Airborne particulate of less than 10 μm (PM10) has a major health impact to humans. PM10 consists of the broad range of toxic compounds, such as transition metals, endotoxins, and ultrafine ...components and can induce oxidative stress and inflammation. The purpose of this study was to identify phenolic antioxidants from marine plants, and to examine their protective effects in keratinocytes exposed to PM10. Of the extracts of 50 marine plants tested, the extracts of Ecklonia cava Kjellman showed the highest ‘total phenol content’ and the highest ‘free radical-scavenging activities’ against of 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radicals in vitro. Therefore, the extract of Ecklonia cava Kjellman was tested in the subsequent cell experiments. When HaCaT keratinocytes were exposed to PM10, reactive oxygen species production and lipid peroxidation increased, in a dose-dependent manner. The extract of Ecklonia cava Kjellman attenuated reactive oxygen species production and lipid peroxidation in HaCaT keratinocytes exposed to PM10 at its non-toxic concentrations. Of its solvent fractions, ethyl acetate fraction was the most effective at inhibiting cellular lipid peroxidation. This study suggests that marine plants are useful sources of polyphenolic antioxidants which mitigate oxidative stress due to airborne particulates.
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•A hierarchical composite ZnO@Carbon foam/PVA cryogel sorbent was developed.•The developed sorbent was applied to extract and enrich parabens and an antioxidant.•The developed sorbent ...exhibited high extraction efficiency (83.8–99.0%).•The hierarchical composite sorbent was easy to fabricate and was reused 12 times.
A hierarchical composite ZnO@Carbon foam/PVA cryogel was fabricated and applied to extract and enrich parabens and synthetic phenolic antioxidant. A hierarchical porous structure was produced by embedding CaCO3 in the porous PVA cryogel and then removing the CaCO3 with hydrochloric acid, which generated CO2 bubbles. The extracted compounds were quantitatively determined by high performance liquid chromatography (HPLC). The ZnO@Carbon foam loading, elution solvent type and volume, sample flow rate, sample volume, ionic strength and sample pH were optimized. The developed method demonstrated linear responses in the range of 0.25–1000.0 μg L−1 for propyl paraben and butyl paraben, 0.50–1000.0 μg L−1 for methyl paraben and 2.00–1000.0 μg L−1 for tert-butylhydroquinone, with R2 above 0.99. For the four analytes, the limits of detection (LOD) and limits of quantification (LOQ) ranged from 0.25 to 2.0 μg L−1 and from 0.75 to 5.0 μg L−1, respectively. The fabricated porous composite sorbent was used to extract and enrich parabens and a synthetic phenolic antioxidant from fruit juice samples. Relative recoveries were in the range of 83.8–99.0% and the RSDs were lower than 6.0%. The enrichment factor of the developed method ranged from 12.5 to 14.9. Low concentrations of tert-butylhydroquinone and butyl paraben were found in some samples at 2.20 and 2.52 μg L−1, respectively. Repeatability was evaluated in terms of intra-day precision and inter-day precision. RSDs were in the range of 2.1–3.0% and 3.5–4.5%, respectively. The developed sorbent was easy to fabricate, and could be reused up to 12 times.
The aim of this study is to investigate the exposure of novel high-molecular-weight (HMW) synthetic antioxidants (AOs), including nine synthetic phenolic antioxidants (SPAs), one low-molecular-weight ...(LMW) SPA, two organophosphite antioxidants (OPAs) as well as one transformation product in children's urine from eastern (n = 82) and western (n = 105) China. For the first time, all analytes were detected in children's urine such as the representative HMW SPAs pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate) (AO1010, median = 0.447 ng/mL), octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate (AO1076, median = 0.0300 ng/mL), and 1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenyl)methyl-1,3,5-triazinane-2,4,6-trione(1,2-dioxoethylene)bis(iminoethylene) (AO3114, median = 0.0166 ng/mL) and representative OPAs bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite (AO626, median = 0.00216 ng/mL), tris(2,4-di-tert-butylphenyl) phosphite (AO168, median = 0.0296 ng/mL) as well as its transformation product tris(2,4-di-tert-butylphenyl) phosphate (AO168O, median = 1.53 ng/mL). Significant differences were observed in the concentrations of AO1010, AO3114, AO168, and AO168O between urine samples from eastern and western China (p < 0.01). The high-frequency combination of AOs from binary to a mixture of six AOs was acquired, which would provide a better investigation of the mixture toxicity. The high estimated daily intakes of AO1010 (85.4 ng/kg/day), AO1076 (10.2 ng/kg/day), AO3114 (4.50 ng/kg/day), and AO168 (1231 ng/kg/day) were less than the values of the tolerable daily intake (3,020,000, 1,500,000, 10,000,000, and 580,000 ng/kg/day for AO1010, AO1076, AO3114, and AO168, respectively), indicating low health risk to children. Our findings showed the co-occurrence of those novel AOs and transformation products in children, the overall risks associated with the mixture of transformation products and the mixture with other emerging pollutants need to be considered when assessing the risks of AOs in further studies.
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•Novel HMW synthetic antioxidants (AOs) were firstly detected in Chinese children.•Levels of AO1010 and AO168 were higher in urines from western than eastern China.•High-frequency combination of AOs from binary to a mixture of six AOs was found.•Overall risks associated with the TPs warrant further study when assessing the risks of AOs.
To fulfill the growing demand for retarding the oxidation of polymers and minimizing their migration from various products, new macromolecular synthetic phenolic antioxidants (SPAs) have emerged in ...the market. There is a concern that these SPAs may be released into wastewater streams during their manufacturing and use, eventually ending up in wastewater treatment plants (WWTPs). Nevertheless, information regarding the occurrence of these SPAs in sludge, particularly on a national scale, is scarce. In this study, several macromolecular SPAs and their transformation products (TPs) were investigated in sludge samples from 45 Chinese municipal WWTPs. All 14 analytes were detected in the sludge samples, among which, 12 analytes were first reported in sludge. 2,4,6-tri-tert-butylphenol (AO246) and 2 macromolecular SPAs, pentaerythritol tetrakis3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO1010) and octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (AO1076), were the most dominant SPAs, with geometric mean (GM) concentrations of 547, 212, and 35.2 ng/g dw, respectively. Two TPs, 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoic acid (fenozan) and 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHT-COOH), were found in some sludge samples (48.9–71.1 %) with GM of 45.5 and 12.8 ng/g dw, respectively. By using LC-Q-TOF-MS/MS analysis, we tentatively identified previously unknown TPs of 10 macromolecular SPAs in sludge. This suggests that there are still unclear mechanisms modulating the transformation of these SPAs, which underscores the complexity of their fate. Additionally, using the freshwater photobacteria Vibrio qinghaiensis sp.-Q67 (Q67) as model organism, the acute and chronic EC50 of the 14 analytes were assessed for ecological risk assessment. By considering toxicity data obtained from algae, daphnia, and fish collected or predicted from various databases, we found that these analytes, including their mixture at low detected concentrations, pose risks to aquatic systems that should not be disregarded. Overall, the current study provides a comprehensive overview of novel SPAs and their TPs in sludge, offering valuable insights for investigating their environmental behavior, fate, and risks.
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•Novel macromolecular SPAs were firstly detected in the sludge samples from WWTPs.•Nine of ten macromolecular SPAs exhibited relatively high detection frequency (>90 %).•Multiple potential TPs of the ten macromolecular SPAs in sludge were tentatively identified.•Time- and dose-dependent toxicity patterns of analytes to photobacteria were observed.•Individual compounds and the mixtures showed unexpected ecological risks to the aquatic.
The enhancement of cold flow properties (CFPs) and oxidative stability (OS) in biodiesel-diesel blends typically involves the use of pour point depressants and antioxidants. However, a scant number ...of additives are capable of manifesting both pour point depression and antioxidant functionalities concurrently. This study explored the grafting of syringic acid (SA), 3,5-di-tert-butyl-4-hydroxybenzoic acid (DTBHA), and gallic acid (GA) onto polymethacrylate (PMA) type copolymers, culminating efficacious copolymers, namely PTG-SA, PTG-DTBHA and PTG-GA. The findings reveal that with the addition of 1500 ppm of PTG-GA, the CFPP and PP of B20 (20 vol% soybean biodiesel+80 vol% diesel) decrease by 10 and 18 °C respectively, and with the addition of 2000 ppm, the induction period (IP) of B20 can be extended from 1.34 to 8.69 h. In contrast, the application of PTG-SA and PTG-DTBHA to B20 led to inferior OS and CFPs as compared to PTG-GA. The inherent scientific mechanism that underlies this performance discrepancy was thoroughly investigated, scrutinizing it through the lens of co-crystallization and nucleation processes. This research underscores the potential of post-modification of PMA type pour point depressants with antioxidants, a strategy that not only bolsters the CFPs of B20 but also confers antioxidant attributes to the pour point depressants.
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For the first time AFM (atomic-force microscopy) was used to record significant changes in the geometric parameters of the image of erythrocytes in vitro under conditions of glycolytic starvation ...(ATP (Adenosine triphosphate) deficiency). The difference in the action of antioxidants, phenosan K, and Ihfan-10 on erythrocytes that we detected with AFM seems to be mainly due to their difference in hydrophobicity. We used the AFM method to research the self-organization of the components of the active center of P450 (Porphyrin-450) metalloenzymes that are part of a class of hemoproteins with functions of affinity to molecular oxygen O2. Stable supramolecular nanostructures in the form of triangular prisms based on the iron porphyrin complex with amino acids due to self-assembly involving intermolecular hydrogen bonds were received. A possible scheme for the formation of such structures is proposed.
Surface-Enhanced Raman Spectroscopy (SERS) is a powerful surface-sensitive technique to study the vibrational properties of analytes at very low levels of concentration. In particular, detection of ...bioactive molecules, specifically antioxidants, is an area of interest to gain insights into the reproducible and quantitative SERS-determination. In this study, SERS measurements were systematically evaluated for ferulic acid, p-coumaric acid, caffeic acid and sinapic acid. The study objective in this research was to: 1) prepare and characterize SERS-active silver colloids; 2) cluster the as-obtained colloids through Principal Component Analysis on the basis of concentration and nanoparticle size; and 3) develop a highly sensitive SERS-based method for phenolic antioxidant detection. The reliability of the proposed method was demonstrated through detection of the phenolic antioxidants evaluated at low levels of concentration. In particular, sinapic acid was evaluated for the first time, with a limit of detection of 2.5×10−9M.
•Multi-analytical approach for “green” valorization strategies of food by-products.•PLE optimization led to withanolides-rich extracts with antioxidant activity.•Selection of suitable green solvents ...applying Hansen solubility parameters approach.
In this work, a multi-analytical platform that allows obtaining and characterizing high-added value compounds from natural sources is presented, with a huge potential in traditional medicine, natural products characterization, functional foods, etc. Namely, the proposed multi-analytical platform is based on the combination of pressurized liquid extraction (PLE), liquid chromatography (LC) and gas chromatography quadrupole time-of-flight mass spectrometry GC-q-TOF-MS(/MS), in vitro assays and modelling tools for guiding extraction optimization. As case study, goldenberry or cape gooseberry fruit (Physalys peruviana L.) was selected. In particular, the potential of P. peruviana calyces, an important by-product of goldenberry processing, as promising source of bioactive compounds was evaluated. Selection of the most suitable solvent for PLE was based on the Hansen solubility parameters (HSP) approach using 4β-hydroxywithanolide E (4βHWE) and withanolide E (WE) as target compounds due to their bioactive potential. A surface response methodology was further applied for the optimization of the PLE parameters: temperature (50, 100 and 150 °C) and solvent composition (% EtOH in the mixture EtOH/EtOAc). The effects of the independent variables on extraction yield, withanolides content (4βHWE and WE), total phenolic content (TPC), total flavonoids content (TFC) and antioxidant activity (EC50 and TEAC) were evaluated in order to obtain withanolide-rich extracts from P. peruviana calyces. The extract obtained under optimal conditions (at 125 °C and 75% EtOH v/v) exhibited satisfactory extraction yield (14.7%) and moderate antioxidant activity (with an EC50 value of 77.18 μg mL−1 and 1.08 mM trolox g−1), with 4βHWE and WE concentrations of 8.8 and 2.3 mg g−1, respectively. LC-q-TOF-MS/MS analysis of the extract allowed the quantitation of 4βHWE and WE and the tentative identification of several other withanolides structures. The obtained results demonstrate the great potential of this multi-analytical approach for developing valorisation strategies of food by-products under sustainable conditions, to obtain bioactive-enriched extracts with potential medicinal or health-promoting properties.
Synthetic phenolic antioxidants (SPAs) are widely used as food additives to delay the oxidation rate of oils and oil products. The concentrations and compositions of SPAs in Chinese residents' most ...popular daily foods and the resulting exposure risk of SPAs are not clear. Therefore, this study collected food samples in 13 food categories (n = 289) from 10 provinces in China. At least one of the SPAs was detected in approximately 99.7% of foodstuffs, and the concentration of ∑SPAs ranged from not detected to 7830 (geometric mean (GM): 296 ng/g wet weight). 2,6-2 tert butyl p-1,4-benzoquinone (BHT-Q) was the main transformation product, but SPAs in food tend to exist in the parent form. A significant difference between food categories was analyzed. The highest GM of ΣSPAs occurred in cereals and cereal products, which was approximately 8 times higher than that in beverages. The estimated daily intakes of ΣSPAs in Chinese preschoolers, school-age children, adults and elderly individuals were 22200, 9970, 7540 and 7700 ng/kg bw/day, respectively. The exposure risks of SPAs decreased with age. This is the first simultaneous analysis of SPAs in multiple provinces and multiple categories of foodstuffs.
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•SPAs were measured in 289 food samples in 13 categories from 10 provinces in China.•The concentrations of ∑9SPAs in foods were of n.d.-7830 ng/g wet weight.•The highest GM concentrations of ∑9SPAs were found in cereals and cereal products.•The preschoolers are at the highest risk of exposure to SPAs through food intake.•The first simultaneous analysis of SPAs in multiprovince and multicategory of foods in China.
The development and validation of a simple, low-cost, and sensitive method for the determination of nine compounds expected in beverages and vinegar as a result of migration from food contact ...material (parabens, phenolic antioxidants, sulfonamide plasticizer, and flame retardant) is presented. The analytes were preconcentrated using solid-phase microextraction and analyzed by gas chromatography – tandem mass spectrometry. The method required no derivatization procedure and an affordable chemical was used as internal standard. The LODs were in the range of 0.005–0.2 μg/L, the relative standard deviations 0.8–5.4%, and the mean recoveries 98–109%. Different alcoholic beverages and vinegars were analyzed. A crown cap migration study using several food simulants was conducted for 6 months. Moreover, migration from a home brewing plastic fermenter in a time span of 4 weeks was studied. Analyte concentrations up to 2220.99 μg/L were detected in real samples and up to 4.75 μg/L in migration experiments.
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•First SPME-GC-MS/MS method for 9 analytes from 4 different groups of compounds in alcoholic beverages and vinegars.•No derivatization procedure required.•An affordable chemical is used as an internal standard.•Sample preparation procedure is fast, simple and applicable to a large variety and number of samples.
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