Antioxidants
·
2023
·Vol. 12
·期 2
·468
·
IF 7
Yanbei Wu,Yali Wang,Zhengyan Liu,Jing Wang
3-deoxyanthocyanidins (3-DAs) are typical flavonoids found in sorghum bran, and they have received much attention in recent years owing to their bioactivities. To further enhance the resource utilization of sorghums cultivated in China, three brewing sorghum cultivars (Liaoza-48, Liaonuo-11, and Liaonian-3) commonly used in China were selected as raw materials for the construction of an extraction technology system for 3-DAs and the clarification of their structures and bioactivities. Based on single-factor experiments and response surface analysis, the optimized system for the extraction of 3-DAs from sorghum grains was as follows: a hydrochloric acid-methanol solution (1:100,v/v) was the extraction solvent, the solid-liquid ratio was 1:20 (g/mL), the extraction time was 130 min, and the temperature was 40 °C. This extraction system was simple and feasible. High performance liquid chromatography analysis suggested that the main monomeric compounds of the extracted 3-DAs were Apigeninidin (AE) and Luteolinidin (LE). Among the three selected sorghum grains, Liaoza-48 had the highest amount of AE (329.64 μg/g) and LE (97.18 μg/g). Antioxidant experiments indicated that the 3-DAs extracted from Liaoza-48 showed higher free-radical scavenging activities for DPPH, ABTS+, and hydroxyl radicals than those extracted from Liaonuo-11 and Liaonian-3. These results provide basic data and technical support for the high-value and comprehensive utilization of sorghums in China.Keywords:sorghum;3-deoxyanthocyanidins;solvent extraction;Apigeninidin;Luteolinidin;bioactivity
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高影响因子
Metabolites
·
2023
·Vol. 13
·期 1
·85
·
IF 4.1
Pengmeng Du,Honglun Yuan,Yayu Chen,Haihong Zhou,Youjin Zhang,Menglan Huang,Yiding Jiangfang,Rongxiu Su,Qiyu Chen,Jun Lai,Lingliang Guan,Yuanhao Ding,Haiyan Hu,Jie Luo
Basil (OcimumL.) is widely used as a flavor ingredient, however research on basil flavor is limited. In the current study, nine basil species were selected, includingOcimum basilicumL.var.pilosum(Willd.) Benth.,Ocimum sanctum,Ocimum basilicum cinnamon,Ocimum gratissimumvar. suave,Ocimum tashiroi,Ocimum basilicum,Ocimum americanum,Ocimum basilicumct linalool, andOcimum basilicumvar.basilicum, and their fragrance and flavor characteristics were assessed by sensory evaluation. The results indicated thatOcimum basilicumvar.basilicumandOcimum gratissimumvar.suavehave a strong clove smell and exhibited a piquant taste. Metabolomics and volatilomics analyses measured 100 nonvolatile metabolites and 134 volatiles. Differential analysis showed that eugenol, γ-terpinene, germacrene D and malic acid were among the most varied metabolites in basil species. Combined with sensory evaluation results, correlation analysis revealed that β-pinene and γ-cadinene contributed to the piquant smell, while eugenol and germacrene D contributed to the clove smell, and malic acid and L-(−)-arabitol contributed to the sweet flavor in basil. This study provided comprehensive flavor chemistry profiles of basil species and could be used as a guide for basil flavor improvement. The better understanding of objective sensory attributes and chemical composition of fresh basil could introduce the improved cultivars with preponderant traits, which is also in accordance with the various demands of breeders and growers, food producers, and consumers.Keywords:Ocimum basilicum;basil;aroma;flavor;metabolome;volatilome
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JOURNAL OF MOLECULAR STRUCTURE
·
2022
·
IF 3.841
Shuang Liang,Guanting He,Guozhe Sui,Jinlong Li,Dongxuan Guo,Ze Luo,Rongping Xu,Hong Yao,Chao Wang,Zhiyong Xing
Metal organic frameworks (MOFs) are considered as desirable precursors for the preparation of photocatalyst to improve photocatalytic hydrogen evolution efficiency due to the maintained special morphology. Herein, C-doped rod-like ZnO with porous structure has been successfully prepared by using ZIF-L as precursor via an optimized two-step calcination strategy, which is applied for photocatalytic hydrogen evolution reaction from water splitting. The results show that ZnO-350-450 exhibits the best photocatalytic activity with a hydrogen production rate of 0.35 mmol·g −1 ·h −1 , which is 1.9 times higher than that of ZnO-400 (0.184 mmol·g −1 ·h −1 ) under simulated sunlight illumination. The enhanced photocatalytic performance is attributed to the fact that the two-step calcination provides the regular porous rod-like structure (ZIF-L) and the inclusion of carbon in ZnO photocatalyst. C-doped ZnO with regular morphology offers faster charge transfer rate and higher charge separation efficiency, and the C-doped expands a wider range of light absorption. Overall, the presented work could provide a new idea for designing and preparing of photocatalysts with high efficiency for photocatalytic hydrogen production.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Baoyang Lu,Yao Lu,Yangping Wen,Xuemin Duan,Jingkun Xu,Shuai Chen,Long Zhang
A novel chiral L-alanine-modified 3,4-ethylenedioxythiophene (EDOT) precursor, (2S)-(2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methyl 2-( tert -butoxy carbonylamino)propanoate (EDOT-Boc-Ala), was synthesized and electropolymerized in CH 2 Cl 2 –Bu 4 NBF. The corresponding polymer, poly((2S)-(2,3-dihydrothieno[3,4- b ][1,4]dioxin-2-yl)methyl 2-( tert -butoxy carbonylamino)propanoate) (PEDOT-Boc-Ala) film showed good redox activity and stability. The electrochemical behavior, structural characterization, chirality, solubility, spectroscopic properties, thermal stability, and morphology of PEDOT-Boc-Ala film were investigated. Both doped and dedoped PEDOT-Boc-Ala film could well dissolve in strong polar solvents such as dimethyl sulfoxide, tetrahydrofuran, and acetone, etc. The determination of specific rotation showed that the electropolymerization of EDOT-Boc-Ala did not influence its conformation and the polymer exhibited an enhanced specific rotation ([α] 20.0 = -191.08°) in comparison with that of the monomer ([α] 20.0 = -30.77°). Moreover, the amperometric biosensor based on PEDOT-Boc-Ala film (as immobilization matrix of biologically-active species) was successfully fabricated and employed to determine the concentration of vitamin C.
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International Journal of Electrochemical Science
·
2023
·
IF 1.5
Xianguang Zeng,Lin Zhu,Xingwen Zheng
The inhibitive effect of N-lauroyl L-lysine on the corrosion of mild steel in 0.5 M H 2 SO 4 solution was investigated by electrochemical technique, weight loss measurement, scanning electron microscope (SEM) and quantum chemical calculation. The results showed that N-lauroyl L-lysine was a moderate cathodic inhibitor for mild steel in 0.5 M H 2 SO 4 solution with its inhibition efficiency increasing with concentration, and decreasing with temperature. The adsorption of N-lauroyl L-lysine on the surface of mild steel obeyed El-Awady thermodynamic-kinetic model, and the thermodynamic and kinetic parameters, as well as quantum chemical parameters, were determined to discuss the mechanism of inhibition of N-lauroyl L-lysine on mild steel surface.
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JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Ning Shao,Juan Li,Shenglei Che,Jingwu Zheng,Liang Qiao,Yao Ying,Jing Yu,Wangchang Li
The L -band and S-band electromagnetic waves are widely utilized in radar and satellite communications. This paper reports the successful synthesis of 85.8% content Ba 3 Co 2 Fe 24 O 41 (Co 2 Z) at a relatively low temperature of 1150 °C using the solid-phase method with BaFe 12 O 19 (BaM) and Ba 2 Co 2 Fe 12 O 22 (Co 2 Y) as precursors. The Co 2 Z samples were confirmed to have been successfully synthesized using X-ray diffraction (XRD) and thermogravimetry/differential scanning calorimetry (TG-DSC) spectra. Scanning electron microscopy (SEM) images revealed that the sintered samples exhibited large grains (>10 µm). Vibrating-sample magnetometry (VSM) data indicated that the synthesized Co 2 Z samples possessed distinct soft magnetic properties . X-ray photoelectron spectroscopy (XPS) results showed that the Fe 3+ content decreased with the increase in synthesis temperature. The samples synthesized at 1110 °C − 1280 °C had a permeability of 10–20, a cut-off frequency of approximately 1 GHz, and a dielectric constant of 10–30. When the thickness of the sample synthesized at 1150 °C was 3.9 mm, the frequency range of the reflection loss (RL)< −10 dB was 2.55 GHz (0.98–3.53 GHz), with 1.77 GHz as the center frequency, and RLmin was − 57.8 dB. This observation indicates that the effective absorption bandwidth of the samples covers the entire L and S bands, which significantly satisfies practical applications within the military and civilian sectors.
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ENVIRONMENTAL POLLUTION
·
2023
·
IF 8.9
Yingying Sun,Jie Chen,Wei Wang,Lizhong Zhu
Persistent organic pollutants (POPs) in agricultural soil often triggered metabolic alterations and phytotoxicity in plants, ultimately threatening crop quality. Unraveling the phytotoxic mechanisms of POPs in crops is critical for evaluating their environmental risks. Herein, the molecular mechanism of POP-induced phytotoxicity in rice ( Oryza sativa L.) was analyzed using metabolic profile, enzyme activity , and gene expression as linkages, including polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers , polychlorinated biphenyls, and phthalate esters. Despite no observable changes in phenotypic traits (e.g., biomass and length of aboveground), the levels of reactive oxygen species (ROS) were promoted under stresses of the tested POPs, particularly 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47), dibutyl phthalate (DBP), and di(2-ethylhexyl) phthalate (DEHP). Metabolomics analysis revealed that ROS contents positively correlated with metabolic perturbation levels ( r = 0.83), among which the galactose metabolism was significantly inhibited when exposed to DBP, DEHP, or BDE-47. The α-Galactosidase (α-Gal) involved in galactose metabolism was targeted as the key enzyme for the phytotoxicity of DBP, DEHP, and BDE-47, which was revealed by the inhibition of saccharide levels (45.5−82.1%), the catalytic activity of α-Gal (18.5−24.3%), and the gene expression (28.5−34.5%). Molecular docking simulation suggested that the three POPs occupied the active sites of α-Gal and formed a stable protein-ligand complex, thus inhibiting the catalytic activity of α-Gal. Partial least-squares regression analysis indicated that α-Gal activity was negatively associated with hydrogen bond acceptor, rotatable bond, and topological polar surface area of POPs. The results offered novel insights into the molecular mechanisms of phytotoxicity of POPs and provided important information for evaluating the environmental risk of POPs.
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Nanomaterials
·
2023
·Vol. 13
·期 15
·2153
·
IF 5.3
Hao Cui,Daguang Li,Yu Yang,Yuewu Fu,Yanhui Dong,Jing Yin,Weiping Qin,Zhixu Jia,Dan Zhao
Polymer-based waveguide amplifiers are essential components in integrated optical systems, as their gain bandwidths directly determine the operating wavelength of optical circuits. However, development of the wideband gain media has been challenging, making it difficult to fabricate devices with broadband amplification capability. Rare earth ion-doped nanoparticles (NPs) are a key component in the gain media, and their full width at half maximum (FWHM) of the emission peak decides the final gain bandwidth of the gain media. Here, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs with the broad full width at half maximum (FWHM) of the emission peak covering the S+C band was prepared. The NPs were synthesized using a hydrothermal method, and the FWHM of the emission peak of NPs reached 76 nm under the excitation of a 980 nm laser. The introduction of Ce3+ions and a core-shell structure coating greatly enhanced the emission intensity of NPs at C band. Since KMnF3: Yb, Er, Ce@KMnF3: Yb NPs have exceptional broadband luminescence properties at C band, KMnF3: Yb, Er, Ce@KMnF3: Yb NPs can be the potential gain medium in the future polymer-based waveguide amplifiers.Keywords:KMnF3;nanoparticles;active-shell;core-shell;1.5 μm
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ADVANCED SYNTHESIS & CATALYSIS
·
2022
·Vol. 364
·期 24
·4363-4370
·
IF 5.981
Sai Fang,Haoran Yu,Lanxin Xiao,Zhe Wang,Yixuan Lei,Gang Xu,Lirong Yang,Wenlong Zheng,Jianping Wu
l -threonine aldolase ( L TA) is a vital tool for the production of β -hydroxy- α -amino acids, important pharmaceutical intermediates with two chiral centres. However, the trade-off between activity and diastereoselectivity seriously hinders the application of LTA. Here, microenvironment of the proton transfer was regulated to improve the enzyme activity while avoiding the loss of diastereoselectivity. A combinatorial active-site saturation test (CAST) strategy was applied to engineer the microenvironment of the key histidines H86 and H128 involved in proton transfer. Except for the amino acid residues tunning diastereoselectivity, a total of 18 (9+9) residues lining around H86 and H128 were investigated. As a result, two variants, RS1-T92V and RS1-E123R, were obtained with specific activity from 9.61 U/mg to 11.24 U/mg and 14.41 U/mg, respectively. By combinatorial mutagenesis, a double-point mutant RS1-VR (T92V/E123R) was obtained with specific activity reaching 18.65 U/mg that was two-fold of the original strain (RS1). Notably, the mutant RS1-VR remained a high de value of 94.21%. Molecular dynamics (MD) simulations provided insights into the mechanism of activity-diastereoselectivity trade-off. The improvement of microenvironment contributes to reduce the swing amplitude of the side chain of H86, resulting in the proton transfer more efficient. This work provides a strategy of regulating the proton transfer microenvironment for counteracting the trade-off between activity and diastereoselectivity in protein engineering.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2022
·
IF 5.895
Qing Liu,Huixian Gao,Xinyue Yi,Shengyan Tian,Xianbin Liu
The behavior of organophosphate esters (OPEs) in plants has drawn considerable attention because of their adverse effects to biota. However, the root uptake pathways and cell wall accumulation mechanisms of OPEs in plants are still unclear. In this study, the uptake pathways, subcellular distribution, and accumulation mechanisms of OPEs in wheat roots were elucidated. The results demonstrated that the symplast is the major pathway for uptake of both tris(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPHP) in wheat roots. Inhibitor experiments showed that the transmembrane transport of OPEs is a passive uptake process, and aquaporins and carrier proteins contribute to the uptake of OPEs. More than 69% of TCEP was accumulated in cell sap due to its high hydrophilicity, while the hydrophobic TPHP was mainly stored in the root cell wall. The sorption affinity of TPHP decreased gradually following the sequential fractionation of wheat roots, which confirmed the significant contribution to TPHP sorption on wheat roots. A significant positive correlation between the sorption affinity values and the percentage of aromatic carbon was observed (r2 = 0.856, p < 0.01), indicating that the accumulation of hydrophobic OPEs in roots does not just depend on lipids alone, but the aromatic moieties of lignin in the cell wall also contribute to OPE accumulation.
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INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2022
·Vol. 23
·期 17
·9663
·
IF 6.208
Yawen Zhou,Linshu Jiao,Juan Shen,Huibing Chi,Zhaoxin Lu,Huawei Liu,Fengxia Lu,Ping Zhu
Low catalytic activity is a key factor limiting the widespread application of type II L-asparaginase (ASNase) in the food and pharmaceutical industries. In this study, smart libraries were constructed by semi-rational design to improve the catalytic activity of type II ASNase fromBacillus licheniformis. Mutants with greatly enhanced catalytic efficiency were screened by saturation mutations and combinatorial mutations. A quintuple mutant ILRAC was ultimately obtained with specific activity of 841.62 IU/mg andkcat/Kmof 537.15 min−1·mM−1, which were 4.24-fold and 6.32-fold more than those of wild-type ASNase. The highest specific activity andkcat/Kmwere firstly reported in type II ASNase fromBacillus licheniformis. Additionally, enhanced pH stability and superior thermostability were both achieved in mutant ILRAC. Meanwhile, structural alignment and molecular dynamic simulation demonstrated that high structure stability and strong substrate binding were beneficial for the improved thermal stability and enzymatic activity of mutant ILRAC. This is the first time that enzymatic activity of type II ASNase fromBacillus licheniformishas been enhanced by the semi-rational approach, and results provide new insights into enzymatic modification of L-asparaginase for industrial applications.Keywords:L-asparaginase;protein engineering;saturation mutagenesis;catalytic efficiency;molecular dynamics simulation
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BIOORGANIC & MEDICINAL CHEMISTRY
·
2022
·
IF 3.461
Baoqin Cai,Marco Bocola,Ameng Zhou,Fenshuai Sun,Qing Xu,Jiadong Yang,Tianran Shen,Zhaoqi Zhang,Lei Sun,Yaoyao Ji,Yong Koy Bong,Thomas Daussmann,Haibin Chen
l -Threonine aldolases (LTAs) employing pyridoxal phosphate (PLP) as cofactor can convert low-cost achiral substrates glycine and aldehyde directly into valuable β-hydroxy-α-amino acids such as (2 R ,3 S )-2-amino-3-hydroxy-3-(4-nitrophenyl) propanoic acid (( R,S )-AHNPA), which is utilized broadly as crucial chiral intermediates for bioactive compounds. However, LTAs’ stereospecificity towards the β carbon is rather moderate and their activity and stability at high substrate load is low, which limits their industrial application. Here, computer-aided directed evolution was applied to improve overall activity, selectivity and stability under desired process conditions of a l -threonine aldolase in the asymmetric synthesis of ( R,S )-AHNPA. Selectivity and stability determining regions were computationally identified for structure-guided directed evolution of LTA-variants under efficient biocatalytic process conditions using 40% ethanol as cosolvent. We applied molecular modeling to rationalize selectivity improvement and design focused libraries targeting the substrate binding pocket, and we also used MD simulations in nonaqueous process environment as an effective and promising method to predict potential unstable loop regions near the tetramer interface which are hot-spots for cosolvent resistance. An excellent LTA variant EM-ALDO031 with 18 mutations was obtained, which showed ∼ 30-fold stability improvement in 40% ethanol and diastereoselectivity ( de ) raised from 31.5% to 85% through a three-phase evolution campaign. Our fast and efficient data-driven methodology utilizing a combination of experimental and computational tools enabled us to evolve an aldolase variant to achieve the target of 90% conversion at up to 150 g/L substrate load in 40% ethanol, enabling the biocatalytic production of β-hydroxy-α-amino acids from cheap achiral precursors at multi-ton scale.
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