查找使用阿拉丁产品的科研文献

Thermal activation in oxidative model drives catechin assembly into theaflavins with enhanced antioxidant capacity

Yuxuan Zhao,Jingyimei Liang,Rui Lu,Zebin Zou,Haoming Wu,Shengxiong Chen,Hui Cao,Jianbo Xiao

Theaflavins are important bioactive pigments in tea, but their non-enzymatic formation pathways under heating remain incompletely understood. This study investigated the temperature-dependent formation of four theaflavins using aqueous catechin model systems. Potassium ferricyanide was used as a controlled oxidant to initiate catechin oxidation and subsequent coupling reactions. Liquid chromatography-mass spectrometry (LC-MS), ultraviolet-visible spectroscopy (UV–Vis), DPPH and ABTS assays were applied to track product profiles and antioxidant capacity. Moderate temperatures promoted catechin oxidation to ortho-quinones and favored the accumulation of theaflavins, leading to higher antioxidant activity. Low temperatures limited conversion, whereas high temperatures accelerated precursor consumption and theaflavin degradation. Across all model systems, theaflavin levels peaked at 30 min and then declined with prolonged heating. Among the four products, TF3 showed the strongest thermoresponsive and the highest antioxidant capacity. These findings reveal a thermally activated catechin self-assembly mechanism in an oxidant-assisted model system.

Synthesis, characterization of catechin-loaded folate-conjugated chitosan nanoparticles and their anti-proliferative effect

Buyun Liu,Yongli Wang,Qijian Yu,Dapeng Li,Feng Li

Integration of (+)-catechin and β-sitosterol to achieve excellent radical-scavenging activity in emulsions

Shanshan Wang,Shanshan Wu,Songbai Liu

Novel amphiphilic antioxidant, (+)-catechin-β-sitosterol (CS), was designed and successfully prepared with integration of (+)-catechin and β-sitosterol through the linkage of succinic acid. Sequential esterification was carried out to connect (+)-catechin and β-sitosterol. The identity of CS was confirmed by NMR, IR and MS spectroscopies. DSC analysis revealed that ΔH of CS was much lower than those of (+)-catechin and β-sitosterol, indicating ameliorated crystallinity. The logP measurement demonstrated significantly increased lipophilicity. Then excellent antioxidant activities of the novel antioxidant in typical polyunsaturated lipid O/W and W/O emulsions were unveiled applying β-sitosterol bleaching assay and 5-dodecanoylaminofluorescein (DAF) fluorescent probe method. The antioxidative behavior of CS in emulsion was beyond the polar paradox hypothesis and could be rationalized by effective accumulation at oil/water interface owing to its amphiphilic nature. This study offers a promising solution for development of naturally derived amphiphilic antioxidants for lipid-based systems.

Catechin-inspired gold nanocluster nanoprobe for selective and ratiometric dopamine detection via forming azamonardine

Ying Liu,Yang Liu,Jing Zhang,Jiaojiao Zheng,Zhiqin Yuan,Chao Lu

The sensitive and selective perception of dopamine (DA, a typical neurotransmitter) is important to evaluate the biological environment. In this study, a catechin-functionalized gold nanocluster (C-Au NC) nanoprobe has been explored for the ratiometric DA sensing. The detection mechanism is based on the formation of azamonardine via selective DA-catechin chemical reaction and subsequent enhanced fluorescence emission. Using Au NC emission as the internal reference, ratiometric fluorescence variation is realized, which allows sensitive DA analysis with a limit of detection of 1.0 nM (S/N = 3) and linear response concentration range from 0 to 500 nM. The characteristic chemical reaction between catechin and DA affords favorable selectivity over other amino acids, metal ions and small molecules. In addition, the practical application of the proposed nanoprobe is validated by the accurate detection of DA content in urea and cell lysate samples.

Antioxidant Activity and α-Glucosidase Inhibitory Activities of the Polycondensate of Catechin with Glyoxylic Acid

Sheng Geng,Sharui Shan,Hanjun Ma,Benguo Liu

In order to investigate polymeric flavonoids, the polycondensate of catechin with glyoxylic acid (PCG) was prepared and its chemically antioxidant, cellular antioxidant (CAA) and α -glucosidase inhibitory activities were evaluated. The DPPH and ABTS radical scavenging activities and antiproliferative effect of PCG were lower than those of catechin, while PCG had higher CAA activity than catechin. In addition, PCG had very high α -glucosidase inhibitory activities (IC 50 value, 2.59 μg/mL) in comparison to catechin (IC 50 value, 239.27 μg/mL). Inhibition kinetics suggested that both PCG and catechin demonstrated a mixture of noncompetitive and anticompetitive inhibition. The enhanced CAA and α -glucosidase inhibitor activities of PCG could be due to catechin polymerization enhancing the binding capacity to the cellular membrane and enzymes.

Characteristics of catechin loading rice porous starch/chitosan functional microsphere and its adsorption towards Pb2+

Suwei Jiang,Hailiang Hu

In this paper, we explore the adsorption potential of catechin (CT) loaded composite microspheres and provide a new micron scale carrier of functional factor. Chitosan (CS) modified rice porous starch (RPS/CS) was used as a CT adsorption carrier to prepare bioactive CT-loaded composite microspheres (CT@RPS/CS). The adsorption kinetics, storage characteristics, and biological activity maintenance of CT@RPS/CS were studied in an aqueous solution, and the sustained-release characteristics of CT@RPS/CS were studied in vitro during simulated gastrointestinal digestion. An aqueous solution further studied the removal characteristics of adsorbed heavy metal ion Pb 2+ . RPS/CS can significantly improve the ability to adsorb CT. RPS/CS can also significantly improve CT's storage stability, antioxidant stress, and slow-release characteristics, and the sustained release effect in gastric and intestinal juice. CT@RPS/CS can be removed Pb 2+ by adsorbing in the solution, and their adsorption was physical adsorption and chemisorption, but the primary interaction is chemisorption. CT@RPS/CS can be used as a micron carrier of new food functional factors, which has potential space for improving and expanding the functional characteristics of its loaded functional factors and the endowing of new functions.

Online monitoring of catechin compounds transformation by the stationary phase of star phenylalanine cyclodextrin polymer

Hui Bai,Yinan Zhao,Shuxian Zhang,Lei Chen

Star-Phe-CD exhibited enhanced host-guest recognition. • The prepared CSP presents superior selectivity with an α value from 1.55 to 1.9. • Simultaneous separation of two catechin epimer pairs is realized. • The CSP enables efficient monitoring of epimer transformation by LC-MS. • The chiral recognition mechanism is clarified via molecular docking. The active ingredients of natural products represent a critical source for innovative drug discovery. However, the poor stereochemical stability and transformation of stereoisomers during storage directly influence therapeutic efficacy and safety. Therefore, the development of new chiral stationary phases (CSPs) with high chiral and structural selectivity is imperative for reliable quality control of natural products. Here, a star phenylalanine cyclodextrin (CD) polymer, Star-Phe-CD, was designed and synthesized. It features a CD parent nucleus, with Phe-derivatized CD as the sidechain monomers. Subsequently, a mixed-mode Sil-Star-Phe-CD CSP was fabricated with Star-Phe-CD as the chiral ligand, which exhibited significant fluorescence enhancement effects and multiple mixed-mode chromatographic retention mechanisms. The Sil-Star-Phe-CD CSP exhibits exceptional shape selectivity and stereoselectivity towards structurally similar analytes, demonstrating outstanding stereoseparation selectivity for analytes with rigid structures or multiple benzene rings with α lansoprazole = 1.90 and α atropine = 1.55, respectively. Coupled with LC-MS analysis, an online approach was established to simultaneously separate two pairs of catechin epimers and monitor their epimerization process. Molecular docking studies revealed the mechanism of chiral recognition, which relies on the cooperative effects of diverse intermolecular interactions, including hydrogen bonding, π–π interactions, and hydrophobic interactions. These interactions are crucial for recognizing structurally similar stereoisomers in complex systems.

Antibacterial activity of catechin-mediated green-synthesized selenium nanoparticles and their application in strawberry preservation

Lyu Haiheng,Chen Weixuan,Ye Haibo,Xiao Tianxin,He Puming,Liu Junsheng,Li Bo,Tu Youying,Wang Jian,Wu Yuanyuan

Strawberries are highly perishable due to their soft texture, susceptibility to water loss, and vulnerability to microbial contamination, posing significant post-harvest challenges. The development of green, efficient, and health-promoting antibacterial preservation materials is therefore of critical importance. In this study, we developed a novel catechin-chitosan oligosaccharide-selenium nanoparticles (Catechin-CSeNPs) with particle sizes ranging from 19.1 to 78 nm. Chemical structure analysis indicated that there was dual stabilization of hydrogen bonding via phenolic hydroxyls and chelation through carbonyl groups. The epigallocatechin-3-gallate (EGCG)-CSeNPs was found to have the highest antibacterial activity among four Catechin-CSeNPs; its antibacterial mechanism was elucidated as a reduction in membrane potential, the release of nucleic acids and proteins, and the suppression of ATPase activity. Notably, EGCG-CSeNPs exhibited remarkable safety in the zebrafish evaluation model. The application of EGCG-CSeNPs has the potential to effectively double the shelf life of strawberries while enhancing their quality. This work provides a stable, safe, and efficient material for enhancing the post-harvest preservation of berry fruits.

Optimization, Characterization, and Application of Soy Protein Isolate–Catechin Composite Microspheres in Emulsified Beef Balls

Aabideen Muhammad Zain Ul,Geng Lijing,Shafique Aqsa,Fu Hang,Huang Wei,Wang Dan,Jia Dongsheng,Wang Ao,Qi Rong,Tertulliano Mbinga Isequias Elamba,Wei Zhou

Although catechins are strong dietary antioxidants with proven health benefits, yet they are very sensitive and unstable under normal condition to be used in practical food applications. To address this, a food-grade delivery system was developed through pH-driven co-assembly of catechin (CAT) with soy protein isolate (SPI), forming composite microspheres without the addition of chemical solvents or crosslinkers. The final assembly pH was identified as the primary factor affecting encapsulation, achieving a loading of 62.01%. The resulting microspheres (~ 16.8 nm) were stable, with analyses confirming encapsulation via hydrogen bonding and hydrophobic interactions, alongside a crystalline-to-amorphous transition of catechin. This improved stability under heat, salt, and pH stress while preventing loss in antioxidant activity. When applied to emulsified beef balls, 1.0% SPI-CAT reduced cooking loss (27% to 21%), increased yield (78%), and improved texture without affecting sensory quality. By linking molecular-scale composite characterization directly to functional performance in a real meat matrix within a single study, these results highlight its potential as a plant-based ingredient for stabilizing bioactives in food systems. Graphical

Green Tea Catechin-Based Complex Micelles Combined with Doxorubicin to Overcome Cardiotoxicity and Multidrug Resistance

Tangjian Cheng,Jinjian Liu,Jie Ren,Fan Huang,Hanlin Ou,Yuxun Ding,Yumin Zhang,Rujiang Ma,Yingli An,Jianfeng Liu,Linqi Shi

Chemotherapy for cancer treatment has been demonstrated to cause some side effects on healthy tissues and multidrug resistance of the tumor cells, which greatly limits therapeutic efficacy. To address these limitations and achieve better therapeutic efficacy, combination therapy based on nanoparticle platforms provides a promising approach through delivering different agents simultaneously to the same destination with synergistic effect. In this study, a novel green tea catechin-based polyion complex (PIC) micelle loaded with doxorubicin (DOX) and (-)-Epigallocatechin-3-O-gallate (EGCG) was constructed through electrostatic interaction and phenylboronic acid-catechol interaction between poly(ethylene glycol)- block -poly(lysine- co -lysine-phenylboronic acid) (PEG-PLys/PBA) and EGCG. DOX was co-loaded in the PIC micelles through π-π stacking interaction with EGCG. The phenylboronic acid-catechol interaction endowed the PIC micelles with high stability under physiological condition. Moreover, acid cleavability of phenylboronic acid-catechol interaction in the micelle core has significant benefits for delivering EGCG and DOX to same destination with synergistic effects. In addition, benefiting from the oxygen free radicals scavenging activity of EGCG, combination therapy with EGCG and DOX in the micelle core could protect the cardiomyocytes from DOX-mediated cardiotoxicity according to the histopathologic analysis of hearts. Attributed to modulation of EGCG on P-glycoprotein (P-gp) activity, this kind of PIC micelles could effectively reverse multidrug resistance of cancer cells. These results suggested that EGCG based PIC micelles could effectively overcome DOX induced cardiotoxicity and multidrug resistance.

Absorptive interactions of concurrent oral administration of (+)-catechin and puerarin in rats and the underlying mechanisms

Su Hui-fang,Lin Qing,Wang Xin-yi,Fu Yao,Gong Tao,Sun Xun,Zhang Zhi-rong

Aim: (+)-Catechin and puerarin are polyphenol and flavonoid, respectively, in green tea and foodstuffs. They exhibit potent antioxidant activity and are widely used for treating cardiocerebrovascular diseases. The aim of this work was to investigate the potential interactions between (+)-catechin and puerarin following concurrent oral administration in rats, and their absorption mechanisms in Caco-2 cell monolayers. Methods: Pharmacokinetic studies were conducted in male rats received (+)-catechin (140 mg/kg, po ) and/or puerarin (200 mg/kg, po ). The cell uptake and transport behavior in Caco-2 cell monolayers and the interactions of the two compounds were analyzed. Results: When (+)-catechin and puerarin were administered concurrently, the AUC 0-12 h and C max values of puerarin were 2.48-fold and 3.91-fold, respectively, as large as those of puerarin alone; the AUC 0-12 h and C max values of (+)-catechin were decreased to 57.62% and 77.55%, respectively, compared with those of (+)-catechin alone. In Caco-2 cell monolayers, (+)-catechin (300 and 600 μmol/L) significantly increased the cell uptake and transport of puerarin, whereas puerarin (300 and 600 μmol/L) significantly decreased the cellular uptake and transport of (+)-catechin. Furthermore, both cyclosporine A (P-glycoprotein inhibitor) and MK-571 (MRP-2 inhibitor) significantly increased the cellular uptake and transport of (+)-catechin and puerarin. Conclusion: Concurrent oral administration of (+)-catechin and puerarin significantly increased the absolute oral bioavailability of puerarin, but decreasing that of (+)-catechin. The competitive efflux of (+)-catechin and puerarin by P-glycoprotein and MRP-2 might lead to this interaction during their absorption process in the small intestine.

MIL-88B-Stabilized Anthocyanin-Catechin Films with DFT-Revealed Electron Transfer for Biodegradable Meat Freshness Indicators

Li Huina,Wang Guangxian,Wang Songlei,Xia Hongqiang,Lu Yuzhe,Tian Tian,Luo Yulong,Zheng Hao-Bo

This study describes the development of a biodegradable colorimetric membrane by co-pigmenting Lycium ruthenicum anthocyanins (LRA) with catechins, and loading the stabilised complex onto MIL-88B(Fe) dispersed in a chitosan/polyvinyl alcohol (PVA) matrix. Molecular docking simulations revealed favorable non-covalent interactions, primarily hydrogen bonding and π-π stacking, between the anthocyanin and the MIL-88B framework, particularly in proximity to its iron-based coordination nodes. The LRA complex exhibited the highest binding affinity and conformational stability. Density functional theory (DFT) calculations revealed interfacial electron transfer between the LRA and Fe centers, Bader charge analysis indicated electron transfer, with the Fe center losing ~ 0.927 e upon adsorption, providing a possible electronic-level explanation for the enhanced photothermal stability observed in thermogravimetric analysis (TGA) and color retention tests. The optimized film (containing LRA 3% + MIL-88B) exhibits enhanced tensile strength, increased water contact angle to 89.9°, indicating reduced surface hydrophilicity, and significant antioxidant activity, with ABTS radical scavenging rates exceeding 80%. The films exhibited rapid (< 5 min) pH responsiveness over a wide pH range (pH 2–13), demonstrating the potential to reflect the spoilage of beef, lamb, and shrimp through visible colour changes. Soil burial experiments confirmed that the film degraded by approximately 70% within 30 days. This MOF-assisted strategy significantly improved the inherent instability of anthocyanins and provides a sustainable functionalisation solution for smart food packaging systems.