Hedgehogs as Amplifying Hosts of Severe Fever with Thrombocytopenia Syndrome Virus, China.

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a tickborne bandavirus mainly transmitted by Haemaphysalis longicornis ticks in East Asia, mostly in rural areas. As of April 2022, the amplifying host involved in the natural transmission of SFTSV remained unidentified. Our epidemiologic field survey conducted in endemic areas in China showed that hedgehogs were widely distributed, had heavy tick infestations, and had high SFTSV seroprevalence and RNA prevalence. After experimental infection of Erinaceus amurensis and Atelerix albiventris hedgehogs with SFTSV, we detected robust but transitory viremias that lasted for 9-11 days. We completed the SFTSV transmission cycle between hedgehogs and nymph and adult H. longicornis ticks under laboratory conditions with 100% efficiency. Furthermore, naive H. longicornis ticks could be infected by SFTSV-positive ticks co-feeding on naive hedgehogs; we confirmed transstadial transmission of SFTSV. Our study suggests that the hedgehogs are a notable wildlife amplifying host of SFTSV in China.

Components and Persistent Free Radicals in the Volatiles during Pyrolysis of Lignocellulose Biomass.

Persistent free radicals (PFRs) may cause negative impacts to human health and the environment because of the induced reactive oxygen species. We expect that PFRs could be generated in the condensable volatiles formed during lignocellulose biomass pyrolysis. Elucidating the structural origin and the formation mechanism of PFRs is important for an in-depth understanding of air pollutants from the pyrolysis or combustion of lignocellulose biomass. This work selected rice straw and pine sawdust to represent agricultural and forest biomass residues. The pyrolysis mechanism, volatile components, and PFR generation were discussed based on the analysis of thermogravimetry-Fourier transform infrared spectroscopy-mass spectrometry (MS), pyrolysis-gas chromatography/MS, and electron spin resonance (ESR). Levoglucosan, furans, and 2-methoxyphenols were the main pyrolytic compounds for cellulose (CL), hemicellulose (HC), and lignin (LG), respectively. Obvious ESR signals were detected in the condensable volatiles of LG, while no ESR signals were detected for those of CL and HC. Higher ESR signals were detected in lignocellulose with a higher content of LG. Therefore, LG was the main structural basis to generate PFRs in lignocellulose condensable volatiles, mostly attributed to the methoxyphenol components. This study provides useful information regarding the generation mechanisms of and the structures related to PFRs, which is essential to understand the risks of lignocellulose pyrolytic volatiles.

Flexible molecularly imprinted fiber library for the metabolic analysis of bisphenol F and ecological risk evaluation.

Bisphenol F (BPF) has evoked global attentions due to its ubiquity and detrimental effects. Herein, a flexible molecularly imprinted fiber library was firstly proposed for the metabolic analysis of BPF in aquatic ecosystems. The library includes flexible single fibers and fiber arrays to precisely identify BPF and its metabolites with a wide range of polarities. Compared to commercial polyacrylate, the performance increased 11.56-570.98-fold. The adsorption capacity and the LogKow value were positively related. These arrays were used for the acquisition of environmental metabolomics data from aquatic ecosystems. In-depth data analysis showed that risk quotient was lower than 0.76, and bioaccumulation factor was lower than 2000 L/kg. Distribution concentration of BPF and its metabolites changed seasonally, and accumulation in sediment was much larger than that in surface water and hydrobionts. The risk is gradually increasing in sediment, but it does not reach high risk. The likelihood of bioaccumulation of parent compounds was greater than its metabolites. The library can be used in the metabolic diagnosis of pollutants with a broad range of polarities, providing a new method to acquire data for further ecological risk assessment, and offering a revolutionary strategy for environmental metabolomics investigation in aquatic ecosystems.

A molecularly imprinted fiber array solid-phase microextraction strategy for simultaneous detection of multiple estrogens.

A kind of selective enrichment material based on a homemade molecularly imprinted polymer (MIP) fiber array with high adsorption capacity was developed for the accurate analysis of estrogens in food samples. Here, the MIP with 17ß-estradiol as the template was obtained by in situ polymerization. The chemical composition, morphologies, surface area, and pore size of the polymer were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and Brunauer-Emmett-Teller theory. The extraction time, desorption solvent, desorption time, ionic strength, and the pH of solution were investigated to ascertain the best extraction conditions. Under the optimal extraction conditions, three fiber coatings of 17ß-estradiol MIP and commercial polyacrylate (PA) were bound to a homemade handle to assemble the fiber array, respectively. The findings showed that the three-fiber array of the MIP significantly improved the extraction capacity by 145 times compared to PA. The MIP fiber array showed high adsorption capacity for the template molecule 17ß-estradiol and its structural analogues estrone, bisphenol F, bisphenol B, and bisphenol A, with enrichment factors of 99.60-133.16. A molecularly imprinted polymer solid-phase microextraction fiber array (MIP-SPME fiber array) coupled with high-performance liquid chromatography-diode array detection was used for the analysis and detection of the five estrogens in milk and yogurt samples. Satisfactory recoveries were achieved ranging from 74.75-119.41% with <9.42% relative standard deviations. The developed method for the simultaneous determination of trace estrogens in food samples exhibited a limit of detection of 0.33 µg L-1. The MIP-SPME fiber array provided an available strategy for improving the selectivity and adsorption capacity of SPME for trace target component analysis in complex matrices and increasing the sensitivity of the analytical method.

Nontargeted screening of aldehydes and ketones by chemical isotope labeling combined with ultra-high performance liquid chromatography-high resolution mass spectrometry followed by hybrid filtering of features.

Aldehydes and ketones are important carbonyl compounds that are widely present in foodstuffs, biological organisms and human living environment. However, it is still challenging to comprehensively detect and capture them using liquid chromatography - mass spectrometry. In this work, a chemical isotope labeling (CIL) coupled with ultra-high performance liquid chromatography - high resolution mass spectrometry (UHPLC-HRMS) strategy was developed for the capture and detection of this class of compounds. 2,4-Dinitrophenylhydrazine (DNPH) and isotope-labeled DNPH (DNPH-d3) were utilized to selectively label the target analytes. To address the difficulties in processing UHPLC-HRMS data, a post-acquisition data processing method called MSFilter was proposed to facilitate the screening and identification aldehydes and ketones in complex matrices. The MSFilter consists of four independent filters, namely statistical characteristic-based filtering, mass defect filtering, CIL paired peaks filtering, and diagnostic fragmentation ion filtering. These filters can be used individually or in combination to eliminate unrelated interfering MS features and efficiently detect DNPH-labeled aldehydes and ketones. The results of a mixture containing 48 model compounds showed that although all individual filtering methods could significantly reduce more than 95% of the raw MS features with acceptable recall rates above 85%, but they had relatively high false positive ratios of over 90%. In comparison, the hybrid filtering method combining four filters is able to eliminate massive interfering features (> 99.5%) with a high recall rate of 81.25% and a much lower false positive ratio of 15.22%. By implementing the hybrid filtering method in MSFilter, a total of 154 features were identified as potential signals of CCs from the original 45,961 features of real tobacco samples, of which 70 were annotated. We believe that the proposed strategy is promising to analyze the potential CCs in complex samples by UHPLC-HRMS.

Isolation of fucoxanthin from edible brown algae by microwave-assisted extraction coupled with high-speed countercurrent chromatography.

A rapid and efficient method for the separation and purification of fucoxanthin from edible brown algae by microwave-assisted extraction coupled with high-speed countercurrent chromatography was developed. The algae were first extracted using microwave-assisted extraction, then the dried extract was dissolved and directly introduced into the high-speed countercurrent chromatography system with a two-phase solvent system consisting of hexane-ethyl acetate-ethanol-water (5:5:6:4, v/v/v/v). The isolation was done in less than 75 min, and a total of 0.83 mg, 1.09 mg, and 0.20 mg fucoxanthin were obtained from 25.0 g fresh Laminaria japonica Aresch, 1.5 g dry Undaria pinnatifida (Harv) Sur, and 15.0 g dry Sargassum fusiforme (Harv) Setch, respectively. The purity of fucoxanthin determined by HPLC was over 90% and its structure was further identified by LC-ESI-MS and (1) H-NMR.

Ultrasonic microwave-assisted extraction coupled with high-speed counter-current chromatography for the preparation of nigakinones from Picrasma quassioides (D.Don) Benn.

INTRODUCTION: Nigakinones are the main effective compounds of Picrasma quassioides (D. Don) Benn and are widely used in traditional Chinese medicine, therefore a rapid and efficient separation and purification method is necessary. OBJECTIVE: To develop a new method based on ultrasonic microwave-assisted extraction (UMAE) and high-speed counter-current chromatography (HSCCC) for the rapid separation and purification of nigakinone and methylnigakinone from P. quassioides (D.Don) Benn. METHODOLOGY: Response surface methodology (RSM) was used to optimise the extraction conditions of UMAE: 10.0 g of original sample was extracted with 210 mL of 90% (v/v) aqueous methanol at 60°C for 13 min, ultrasonic power was 100 W and microwave power was dynamically adjusted to the given temperature. After extraction, the extract was introduced into the HSCCC and separated with a hexane:ethyl acetate:methanol:2% acetic acid (9:11:9:11, v/v/v/v) solvent system. RESULTS: About 2.1 mg nigakinone with purity of 96.8% was obtained in one step within 200 min, methylnigakinone was also obtained with a purity of 75.6%. Their chemical structures were identified with ESI-MS and ¹H-NMR. CONCLUSION: UMAE coupled with HSCCC was found to be a promising and feasible alternative method to separate and purify alkaloids from natural herbs such as P. quassiodes.

Generic imprinted fiber array strategy for high-throughput and ultrasensitive simultaneous determination of multiple neonicotinoids.

Herein, a new generic fiber array based on molecular imprinting solid-phase microextraction (MIP-SPME) technology, was described to enrich trace multiple neonicotinoids with high flux from the food matrix. To begin with adsorption experiments coupled with theoretical calculations provided universal means for selecting the preferred template molecule clothianidin (CLT). Results demonstrated that the CLT-MIP fiber array exhibited significantly superior enrichment ability of 1189-2356-folds for six neonicotinoids compared with two kinds of commercial fiber arrays. Furthermore, the practicability of the CLT-MIP fiber array was verified by simultaneously determining multiple neonicotinoids in tea and honey samples. The CLT-MIP fiber array showed a limit of detection (LOD) of 0.03-0.58 µg/L for six neonicotinoids. The method also exhibited satisfactory recoveries ranging from 85.4% to 116.8% with RSD (n = 3) less than 8.8%. The imprinted fiber array has the advantages of high-throughput, predominant reproducibility, and accurate quantitation multi-component, and it may open up a new mean to efficiently enrich high-throughput and simultaneously detect multiple compounds from food samples.

Botanical discrimination and classification of Mentha plants applying two-chiral column tandem GC-MS analysis of eight menthol enantiomers.

The concentration and distribution of menthol enantiomers have great significance in discriminating natural mint varieties and evaluating the origin of foodstuffs containing menthol additives. However, the chiral separation of eight chiral menthol enantiomers in Mentha plants offers an easy approach to eliminating or reducing the identification technology problem. The application of derivatized ß-cyclodextrin capillary chiral column coupled with derivatized γ-cyclodextrin capillary chiral column, and gas chromatography-mass spectrometry (GC-MS) technology, to isolate and analyze eight chiral menthol enantiomers in 23 natural Mentha plants was investigated. The results showed that the two-chiral columns tandem technology enabled the baseline separation of the eight menthol enantiomers. Four different menthol compounds were only detected in seven out of the 23 natural mint plants. (1R,3R,4S)-(-)-menthol and (1R,3S,4S)-(+)-neomenthol were detected in the seven mint plant samples, while (1S,3S,4R)-(+)-menthol and (1S,3R,4R)-(-)-neomenthol could not be detected in the seven mint plant samples. For the two enantiomer couples of (+/-)-isomenthol and (+/-)-neoisomenthol, only (+)-isomers were detected in field mint, candy mint, and peppermint. The Mentha plant samples were distinguished and identified by principal component analysis and radar chart statistical analysis based on the data of the menthol content and isomer ratio. Furthermore, the presence or absence of (1S,3S,4R)-(+)-menthol in the samples can be used as an identification factor for discriminating between synthetic menthol and natural sources of menthol.

Fe3O4@SiO2@VAN Nanoadsorbent Followed by GC-MS for the Determination of Polycyclic Aromatic Hydrocarbons at Ultra-Trace Levels in Environmental Water Samples.

In the present study, silica-coated magnetic nanoparticles functionalized with vancomycin (Fe3O4@SiO2@VAN) were synthesized. The Fe3O4@SiO2@VAN nanocomposite was used as a sorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) from environmental water, followed by GC-MS. The nanocomposite was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, and nitrogen sorption. Various experimental parameters were optimized, including extraction condition and desorption condition. Results show that Fe3O4@SiO2@VAN combined the advantages of nanomaterials and magnetic separation technology, showing excellent dispersibility and high selectivity for PAHs in environmental water sample. Under the optimal extraction conditions, an analytical method was established with the sensitive limit of detection (LOD) of 0.03-0.16 µg L-1. The method was successfully applied for the analysis of environmental water samples. The relative standard deviations (%) were in the range of 0.50-12.82%, and the extraction recovery (%) was in the range of 82.48% and 116.32%. MSPE-coupled gas chromatography-mass spectrometry quantification of PAHs is an accurate and repeatable method for the monitoring of PAH accumulation in environmental water samples. It also provides an effective strategy for the tracing and quantification of other environmental pollutants in complex samples.

Determination and Difference Analysis of Phenolic Compounds in Smokers' Saliva and Mainstream Smoke.

To study the differences in phenolic compounds between tobacco smokers' saliva and mainstream smoke, a method was developed for the analysis of 12 phenolic compounds in saliva and mainstream smoke based on ultrahigh-performance liquid chromatography with fluorescence detection (UPLC-FLD). The contents and distributions of phenolic compounds in tobacco smokers' saliva and mainstream smoke were compared. The results were as follows: (1) Phenolic compounds were quantitatively analyzed by the internal standard method using 4-fluorophenol as an internal standard. For smokers' saliva samples, the limits of quantification (LOQs) ranged from 2.2 to 19.1 µg/L, and the recoveries were from 80.2% to 119.2% at the three spiked levels. For mainstream smoke samples, the LOQs ranged from 0.03 to 0.26 µg/cig, and the recoveries ranged from 84.9% to 107.0% at the three spiked levels. (2) The contents of phenolic compounds from 14 cigarettes in mainstream smoke and smokers' saliva were determined. In mainstream smoking, the main phenolic compounds were hydroquinone, catechol, phenol, meta- and para-Cresol, and o-methylhydroquinone. In smokers' saliva, the main phenolic compounds were phenol and meta- and para-Cresol and the contents of phenolic compounds in smokers' saliva from different cigarettes were significantly different. (3) The content distribution patterns of phenolic compounds in smokers' saliva differed from those in mainstream smoke. The predominant phenolic compound in mainstream smoke was dihydroxybenzene, while monophenols predominated in smokers' saliva. (4) The contents of phenolic compounds from five kinds of cigarettes were analyzed in the saliva of different smokers using principal component analysis, which indicated that cigarettes with different sensory effects were clearly distinguished by differences in the contents of phenolic compounds in saliva.

Direct adsorption sampling and ambient mass spectrometry analysis of tobacco smoke with porous paper strips.

Chemical analysis of atmospheric aerosols by conventional analytical methods is usually required to perform complicated and time-consuming sample preparation processes. In recent decades, ambient ionization mass spectrometry (AI-MS) methods have been proven to be simple, rapid, and effective analytical tools for direct analysis of various complex samples. In this work, we applied porous paper filters for direct adsorptive sampling of tobacco smoke, and then the sampled paper filters were performed the emitters of the paper spray ionization (PSI) device. An auto-sampling device was made to control the generation and collection of tobacco smoke. Nicotine, the typical compound of tobacco smoke, was used to optimize the key conditions of auto-sampling. Moreover, different types of tobacco smoke were also compared with multivariate variable analysis, and the makers of tobacco smoke from different sources of tobacco smoke were investigated. By using this method, direct sampling and analysis of a single tobacco sample can be completed within minutes. Overall, our results show that PSI-MS is a powerful tool that integrates collection, extraction, ionization, and identification analytes in smoke.

Chiral molecularly imprinted polymeric stir bar sorptive extraction for naproxen enantiomer detection in PPCPs.

Chiral micropollutant analysis in pharmaceuticals and personal care products (PPCPs) is interesting but challenging. We firstly developed a series of chiral molecularly imprinted polymeric (CMIP) stir bar sorptive extraction coatings by combining a chiral template with chiral functional monomers via a click reaction for naproxen enantiomer analysis in PPCPs. Heterochiral selectivity was observed in the molecule recognition of the CMIP coatings, which demonstrated good adsorption capability for the chiral template and its structurally similar chiral compounds. The coatings also exhibited excellent enrichment capability for chiral analytes in an aqueous matrix. The surface morphology and pore structure of the CMIP coatings were characterized. The molecular interactions between the chiral template and chiral functional monomer were investigated through UV-vis spectroscopy and theoretical calculations to prove the effective interactions existing in the heterochiral MIPs. The CMIP coatings were used to enrich naproxen enantiomers in chiral drug and environmental water samples, and satisfactory recoveries (83.98 %-118.88 %) with a relative standard deviation of 3.49 %-13.08 % were achieved. The heterochiral imprinted coating-based method provided a sensitive, selective, and effective enrichment strategy for chiral micropollutant analysis in PPCPs. This technique is critical for chiral molecule recognition and enantiomer analysis in complex samples.

Formation of persistent free radicals in biochar derived from rice straw based on a detailed analysis of pyrolysis kinetics.

The presence of persistent free radicals (PFR) in biochars may greatly broaden the application of biochars in pollution control, but may also cause negative impacts to the environment. Understanding the structural basis and the formation mechanisms of PFR is essential for a targeted biochar production and application. This study used rice straw (RS), a ubiquitous agricultural waste, to investigate the generation processes of PFR in relation to RS pyrolysis kinetics. Based on a detailed thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis, the activation energy was calculated by Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) methods. This work combined pyrolysis kinetics analysis and solid particle characterization. Our results showed that lignin started to pyrolyze at a lower temperature than cellulose and hemicellulose. Lignin was the main factor for PFR generation. Chemical bond breaking contributed only slightly to PFR formation. The reconfiguration of the carbonaceous structures may be a more important contributor to PFR formation, while the cross-linking between different compositions and the interactions between the chemical compositions and inorganic minerals may play a significant role for PFR generation and stabilization in RS. This study provides useful theoretical basis to understand the thermal pyrolysis process of RS and the manipulation of biochar properties.

[Tandem technologies in chromatographic analysis].

The acquisition of chemical compounds information from samples depends on the separation as well as detection techniques. Usually, it is difficult to achieve the separation and identification of all components in complex samples by a simple one-dimensional chromatographic method. Thus, tandem technologies, which mainly include column tandem connection techniques, detector tandem connection techniques, and multidimensional chromatography, have aroused widespread interest. In this paper, advances in the three aforementioned tandem techniques (not including chromatography tandem mass spectrometry) since 2010 are discussed. Typical applications for obtaining more comprehensive and accurate information from samples are also reviewed. Finally, the development of chromatographic tandem technologies is summarized and future prospects are examined.

Three new isoflavones from the Pueraria montana var. lobata (Willd.) and their bioactivities.

Three new isoflavones, 7-acetyl-4',6-dimethoxy-isoflavone (1), 7-acetyl-4'-hydroxy-6-methoxy-isoflavone (2) and 7-acetyl-6,8-dimethoxy-4'-hydroxy-isoflavone (3), together with five known flavones (4-8), were isolated from the Pueraria montana var. lobata (Willd.). Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D NMR techniques. Compounds 1-8 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1 and 2 exhibited high anti-TMV activities with inhibition rates of 36.8 and 33.6%, respectively. The inhibition rates are higher than that of positive control. The other compounds also showed potential anti-TMV activities with inhibition rates in the range of 21.8~28.4%, respectively. The cytotoxicities of compounds 1-3 against five human tumour cell lines (NB4, A549, SHSY5Y, PC3 and MCF7) were also tested. The results revealed that compounds 1-3 showed weak inhibitory activities against some tested human tumour cell lines with IC50 values in the range of 1.2-3.6 µM.

Two new benzolactones from the leaves of Nicotiana tabacum and their anti-tobacco mosaic virus activities.

Two new benzolactones, 5-methyl-6-prenyl-isobenzofuran-1(3H)-one (1), 5-hydroxymethyl-6-prenyl-isobenzofuran-1(3H)-one (2), together with four known phenolic compounds (3-6), were isolated from the leaves of Nicotiana tabacum. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-6 were evaluated for their anti-tobacco mosaic virus (anti-TMV) activities. The results showed that compounds 1-6 exhibited high anti-TMV activities with inhibition rates in the range of 16.9-26.2%, respectively.

Unintended compositional changes in transgenic rice seeds ( Oryza sativa L.) studied by spectral and chromatographic analysis coupled with chemometrics methods.

Unintended compositional changes in transgenic rice seeds were studied by near-infrared reflectance, GC-MS, HPLC, and ICP-AES coupled with chemometrics strategies. Three kinds of transgenic rice with resistance to fungal diseases or insect pests were comparatively studied with the nontransgenic counterparts in terms of key nutrients such as protein, amino acids, fatty acids, vitamins, elements, and antinutrient phytic acid recommended by the Organization for Economic Co-operation and Development (OECD). The compositional profiles were discriminated by chemometrics methods, and the discriminatory compounds were protein, three amino acids, two fatty acids, two vitamins, and several elements. Significance of differences for these compounds was proved by analysis of variance, and the variation extent ranged from 20 to 74% for amino acids, from 19 to 38% for fatty acids, from 25 to 57% for vitamins, from 20 to 50% for elements, and 25% for protein, whereas phytic acid content did not change significantly. The unintended compositional alterations as well as unintended change of physical characteristic in transgenic rice compared with nontransgenic rice might be related to the genetic transformation, the effect of which needs to be elucidated by additional studies.