined by measuring 1,1-diphenyl-2-picrylhydrazyl (DPPH), reducing power assay, and the protective effect against hydroxyl-radical-induced DNA damage. The amino acid sequence of the purified antioxidant oligopeptide was found to be Gly-Asp-Gln-Gln-Lys.     

Effects of genotype and environment on avenanthramides and antioxidant activity of oats grown in northwestern China

To investigate the effects of genotype and growing environment on avenanthramides and antioxidant activity of oats, the total phenolic content (TPC), avenanthramide compositions, and antioxidant activity were determined for whole oat from 39 cultivars grown in four locations in northwestern China (Inner Mongolia, Qinghai, Shanxi and Gansu). The results demonstrated that environment (E), genotype (G) and the interaction of these factors (E × G) significantly affected TPC, concentration of avenanthramide 2c (2c, ranged from 6.24 to 136.20 mg kg⁻¹), avenanthramide 2p (2p, 6.07–112.25 mg kg⁻¹), avenanthramide 2f (2f, 7.26–222.77 mg kg⁻¹) and antioxidant activity of oats. The effect of E was considerably greater than that of G or E × G. Based on G plus G × E interaction biplots (GGE biplots) analysis, the four locations in northwestern China can be divided into either two or three regions. Qinghai was determined to be distinct from the other locations. Cultivar Bayou 9 and oats grown in Gansu exhibited the highest TPCs, concentrations of 2c, 2p, 2f and antioxidant activity. The results suggest that oats containing more avenanthramides and exhibiting high levels of antioxidant activity could be obtained by selecting an appropriate genotype and growth location.     

大孔树脂纯化白背天葵多酚及其体外抗氧化研究

为了分离纯化白背天葵多酚,并探讨其体外抗氧化活性,本研究比较了8种大孔树脂对白背天葵多酚的静态吸附和解吸能力,优选出D101为最适宜纯化白背天葵多酚的树脂,并对其分离纯化的工艺进行了优化。采用DPPH和ABTS法评价其抗氧化活性。结果表明,D101树脂最佳纯化工艺为上样液浓度1 mg/mL、pH 3.1、上样液流速2 mL/min,解吸的乙醇体积分数70%、体积60 mL、流速2 mL/min;白背天葵多酚的含量由14.73%提高到45.21%;其清除DPPH及ABTS自由基的能力为 Vc>纯化物>粗提物。研究结果为进一步开发利用白背天葵多酚提供了数据支持。     

Effects of gamma irradiation on starch granule structure and physicochemical properties of brown rice starch

In the present research effects of gamma irradiation (5–20 kGy) on the physicochemical, antioxidant and thermal properties of brown rice starch were studied. Scanning electron microscopy displayed mostly polyhedral shapes with no surface fractures. XRD displayed characteristic A type pattern and decrease in per cent crystallinity (22.53–20.41%) was observed as the dose increased from 5 to 20 kGy. DPPH % inhibition and FRAP values were increased in a dose dependent manner. Pasting properties (peak, final and setback viscosity) decreased with irradiation. Pasting temperature also significantly decreased with irradiation for all the irradiated starches. The transition temperatures, enthalpy of gelatinization, pH and apparent amylose content of starch decreased significantly with increase in irradiation dose.     

Kinetics of Antioxidant-Producing Maillard Reaction in the Mixture of Ribose and Sea Cucumber (Stichopus japonicus) Gut Hydrolysates

Maillard reaction products (MRPs) were produced in sea cucumber gut hydrolysates (SCGHs)-ribose system at 75°C, 85°C, and 95°C with a pH value of 7.0 or 8.0 for 12 hour. The parameters of amount of intermediate products, fluorescence intensity, browning development, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability showed a positive correlation with each other in SCGHs-ribose system. The amount of intermediate products, fluorescence intensity, and browning development followed the zero-order kinetic with activation energy from 62 to 91 kJ/mol in the Maillard reaction of SCGHs-ribose system. Moreover, 2-methyl-butanal has positive and significant correlation with DPPH radical scavenging ability of SCGHs-ribose MRPs. These results suggest that Maillard reaction improves the antioxidant activity of SCGHs, which contributes to the generation of intermediate, fluorescent, browning, and volatile products of SCGHs-ribose system.     

Antioxidant activity of nine Fabaceae species growing in Serbia and Montenegro

The aim of this study was to investigate antioxidant capacity of nine Fabaceae species collected on the mountains of Serbia and Montenegro. Antioxidant assays with various reaction mechanisms were used, including total phenolic content by Folin-Ciocalteu, DPPH radical scavenging capacity, Trolox equivalent antioxidant capacity (TEAC) values by ABTS radical cation and inhibition of liposome peroxidation. The investigated plants exhibited strong antioxidant capacity in all the tested methods, and among them, Lathyrus binatus, Trifolium pannonicum, and Anthyllis aurea were found to be the most active.     

Apoptotic and free radical scavenging properties of the methanolic extract of Gentianella alborosea

Gentianella alborosea ("Hercampure") is a Peruvian species used in folk medicine for the treatment of a variety of health disorders. We tested the free radical scavenging (DPPH) and induction of apoptosis on a human uterus tumor cell line (HeLa) by its methanolic extract. The results showed a noticeable radical scavenging activity and a dose-dependent apoptotic effect.     

Antioxidant and 15-lipoxygenase inhibitory activity of rotenoids, isoflavones and phenolic glycosides from Sarcolobus globosus

From Sarcolobus globosus, two rotenoids (villosinol and 6-oxo-6a,12a-dehydrodeguelin), one isoflavone (genistin) and four phenolic glycosides (vanillic acid 4-O-beta-d-glucoside, glucosyringic acid, tachioside and isotachioside) were identified for the first time from this species. Extracts and compounds from S. globosus were evaluated for their DPPH radical scavenging and 15-lipoxygenase (15-LO) inhibitory activities. All tested rotenoids were found to inhibit 15-LO, while they lacked DPPH radical scavenging effect.     

In vitro antioxidant activity of Argyreia cymosa bark extracts

The Argyreia cymosa bark extracts were subjected to in vitro antioxidant activity with different methods. The petroleum ether extract has shown antioxidant activity in ABTS, nitric oxide, hydroxyl radical (by p-NDA) and lipid peroxidation methods. The ethyl acetate extract has shown antioxidant activity in DPPH, H(2)O(2) and hydroxyl radical (by deoxyribose) scavenging methods.