•Helianthus tuberosus L. leaf was used as a new source of chlorogenic acid (3-CQA).•Macroporous resins were used for enrichment and purification of 3-CQA.•Adsorption isotherms and kinetics were systematically investigated.•Efficient method for the separation of 3-CQA on ADS-21 resin was developed.•Good separation and high recovery was achieved after one run treatment with ADS-21.In the present study, a simple and efficient method for the preparative separation of 3-CQA from the extract of Helianthus tuberosus leaves with macroporous resins was studied. ADS-21 showed much higher adsorption capacity and better adsorption/desorption properties for 3-CQA among the tested resins. The adsorption of 3-CQA on ADS-21 resin at 25 °C was fitted best to the Langmuir isotherm model and pseudo-second-order kinetic model. Dynamic adsorption/desorption experiments were carried out in a glass column packed with ADS-21 to optimise the separation process of 3-CQA from H. tuberosus leaves extract. After one treatment with ADS-21, the content of 3-CQA in the product was increased 5.42-fold, from 12.0% to 65.2%, with a recovery yield of 89.4%. The results demonstrated that the method was suitable for large-scale separation and manufacture of 3-CQA from H. tuberosus leaves.

A combination technique for remediation of DDT and its metabolites (DDTr) contaminated soil based on successive steps of solvent extraction, followed by catalytic hydrodechlorination (HDC) was studied. Firstly, solvent extraction was applied to extract DDTr contaminated soil at ambient temperature and pressure. According to GC-MS analysis, the extracts from DDTr contaminated soil are mainly composed of p,p′-DDT, o,p′DDT, p,p′-DDE, o,p′-DDE, p,p′-DDD, and DCBP. Subsequently, catalytic HDH over a Pd/C catalyst was introduced to treat the extract from DDTr contaminated soil, and the HDC process of DDTr was surveyed by monitoring the GC-MS analysis. These results demonstrate that the combined technique of solvent extraction and catalytic HDC can effectively remediate DDTr contaminated soil and reduce its toxicity.

The catalytic hydrogenation reactivity of aromatic nitro compounds over RANEY® Ni was substantially improved when a moderate amount of metal fluoride (NaF, KF, MgF2, and CaF2) was added into the reaction system.

•The HPD-400 resin had good adsorption/desorption capacities of VOG and VOR.•Adsorption isotherms were constructed for the HPD-400 resin and well fitted to Langmuir and Freundlich models.•The variables for the dynamic adsorption and desorption were optimized.•The developed method is suitable for large-scale purification of VOG and VOR.Vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside are the major flavonoids of hawthorn leaves. In this work, the adsorption and desorption characteristics of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside on seven macroporous resins were evaluated. Among the tested resins, the HPD-400 resin showed the best adsorption and desorption capacities. Adsorption isotherms were constructed for the HPD-400 resin and well fitted to Langmuir and Freundlich models. Dynamic adsorption and desorption tests were performed on column packed with the HPD-400 resin to optimize the chromatographic parameters. After one run treatment with the HPD-400 resin, the contents of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside in the product were increased 8.44-fold and 8.43-fold from 0.720% and 2.63% to 6.08% and 22.2% with recovery yields of 79.1% and 81.2%, respectively. These results show that the developed method is a promising basis for the large-scale purification of vitexin-4″-O-glucoside and vitexin-2″-O-rhamnoside from hawthorn leaves and other plant materials.

A concise, fast and efficient one-pot methodology has been developed for preparing 2,3-unsubstituted indoles from 2-nitrotoluenes and dimethylformamide dimethyl acetal. Compared with the classical Leimgruber–Batcho reaction, such a one-pot process simplified the operation procedures, generated less by-products and chemical residues, and resulted in higher overall yields in a shorter reaction time.

Liquid phase catalytic oxidation of chlorophenols (CPs) was carried out over Cu–Al hydrotalcite/clay composite at ambient temperature and pressure using hydrogen peroxide as oxidant. The results showed that the catalyst had high catalytic activity, with complete oxidation of 4-CP within 40 min at 40 °C. The content and position of chlorine on the aromatic ring had significantly different effects on the oxidation rate of CPs, with the rate sequence of phenol > monochlorophenol (MCP) > dichlorophenol (DCP) > trichlorophenol (TCP), 3-CP > 2-CP > 4-CP, and 3,5-DCP > 3,4-DCP > 2,5-DCP > 2,4-DCP > 2,6-DCP. This was ascribed to the interactions among σ-electron withdrawing conductive effect, π-electron donating conjugative effect, and steric hindrance effect of chlorine. It was evidenced that the catalytic peroxide oxidation of CPs in the first step was selective and rate-limiting, where chlorinated 1,4-benzoquinones formed.Graphical abstractThe catalyst was a polymer of hydrotalcite and clay, with a large number of cavities and crevices on the surface, which showed high activity for catalytic wet peroxide oxidation of CPs.Research highlights► The catalytic peroxide oxidation of CPs in the first step was selective. ► The content and position of chlorine influenced the oxidation rate of CPs. ► The hydrotalcite/clay composite exhibited high catalytic activity. ► There was an appropriate concentration ratio among catalyst, H2O2, and CPs.

•HQ had high inhibitory effects on marine microalgae P. tricornutum.•HQ exposure results in the changes of the ratio of carotenoids and Chlorophyll a.•HQ induced oxidative stress in P. tricornutum.•HQ altered the permeability of cell membrane and mitochondrial membrane potential.•HQ inhibited the transcription of photosynthesis and respiration related genes.Algal blooms have been occurring in many regions all over the world and allelochemical is considered as one of the important and promising algaecides to control algal blooms. In the present study, we investigated the effects of allelochemical hydroquinone (HQ) on growth, photosynthesis and other physiological levels of Phaeodactylum tricornutum (P. tricornutum). The results showed that HQ (above 3 × 10− 7 mol/L) significantly inhibited the growth and specific growth rate of algae. EC50 values were calculated at four different incubation times, i.e. 24, 48, 72 and 96 h. EC50 values increased with the treated-time increasing, which suggested that HQ stress on the algae gradually weakened with time prolonging. The contents of cellular pigments including Chlorophyll a (Chl.a) and carotenoids were significantly decreased by HQ. However, the ratios of carotenoids to Chl.a increased obviously when algae were exposed to 6 and 7 × 10− 7 mol/L of HQ for 72 h, which implied that the ratios of pigments changed in extreme conditions to resist environmental stress. At the same time, HQ also induced the responses of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST) and non-enzymatic antioxidant reduced glutathione (GSH). Additionally, flow cytometric assays showed that HQ stress altered the permeability of cell membrane and mitochondrial membrane potential in different degrees and HQ significantly inhibited the transcription of photosynthesis and respiration related genes. All these results showed that HQ might have the potential as an algaecide to control marine microalgae.

A practical and efficient disposal method for 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane (DDT)-contained soil is reported. The treatment process was a combination technique: first to extract DDT in the soil, and then to hydrogenate the extract containing DDT. 4, 4’-DDT was effectively extracted in the soil and hydrodechlorinated in this treatment process. Additionally, solvent media and extracting time for DDT removal were investigated. An efficient heterogeneous catalytic method was also developed by comparing the rates of dechlorination of DDT over two different catalysts in organic-aqueous heterogeneous system. Compared to Raney Ni, Pd/C is a more efficient catalyst in disposing DDT.

Cadmium ion (Cd2+) is a ubiquitous toxic heavy metal in the environment and presents a potential threat to human health via the food chain through plant root uptake systems. The halophyte, Suaeda salsa is the pioneer plant in the Yellow River Delta and has been widely applied as a model plant in environmental pollution assessment. In this work, the study was conducted using a liquid culture with a series of Cd2+ concentrations. Germination rates and activities of three enzymes (catalase (CAT), glutathione peroxidase (GPX), glutathione S-transferase (GST)) in the seedling were investigated. Results showed that the germination indices and growth inhibition indices of S. salsa decreased significantly (p<0.05) at the concentration of 0.1 mg/L CdCl2, and the inhibition effect was increased with the increasing concentration of Cd2+. GPX and GST changed similarly, which reached the maximum when Cd2+ was 0.1 mg/L, then it declined sharply with the increasing concentration of Cd2+. However, for CAT, the reverse trend was observed. Overall, these results indicated that all the bio-indicators mentioned above for S. salsa were quite sensitive to Cd2+. It could be applied to monitor Cd2+ pollution in Yellow River Delta.

The hydrodechlorination (HDCl) of 2,4-dichlorophenol (2,4-DCP), 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP) over Raney Ni in liquid phase with triethylamine (Et3N) under mild conditions was studied. The results showed that Et3N together with solvents significantly affected the HDCl reactivity or selectivity, in which ortho-positioned Cl of chlorophenols (CPs) was easier to be dechlorinated in methanol (MeOH) and ethanol (EtOH), whereas para-positioned Cl was preferentially dechlorinated in water. Different species and action mechanisms of Et3N in water and organic solvents possibly affected the HDCl reactivity or selectivity of CPs over Raney Ni.Et3N together with solvents significantly affected the HDCl reactivity or selectivity of 2,4-DCP, in which ortho-positioned Cl was easier to be dechlorinated in methanol (MeOH) and ethanol (EtOH), whereas para-positioned Cl was preferentially dechlorinated in water.Download full-size imageResearch Highlights►Solvent influenced the hydrodechlorination of chlorophenols. ►Et3N influenced the hydrodechlorination selectivity of chlorophenols. ►Ortho-positioned Cl was easier to be dechlorinated in organic solvents with Et3N. ►Et3N played different roles in different solvents.