查找使用阿拉丁产品的科研文献

Establishment of an in vitro propagation system to acquisition of nematode-repellent secondary metabolites of Waltheria indica L.

Tang Meihua,Lu Xinyi,Gan Yongdie,Ahmed Sher,Hu Zhan,Li Dong,Wang Shuai,Sun Ranfeng

Waltheria indica L. is a traditional officinal plant with many medicinal and insecticidal properties. This study established an in vitro propagation system for W. indica and evaluated the repellent activity of the compounds from in vitro-derived plants against the nematode Meloidogyne incognita . We optimized the medium for axillary bud proliferation and rooting of sterile shoots. Adventitious buds were induced from hypocotyls on Murashige and Skoog (MS) + 0.1 mg/L 6-benzyladenine (BA). MS + 1.0 mg/L 6-BA + 0.2 mg/L 1-napthaleneacetic acid (NAA) + 1.0 mg/L 2,4-dichlorophenoxyacetic acid was the best media for adventitious root induction from callus. An adventitious root suspension culture system was successfully induced and established in MS medium supplemented with 1.0 mg/L NAA, using a 1% inoculum size and a 30-day subculture interval. We isolated and identified antidesmone and trans-tiliroside from W. indica plants. They demonstrated repellent activity against J2 of M. incognita with chemotaxis index of 0.41 and 0.22, respectively, at a concentration of 10 mg/L. The relative content of antidesmone in adventitious roots cultured in liquid suspension was significantly higher than that in tissue-cultured plantlets. Exogenous supplementation of 0.05 mg/L 6-BA significantly improved the accumulation of trans-tiliroside synthesis in stems and leaves by reversing the inhibitory effect of tissue culture conditions. This study provides a theoretical basis and technical support for the large-scale propagation, germplasm improvement, and regulation of active secondary metabolite production in W. indica.

Multifunctional Polyvinyl Alcohol/Chitosan Composite Film Containing L-Cysteine and Pomegranate Peel Carbon Dots for Cherry Tomato Preservation

Limin Guo,Silong Jia,Linna Wang,Hesheng Wang,Qiyuan Feng,Xinyu Yang,Xi Lv,Yaqian Yang,Tian Li,Shaoying Zhang,Youwei Yu

Currently, the resource wastage and safety hazards caused by fruit and vegetable spoilage are becoming increasingly prominent. Developing green, efficient, and non-toxic novel preservation materials has emerged as a hot spot in fruit and vegetable research. Based on this, this study utilized pomegranate peel as a raw material to prepare spherical multifunctional carbon dots (P-CDs) with an average particle size of 1.98 ± 0.58 nm through a one-step hydrothermal reaction. Subsequently, P-CDs were co-incorporated with L-cysteine (L-Cys) into a polyvinyl alcohol (PVA) and chitosan (CS) matrix to construct a novel composite coating material with combined antibacterial, antioxidant, and preservation functions. Experimental results demonstrate that P-CDs exhibit outstanding antioxidant activity and antibacterial performance. Compared to PVA/CS film, the P-CDs/L-Cys/PVA/CS film exhibited a 6.55 MPa increase in tensile strength and significantly enhanced thermal stability. Furthermore, the incorporation of P-CDs and L-Cys markedly boosted the PVA/CS film’s antioxidant activity (97% for ABTS; 85.69% for DPPH), antibacterial performance, and ultraviolet (UV) shielding capability. Coating cherry tomatoes with the P-CDs/L-cysteine/PVA/CS composite extended their shelf life by 6 days. This composite coating material exhibits preliminary biocompatibility and eco-friendly properties, aligning with green sustainable development needs and offering a novel potential solution for food preservation technology, while its practical applicability to food safety requires further comprehensive verification.

Chiral covalent organic frameworks synthesized via a Suzuki–Miyaura-coupling reaction: enantioselective recognition of D/L-amino acids

Dongdong Tan,Tianmiao Wang,Jing Hu,Donglian Deng,Tingting Li,Ruijun Li

Considering chiral covalent organic frameworks (COFs) featuring the intriguing properties of porous organic materials, chiral recognition, and separation, the design and synthesis of chiral COFs with high crystallinity has remained a daunting challenge. A brominated functionalized COF (COF-Br) with high crystallinity and stability was synthesized. Using the post-synthetic modification strategy of the Suzuki–Miyaura cross-coupling reaction, a chiral COF (COF-L-Phe) was successfully constructed by combining COF-Br and the chiral functional groups of 4-borono-L-phenylalanine. The chiral recognition ability of COF-L-Phe was verified using an experimental adsorption model. Furthermore, COF-L-Phe-modified capillary columns have been used for the separation of racemic phenylalanine using capillary electrochromatography. This work will provide guidance for constructing chiral COFs for chirality related applications.

Metabolomics and transcriptomics reveal the toxic mechanism of Cd and nano TiO2 coexposure on rice (Oryza sativa L.)

Liwen Qiang,Nan Zhao,Kaizhen Liao,Xichao Sun,Qiang Wang,Hangbiao Jin

Engineered nanoparticles (ENPs) can resist heavy metal toxicity in plants, but their coexposure still exhibits toxicity to plants compared to plants without exposure to ENPs and heavy metals. There have been few studies on the toxic mechanism of nano TiO 2 -heavy metal coexposure and the effect mechanism of nano TiO 2 in plants. Thus, transcriptomics and metabolomics were used to study the toxic mechanism of rutile nano TiO 2 or TiO 2 -Cd (rutile nano TiO 2 and CdCl 2 mixture) on rice ( Oryza sativa L.). After 40 days of exposure, the plant height and root dry weight of rice were significantly decreased in the nano TiO 2 -Cd group compared to the blank group (nano TiO 2 and CdCl 2 free). After Cd treatment, 423 differentially expressed genes (DEGs) and 16 differential metabolites were identified. Nano TiO 2 exposure induced significant regulation of 299 DEGs and 6 metabolites. After nano TiO 2 -Cd coexposure, 1660 DEGs and 181 differential metabolites were identified. Notably, the EDGs (e.g., chalcone isomerase and hydroxycinnamoyl transferase) and differential metabolites (e.g., chrysin and galangin) demonstrated the disruption of flavonoid biosynthesis in Cd-treated rice. After rice was exposed to nano TiO 2 , the DEGs were related to ribosome, whereas the differential metabolites were associated with pyruvate metabolism and valine, leucine , and isoleucine biosynthesis. Furthermore, 14 DEGs (e.g., asparaginyl-tRNA synthetase and methionyl-tRNA formyltransferase) involved in aminoacyl-tRNA biosynthetic pathways were significantly upregulated in rice treated with nano TiO 2 -Cd, in line with the changes in related metabolites (e.g., L -asparagine and 10-formyltetrahydrofolate). Our results show that it is necessary to pay close attention to the toxicity of nano TiO 2 -Cd coexposure in paddy ecosystems and use ENPs with caution to combat the phytotoxicity of heavy metals.

Novel lactoferrin-conjugated amphiphilic poly(aminoethyl ethylene phosphate)/poly(L-lactide) copolymer nanobubbles for tumor-targeting ultrasonic imaging

Binhua Luo,Huageng Liang,Shengwei Zhang,Xiaojuan Qin,Xuhan Liu,Wei Liu,Fuqing Zeng,Yun Wu,Xiangliang Yang

A novel electrochemical sensor based on gold nanobipyramids and poly-L-cysteine for the sensitive determination of trilobatin

Xue Mei,Wenchang Wang,Qingyi Li,Minxian Wu,Liyin Bu,Zhidong Chen

Trilobatin is a flavonoid that has wide application prospects due to its various pharmacological effects, such as anti-inflammation and anti-oxidation. In this work, a novel electrochemical sensor based on gold nanobipyramids (AuNBs) and L-cysteine (L-cys) was constructed for the sensitive and selective determination of trilobatin. The AuNBs, which were prepared by a seed-mediated growth method, had large specific surface areas and excellent electrical conductivity. A layer of L-cys film, which provided more active sites through the amino and hydroxyl groups, was modified on the surface of the AuNBs by electropolymerization. Significantly, the Au–S bond between the L-cys film and AuNBs could improve the stability of the sensor and it exhibited satisfactory electrocatalytic oxidation activity for trilobatin. Under optimized conditions, the sensor based on poly-L-cys/AuNBs/GCE was used to determine trilobatin by differential pulse voltammetry (DPV). Two wide linear ranges between the current peak and the concentration of trilobatin were obtained in the range from 5 to 100 μM and 100 to 1000 μM, and the low detection limit (LOD) was up to 2.55 μM (S/N = 3). The sensor demonstrated desirable reproducibility, stability, and selectivity and was applied to detect real trilobatin samples extracted from Lithocarpus polystachyus Rehd.'s leaves, showing recoveries of 98.36%–104.96%, with satisfactory results.

Tuning an efficient Escherichia coli whole-cell catalyst expressing l-pantolactone dehydrogenase for the biosynthesis of d-(−)-pantolactone

Fang-Ying Zhu,Qing Yang,Min Cao,Ken Zheng,Xiao-Jian Zhang,Qi Shen,Xue Cai,Zhi-Qiang Liu,Yu-Guo Zheng

d -(−)-Pantolactone (DPL) is a key intermediate for the production of d -(+)-pantothenate (vitamin B5). Deracemization of d , l -pantolactone (D, L -PL) through oxidizing l -(+)-pantolactone (LPL) to ketopantoyl lactone (KPL) and subsequently reducing KPL to DPL is a promising route for synthesizing DPL. Herein, a newly mined l -pantolactone dehydrogenase from Rhodococcus hoagie ( Rho LPLDH) was used for the oxidative dehydrogenation of LPL. To alleviate inclusion bodies formed by membrane-bound Rho LPLDH intracellular expression in E. coli , strategies involving chaperone assistance and decreasing induction temperature were used to achieve Rho LPLDH soluble expression. To enhance its activity, directed evolution and hydrophilicity-based engineering yielded increased catalytic activity and thermostability . 1 M LPL was efficiently converted to KPL by engineering strain CM5 co-expressing Rho LPLDH L254I/V241I/I156L/F224Q/N164K and chaperone. A “two stages in one-pot” method was employed in deracemization of 1 M D, L -PL with 91.2% yield. These results demonstrated that CM5 catalyst exhibits great potential in enzyme cascade deracemization for the production of DPL.

Effects of ethanol pretreatment on osteogenic activity and off-flavors in blue mussel (Mytilus edulis L.) enzymatic hydrolysates

Xinyu Qiao,Han Li,Yunjiao Ma,Xianbing Xu,Junjie Yi,Hesham R. El-Seedi,Ming Du

Aquatic protein hydrolysates have many biological activities, but the off-flavor seriously decreases their commercial acceptability. Therefore, it is important to invest in finding an effective deodorization of aquatic hydrolysates that do not affect activities. In this study, ethanol pretreatment of mussel was applied to establish a new method to deodorize the blue mussel ( Mytilus edulis L. ) hydrolysates. LC-MS and GC–MS analysis results showed that 87.34% of fatty acids, 83.94% of aldehydes, most volatile flavor compounds including aldehydes, ketones, alcohols, acids, and hydrocarbons were decreased after ethanol pretreatment. Besides, it was found that the enzymatic hydrolysates of mussel with or without ethanol pretreatment showed high osteogenic activity, which induced an increase of 33.65 ± 4.36% and 31.77 ± 5.45% in MC3T3-E1 cell growth. These results suggest that ethanol pretreatment has beneficial potential for improving the flavor aspects of blue mussel peptides which may have the potential to stimulate bone regeneration and formation.

Effect of the N-hexanoyl-L-homoserine Lactone on the Carbon Fixation Capacity of the Algae–Bacteria System

Lei Liao,Bin Chen,Kaikai Deng,Qiang He,Guijiao Lin,Jinsong Guo,Peng Yan

Algae–bacteria systems are used widely in wastewater treatment. N-hexanoyl-L-homoserine lactone (AHL) plays an important role in algal-bacteria communication. However, little study has been conducted on the ability of AHLs to regulate algal metabolism and the carbon fixation ability, especially in algae–bacteria system. In this study, we used theMicrocystis aeruginosa + Staphylococcus ureilyticusstrain as a algae–bacteria system. The results showed that 10 ng/L C6-HSL effectively increased the chlorophyll-a (Chl-a) concentration and carbon fixation enzyme activities in the algae–bacteria group and algae group, in which Chl-a, carbonic anhydrase activity, and Rubisco enzyme increased by 40% and 21%, 56.4% and 137.65%, and 66.6% and 10.2%, respectively, in the algae–bacteria group and algae group, respectively. The carbon dioxide concentration mechanism (CCM) model showed that C6-HSL increased the carbon fixation rate of the algae–bacteria group by increasing the CO2transport rate in the water and the intracellular CO2concentration. Furthermore, the addition of C6-HSL promoted the synthesis and secretion of the organic matter of algae, which provided biogenic substances for bacteria in the system. This influenced the metabolic pathways and products of bacteria and finally fed back to the algae. This study provided a strategy to enhance the carbon fixation rate of algae–bacteria consortium based on quorum sensing.Keywords:algae–bacteria system;C6-HSL;inorganic carbon;CCM model;carbon fixation capacity

GBAP/L-proline assist of self-healing nanocomposite hydrogels and their applications in antifreeze, high-sensitivity flexible sensors

Yu Gao,Yuxin Wu,Yuejie Chen,Tianjun Zhou,Liangjiu Bai,Wenxiang Wang,Hou Chen,Huawei Yang

For novel wearable flexible electronics, the design of hydrogels materials with anti-freezing capability is of great significance to meet the mechanical flexibility and smart sensing at cryogenic temperatures. Herein, glycosyl cross-linking boron acid and ammonium salt of phytic acid (PA) (GBAP) was synthesized based on eco-friendly organic materials, which was successfully wrapped on the surface of graphene oxide (GO) to obtain GO@GBAP. L-proline (L-Pro) as an antifreeze zwitterion and GO@GBAP were implanted in polyvinyl alcohol (PVA) and xanthan gum (XG) three-dimensional network structure. PA with antifreeze property was further introduced as a crosslinking agent, the PVA-XG/GO@GBAP/PA/L-Pro (PGPL) composite hydrogels were successfully prepared. While at −20°C, the PGPL hydrogels had remarkable mechanical strength (0.80 MPa), and they revealed the splendid self-healing efficiency (89.2%) after 4 h of healing. The high-sensitivity flexible sensors based on these PGPL hydrogels exhibited a rapid response time (220.0 ms) and electrical conductivity (detection mean 2.1 S/m at −20°C). Even at −20°C for 24 h, it could still respond to various physical and physiological movements such as swallowing and wrist activities. This nanocomposite hydrogels constructed in this work had expanded their application scope in the field of cryogenic sensing.

Preparation and application of high-brightness red carbon quantum dots for pH and oxidized L-glutathione dual response

Yuwei Du,Lei Cao,Xinlu Li,Tongtong Zhu,Ruhong Yan,Wen-Fei Dong,Li Li

Carbon dots (CDs) with red fluorescence emission are highly desirable for use in bioimaging and trace- substance detection, with potential applications in biotherapy, photothermal therapy, and tumor visualization. Most CDs emit green or blue fluorescence, thus limiting their applicability. We report a novel fluorescent detection platform based on high-brightness red fluorescence emission carbon dots (R-CDs) co-doped with nitrogen and bromine, which exhibit pH and oxidized L-glutathione (GSSG) dual-responsive characteristics. The absolute quantum yield of the R-CDs was as high as 11.93%. We discovered that the R-CDs were able to detect acidic pH in live cells and zebrafish owing to protonation and deprotonation. In addition, GSSG was detected in vitro over a broad linear range (8–200 μM) using the R-CDs with excitation-independent emission. Furthermore, cell imaging and bioimaging experiments demonstrated that the R-CDs were highly cytocompatible and could be used as fluorescent probes to target lysosomes and nucleolus. These studies highlight the promising prospects of R-CDs as biosensing tools for bioimaging and trace-substance detection applications.

Multiple stimuli-switchable electrocatalysis and logic gates of l-cysteine based on P(DEA–co-VPBA) hydrogel films

Zhenhua Zhai,Xiaoyan Shan,Mingming Li,Ying Liu,Feng Yang,Fuke Wang,Zhiqiang Tian,Keren Shi,Huiqin Yao

In this work, poly(N',N-diethylacrylamide-co-4-vinylphenylboronic acid) (P(DEA-co-VPBA)) hydrogel films were successfully assembled on the pyrolytic graphite (PG) electrode by a simple radical polymerization. Reversible thermal, glucose and pH-triggered electrochemical reactions were obtained in the presence of 1,1′-ferrocene dicarboxylic acid (FDA) with electro-redox properties. The thermal response performances of the thin-film electrode were attributed to the PDEA component, the sensitive behaviors of glucose were ascribed to the VPBA component, and the sensitive behaviors of pH were affected by PDEA and VPBA. The electrocatalytic oxidation of l -cysteine by FDA on the hydrogel film electrodes significantly enhanced the difference between the on and off states of the multi-response cyclic voltammetry (CV) signals. This smart polymer hydrogel film electrode with amplified signals could be further used to realize a 4-input/9-output binary logic circuit, which was constructed with temperature, glucose, pH, and cysteine as inputs and different levels of I pa and I pc responses as outputs. Furthermore, a 2-to-4 decoder, a 4-to-2 encoder, and a 4-input keypad lock were built on the same platform. This polymer electrocatalysis system provides a novel idea for constructing complex biological computing systems.