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Nanosensors for the Food Industry
Published in V. Chelladurai, Digvir S. Jayas, Nanoscience and Nanotechnology in Foods and Beverages, 2018
V. Chelladurai, Digvir S. Jayas
Gallic acid (GA) is one of the major phenolic compounds available in fruits (blueberries, grapes, banana, cantaloupes, and many other fruits), and GA has strong antioxidant properties. GA also has anti-mutagenic and anti-carcinogenic properties. The food industry extensively uses GA as main additive during processing. Traditionally, chromatographic (GC and GCMS) and spectrophotometric techniques were used for quantification of GA, and now electrochemical sensors are the most commonly used technique for GA quantification by the analytical chemists around the globe. The major concern with the electrochemical sensor during GA quantification is direct oxidation of GA on the electrodes of the sensor, which affects the sensitivity and accuracy of the electrochemical sensor. Ghaani et al. (2016) developed a modified electrochemical sensor using glassy carbon electrode (GCE) with AgNP for GA quantification. Delphinidin coating was added on the GCE/AgNP electrode for selective oxidation of GA. First, the GCE electrode was polished with alumina abrasive slurry followed by rinsing with double-distilled water. Then the GCE was introduced to a continuous potential cycling in an AgNO3 (1 mmol/L) nitric acid (100 mmol/L) solution from 0.7 to 1.9 V with the sweep rate of 80 mV/s for 8 cycles. In the second step of sensor fabrication, delphinidin coating was added by rinsing the GCE/AgNP electrode with double-distilled water, followed by continuous potential cycling at a sweep rate of 20 mV/s from 100 to 400 mV for 8 cycles in delphinidin (1.0 mmol/L) solution in a phosphate buffer solution (0.1 mmol/L, 7.0 pH). Ghaani et al. (2016) tested this GCE/AgNP/Delph sensor to measure GA levels in 5 different commercial juices (apple, peach, lemon, orange, and green tea) by measuring the GA oxidation current and found the final recovery rate >99.0%, which demonstrated the feasibility of using this sensor for GA quantification in real food samples.
Toxicological safety, antioxidant activity and phytochemical characterization of leaf and bark aqueous extracts of Commiphora leptophloeos (Mart.) J.B. Gillett
Published in Journal of Toxicology and Environmental Health, Part A, 2023
Lucas Felipe de Melo Alcântara, Pedro Thiago da Silva, Quesya Mamede de Oliveira, Talita Giselly dos Santos Souza, Marllyn Marques da Silva, George Souza Feitoza, Wendeo Kennedy Costa, Maria Aparecida da Conceição de Lira, Cristiano Aparecido Chagas, Francisco Carlos Amanajás de Aguiar Júnior, Maria Tereza dos Santos Correia, Márcia Vanusa da Silva
Gallic acid is a phenolic compound with anti-inflammatory, antioxidant, anticancer, and antimicrobial properties (Ferraris et al. 2020; Khantamat et al. 2021; Kour et al. 2023). Chlorogenic acid has a total cholesterol-lowering effect, modulates glucose metabolism, inhibits adipocyte progenitor proliferation, and exerts a protective effect against DNA damage (Corti, Marcucci, and Bachetti 2018; Naveed et al. 2018; Xu, Hu, and Liu 2012). Both substances were also identified in the study undertaken by Pereira et al. (2017), while catechin and epicatechin were first identified in this study. Catechin exerts antilipemic and antidiabetic potential, and also a protective effect against cardiovascular diseases (Hashimoto et al. 2003; Mechchate et al. 2021; Wang et al. 2011; Yang, Kotani, and Kusu 2001; Zaveri 2006). It is of interest that epicatechin reduced platelet aggregation, indicating an anticoagulant and pro-fibrinolytic profile (Abou-Agag et al. 2001; Sinegre et al. 2019). Isoorientin, orientin, vitexin, isoquercetin, quercitrin, luteolin and quercetin were also found in the leaves (Dantas-Medeiros et al., 20201a; Pessoa et al. 2021) and quinic acid in the bark (Dantas-Medeiros et al. 2021). This phytochemical variation might account for the different compositions of plant tissues, period of the year in which it was collected and location of the specimen, as well as the procedure for extraction and preparation of crude extracts (Jones and Kinghorn 2012). To complement this gap studies would be necessary that delineate the chemical variation of the species, according to location and periods of the year.
Green synthesis of silver nanoparticles using gallic acid as reducing and capping agent: effect of pH and gallic acid concentration on average particle size and stability
Published in Inorganic and Nano-Metal Chemistry, 2022
Mina Ahani, Marziyeh Khatibzadeh
Gallic acid (GA) (3,4,5-trihydroxybenzoic acid), a naturally occurring low molecular weight triphenolic compound, is abundant in many of plants, such as gallnut, green tea, oak bark, red wine, and white wine and fruits, such as banana, strawberry, and grape. GA has been extensively used as antioxidants in food, and as derivate in color, cosmetic and pharmaceutical formulations. GA possesses many potential therapeutic properties including antiallergic, anti-obesity, anticancer, antiviral and antibacterial properties.[14–16] GA has been also used in the green synthesis of AgNPs by other researchers because of GA is water soluble and is found to be very strong reducing and capping agent for reduction of Ag ions into AgNPs in synthesis process. Few studies have focused on the synthesis AgNPs by GA. To the best our knowledge, there have been no studies investigating the pH value and GA concentration effects in the synthesis of AgNPs by GA on the average particle size and stability of prepared NPs. In the present study, AgNPs were synthesized using a green strategy in a one-step and rapid process by Gallic acid as both reducing and capping agent without using any other chemicals, and investigated the effect of pH value and GA concentration on the prepared AgNPs average particle size and stability in process. With this method, we are able to obtain AgNPs with different sizes by just changing reaction parameters, i.e., pH value and GA concentration. At each synthesis, the obtained NPs were characterized using ultraviolet–visible (UV–Vis) absorption spectroscopy, dynamic light scattering (DLS) and zeta potential analysis. Finally, the AgNPs synthesized under optimum conditions were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques.
Recent advances in multifunctional dendrimer-based nanoprobes for breast cancer theranostics
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Prashant Kesharwani, Rahul Chadar, Rahul Shukla, Gaurav K. Jain, Geeta Aggarwal, Mohammed A.S. Abourehab, Amirhossein Sahebkar
Similarly, Sharma et al evaluated the uptake and cytotoxic activity of G4 PAMAM dendrimer modified with the gallic acid conjugate. Gallic acid is a polyhydroxyphenol that is derieved naturally from green tea, grapes, gallnuts, bananas and other fruits as such. It is well known for its antibacterial, antioxidative, antiminflammatory, anticancer and overall antimicrobial activity. The cytotoxic activity of gallic acid have been reported in different studies against various tumors including cancer of breast, lung, colon, cervical, prostate and many more. Gallic acid is a chemopreventive agent and acts as a free radical scavenger, inhibhitor of cell proliferation and inducer of apoptosis in cancerous cells. The apoptosis is caused as a result of oxidative stress built as a result of ROS production, increased level of intracellular Ca2 + level and mitochondrial dysfunction. GA shows strong antioxidant activity and is a good scavenger of ROS. This polyphenolic compound stimulates the pre-existing apotosis pathway, causing the activation of PARP, caspase-9 and caspase-3. Moreover, studies has also evidenced that it downregulates cyclin B1, Cdc2 and Cdc25C resulting in the arrest G2 and M phase, thereby inhibhiting cell proliferation. Scientist have since then worked upon the effective delivery of gallic acid. In this study, gallic acid was easily conjugated with surface functional groups of dendrimers via electrostatic interaction. An increase in cytotoxic activity against MCF-7 was found when cells were treated with GA-PAMAM-dendrimer [39]. In another study, Abdel-Rahman et al designed different generations- G1, G2 and G3 of thermoresponsive dendrimer and tested them for their cytotoxic activity against MCF-7 BC cell lines. Tetrabromohydroquinone was used as thermoresponsive materials. The thermal response of these materials generally depend on the generation of the dendrimer used. It was noted that dendrimer of generation G2 with tetrabromohydroquinone showed the highest cytotoxic activity against MCF-7 BC cell lines, which might be attributed from its appropriate physicochemical properties (lipophilicity and surface functional group) needed for effective anticancer activity.The study in whole highlighted how thermal stimulated dendrimers can be successfully incorporated with drug for treatment of breast cancer [90].