INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 6
·2917
·
IF 6.208
Yuhong Mao,Zhenling Cai,Chenxi Zhou,Hangzhen Lan,Xiuyun Ye
This study aimed to improve the stability and catalytic properties ofThermomyces lanuginosuslipase (TLL) adsorbed on a hydrophobic support. At the optimized conditions (pH 5 and 25 °C without any additions), the Sips isotherm model effectively fitted the equilibrium adsorption data, indicating a monolayer and the homogenous distribution of immobilized lipase molecules. To preserve the high specific activity of adsorbed lipase, the immobilized lipase (IL) with a moderate loading amount (approximately 40% surface coverage) was selected. Polyethylenimine (PEI) and chitosan (CS) were successfully applied as bridging units to in situ crosslink the immobilized lipase molecules in IL. At the low polymer concentration (0.5%,w/w) and with 1 h incubation, insignificant changes in average pore size were detected. Short-chain PEI and CS (MW ≤ 2 kDa) efficiently improved the lipase stability, i.e., the lipase loss decreased from 40% to <2%. Notably, CS performed much better than PEI in maintaining lipase activity. IL crosslinked with CS-2 kDa showed a two- to three-fold higher rate when hydrolyzing p-nitrophenyl butyrate and a two-fold increase in the catalytic efficiency in the esterification of hexanoic acid with butanol. These in situ crosslinking strategies offer good potential for modulating the catalytic properties of TLL for a specific reaction.Keywords:polyethylenimine;chitosan;anti-desorption;hydrolytic activity;esterification
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CHEMBIOCHEM
·
2022
·Vol. 23
·期 9
·e202200063
·
IF 3.461
Ya-Li Dong,Gang-Gang Chong,Chun-Xiu Li,Qi Chen,Jiang Pan,Ai-Tao Li,Jian-He Xu
Graphical Make activation of C-H bond feasible : Cytochrome P450 monooxygenases (P450s) catalyze the terminal hydroxylation of fatty acids to form ω-hydroxy fatty acids. To date, available P450s for the terminal hydroxylation of fatty acids stalls at CYP153A subfamily members, which have the limitation of low activity and poor thermostability. We, therefore, adopted directed evolution to generate P450pyr mutants with higher catalytic efficiency toward medium-chain fatty acids. The results show that mutants toward C6−C12 fatty acids display improved analytical yields of ω-hydroxy fatty acids. The P450-mediated terminal hydroxylation of non-activated C−H bonds is a chemically challenging reaction. CYP153A7 monooxygenase, discovered in Sphingomonas sp. HXN200, belongs to the CYP153A subfamily and shows a pronounced terminal selectivity. Herein, we report the significantly improved terminal hydroxylation activity of CYP153A7 by redesign of the substrate binding pocket based on molecular docking of CYP153A7−C 8:0 and sequence alignments. Some of the resultant single mutants were advantageous over the wild-type enzyme with higher reaction rates, achieving a complete conversion of n- octanoic acid (C 8:0, 1 mM) in a shorter time period. Especially, a single-mutation variant, D258E, showed 3.8-fold higher catalytic efficiency than the wild type toward the terminal hydroxylation of medium-chain fatty acid C 8:0 to the high value-added product 8-hydroxyoctanoic acid.
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JOURNAL OF CHROMATOGRAPHY A
·
2022
·
IF 4.601
Ruijuan Duan,Meiling Qi
This work presents the investigation of two new pentiptycene (PP)-functionalized triblock copolymers (PEPE1, PEPE2) for gas chromatographic (GC) analyses with an aim to address the separation problems toward analytes of high resemblance in properties and a wide variety of components in complex samples. Up to date, these two materials are not reported in any fields. The PEPE1 and PEPE2 columns showed close column efficiency (above 4000 plates/m) but differed in polarity, morphology and separation performance. As testified by the challenging Grob test mixture, the PEPE1 column exhibited comprehensively higher separation capability than the PEPE2 column and the commercial reference columns. Also, the PEPE1 column achieved high-resolution performance for both apolar and polar isomers of high resemblance, such as xylenes, phenols and anilines. Moreover, it displayed high inertness towards carboxylic acids and excellent separation repeatability and reproducibility tested by the aniline isomers with the RSD values in the range of 0.01–0.04% for run-to-run, 0.09–0.13% for day-to-day and 1.2–2.0% for column-to-column, respectively. Its application to GC–MS analysis of the essential oil from tea flowers demonstrated its advantageous separation performance towards a wide range of components and proved its feasibility for practical analyses of complex samples.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Yu Mu,Jun Huang,Rongqing Zhou,Suyi Zhang,Hui Qin,Hanlan Tang,Qianglin Pan,Huifang Tang
Bioaugmenting Daqu is an effective strategy to improve the quality of Baijiu, but its effect on overall flavor profiles and aroma-active compounds is unknown. Here, 168 volatiles were determined from fresh strong-flavor Baijiu (SFB) and bioaugmented Daqu increased their diversity and altered the flavor characteristics. Among 49 odorants identified by aroma extraction dilution analysis, 29 aroma-active compounds had odor activity values ≥1, of which 18, 8, and 3 components exhibited the highest content in the SFB fermented by fortified-, space- and conventional- Daqu , respectively. The contribution of increasing ethyl hexanoate and decreasing ethyl lactate of fresh SFB by bioaugmented Daqu was confirmed, and their content changed from 4650 and 1890 mg/L (conventional-SFB) to 6680 and 1760 mg/L (fortified-SFB) and 6130 and 1710 mg/L (space-SFB). Meanwhile, the discriminators among different samples were determined by multivariate statistical analysis. These findings are beneficial for the optimization and improvement of Baijiu aroma.
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FOOD CHEMISTRY
·
2023
·
IF 8.8
Xinmiao Wang,Qian Wang,Jinghan Yu,Xu Guo,Peiyong Tong,Fawen Yin,Xiaoyang Liu,Dayong Zhou
HPLC-UV analysis in rat everted gut sac and in vitro simulated digestion models indicated that hydroxytyrosol fatty acid esters (HTy-Es) could be hydrolyzed by pancreatic lipase to slow-release of free fatty acids (FAs) and HTy. Meanwhile, the HTy-Es, the liberated FAs and the HTy could cross the membrane and were transported into blood circulation. HTy-Es were further hydrolyzed by carboxylesterase in in vitro rat plasma hydrolysis model, which also showed slow-release of FAs (C1-C4) and HTy. Especially, the rates of hydrolysis and transport initially increased and then decreased with the increasing alkyl chain length. Besides, the above rates of the HTy-Es with a straight chain were greater than those of its isomer with a branched chain. Therefore, the above-mentioned continuous and slow-release of FAs and HTy in small intestine and blood clearly demonstrated that HTy-Es would be an effective approach to enhance oral bioavailabilities of free fatty acids and hydroxytyrosol.
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MICROCHEMICAL JOURNAL
·
2023
·
IF 4.8
Ruiyu Fu,Tingze Ren,Yanhui Zhang,Qingxin Lu,Xiaoli Guo,Xin Di
A new supramolecular solvent (SUPRAS) was synthesized using hexafluoroisopropanol (HFIP) as hydrogen bond donor and undecanol as hydrogen bond acceptor. Then SUPRAS was used as extraction solvent to enrich triazole fungicides in drinking water and beverages by liquid phase microextraction (LPME). Additionally, several variables that influence extraction efficiency were optimized, and the significant factors were investigated by Box-Behnken design. At optimum condition, the method shows desirable precision (RSDs less than 19.4%) and acceptable recovery (63.4%-112.1%). The low limits of detection and limits of quantitation of this method were found to be in the range of 1.0–5.0 μg/L and 5.0–20 μg/L, respectively. Compared with other analytical techniques, the method demonstrated comparable sensitivity, consumed less extractant (750 μL) and a shorter pre-treatment time (10 min). The formation mechanism of SUPRAS was investigated by density functional theory. The proposed methodology was green, sensitive, time-saving and successfully applied to determine triazole fungicides in drinking water and beverages, making it an alternative technique for the analysis of trace analytes with satisfactory sensitivity.
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Polymers
·
2021
·Vol. 13
·期 22
·3906
·
IF 4.329
Guozhe Deng,Li Xie,Shengjia Xu,Xuejun Kang,Jizheng Ma
Short-chain fatty acids (SCFAs) are among the active metabolites in biological process both in the intestinal tract and the bioconversion of organic wastes, which has resulted in various human diseases and environmental problems. In order to accurately detect SCFAs, we introduced a novel extraction sorbent. Electrospun polyacrylonitrile (PAN) nanofiber membrane was synthesized, then poly (3, 4-Ethylenedioxythiophene) (PEDOT) was deposited onto the surface of electrospun PAN nanofibers by in situ polymerization. The morphology of the composite PAN/PEDOT nanofiber was characterized by scanning electronic microscopy (SEM) and FTIR spectrum. PAN/PEDOT was used to isolate and concentrate the SCFAs in waste water and fecal samples before gas chromatography mass spectrometry (GC-MS) analysis. The analytical method was evaluated systematically, and low limits of detection (LODs) of 0.34–0.87 μg/L and good linearity (R2≥ 0.9953) were obtained. The method was applied successfully for the determination of SCFAs in waste water and fecal samples, with good recovery (87.5–104.6%) and satisfactory reproducibility (relative standard deviation: 6.5–14.1%). The results indicated that the proposed method can be used as a potential approach for the determination of SCFAs with high sensitivity in waste water and biological samples.Keywords:adsorbent;conducting polymer;electrospinning;polyacrylonitrile;solid phase extraction
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JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Zhibo Fu,Qiangqiang Jia,Hongyang Zhang,Lu Kang,Xuezhi Sun,Min Zhang,Yuerong Wang,Ping Hu
As metabolites of the gut microbiome, short-chain fatty acids (SCFAs) played an important role in the diagnosis of the metabolic diseases. Because of the high polarity, high volatility and complex matrix of biological samples, the highly sensitive, selective and accurate method to determine SCFAs remains a major challenge. Herein, a new method for simultaneous quantification of eleven SCFAs by derivatization combined with solid phase microextraction (SPME) and gas chromatography tandem mass spectrometry (GC–MS/MS) was developed. Isobutyl chloroformate coupled with isobutanol was used as the reaction reagent to derivatize SCFAs. The method validation data showed a satisfactory linearity with the linear regression coefficients (R) ranging from 0.9964 to 0.9996. The limit of detection (LOD) of all SCFAs ranges from 0.01 ng·mL −1 to 0.72 ng·mL −1 and the limit of quantification (LOQ) ranges from 0.04 ng·mL −1 to 2.41 ng·mL −1 . The intra-day and inter-day precision (RSDs) ranged from 0.65% to 8.92% and 1.62% to 15.61%, respectively. The recovery ranged from 88.10% to 108.71%. Finally, the developed method was successfully used to determine SCFAs in mice fecal sample, and ten of the SCFAs were found in feces of mice, including formic acid.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Nanhang Zhu,Yujia Zhang,Jia Cheng,Yanchao Mao,Ke Kang,Guohao Li,Qiangying Yi,Yao Wu
Enriching small extracellular vesicles (sEVs) with undamaged structure and function is a pivotal step for further applications in biological and clinical fields. It has prompted researchers to explore a carrier material that can efficiently capture sEVs while also gently release the captured sEVs. Here, 1-adamantylamine (1-ADA) responsive immuno-affinitive supramolecular magnetic nanoparticles (ISM-NPs) incorporating ternary host-guest complexation structures mediated by CB[8] were proposed to achieved the goal. In particular, the ternary host-guest complexation was constructed by the host molecule (cucurbit[8]uril, CB[8]) mediated assembly of two guest molecules (naphthol and bipyridine), and served as a cleavable bridge to connect the magnetic core and peripheral antibody. These constructed ISM-NPs performed well in the applications of capturing sEVs with a high capture efficiency of 85.5%. Further, the CB[8]-mediated ternary host-guest complexation structures can be disassembled with addition of the 1-ADA. Thus, the sEVs recognized by the anti-CD63 were released competitively, with a decent release efficiency more than 82%. The released sEVs kept intact morphology and exhibited appropriate size distribution and concentration. This supramolecular magnetic system, with 1-ADA responsive ternary host-guest complexation structures, may contribute to efficient enrichment of any other biomarkers, likely cells, proteins, peptides, etc.
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ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Huaying Zhong,Yi Zhang,Yangmin Gong,Chuyun Wan,Yufei Zhang,Mingming Zheng
Stimuli-responsive Pickering interfacial biocatalysis (PIB) platforms are highly desirable due to their convenient product extraction and catalyst recovery. Light-responsive PIB stabilized by immobilized biocatalyst particles, which serve as both emulsifiers and catalysts, have not attracted enough attention. Herein, a novel and effective ultraviolet/visible light-responsive PIB system is proposed to facilitate reversible emulsification/demulsification. The modified hollow mesoporous silica nanospheres (HMSS-N) with photochromic spiropyran (SP-COOH) were utilized as a light-responsive emulsifier and carrier of lipase CL (CL@HMSS-SP). The light-responsive performance and catalytic performance of the PIB system were also studied in detail. As a result, the O/W emulsion demulsification or emulsification could be easily accomplished by inducing ultraviolet or visible light to change the surface wettability of the smart emulsifiers. The system exhibited the highest catalytic activity in the model esterification reaction between n-hexanol acid and 1-hexanol that has been reported so far (a catalytic efficiency value of 80.9 mmol g–1 h–1), which is a 12.6-fold enhancement compared with the conventional free enzyme one-phase system. The robust system maintained high catalytic activity even after 10 cycles, averaging 148.2 g of product g–1 biocatalyst. Thus, the ultraviolet/visible light-responsive PIB gives insights into the biocatalytic synthesis of flavor esters with high efficiency and stable reusability and shows great potential for cleaner production in the future.
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Foods
·
2023
·Vol. 12
·期 24
·4460
·
IF 5.2
Chao Ye,Zhankai Zhang,Zhi-Hong Zhang,Ronghai He,Xue Zhao,Xianli Gao
Beef potentiator is an important flavour enhancer in the food industry, while it is prone to generating insufficient compounds with umami and sweet tastes and compounds with a fishy odour during enzymatic hydrolysis of beef, resulting in poor flavour of beef potentiator. It has been extensively reported that sonication is capable of improving food flavour. However, the effect of sonication on the flavour of enzymatically hydrolysed beef liquid (EHBL) was scarcely reported. Herein, we investigated the effect of sonication on the flavour of EHBL using quantitative descriptive analysis (QDA), physicochemical analysis and SPME-GC-olfactometry/MS. QDA showed that sonication had a significant effect on taste improvement and off-odour removal of EHBL. Compared with the control, sonication (40 kHz, 80 W/L) increased the contents of total nitrogen, formaldehyde nitrogen, total sugars, reducing sugars, free amino acids (FAAs) and hydrolysis degree of EHBL by 19.25%, 19.80%, 11.83%, 9.52%, 14.37% and 20.45%. Notably, sonication markedly enhanced the contents of sweet FAAs, umami FAAs and bitter FAAs of EHBL by 19.66%, 14.04% and 9.18%, respectively, which contributed to the taste improvement of EHBL. SPME-GC-olfactometry/MS analysis showed that aldehydes and alcohols were the main contributors to aroma compounds of EHBL, and sonication significantly increased the contents of key aroma compounds and alcohols (115.88%) in EHBL. Notably, sonication decreased the contents of fishy odorants, hexanoic acid and nonanal markedly by 35.29% and 26.03%, which was responsible for the aroma improvement of EHBL. Therefore, sonication could become a new potential tool to improve the flavour of EHBL.Keywords:beef potentiator;enzymatically hydrolysed beef liquid;ultrasound;aldehydes;alcohols;flavour
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Advanced Healthcare Materials
·
2026
·
IF 11
Shanan Chen,Kaiwen Wu,Mengzhuo Li,Yoav D. Livney,Xing Li,Wei Shang,Zhicheng Wei,Qiming Li,Rongmei Liu,Jie Xiao,Yuan Li
The in vivo functionality of oral probiotics is often compromised by their susceptibility to environmental and gastrointestinal stressors, coupled with limited mucosal retention. To overcome these challenges, we developed a smart, pH-responsive biomaterial platform based on shellac microgels (SCM), derived from a natural, biocompatible insect resin. Combining experimental characterization with finite element analysis, we verified that the densified molecular network of SCM functions as a potent physical barrier that effectively hinders the diffusion of O 2 , moisture, and UV radiation, as well as physiological assaults (H + and bile salts), protecting the viability of probiotics throughout storage and gastrointestinal transit. Crucially, the pK a -dependent phase transition of SCM enabled precise colon-targeted bio-interface, where its abundant functional groups facilitated strong mucosal anchoring via non-covalent interactions. In a DSS-induced colitis mouse model, this precision-release strategy significantly improved therapeutic outcomes by suppressing the inflammation, restoring gut homeostasis, and repairing the epithelial barrier. This study presents a sustainable, potent, and naturally derived biomaterial strategy for the controlled delivery of sensitive bacterial therapeutics.
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