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Bioinspired Synthesis of Silver Nanoparticles: Characterisation, Mechanism and Applications
Published in Huiliang Cao, Silver Nanoparticles for Antibacterial Devices, 2017
Neeraj S. Thakur, Bharat P. Dwivedee, Uttam C. Banerjee, Jayeeta Bhaumik
FTIR spectroscopic analysis is performed in order to identify the possible bioconstituents responsible for the reduction of silver ions to nanoparticles and their effective stabilisation and capping. Thus, FTIR data are collected for phytochemical capped metal nanoconstructs. Biosynthesised AgNPs prepared using C. sinensis showed peaks around 3400, 2900 and 1600 cm−1, some of which were also found in the FTIR spectra of the corresponding plant extracts (Bhaumik et al. 2015). The peak at 3400 cm−1 indicates -OH structural polymeric association. Overall spectral pattern indicated the presence of catechin (flavonoid)-like molecules (from the phytochemical capping) in the plant extracts that might be responsible for the coating of hydroxyl groups on the nanoparticles (Bhaumik et al. 2015; Mittal et al. 2014). Therefore, it can be concluded that the nanoparticle surface is capped by polyphenolics and flavonoids. In can also be noted that the hydroxyl groups present on the nanoparticle surface can be functionalised by reacting with carboxylic acid groups present in drugs or imaging agents to construct nanotheranostic scaffolds.
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.
Hepatoprotectant potential of sodium alginate coated catechin nanoparticles (SACC-NPs) in rat model
Published in Inorganic and Nano-Metal Chemistry, 2020
Jithin Mullakkalparambil Velayudhan, Debabrata Mondal, Raguvaran Raja, Bipin Kumar, Ravi Shankar Kumar Mandal, Sonam Bhatt, Karam Pal Singh, Karikalan Madhesh
Natural products with antioxidant property have attracted great attention as potential functional ingredients for therapy of hepatopathy.[4,5] Many plant ingredients contain piperine, quercitin, curcumin, catechin, naigirin, glycurrhizin etc. which are potent antioxidant and may help in regeneration of hepatic injury with proper bioavailability at the target organ. Catechins are predominant form of flavanoids present in plants and have attracted particular attention due to their relatively high antioxidant capacity in biological systems. Many of the biologic activities of tea appear to be related to its flavonoid content.[6] Catechin has various pharmacological effects including antioxidant, anti-diabetic, anti-inflammatory, anti-mutagenic, anti-carcinogenic and antimicrobial activities. However, the application of catechin is limited because catechin is unstable in solution and has poor bioavailability in the body.[3] Bioavailability of the catechin molecules is as low as 5%.[7] Lack of long term stability,[8] sensitivity to light and temperature[9] makes these molecules unpopular in pharmaceutical and other industries.
Identification of phenolic compounds and antioxidant activity of guava dehydrated by different drying methods
Published in Drying Technology, 2020
Xuan Liu, Xu Yan, Jinfeng Bi, Xinye Wu, Jianing Liu, Mo Zhou
The flavanol compounds of guava were categorized as catechin (catechin and catechin hydrate), catechin derivatives (gallocatechin, galloepicatechin, gallocatechin-catechin isomer) and procyanidins oligomers (dimers and trimers). The content of catechin decreased significantly after drying process with retention of 30.93–75.21%, illustrating remarkable differences evoked by different drying methods. FD and VD samples presented higher retention in catechin of 75.21 and 61.26%, respectively. IRD and PSDFD showed similar moderate catechin retention of 38.77 and 34.45%, respectively. The lowest catechin content of 46.71 ± 0.78 mg CAE/kg dw was found in HAD sample accounting 30.93% retention.