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Total polyphenol quantitation using integrated NIR and MIR spectroscopy: A case study of Chinese dates ( <i>Ziziphus jujuba</i> )
摘要： Polyphenols are the foremost measure of phytochemicals in Chinese dates due to their many potential health benefits such as averting cancers, reducing the risk of coronary artery disease, diuretic activity, myocardial stimulant, coronary dilator and muscle relaxant. To quantitate the polyphenols in Chinese dates using a data fusion approach with near‐infrared (NIR) and mid‐infrared (MIR) spectroscopy. A total of 80 Chinese dates samples were used for data acquisition from both NIR and MIR spectroscopy. The efficient spectral intervals were extracted by the synergy interval partial least square (Si‐PLS) algorithm as input variables for NIR‐MIR fusion model. A genetic algorithm (GA) was used to construct the model based on NIR‐MIR fusion. The performance of the developed models was evaluated using correlation coefficients of calibration (R2) and prediction (r2), root mean square error of prediction (RMSEP), bias and residual prediction deviation (RPD). The data fusion model based on the GA was superior compared to NIR and MIR build model. The optimal GA‐fusion model yielded R2 = 0.9621, r2 = 0.9451, RPD = 2.44, calibration set bias = 0.004 and prediction set bias = 0.061, computing only 15 variables. These findings reveal that integration of NIR and MIR is possible for the prediction of total polyphenol content in Chinese dates.
关键词： spectroscopy techniques,polyphenols,genetic algorithms,principal component analysis,spectral interval selection
更新于2025-09-23 15:23:52
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Stress Physiology of Tea in the Face of Climate Change || UV-B Radiation-Induced Changes in Tea Metabolites and Related Gene Expression
摘要： UV-B radiation is an inevitable abiotic stress, which could induce a series of changes in metabolites and related metabolisms in plants. UV-B-induced metabolic changes in leaves of Camellia sinensis affect the tea quality. This review summarizes the recent investigations into UV-B radiation-induced changes in tea metabolites and their related gene expression, involving in flavonoids, amino acids, and volatile compounds. UV-B radiation induces flavonoid accumulation by increasing expression of key genes in general phenylpropanoid pathway and flavonoid pathway. The UV-B radiation-induced gene expressions in flavonoid biosynthesis pathway also are affected by transcription factors and endogenous phytohormones signaling pathway. Changes of individual amino acids under UV-B radiation exhibit significant variation among different plants, and their responses to UV-B radiation dose are different. These regulations involve in modulation of gene expressions related to GABA shunt and tricarboxylic acid cycle (TCA). Volatile compounds in Camellia sinensis under UV-B radiation are regulated by both metabolites biosynthesis and volatile glycosidic-precursors hydrolysis. In a word, UV-B radiation influences metabolisms in tea in a rather complex way. More researches on UV-B-induced transcriptional regulation, endogenous-phytohormone signal regulation, metabolisms diversions regulation, etc. are needed in the future.
关键词： Gene expression,Signal regulation,Amino acids,Volatile compounds,Tea polyphenols,UV-B radiation
更新于2025-09-23 15:21:01
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Nanostructured TiO2-induced photocatalytic stress enhances the antioxidant capacity and phenolic content in the leaves of Vitis vinifera on a genotype-dependent manner
摘要： Over the past decades, nanotechnology has received great attention and brought revolutionary solutions for a number of challenges in scientific fields. Industrial, agricultural and medical applications of engineered nanomaterials have increased intensively. The ability of titanium dioxide nanoparticles (TiO2 NPs) to produce reactive oxygen species (ROS), when excited by ultra-violet (UV) light, makes them useful for effectively inactivate various pathogens. It is known that ROS also have signalling role in living organisms, therefore, TiO2 NPs-induced ROS can influence both enzymatic and non-enzymatic defence systems, and could play a role in the resistance of plants to pathogens. Herein, we studied the photocatalytic stress responses of grapevine (Vitis vinifera L.) as model plant, when exposed to a well-known photocatalyst, Degussa P25 TiO2 NPs. The photocatalytically produced ROS such as superoxide anion, hydroxyl radical and singlet oxygen were confirmed by electron paramagnetic resonance spectroscopy. Foliar exposure of five red cultivars (Cabernet sauvignon, Cabernet franc, Merlot, Kékfrankos and Kadarka) was carried out in blooming phenophase under field condition where plants are exposed to natural sunlight with relatively high UV radiation (with a maximum of ~ 45 W m-2). After two weeks of exposure, the effects of photogenerated ROS on the total phenolic content, antioxidant capacity, flavonol profile and the main macro-, microelements of the leaves were studied in detail. We found that foliar application of TiO2 NPs boosted the total phenolic content and biosynthesis of the leaf flavonols depending on the grapevine variety. Photocatalytically active TiO2 NPs also increased K, Mg, Ca, B and Mn levels in the leaves as shown by ICP-AES measurements.
关键词： micro- and macroelements,photocatalytic stress,antioxidant capacity,grape leaf polyphenols,flavonols
更新于2025-09-10 09:29:36
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Functional Protein-Assisted Fabrication of Fe-Gallic Acid Coordination Polymer Nanonetworks for Localized Photothermal Therapy
摘要： Fe-polyphenols coordination polymers have emerged as a versatile theranostic nanoplatform for biological applications owing to the appealing biocompatibility of precursors from nature. Incorporating bioactive molecules with Fe-polyphenols coordination polymers is greatly significant to take full advantages of their superiorities for advanced application. Herein, we show functional protein-assisted fabrication of Fe-gallic acid (GA) nanonetworks via a mild and facile biomineralization for photothermal therapy. Mild alkaline condition is crucial to obtain protein-Fe-GA nanonetworks with intense near-infrared absorption and their unique network structure allows reducing the leakage to the surrounding normal tissues, benefiting high photothermal therapeutic efficacy and minimal side effects. The proposed bovine serum albumin-Fe-GA nanonetworks are successfully used to eradicate tumor in vivo. In addition, this universal method can be extended to synthesize other protein-involved nanonetworks, such as human serum albumin-Fe-GA and ovalbumin-Fe-GA. More importantly, the intrinsic bioactivity of protein can be retained in the nanonetworks, and the ovalbumin-Fe-GA nanonetworks enable inducing the maturation of immune cells, showing the successful fusion of immune activity of ovalbumin into the nanonetworks. The proposed biomineralization strategy shows a bright prospect in incorporating various functional proteins, such as enzymes and antibodies, to form protein-Fe-GA nanonetworks with good biocompatibility, favorable photothermal effect and specific biological function.
关键词： immune activation,coordination polymer,biocompatibility,photothermal therapy,biomineralization,polyphenols
更新于2025-09-10 09:29:36