卤素盐参与下有机电合成含氮杂环化合物的研究进展

含氮杂环化合物广泛存在于医药、农药及天然产物中,是许多具有生理活性的化合物和药物的基本骨架.开发高效、绿色的含氮杂环化合物的构建方法具有重要意义.近年来,卤素盐参与下有机电合成含氮杂环化合物取得了诸多进展.该类反应具有操作简单、绿色环保等特点.综述了有机电化学合成反应中,卤素盐作媒介,含氮杂环化合物的合成研究新进展.     

Production of a water disinfectant by membrane electrolysis of brine solution and evaluation of its quality change during the storage time

Anolyte solution produced by membrane electrolysis of NaCl solution contains a high level of available chlorine content (ACC) and other oxidizing compounds, rendering this solution a strong disinfectant property. In this paper, some process parameters affecting the anolyte production efficiency, such as total inlet flow (240–320 L/h), saline solution concentration (1.65–3.50 g/L), and the type of membrane (cation exchange, anion exchange, and bipolar membranes) were investigated in an electrolysis cell. Changes in the quality of anolytes produced at three initial concentrations of very high (ACC₁ = 816.5 mg/L), relatively high (ACC₂ = 461.5 mg/L), and medium (ACC₃ = 355.0 mg/L) during storage (from the production up to 20 weeks) were examined by adjusting the total inlet flow, saline concentrations, and membrane types. Changes in the ACC of the produced anolyte solution were generally affected by the type of membrane used in the electrolysis cell. The use of anion exchange membrane resulted in the lowest durability of anolyte quality (60–80% ACC reduction after 4 weeks of storage) and the cation exchange membrane had the highest durability (less than 40% decrease after 4 weeks of storage). In addition, changes in the pH and the oxidation–reduction potential of the anolyte were investigated during the storage period, which had a different trend depending on the type of applied membrane.     

Enzymatic Extraction and Characterization of Pectin from Cocoa Pod Husks (Theobroma cacao L.) Using Celluclast® 1.5 L

Cocoa pod husks are a waste generated during the processing of cocoa beans. We aimed to explore the enzymatic extraction of pectin using cellulases. The extraction process was optimized using a central composite design (CCD) and analyzed by response surface methodology (RSM). The parameters optimized were feedstock concentration (%), enzyme dosage (µL/g), and time (h). Three dependent variables were studied: pectin yield (g/100 g dry husk) (R² = 97.02), galacturonic acid content (g/100 g pectin) (R² = 96.90), and galacturonic acid yield (g/100 g feedstock) (R² = 95.35). The optimal parameters were 6.0% feedstock concentration, 40 µL g⁻¹ of enzyme, and 18.54 h, conditions that produced experimentally a pectin yield of 10.20 g/100 g feedstock, 52.06 g galacturonic acid/100 g pectin, and a yield 5.31 g galacturonic acid/100 g feedstock. Using the chemical extraction method, a yield of 8.08 g pectin/100 g feedstock and a galacturonic acid content of 60.97 g/100 g pectin were obtained. Using assisted sonication, a pectin yield of 8.28 g/100 g feedstock and a galacturonic acid content of 42.77 g/100 g pectin were obtained. Enzymatically optimized pectin has rheological and physicochemical features typical of this biomaterial, which provides an interesting alternative for the valorization of cocoa husks.     

气相色谱法同时测定水中12种挥发性消毒副产物

建立液-液萃取气相色谱法电子捕获检测器(GC/ECD)同时测定饮用水中12种挥发性消毒副产物(Disinfection byproducts, DBPs)的方法.采用过程标准校正降低预处理过程中引入的误差,方法检出限为0.08~0.21 μg/L, 全部组分在21.50 min内测定完成.不同浓度的DBPs在自来水和地表水中的回收率为80.9%~115.7%,相对标准偏差在0.9%~9.9%之间.各组分在0.5~200 μg/L浓度范围内线性关系良好,相关系数R>0.99.应用本方法测定了饮用水和地表水及其氯化后样品中DBPs的含量.本方法简便、快速、稳定,满足饮用水中挥发性DBPs的检测要求.     

Rapid Screening of Haloacetonitriles in Water Samples by Optimized Vortex‐assisted Liquid–Liquid Microextraction

This paper describes an optimized method for the quick screening of low levels of haloacetonitriles (HANs), a nitrogenous disinfection byproduct. The method is especially geared toward screening of water used for drinking and in swimming pools. The method is based on vortex‐assisted liquid–liquid microextraction (VALLME), which is carried out before determination of the gathered samples by gas chromatography‐mass spectrometry (GC‐MS). Factors that can potentially affect the extraction efficiency of the desired trace chemicals from the gathered sample were enhanced using the Box–Behnken design method. The optimal VALLME parameters for a 10‐mL water sample (pH 4, containing 3 g of sodium sulfate), according to the Box–Behnken design method, are extractant 160 μL dichloromethane and vortex extraction time of 1 min at the maximum speed (2500 rpm). The limits of quantitation calculated were 16–35 ng/L. Precision for both intra‐ and inter‐day analysis was also calculated, which was less than 11% on three concentration levels. Mean extraction recovery, otherwise known as trueness, was between 71 and 92%. The developed method was applied successfully to extract HANs from drinking and swimming pool water samples.     

Combination of ozone and ultrasonic-assisted aerosolization sanitizer as a sanitizing process to disinfect fresh-cut lettuce

Reduction of sanitizer dosage and development of non-immersion disinfection methods have become major focuses of research. Here, we examined the disinfection efficacy of combining gaseous ozone (4 and 8 ppm) with aerosolized oxidizing sanitizer [sodium hypochlorite (SH, 100 and 200 ppm)] and aerosolized organic acid [acetic acid (AA, 1% and 2%) and lactic acid (LA, 1% and 2%)]. Notably, 1% AA and 4 ppm gaseous ozone were ineffective for disinfecting Salmonella Typhimurium, and treatment with 1% AA + 8 ppm ozone caused browning of lettuce leaves and stimulated increases in aerobic mesophilic count (AMC), aerobic psychrotrophic count (APC), S. Typhimurium, and Escherichia coli O157:H7. Treatment with 2% LA + 8 ppm ozone resulted in the lowest S. Typhimurium, E. coli O157:H7, Listeria monocytogenes, AMC, APC, and molds and yeasts during storage (0–7 days at 4 °C). Quality analysis indicates that LA + 8 ppm ozone and SH + 8 ppm ozone did not negatively affect L*, a*, b*, polyphenolic content, weight loss, and sensory properties; however, the levels of two individual phenolic compounds (3,4-dihydroxybenzoic acid and vanillin), responsible for phenylpropanoid synthesis, were significantly increased after treatment with 2% LA + 8 ppm ozone. These findings provided insights into the use of LA combined with gaseous ozone for application in disinfecting fresh produce.     

Applicability of an In-Vitro Digestion Model to Assess the Bioaccessibility of Phenolic Compounds from Olive-Related Products

The Mediterranean diet includes virgin olive oil (VOO) as the main fat and olives as snacks. In addition to providing nutritional and organoleptic properties, VOO and the fruits (olives) contain an extensive number of bioactive compounds, mainly phenolic compounds, which are considered to be powerful antioxidants. Furthermore, olive byproducts, such as olive leaves, olive pomace, and olive mill wastewater, considered also as rich sources of phenolic compounds, are now valorized due to being mainly applied in the pharmaceutical and nutraceutical industries. The digestive system must physically and chemically break down these ingested olive-related products to release their phenolic compounds, which will be further metabolized to be used by the human organism. The first purpose of this review is to provide an overview of the current status of in-vitro static digestion models for olive-related products. In this sense, the in-vitro gastrointestinal digestion methods are widely used with the following aims: (i) to study how phenolic compounds are released from their matrices and to identify structural changes of phenolic compounds after the digestion of olive fruits and oils and (ii) to support the functional value of olive leaves and byproducts generated in the olive industry by assessing their health properties before and after the gastrointestinal process. The second purpose of this review is to survey and discuss all the results available to date.     

Cold Atmospheric Plasma Jet as a Possible Adjuvant Therapy for Periodontal Disease

Due to the limitations of traditional periodontal therapies, and reported cold atmospheric plasma anti-inflammatory/antimicrobial activities, plasma could be an adjuvant therapy to periodontitis. Porphyromonas gingivalis was grown in blood agar. Standardized suspensions were plated on blood agar and plasma-treated for planktonic growth. For biofilm, dual-species Streptococcus gordonii + P. gingivalis biofilm grew for 48 h and then was plasma-treated. XTT assay and CFU counting were performed. Cytotoxicity was accessed immediately or after 24 h. Plasma was applied for 1, 3, 5 or 7 min. In vivo: Thirty C57BI/6 mice were subject to experimental periodontitis for 11 days. Immediately after ligature removal, animals were plasma-treated for 5 min once—Group P1 (n = 10); twice (Day 11 and 13)—Group P2 (n = 10); or not treated—Group S (n = 10). Mice were euthanized on day 15. Histological and microtomography analyses were performed. Significance level was 5%. Halo diameter increased proportionally to time of exposure contrary to CFU/mL counting. Mean/SD of fibroblasts viability did not vary among the groups. Plasma was able to inhibit P. gingivalis in planktonic culture and biofilm in a cell-safe manner. Moreover, plasma treatment in vivo, for 5 min, tends to improve periodontal tissue recovery, proportionally to the number of plasma applications.     

饮用水消毒副产物及其分析技术

介绍了饮用水中液氯、臭氧、二氧化氯消毒副产物的特性和现状,总结了近年来消毒副产物分析领域中常用的各种样品前处理技术及检测方法,展望了今后研究的发展方向.     

Influence of Hydrogen Peroxide on Disinfection and Soil Removal during Low-Temperature Household Laundry

In the Water, Energy and Waste Directive, the European Commission provides for the use of household washing programmes with lower temperatures (30–40 °C) and lower water consumption. However, low washing temperatures and the absence of oxidising agents in the liquid detergents, and their reduced content in powder detergents, allow biofilm formation in washing machines and the development of an unpleasant odour, while the washed laundry can become a carrier of pathogenic bacteria, posing a risk to human health. The aim of the study was to determine whether the addition of hydrogen peroxide (HP) to liquid detergents in low-temperature household washing allows disinfection of the laundry without affecting the properties of the washed textiles even after several consecutive washes. Fabrics of different colours and of different raw material compositions were repeatedly washed in a household washing machine using a liquid detergent with the addition of 3% stabilised HP solution in the main wash, prewash or rinse. The results of the antimicrobial activity, soil removal activity, colour change and tensile strength confirmed the excellent disinfection activity of the 3% HP, but only if added in the main wash. Its presence did not discolour nor affect the tensile strength of the laundry, thus maintaining its overall appearance.