Structural characteristics, functional properties, antioxidant and hypoglycemic activities of pectins from feijoa (Acca sellowiana) peel.

The structure characteristics, functional properties, antioxidant and hypoglycemic activities of pectins extracted from feijoa peel with water (FP-W), acid (FP-A) and alkali (FP-B) were investigated. Results showed that the feijoa peel pectins (FPs) were mainly composed of galacturonic acid, arabinose, galactose and rhamnose. FP-W and FP-A had higher proportion of homogalacturonan domain, degree of esterification and molecular weight (for main component) than FP-B; FP-B owned the highest yield, protein and polyphenol contents. FP-W had a compact and smooth surface morphology unlike FP-A and FP-B. FP-W and FP-A had better thermal stability than FP-B. The rheological analysis suggested that the FPs exhibited pseudoplastic fluid behavior, and the elastic characteristics were dominant. Results showed that FP-W and FP-B had superior antioxidant and hypoglycemic activities than FP-A. According to correlation analysis, monosaccharide composition, sugar ratios and degree of acetylation were chief factors affecting the functional properties, antioxidant and hypoglycemic activities of the FPs.

Can the apparent transverse relaxation rate (R2*) evaluate the efficacy of concurrent chemoradiotherapy in locally advanced nasopharyngeal carcinoma? a preliminary experience.

BACKGROUND: The use of the apparent transverse relaxation rate (R2*) in nasopharyngeal carcinoma (NPC) has not been previously reported in the literature. The aim of this study was to investigate the role of the R2* value in evaluating response to concurrent chemoradiotherapy (CCRT) in patients with NPC. METHODS: Forty-one patients with locoregionally advanced NPC confirmed by pathology were examined by blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) before and after CCRT, and conventional MRI was performed 3 months after the completion of CCRT. All patients were divided into a responding group (RG) and a nonresponding group (NRG), according to MRI findings 3 months after the end of treatment. The R2* values before (R2*preT) and after (R2*postT) CCRT and the ΔR2* (ΔR2*=R2*postT - R2*preT) were calculated in the tumor. RESULTS: Among the 41 patients, 26 were in the RG and 15 were in the NRG. There was no statistical difference in the R2*preT between RG and NRG (P = 0.307); however, there were significant differences in R2*postT and ΔR2* (P < 0.001). The area under the curve of R2*postT and ΔR2* for predicting the therapeutic response of NPC was 0.897 and 0.954, respectively, with cutoff values of 40.95 and 5.50 Hz, respectively. CONCLUSION: The R2* value can be used as a potential imaging indicator to evaluate the therapeutic response of locoregionally advanced NPC.

Chemical structure and antioxidant activity of a neutral polysaccharide from Asteris Radix et Rhizoma.

Asteris Radix et Rhizoma (AR) has been widely used as a herbal medicine for treating various symptoms and possesses a number of bioactivities. A neutral polysaccharide ARP-1 was isolated from AR with weight-average molecular weight of 214 kDa. The heteropolysaccharide ARP-1 was composed of fucose, arabinose, galactose, glucose and mannose with a molar ratio of 0.40:14.25:10.22:1.06:0.41. Linkage and NMR analysis showed that ARP-1 had a backbone containing →3,6)-ß-d-Galp-(1→ and →6)-ß-d-Galp-(1 â†’ residues, and oligosaccharide side chains containing Araf and Galp units were attached to the backbone at C-3 of →3,6)-ß-d-Galp-(1 â†’ residues. Antioxidant activity assays showed that ARP-1 exhibited potent antioxidant activities, including ABTS, hydroxy and DPPH radicals scavenging and reducing power. Besides, ARP-1 decreased the production of ROS and MDA, and improved the activities of SOD, which resulted in the protection of PC12 cells against H2O2-induced oxidative stress. The findings indicated that ARP-1 might be used as a potential natural antioxidant.

Changes in Physicochemical Properties, Volatile Profiles, and Antioxidant Activities of Black Apple During High-Temperature Fermentation Processing.

Black apple is a new elaborated product obtained from whole fresh apple through fermentation at controlled high temperature (60~90°C) and humidity (relative humidity of 50~90%). The appearance, color, texture, and taste of black apple changed dramatically compared with those of fresh apple. In this study, changes in the physicochemical and phytochemical properties, volatile profiles, and antioxidant capacity of apple during the fermentation process were investigated. Results showed that the browning intensity and color difference increased continuously during the whole 65-day fermentation process (p < 0.05). Sugars decreased in the whole fermentation process (p < 0.05), whereas the contents of organic acids increased first and then decreased with prolonged 35 days of fermentation (p < 0.05). Total polyphenol content of black apple showed an increase of 1.5-fold as that of fresh apple, whereas 12 common polyphenolic compounds present in fresh apple decreased dramatically in the whole fermentation process (p < 0.05). The analysis of flavor volatiles showed that high-temperature fermentation decreased the levels of alcohols and esters and resulted in the formation of furanic and pyranic compounds, which are the main products of Maillard reaction (MR). Antioxidant activities of black apple were enhanced compared with those of fresh apple, and results indicated that the enhancement of antioxidant activities was related to the polyphenols and products of MR.