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The development of selenized polysaccharides is a promising strategy for the dietary selenium supplementation. The purpose of this research is to determine the influence of selenium on the structure and bioactivity of a polysaccharide fraction (MPN) isolated from Ganoderma lucidum mycelia. After biological selenium enrichment, the selenium content in the selenized polysaccharide (SeMPN) was 18.91 ± 1.8 μg/g. SeMPN had a slightly lower molecular weight than MPN, but the carbohydrate content and monosaccharide composition remained identical. Additionally, the band at 606 cm−1 in MPN changed to 615 cm−1 in SeMPN as revealed by FT-IR spectra. No significant changes were observed in the types and ratios of glycosidic linkages, as determined by NMR spectroscopy. Extracellular and intracellular antioxidant assays demonstrated that SeMPN was more effective than MPN in scavenging free radicals, inhibiting AAPH-induced erythrocyte hemolysis, and protecting catalase (CAT) and glutathione peroxidase (GSH-Px) activity in H2O2-injured PC12 cells. Additionally, SeMPN had a higher increase effect on RAW 264.7 cells's pinocytic and phagocytic capacity, as well as their production of NO, TNF-α, and IL-6. SeMPN could be as potential functional selenium supplementation.

Two major polysaccharides (SLT-3, SLT-4) were isolated from the torus of Saussurea laniceps. Their molecular weight, monosaccharide compositions and the ability to protect human erythrocytes from oxidative damage induced by AAPH were assessed. Results showed that the Mw of SLT-3 and SLT-4 were 10,113 Da and 12,392 Da. SLT-3 was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, xylose, and arabinose in a molar ratio of 0.25:0.53:0.19:15.35:0.51:1.10:0.63:1.73, whereas SLT-4 was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, and arabinose in a molar ratio of 0.92:5.61:0.93:19.50:2.42:5.27:3.01. Pretreatment with SLT-3 and SLT-4 reduced MDA content, inhibited the generation of intracellular ROS and maintained the balance of GSH and GSSG in AAPH-treated erythrocytes. Furthermore, the activities of intracellular antioxidant enzymes, such as SOD, GSH-Px and CAT, were attenuated in polysaccharide treated cells. The results provide an important basis for the development of S. laniceps as a natural antioxidant.

DA‐P, fraction of peptides with a molecular weight

Four types of carbohydrates, including Dendrobium officinale polysaccharide, Dendrobium aphyllum polysaccharide and β‐glucans from yeast and barley, were examined, and their structures were found to mainly contain 1,4‐linked‐β‐d‐Glcp. Artificially simulated gastrointestinal digestion was conducted to characterise the changes of molecular weight, reducing sugars and released free monosaccharides by high‐performance liquid chromatography, kits and the newly developed gas chromatography (GC)‐mass spectrometry (MS)/MS analysis, which indicated that high molecular weight and complex spatial structures contributed to delayed monosaccharide release following exposure to digestive solution. The spatial structures of carbohydrates were changed during gastric digestion, but their primary structures were destroyed during intestinal digestion. Additionally, for the developed 7890A/7000 GC‐TQ/MS‐MS, the new analytical method was successfully used to analyse very low concentrations of monosaccharides in the simulated gastrointestinal digestive system.

Two fractions of non-starch polysaccharides termed TPS-1 and TPS-2 were sequentially purified from the corms of Colocasia esculenta. Structural characterizations of TPS-1 and TPS-2 were determined. The average molecular weight of TPS-1 and TPS-2 were estimated to be 10.502 and 10.191 kDa, respectively. TPS-1 consisted of Rha (8.5%), Xyl (0.73%), Glc (88.57%), and Gal (2.56%), while TPS-2 consisted of Rha (3.54%), Arf (1.6%), Glc (87.92%), and Gal (6.94%). The presence of glycosidic linkages in the two fractions of polysaccharides were identified and were significantly different. TPS-2 exhibited a higher immunomodulatory activity than TPS-1 through an immunostimulation assay promoting NO, TNF-α, and IL-6 production in RAW 264.7 cells. Furthermore, TPS-2 could significantly enhance the phagocytosis ability of macrophages. The membrane receptors of TPS-2 were identified to be TLR2, TLR4, GR, and SR. Taken together, TPS-1 and TPS-2 could be considered as novel potential immunostimulants of food and pharmaceutical supplements for hypoimmunity.

Two kinds of flavone extracts were extracted and purified from Labisia pumila (LP). High-performance liquid chromatography (HPLC) analysis was used to determinate the flavones in the extracts, and catechin, glycitin, rutin, naringin, and myricetin were identified in the LP leaf extract (LPL-F) while genistin, naringin, and myricetin were found in the stem extract (LPS-F). Specific flavonol compounds mediated the satisfactory scavenging abilities. The flavone leaf extracts performed better than the stem extracts in chemical antioxidative activities but worse in cellular antioxidative capabilities. The chemical and cellular antioxidative activities were not obviously changed by gastrointestinal digestion but slightly changed at the last 2 hours of intestinal digestion because prolonged exposure to alkaline conditions could destroy the structure of flavonoids. Changes in MDA and GSH content, and enzyme activities of SOD and GSH-Px in human erythrocytes during GI digestion indicated the possible intracellular antioxidant-detoxifying mechanisms were through attenuating AAPH-induced oxidative stress by inhibiting ROS generation, in which stem extracts performed the better.

Acylation modification of phenol glycosides is currently of great interest due to the improved bioavailability and multiple functions. In this work, mono- or diesters of arbutin, an important phenol glycoside derivative, can be controllably synthesized by using whole-cell biocatalytic systems. Among fourteen microbial strains selected, Candida parapsilosis cells showed the best catalytic activity and high organic solvent tolerance. Compared with the best pure solvent tetrahydrofuran, the use of a binary solvent pyridine-isooctane gave a slightly lower conversion (98.3% vs. 97.2%) and selectivity (85.3% vs. 80.5%) and much higher substrate solubility (37.1 vs. 214.0 mg mL−1), in a 24 h bioconversion of arbutin with a VP-arbutin molar ratio of 15 and whole cell dosage of 30 mg mL−1. The production of various arbutin esters with different fatty acid chain lengths can be realized by using this whole-cell strategy, with the substrate conversion and 6′-regioselectivity of 54.1–98.3% and 83.2–99.0%, respectively.

Mulberry leaf protein fractions were extracted by the ultrasonic cell disrupter-assisted Osborne method. The physicochemical, functional properties, and antioxidant activities of mulberry leaf prot...

Summary Proteins and peptides must be degraded and modified in the gastrointestinal (GI) tract prior to absorption; this process changes their physicochemical and biological properties. Mulberry leaf protein (MP) and its hydrolysates (HMP) have favourable antioxidant activities. To investigate, in vitro and separately, the effects of GI digestion and intestinal digestion on the stability of MP and HMP, we monitored the changes in secondary structures, amino acids, molecular weights and antioxidant activities. We found that MP was more hydrolysed by pepsin than by pancreatin, unlike HMP. The final digests of MP and HMP were mainly composed of polypeptides (0.5–6.5 kDa) and oligopeptides (

Esculin has many pharmacological effects, but these are difficult to observe after oral administration owing to poor lipid solubility. In our previous study, five acylated derivatives with different acyl chain lengths (EA, EP, EO, EL, and EM) were synthesized to improve the lipophilicity of esculin. In this study, the bioavailability and antioxidant activity of the five derivatives were investigated. The logP of esculin, EA, EP, EO, EL, and EM were −1.1 ± 0.1, −0.3 ± 0.14, 0.1 ± 0.17, 1.6 ± 0.09, 2.4 ± 0.11, and 2.8 ± 0.18, and their Papp were 0.71 ± 0.02, 1.24 ± 0.18, 1.74 ± 0.11, 11.6 ± 3.6, 4.11 ± 1.03, and 2.64 ± 0.97 × 10–6 cm/s, respectively. Besides, the bioavailability of EO, EL, and EM were seriously affected by carboxylesterase. The results of ABTS, ORAC, and DPPH assays indicated that the antiradical ability of the five derivatives did not exceed that of esculin. However, EA, EP, and EO showed more effective inhibition of AAPH-induced oxidative hemolysis than esculin did (p < 0.05), and EL and ...

Albumin (Alb), globulin (Glo), glutelin (Gll) and glutenin (Gln) were separately extracted from wheat germ and wheat gluten. Amino acisd composition, molecular weight distribution, solubility, in vitro digestibility, and immunomodulatory activities were all analyzed. Gll and Gln have similar molecular weight distributions, which differed from those of Alb and Glo. Alb showed the highest solubility at various pH values (except pH 4.0), whereas Glo showed the highest in vitro digestibility. Glo and Gll have the highest proportion of essential to total amino acids, while Alb and Gll have the highest protein digestibility-corrected amino acid scores. Gll had the strongest immunomodulatory effects in terms of stimulation of RAW 264.7 cells to produce IL-6, TNF-α, and IL-10, and good stimulatory effects on splenocyte proliferation, production of IL-2, phagocytosis, and secretion of nitric oxide in RAW 264.7 cells. Gll can be considered a good protein source for use in health foods.

A novel polysaccharide with a molecular weight of 12.3 kDa, was isolated from the root of Pueraria lobata (Willd.) Ohwi using cold water extraction method. Methylation analysis, Periodate oxidation, Smith degradation, and nuclear magnetic resonance analysis showed that 1,4-α-D-Glcp and 1,3,6-α-D-Glcp were the main linkage types of this polysaccharide. It exhibited immunomodulatory activity by enhancing the pinocytic and phagocytic capacities and promoting the secretion of nitric oxide, interleukin (IL)-6, and tumor necrosis factor alpha by RAW 264.7 cells. The beta glucan receptor, scavenger receptor I, and toll-like receptor 4 were identified as the main receptors of the polysaccharide on the membrane of RAW 264.7 cells. These results suggested that this polysaccharide is a candidate functional food supplement for hypoimmune populations.

A novel acid polysaccharide (PPRLMF-2) with the Mw of 137,123 Da and a triple-helix conformation was first isolated from the pulp of Rosa laevigata Michx fruit. Structural characterization showed that PPRLMF-2 consisted of rhamnose (7.6%), arabinose (26.5%), xylose (3.5%), mannose (0.9%), glucose (5.7%), galactose (31.9%) and galacturonic acid (23.9%). The methylation and NMR (1D and 2D) analysis revealed that PPRLMF-2 contained 16 types of glycosidic linkages. The immunomodulatory activity assays indicated that PPRLMF-2 could significantly enhance phagocytosis, the secretion and mRNA expression of cytokines in RAW 264.7 cells. Additionally, SR, GR, TLR-2, and TLR-4 were the main pattern recognition receptors (PRRs) of PPRLMF-2 to upregulate the p-ERK, p-JNK, p-p38, and p-p65. These results suggested that PPRLMF-2 could recognize the PRRs of the macrophages to enhance the immunomodulatory activity via activation of the MAPKs and NF-κB signaling pathways. This study provides important implications of PPRLMF-2 as an attractive immunomodulatory functional food.

Maca protein isolate (MPI) was extracted from maca root, and its physicochemical and functional properties, and the secondary structure and immunomodulatory activity of its major protein component, MMP, were investigated. The MPI lacked essential amino acids compared with soybean protein isolate (SPI) and casein, but was rich in cysteine and proline. The MPI had rich free sulfhydryl (20.6 μmol g-1), and its surface hydrophobicity (H0, 812.4), oil absorption capacity (7.4 g g-1), foaming capacity (100%) and emulsifying activity (58.2 m2 g-1) were higher than that of SPI. However, the thermal stability (Td, 87.4 °C), foaming stability (75%) and emulsifying stability (26.3 min) of the MPI were weaker than that of the SPI. MMP was a pentamer with a molecular weight of 22 kDa and rich in β-sheets. MMP could significantly enhance the phagocytic capacity and promote the NO, TNF-α and IL-6 secretion of RAW 264.7 cells, involving toll-like receptor 4 and complement receptor 3 mainly.

The profile of caffeic acid in tissues of peanut sprouts and its antioxidant activity in erythrocyte-based assays were investigated. Caffeic acid was found to accumulate in the epicotyl-plumule (reached 2097.13±96μg/g DW on day 10 after peanut germination). It was purified by semipreparative high-performance liquid chromatography. The purified caffeic acid showed noticeable protective effects on human erythrocytes against 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH)-induced hemolysis. It also contributed to maintenance of normal morphological features and inhibited malondialdehyde formation and the lactate dehydrogenase release in erythrocytes under oxidative stress. Further analysis revealed that caffeic acid effectively inhibited AAPH-induced free-radical production and maintained the normal metabolism of the erythrocytic redox system, including superoxide dismutase, glutathione peroxidase, and glutathione. Our work showed that caffeic acid, which is greatly enriched in peanut sprout, can effectively protect erythrocytes from oxidative damage. These results provide valuable information for the use of peanut sprouts as a functional food.

Summary Defatted wheat germ globulin (DWGG) was hydrolysed using the enzymes alcalase, neutrase, papain, pepsin or trypsin to improve the immunomodulatory effects of the protein. The degree of hydrolysis (DH), molecular weight distribution, hydrophobicity, secondary structures and immunomodulatory activities were determined. The DH of hydrolysate using alcalase or neutrase was higher (P

Betaine (BET) is a native compound known for its ability to protect the liver from toxicants. However, few studies have examined the effects of BET on the most common cause of liver disease, hepatitis B virus (HBV). In this study, the anti-HBV activity of BET was assessed in vitro and in vivo using enzyme-linked immunosorbent assay, quantitative polymerase chain reaction, and Southern blotting. The resistance of HBV to lamivudine and interferon α is challenging in the clinical treatment of HBV. The effect of BET on resistance was also investigated. The results showed that the secretion of HBsAg (HBV surface antigen), HbeAg (HBV e antigen), and HBV DNA in HepG2.2.15 cells was significantly decreased by BET via suppression of GRP78 expression. In duck HBV (DHBV)-infected ducklings, 1.0 or 2.0 g/kg BET significantly reduced serum DHBV DNA, and DHBV DNA did not rebound after the 5 day withdrawal period. BET suppressed HBV DNA rebound produced by the resistance of HBV to lamivudine and decreased the resistance mutation (rtM204V/I) of HBV DNA. Supplementation of BET may improve the anti-HBV effect of interferon α by increasing the expression of antiviral dsRNA-dependent protein kinase induced by the JAK-STAT (JAK = Janus kinase; STAT = signal transducer and activator of transcription) signaling pathway. These results may provide useful information for the clinical application of BET and solution of HBV drug resistance in anti-HBV therapy.

A novel polysaccharide named as MC-1 was isolated from the roots of Lepidium meyenii using a water extraction method. Structural characterization revealed that MC-1 had an average molecular weight of 11.3 kDa and consisted of arabinose (26.21%), mannose (11.81%), glucose (53.66%), and galactose (8.32%). The main linkage types of MC-1 were proven to be (1 → 5)-α-L-Ara, (1 → 3)-α-L-Man, (1 → 2,6)-α-L-Man, (1 → )-α-D-Glc, (1 → 4)-α-D-Glc, (1 → 6)-α-D-Glc and (1 → 6)-β-D-Gal by methylation analysis, periodate oxidation-Smith degradation and NMR analysis. The immunostimulating assay indicated that MC-1 could significantly enhance the pinocytic and phagocytic capacity and promote the NO, TNF-α, and IL-6 secretion of RAW 264.7 cells, involving toll-like receptor 2, complement receptor 3, and mannose receptor mainly. These results suggested the potential utilization of MC-1 as an attractive functional food supplement candidate for hypoimmunity population.

Selenite can enhance the selenium nutrition level of crops, but excessive selenite may be toxic to plant growth. To elucidate the mechanisms underlying the role of selenite in production and detoxification of oxidative toxicity, peanut seedlings were developed with sodium selenite (0, 3, and 6 mg/L). The effects of selenite on antioxidant capacity, transcript levels of antioxidant enzyme genes, and enzyme activities in hypocotyl were investigated. The CuZn-SOD, GSH-Px, GST, and APX gene expression levels and their enzyme activities in selenite treatments were 1.0-3.6-fold of the control. Selenite also significantly increased the glutathione and ascorbate concentrations by mediating the ascorbate-glutathione cycle, and the selenite-induced hydrogen peroxide may act as a second messenger in the signaling pathways. This work has revealed a complex antioxidative response to selenite in peanut seedling. Understanding these mechanisms may help future research in increasing selenite tolerance and selenium accumulation in peanut and other crops.

An efficient microwave-assisted extraction (MAE) technique was applied to isolate total steroid saponins from Dioscorea zingiberensis C.H. Wright (DZW). The optimal extracting conditions were established as 75% ethanol as solvent, ratio of solid/liquid 1:20 (g/ml), temperature 75 °C, irradiation power 600 W and three extraction cycles of 6 min each. Scanning electron microscopy (SEM) images of DZW processed by four different extractions provided visual evidence of the disruption effect on DZW. Diosgenin was quantified by HPLC and examined further by LC-ESI/MS after acid hydrolysis. Total steroid saponins were calculated using diosgenin from total steroid saponins. The MAE procedure was optimized, validated and compared with other conventional extraction processes. This report provides a convenient technology for the extraction and quantification of total saponins of DZW combining MAE with HPLC and LC-ESI/MS for the first time.

For the first time, whole microbial-cell biocatalysis method was successfully applied by us to the production of glucose esters by transesterification of glucose with vinyl propionate. Among ten bacterial and fungal strains tested, lyophilized cells of Pseudomonas stutzeri strain GIM 1.273 efficiently catalyzed the reaction with the highest conversion and initial rate. 13 C NMR analysis showed that the reaction catalyzed by P . stutzeri yielded 6- O regiomer predominantly (>99%), clearly indicating high regioselectivity of the biocatalyst toward the 6- O -hydroxy group of glucose. Efficiency of the reaction catalyzed by lyophilized cells was evidently solvent-dependent. With the exception of acetonitrile-pyridine and tetrahydrofuran-pyridine systems, the substrate conversion rate clearly increased with increasing hydrophobicity of the organic solvent media used. The best results were obtained in isooctane–pyridine (3:7 v/v) system. Other optimal conditions were: water content 2% (v/v), molar ratio of the acyl donor to glucose 10:1, biocatalyst dosage 80 mg/mL and reaction temperature 35 °C, under which glucose conversion and reaction rate were 97.2% and 29.7 mmol/L h over the duration of 24 h. A tenfold scale-up production of the 6- O -glucose ester further demonstrated that whole-cell P. stutzeri was an efficient and highly-regioselective alternative to purified enzymes for synthesis of glucose esters.

Acylation modification of phenol glycosides is currently of great interest due to the improved bioavailability and multiple functions. In this work, mono- or diesters of arbutin, an important phenol glycoside derivative, can be controllably synthesized by using whole-cell biocatalytic systems. Among fourteen microbial strains selected

Additional file 1. TEER values and the permeability of lucifer yellow transported from the AP to BL side before and after experiments; HPLC chromatograms; mass chromatograms; FT-IR spectra; 13C-NMR spectrum; activity of ALP in Caco-2 cells.

The hydrolysate from duck egg white protein (DEWP) prepared by "SEEP-Alcalase" at degree of hydrolysis (DH) value of 21% (namely HSA21) exhibited high antioxidant capacity in different oxidation systems. A consecutive chromatographic method was then developed for separation and purification of HSA21, including ion-exchange chromatography, macroporous adsorption resin (MAR) and gel filter chromatography. The final peptides "P21-3-75-B" were obtained with significantly enhanced antioxidant activity (p

This study utilized a facile and continuous technique termed Flash NanoPrecipitation (FNP) to produce zein colloidal particles (ZP) without or with sodium caseinate (NaCas) as the stabilizer. The colloidal particle preparations were performed through a self-made Confined Impinge Jet (CIJ) mixer, and compared with traditional antisolvent processes. The influences of FNP processing parameters on the size of zein colloid particles, including flow rates, outlet configurations, solute concentrations and ethanol concentrations, were extensively discussed. The influences of viscous properties, buffering capacity and self-assembly of zein or NaCas on particle size and size distributions were also discussed. Particle sizes of ZP produced by the FNP technique are below 350 nm, even at high zein concentrations (2.5–7.5% w/v). Solvent systems with different ethanol concentrations yielded zein colloid particles with similar size, showing an attractive feature for industrial applications and encapsulating actives with different solubility in ethanol–water binary solvent. This study opens a promising pathway for continuously producing ZP via the FNP procedure.

In our previous study, three novel polysaccharides, named MC-1, MC-2, and MC-3, were separated from the roots of maca (Lepidium meyenii), which is a food source from the Andes region. The structural information and immunomodulatory activity of MC-1 were then investigated. The structure and activity of MC-2 are still unknown. In this study, structural characterization revealed that MC-2 has an average molecular weight of 9.83 kDa and is composed of arabinose (20.9%), mannose (4.5%), glucose (71.9%), and galactose (2.7%). The main linkage types of MC-2 were proven to be (1→5)-α-l-Ara, (1→3)-α-l-Man, (1→)-α-d-Glc, (1→4)-α-d-Glc, (1→6)-α-d-Glc, and (1→6)-β-d-Gal by methylation and NMR analyses. Congo red assay showed that MC-2 possesses a triple-helix conformation. Immunostimulating assays indicated that MC-2 could induce M1 polarization of original macrophages and convert M2 macrophages into M1 phenotype. Although MC-2 could not shift M1 macrophages into M2, it could still inhibit inflammatory reactions induced by lipopolysaccharide. Furthermore, Toll-like receptor 2, tTll-like receptor 4, complement receptor 3, and mannose receptor were confirmed as the membrane receptors for MC-2 on macrophages. These results indicate that MC-2 could potentially be used toward hypoimmunity and tumor therapies.

Betaine (BET) is a native compound widely studied as an antioxidant in agriculture and human health. However, the antioxidant mechanism of BET remains unclear. In this research, radical scavenging assays showed that BET had little free radical scavenging activity. However, the antioxidant activity of BET was confirmed by cellular antioxidant activity (CAA) and erythrocyte hemolysis assays. The results of quantitative PCR (qPCR) and enzyme activity determination kits showed that the antioxidant activity of BET was not due to the gene expression and activity of antioxidases. High-pressure liquid chromatography (HPLC) assessment of the effect of BET on sulfur-containing amino acid metabolism showed that BET increased the levels of nonenzymatic antioxidants,S-adenosylmethionine (SAM) and methionine (p0.05), via the regulation of the methionine-omocysteine cycle. Additionally, the three methyl groups of BET were found to play a key role in its antioxidant activity. The possible reason was that because of the hydrophobicity of the three methyl groups and hydrophilicity of the carboxyl of BET, a tight protective membrane was formed around cells to prevent oxidative stress inducer from inducing ROS generation and cell damage. In conclusion, the antioxidant mechanism of BET was found to enhance nonenzymatic antioxidant defenses via the methionine-homocysteine cycle and form a protective membrane around cells.

Biocatalytic acylation of 1-β-D-arabinofuranosylcytosine (ara-C) was developed using whole cell of Aspergillus oryzae as a novel catalyst. (13)C nuclear magnetic resonance (NMR) analysis indicated that the whole-cell biocatalyst had more specific activity toward the 3'-hydroxyl group than 5'-hydroxyl group among the available hydroxyl groups in sugar moiety of ara-C. Except for glucose and maltose, 11 carbon sources supplemented to basal media, including Spans, Tweens, olive oil and oleic acid, exhibited notable enhancement effects on both the cell growth and the acylation reactions. It was suggested that the carbon sources containing controlled-release oleic acid were the important substrates for the production of fungal cell-bound lipase with specific activity, partially due to a gradual induction effect of their released oleic acid on the cell-bound lipase production. Despite the low initial reaction rate and substrate conversion, the addition of 2.0 g/l Span 80 resulted in a higher 3'-regioselectivity of the cells than 81%. By using Tween 85 at its optimum concentration of 5.0 g/l, however, the highest initial rates (3.2 mmol/l h) and substrate conversion (76%) of the whole-cell catalyzed acylation of ara-C can be achieved. It was also found that the 3'-regioselectivity of the cells showed observable increase by extending the culture time. And the activity of cell-bound lipase drastically increased in the early stage of cell growth and then declined in the late culture stage, whatever the culture media used. Our results thus indicated that A. oryzae whole cell was a promising green tool for biosynthesis of nucleoside esters with potential bioactivities.

Zearalenone is a mycotoxin mainly produced by Fusarium mold, which has been associated with hyperestrogenism and other reproductive disorders in pigs, sheep, and other farm animals. Since zearalenone engendered economic losses to farm animal production, its detoxification in contaminated grains or by-products would be advantageous. In this study, enzymes from the Acinetobacter sp. SM04 extracellular extracts of liquid cultures were isolated by Sephadex G-100 column, and an active fraction capable of efficiently degrading zearalenone was obtained. Zearalenone could be oxidized into smaller estrogenic products by the active fraction, and two intermediate products, ZEN-1([M-H]− at m/z 489) and ZEN-2([M-H]− at m/z 405), were found. Zearalenone degradation activity of the active fraction was significantly inhibited by low oxygen gas content, protease, SDS, and EDTA treatment. Further, enzymes in the active fraction were analysed by SDS–PAGE and MALDI-TOF/TOF/MS, and three proteins were found that matched the database for Acinetobacter genus with great homology. They were identified as peroxiredoxin, a possible cytochrome and a putative fimbrial protein precursor.

Ultrasonic assisted extraction and antioxidant activity of water-soluble polysaccharide (MSP) from mung bean ( Vigna radiata L.) hull were investigated. After deproteinization, MSP was isolated and purified by a DEAE-cellulose anion-exchange column and a Sephadex G-100 gel-permeation column. Two acid polysaccharide fractions, MP1 and MP2, were characterized by FT-IR, GC, and gel-permeation chromatography (GPC). Results indicated that MP1 and MP2 were acid heteropolysaccharide with 9.9% and 36.4% of uronic acid contents respectively. The main composition of MP1 was mannose, whereas MP2 consisted of rhamnose and galactose. The molecule weights of MP1 and MP2 were 83 kDa and 45 kDa, respectively. Although, MP2 showed higher hydroxyl radical-scavenging activity, MP1 exhibited higher reducing power and stronger scavenging capacity for superoxide radical and DPPH radicals as well as higher inhibition on self-oxidation of 1,2,3-phentriol than that of MP2. Thus, MP1 should be explored as a potential antioxidant.

Lipid peroxidation in oil-in-water (o/w) emulsions leads to rancidity and carcinogen formation. This work attempted to protect lipid droplets of emulsions from peroxidation via manipulation of the emulsions' interface framework using dual-function zein/CH complex particles (ZCPs). ZCP with intermediate wettability was fabricated via a simple antisolvent approach. Pickering emulsions were produced via a simple and inexpensive shear-induced emulsification technique. ZCP was irreversibly anchored at the oil-water interface to form particle-based network architecture therein, producing ultrastable o/w Pickering emulsions (ZCPEs). ZCPE was not labile to lipid oxidation, evidenced by low lipid hydroperoxides and malondialdehyde levels in the emulsions after thermally accelerated storage. The targeted accumulation of curcumin, a model antioxidant, at the interface was achieved using the ZCP as interfacial vehicle, forming antioxidant shells around dispersed droplets. The oxidative stability of ZCPEs was further improved. Interestingly, no detectable hexanal peak appeared in headspace gas chromatography of the Pickering emulsions. The novel interfacial architecture via the combination of steric hindrance from ZCP-based membrane and interfacial cargo of curcumin endowed the emulsions with favorable oxidative stability. This study opens a promising pathway for producing antioxidant emulsions via the combination of Pickering stabilization mechanism and interfacial delivery of antioxidant.

A whole-cell based method was developed for the regioselective synthesis of arabinocytosine laurate. Among the seven kinds of bacteria strains tested in the acylation reaction, Pseudomonas fluorescens gave the highest productivity and a higher 5'-regioselectivity than 99%. Compared with pure organic solvents, the use of organic solvent mixtures greatly promoted the yield of the whole-cell catalyzed reaction, but showed little influence on the 5'-regioselectivity. Of all the tested solvent mixtures, the best reaction result was found in isopropyl ether/pyridine followed by isopentanol/pyridine. However, the whole-cells showed much lower thermostability in isopropyl ether/pyridine than in THF-pyridine. To better understand the toxic effects of the organic solvents on P. fluorescens whole-cells and growing cells were further examined. Significant influences of organic solvents on the biomass of the cells were found, which differed depending on the type of solvents used. SEM analysis visually revealed the changes in the surface morphology of whole-cells and growing cells cultured in media containing various organic solvents, in terms of surface smoothness, bulges and changed cell sizes. Results demonstrated that organic toxicity to cell structure played an important role in whole-cell mediated catalysis.

An enzymatic hydrolysis approach was proposed for the preparation of bioactive hydrolysate of scorpion Buthus martensii Karsch (BmK) protein. Results showed that the anticoagulant activity of the hydrolysates of BmK protein was closely related to both the enzyme type and the degree of hydrolysis. Alcalase AF showed to be the best enzymes for the hydrolysis. And the hydrolysis degree (DH) was closely related with the anticoagulant activity of the hydrolyzate. At a DH value of 18% with Alcalase AF, the hydrolyzate exhibited the highest activity. The hydrolysate was then separated and purified by consecutive chromatographic procedures, giving a novel anticoagulant peptide consisting of ten amino acids (MW: 1119.8Da) with its sequence of Val-Glu-Pro-Val-Thr-Val-Asn-Pro- His-Glu identified by MALDI-TOF/TOF MS. The negatively charged amino acids and hydrophobic amino acids may contribute to the anticoagulant activity of the prepared peptides. And the Val residue in N-terminal was also critical for the anticoagulant activity of the BmK peptide. Furthermore, the anticoagulant activity kept stable after in vitro digestive simulation. This research provided a promising bioprocessing route for production of anticoagulant peptides using BmK protein as a potentially valuable bioresource.

The utilization of a dehydrated fungal biocatalyst of Aspergillus oryzae cells was successfully performed to achieve efficient acylation modification of a polar nucleoside cytarabine (ara-C). Organic solvents showed evident influence on the reaction catalyzed by the A. oryzae whole-cells. Except for hexane-pyridine, the catalytic activity and regioselectivity of the whole-cells clearly increased with increasing the polarity of the hydrophobic organic solvents used. The effects of some crucial factors on the reaction were further examined. The best reaction medium, hydrophobic solvent concentration, vinyl propionate/ara-C ratio, reaction temperature and shaking speed were confirmed as isopropyl ether (IPE)-pyridine, 30% (v/v), 90, 30 °C and 140–180 rpm, respectively. The cell biocatalyst also showed good thermal stabilities in both IPE-pyridine and hexane-pyridine systems. In addition, the desired 3′- O -propional derivative of ara-C was synthesized with the yields of 88.3% and regioselectivity (>70%). The resulting biocatalytic system appears to be an effective alternative, and can thus be employed for application in highly regioselective modification of nucleoside analogues.

The binding interaction between (-)-epigallocatechin (EGC) with bovine β-lactoglobulin (βLG) was investigated by fluorescence, circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopy methods. The binding parameters were determined by Stern-Volmer equation and the thermodynamic parameters were calculated according to the van't Hoff equation. The results suggested that βLG was bound by EGC, which resulted in change of native conformation of βLG. van der Waals interactions and hydrogen bonding probably played major roles in the binding process. Our study is helpful for further elucidation of binding interactions between catechins with milk proteins, which would contribute to the development of novel milk products.

The origin of progesterone in butter was investigated using gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). GC/C/IRMS has been rarely used to investigate the origin of natural steroid hormones, which are often found in some foods of animal origin used as feed additives. In this study, an effective pretreatment method for a butter sample was developed using gel permeation chromatography (GPC). The butter sample was dissolved with ethyl acetate–cyclohexane (1/1, v/v). After GPC pretreatment and HPLC purification, the sample was analyzed for progesterone on a GC/C/IRMS system. The δ13C values of endogenous progesterone in butter were found in the range from −26.77 ± 0.26‰ to −24.78 ± 0.32‰ and the δ13C value of exogenous progesterone spiked in the sample was about −30.57 ± 0.12‰. One-way analysis of variance (ANOVA, P-value = 0.01 < 0.05) indicated that there was a highly significant difference between the endogenous and exogenous δ13C values of progesterone. The sensitivity of the method for progesterone was determined to be from 10 to 100 ng. The within-batch precision of the method ranged from 0.09 to 0.15‰ and the between-batch precision was 0.11‰. We found that the HPLC fraction collection step was a critical factor affecting the isotopic fractionation and measurement accuracy. GC/C/IRMS can be a powerful tool to investigate the origin of natural hormones.

Correction for ‘Simultaneous determination of fourteen steroid hormone residues in beef samples by liquid chromatography-tandem mass spectrometry’ by Chaomin Zhao et al., Anal. Methods, 2014, 6, 8030–8038.