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Indole-3-butyric acid (IBA) is an efficient plant growth regulator for promoting germination and the formation of rooting of various plants. Since it is unstable and presents the low utilization ratio, there is a compelling need to design an environmentally friendly formulation for IBA, which can reduce the loss of degradation and improve its utilization. Nano-sized controlled-release formulations can provide better durability and penetrate through the plant epidermis to efficiently deliver the agrochemicals to the target tissues. In this work, a kind of novel nano controlled-release formulation was prepared by conjugating the IBA and 3-glycidoxypropyltrimethoxysilane (GPTMS) through a covalent cross-linking reaction, and subsequently hydrolyzation and polycondensation with tetraethoxysilane. The resulting nanospheres were characterized by Fourier transform infrared spectroscopy, ultraviolet spectrophotometry, scanning electron microscope, and thermal gravity analysis. The results showed that the obtained nanospheres had a remarkable loading efficiency of IBA (about 43% w/w). The formation of covalent between IBA and GPTMS enabled the nanospheres with a good chemical stability that could protect against photo-degradation effectively. The released rate of the IBA from nanospheres was related to the temperature, pH value. With increased temperature as well as acidity and alkality, the release of the IBA was sped up. The IBA could also be released effectively from IBA-silica nanospheres by esterase, and the sustainable release characteristics of IBA-silica nanospheres were in conformity with the Ritger and Peppas equation. The IBA-silica nanospheres displayed excellent dual stimuli-responsive properties under esterase and weak acid conditions, and could obviously promote the growth of root and bud of pea. Thus, the IBA silica nanospheres prepared by covalent cross-linking reaction have a good potential application as a controlled-release formulation and environmentally-friendly plant growth regulator. [ABSTRACT FROM AUTHOR]

Kasugamycin is an aminoglycoside antibiotic originally isolated from Streptomyces kasugaensis , which has been widely used for the management of plant diseases. However, photo-thermal instability and low efficiency limit its application. Therefore, it is an urgent task to prevent unwanted loss of kasugamycin and ensure maximum bioactivity at target site. In this work, a novel formulation of kasugamycin that responds to different biological stimuli produced by pests was prepared using silica microcapsules crosslinked with pectin via special disulfide bonds. The results demonstrated that the silica-SS-pectin microcapsules had a high loading efficiency (20% w/w) and could effectively enhance the thermal and light stability of kasugamycin. The microcapsules displayed excellent pectinase and glutathione dual-responsive properties and the release kinetics investigated by Riger-Peppas model suggested combination of various release mechanisms. Compared with kasugamycin wettable powder, the microcapsules possessed sustained and improved antimicrobial efficacy against Erwinia carotovora . Thus, the dual-responsive microcapsules potentially have agricultural application as a controlled release system. [ABSTRACT FROM AUTHOR]

The fungicide myclobutanil (MYC) is a common contaminant found in surface water. The aim of this study was to determine the acute toxicity, developmental effects, bioconcentration factor (BCF) and potential bio-molecular mechanisms of MYC toxicity in zebrafish. Susceptibility to MYC toxicity was life-stage dependent with adult fish being the most sensitive (96 h-LC 50 , 6.34 mg/L) followed by 72 h post-hatch (hph) larvae (8.90 mg/L), 12 hph larvae (20.53 mg/L) and embryos (42.54 mg/L). Zebrafish embryos and larvae (12 hph) responded with decreased hatching, heartbeat and growth, as well as abnormal spontaneous movement and development. BCFs were calculated by quantifying MYC concentrations from different tissues of adult zebrafish exposed to MYC for up to 11 days. Highest BCFs were obtained from gills (18.25 ± 0.07), followed by viscera (16.78 ± 0.04), head (13.13 ± 0.08) and muscle (8.96 ± 0.10). MYC (0.5 mg/L) inhibited gene expression related to cholesterol synthesis pathway, including 24-dehydrocholesterol reductase (DHCR24), 7-dehydrocholesterol reductase (DHCR7), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCRa), HMGCRb, farnesyl-diphosphate farnesyltransferase 1(FDFT1), squa-lene epoxidase (SQLE), isopentenyl-diphosphate delta isomerase 1 (IDI1) and CYP51, while no cholesterol changes were observed in the MYC treated group. These results will contribute to the literature assessing the environmental risk of MYC in aquatic environment. • Myclobutanil had different lethality to four life stages of zebrafish. • Myclobutanil could affect the development of zebrafish embryos and larvae fish. • Myclobutanil could be accumulated by zebrafish. [ABSTRACT FROM AUTHOR]

The excessive application of water-soluble pesticides poses enormous potential risks to groundwater by leaching or in runoff. Ionic liquids can regulate the physicochemical properties of pesticides and surmount their disadvantages. In this study, five herbicidal ionic liquids (HILs) based on clopyralid have been synthesized and characterized to reduce the risks to the aquatic environment and improve the herbicidal activity. The new HILs are prepared by pairing isopropylamine, 1-dodecylamine, 2-benzothiazolamine, 1-methylimidazole, benzyltriethylammonium chloride respectively. The results of the solubility, soil adsorption, surface activity, leaching characteristic and herbicidal activity of HILs show that the physicochemical properties can be optimized by selecting different counter cations. Compared with clopyralid potassium, HILs have better herbicidal activity, greater adsorption capacity and lower leaching characteristic. The HILs of clopyralid can reduce its hazardous impacts on the aquatic environment, suggesting a desirable candidate in clopyralid application in the future. [ABSTRACT FROM AUTHOR]

Bentazone is one of the widely used herbicides for controlling sedges and broad-leaf weeds. Due to its high mobility in soils, bentazone has been frequently found among the contaminants detected in surface and ground water and poses a potential threat to aquatic organisms by runoff and leaching. In this work, novel herbicidal ionic liquids (HILs) based on bentazone with four typical cations were synthesized and characterized. The physicochemical properties (water solubility, surface activity, leaching and soil adsorption) and herbicidal activity of HILs were investigated. The result showed that the water solubility of HILs was reduced along with the increasing length of alkyl chains in cations. Compared with bentazone sodium, HILs showed higher adsorption capacity, weaker mobility, and excellent surface activity and Pyr-1 substantially performed higher efficacy under field condition. With high activity of weed control and fascinating physicochemical properties, HILs can reduce the risk of bentazone in aquatic environment and they will be applied widely in the future. [ABSTRACT FROM AUTHOR]

Ractopamine (RAC) has been approved as a feed additive for swine, cattle or turkey, and is likely to have residue in edible animal products and may pose a potential risk for consumer health. Therefore, it is essential to establish a method to detect the residue of RAC in animal products. This work presents a rapid and sensitive HPLC method for the determination of RAC in pork samples with pre-column derivatization. The RAC derivative was separated on a kromasil C18 column and detected at 284 nm with a UV detector. The detection capability (CCβ) was 0.078 μg g − 1 and the linearity was established over the concentration range of 0.15–100.0 μg g − 1 . The overall mean recovery in spike range of 0.2 μg g − 1 to 100 μg g − 1 was 89.9% with the overall mean relative standard deviation of 4.1%. This method can be used for the quantification of RAC in pork samples and help to establish adequate monitoring of the residue of RAC. [ABSTRACT FROM AUTHOR]

• SFC-MS/MS was first used to separate the fosthiazate stereoisomers. • The determination of four fosthiazate stereoisomers could be completed within 6 min. • The stereoselective behaviors of fosthiazate stereoisomers were first evaluated. • Different environmental behaviors were observed in five kinds of legume vegetables. • Stereoselectivities exhibited species specificity in legume vegetables. A separation and analysis method of fosthiazate stereoisomers was established utilizing supercritical fluid chromatography-tandem mass spectrometry (SFC-MS/MS) with a CHIRALPAK AD-3 column. The determination of the four fosthiazate stereoisomers could be completed within 6 min. The environmental behaviors of fosthiazate stereoisomers were studied in legume vegetables. After applying fosthiazate granules to soil, the concentrations of fosthiazate stereoisomers in the legume vegetables increased with time, reached maximum values in 7–10 days, and then decreased gradually in all legumes except for in Glycine max. No obvious dissipation behaviors were observed in Glycine max. Interestingly, the stereoselective behaviors were species-specific. A-(−), B-(−) and B-(±)-fosthiazate were preferentially enriched in Phaseolus vulgaris Linn and Vigna unguiculata , while A-(+) and A-(±)-fosthiazate preferentially accumulated in Vicia faba Linn, Pisum sativum Linn and G. max. The opposite stereoselectivity of B-(±)-fosthiazate was observed in different growth stage of G. max. No stereoselective dissipation occurred in soil. [ABSTRACT FROM AUTHOR]