Fluorine poisoning affects human health all over the world and an urgent task is to develop alleviative medicine to recover or ameliorate the damages to the body. Here we studied the effects of gamma-aminobutyric acid (GABA), a liver protector reported previously, on fluoride-induced damage in the mouse liver. Through microscope imaging of the liver tissue, TUNEL immunostaining, real-time RT-PCR, enzyme immunoassay and colorimetric method, we found that GABA supplementation prevented the metabolic toxicity caused by fluoride treatment in mice. This detoxification was reflected by the reduced oxidative stress and apoptosis, enhanced neuron protection and liver function. Collectively, this study provided evidence of the beneficial effects of GABA supplement on liver damage, implicating its therapeutic potential in fluorosis.

•Exogenous chitosan (CTS) reduced detrimental effect of Cd on rape plant growth.•Foliar application of CTS under Cd tress decreased shoot Cd2+ concentration.•CTS enhanced photosynthesis and antioxidant enzymes activities.Chitosan (CTS) induces plant tolerance against several abiotic stresses, including salinity and drought exposure. However, the role of CTS in cadmium (Cd)-induced stress amelioration is largely unknown. In the present study, a hydroponic pot experiment was conducted to study the roles of CTS with different molecular weight (Mw) (10 kDa，5 kDa and 1 kDa) in alleviating Cd toxicity in edible rape (Brassica rapa L .). The results showed that Cd stress significantly decreased plant growth, leaf chlorophyll contents and increased the malondialdehyde (MDA) level in rape leaves. Foliar application of CTS promoted the plant growth and leaf chlorophyll contents, and decreased the malondialdehyde (MDA) level in edible rape leaves under Cd stress. The alleviation effect of CTS on toxicity was depended on its Mw and CTS with Mw of 1 kDa showed the best activity. Spraying 1 kDa CTS onto the leaves of edible rape under Cd-toxicity could decrease shoot Cd2+ concentration and improve photosynthetic characteristics of edible rape. Moreover, 1 kDa CTS also significantly enhanced non-enzymatic antioxidants (ascorbic acid) and enzyme activities (superoxide dismutase, catalase and guaiacol peroxidase) under Cd stress. Based on these findings, it can be concluded that application of exogenous CTS could be an effective approach to alleviate the harmful effects of Cd stress and could be explored in an agricultural production system.

Hollow nestlike α-Fe2O3 spheres were successfully synthesized via a facile template-free, glycerol-mediated hydrothermal process employing microwave heating. The product was characterized using X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption measurements. The as-prepared product was found to consist of hierarchically nanostructured spheres assembled of nanorod subunits. The effect of the relative amount of glycerol in the reaction system on the composition and morphology of the products was systematically studied, and a possible formation mechanism of the hollow nestlike spheres was proposed. Because of their large surface area and unique mesoporous structure, we investigated the potential application of the hollow α-Fe2O3 spheres in water treatment. With maximum removal capacities of 75.3, 58.5, and 160 mg g–1 for As(V), Cr(VI), and Congo red, respectively, these novel nanostructures have the potential to be used as low-cost and efficient adsorbent materials for the removal of toxic metal ions and organic pollutants from water.Keywords: adsorption; Congo red; heavy-metal ions; hollow nanostructures; water treatment; α-Fe2O3;

The preparation of chitooligosaccharides with single degree of polymerization and well-defined degree of acetylation is of significance to identify the components possessing strong biofunction. This study focuses on the preparation of two partially acetylated chitotrioses (N-acetylchitotriose and N,N′-diacetylchitotriose), involving a two-step process: (i) partially N-acetylation of chitotriose and (ii) separation of different acetylated chitotrioses. The chitotriose was N-acetylated and characterized with FT-IR and ESI-MS. N-acetylchitotriose and N,N′-diacetylchitotriose were separated from the acetylated chitotriose mixture by CM Sepharose Fast Flow. Subsequently, the antioxidant activities of two partially acetylated chitotrioses and original chitotriose were investigated, including hydroxyl radical and superoxide radical scavenging activity. The results showed that the activities of the three oligomers were in a dose-dependence manner and related to their degree of acetylation. The N,N′-diacetylchitotriose with high degree of acetylation exhibited the highest antioxidant activity.Highlights► An N-acetylated chitotriose mixture is prepared. ► N-acetylchitotriose (D2A) and N,N′-diacetylchitotriose (DA2) were separated. ► The main isomers of D2A and DA2 were DDA and ADA, respectively. ► N-acetylation enhanced the antioxidant activity of chitotriose.

In this study, ammonium dithiocarbamate chitosan (ADTCCS) and triethylene diamine dithiocarbamate chitosan (TEDADTCCS) derivatives were obtained respectively by mixing chitosan with carbon disulfide and ammonia (triethylenediamine). Their structures were confirmed by FT-IR, 1H NMR, XRD, DSC, SEM, and elemental analysis. Antifungal properties of them against the plant pathogenic fungi Fusarium oxysporum and Alternaria porri were investigated at concentrations ranged from 31.25 to 500 mg/L. The dithiocarbamate chitosan derivatives had enhanced antifungal activity compared with chitosan. Particularly, they showed obvious inhibitory effect on Fusarium oxysporum. At 500 mg/L, TEDADTCCS inhibited growth of F. oxysporum at 60.4%, stronger than polyoxin and triadimefon whose antifungal indexes were found to be 25.3% and 37.7%. The chitosan derivatives described here deserve further study for use in crop protection.Highlights► Two dithiocarbamate chitosan derivatives were obtained. ► The derivatives had enhanced antifungal activity compared with chitosan. ► Both of the derivatives had a better activity against F. oxysporum than polyoxin.

Chitosan’s activities are significantly affected by degree of deacetylation (DDA), while fully deacetylated chitosan is difficult to produce in a large scale. Therefore, this paper introduces a compression method for preparing 100% deacetylated chitosan with less environmental pollution. The product is characterized by XRD, FT-IR, UV and HPLC. The 100% fully deacetylated chitosan is produced in low-concentration alkali and high-pressure conditions, which only requires 15% alkali solution and 1:10 chitosan powder to NaOH solution ratio under 0.11–0.12 MPa for 120 min. When the alkali concentration varied from 5% to 15%, the chitosan with ultra-high DDA value (up to 95%) is produced.

•A new β-chitosan was prepared with high molecular weight and low acetylation degree.•Different molecular weight β-chitosan was obtained by microwave-assisted method.•Degraded β-chitosan has better antiviral activity than degraded α-chitosan.•β-Chitosan with 3–6 kDa molecular weight has best antiviral activity.Beta-chitosan has a parallel structure, which differs from alpha-chitosan's antiparallel structure while producing different properties and difficulties. In this paper, we prepared the beta-chitosan through acid and alkali methods and the resultant material was characterized by elemental analysis, FT-IR, HPLC, XRD, NMR and AFS. To increase the solubility and biological activity of the beta-chitosan, we degraded it through microwave-assisted process. After characterization, we determined that the chitosan had not changed its configuration during the reaction with H2O2 under microwave irradiation. The inhibitory activity of the degraded chitosan for Newcastle disease was revealed by a hemagglutination test and RT-PCR. The yield of the beta-chitosan was approximately 30%, and its molecular weight can be degraded to 1000 to 10,000 g/mol. Moreover, the degraded β-chitosan has higher antiviral activity, reducing the hemagglutination titre to zero, compared with alpha-chitosan. Therefore, beta-chitosan has good development prospects during the development of veterinary drugs for Newcastle disease.

Waste shells create several serious problems, however, only parts of them are being utilized now. Therefore, the ideal solution would be to convert the waste shells into a product that is both environmentally beneficial and economically viable. Scallop and oyster shells were exposed to heat treatment at 1050 °C. SEM and XRD analysis results showed that the resultant powder turned completely into CaO after the treatment. The antifungal activities of non-treated and heat-treated scallop and oyster shell powder slurry were investigated. Non- treated oyster shell powder exhibited a significant antifungal activity at 25,000 ppm. Its antifungal activities against Physalospora piricola Nose (P. piricola) and Rhizoctonia solani Kühn (R. solany) were even up to 100%. Moreover, increasing culture time did not alter the antifungal activities. Heat-treated scallop and oyster shell powder exhibited obvious antifungal activity at 500 ppm, at which concentration 100% inhibition of R. solany was observed. The possible antifungal mechanism of the oyster shell and its heat-treated counterpart was studied using R. solani Kuhn as model. The results illustrated that oyster shell is able to affect the membrane permeability of the fungus. The above-mentioned results showed that it is possible for oyster shell to be an agriculture fungicide.