Miniaturized Methodologies for Determining the Total Phenol and Flavonoid Concentrations and the Antioxidant Activity

Cacique, Ane Patrícia; Barbosa, Érica Soares; Pinho, Gevany Paulino de; Silvério, Flaviano Oliveira

doi:10.1007/s12161-020-01934-w

Cited by 6 publications

(8 citation statements)

References 43 publications

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“…In addition, the amount of the capping agents (quercetin and caffeic acid) that may be of high importance for potential applications of NPs has been determined. As known, quercetin is one of the main reagents used as a reference standard for the quantification of flavonoids in a sample [67]. The total flavonoid content of a sample can be determined by the AlCl 3 colorimetric method using a UV-vis spectrophotometer [67][68][69].…”

Section: Resultsmentioning

confidence: 99%

“…As known, quercetin is one of the main reagents used as a reference standard for the quantification of flavonoids in a sample [67]. The total flavonoid content of a sample can be determined by the AlCl 3 colorimetric method using a UV-vis spectrophotometer [67][68][69]. In this method, quercetin, which gives a light yellow solution, forms a quercetin-AlCl 3 complex after mixing with aqueous AlCl 3 solution, yielding an intensely yellow solution [67].…”

Section: Resultsmentioning

confidence: 99%

“…The total flavonoid content of a sample can be determined by the AlCl 3 colorimetric method using a UV-vis spectrophotometer [67][68][69]. In this method, quercetin, which gives a light yellow solution, forms a quercetin-AlCl 3 complex after mixing with aqueous AlCl 3 solution, yielding an intensely yellow solution [67]. Because of the formation of the quercetin-AlCl 3 complex, a red shift is observed in the absorption peaks of the quercetin.…”

Section: Resultsmentioning

confidence: 99%

“…Similarly, the amount of caffeic acid, which is a phenolic compound, in the Ch/CA-Ag NPs has been determined from the phenolic content assay. To this end, the Folin-Ciocalteau (FC) assay, which is a method frequently used in the literature to determine the phenolic content of the samples, has been used [67][68][69][70]. Here, because of the reaction that takes place in the basic environment, caffeic acid is oxidized, while the FC reagent is reduced, giving the solution a blue color (λ ≈ 760 nm), that is, a colorimetric reaction [67,69,71,72].…”

Section: Resultsmentioning

confidence: 99%

“…To this end, the Folin-Ciocalteau (FC) assay, which is a method frequently used in the literature to determine the phenolic content of the samples, has been used [67][68][69][70]. Here, because of the reaction that takes place in the basic environment, caffeic acid is oxidized, while the FC reagent is reduced, giving the solution a blue color (λ ≈ 760 nm), that is, a colorimetric reaction [67,69,71,72]. This reaction can also be monitored by a UV-vis spectrophotometer, and the observed broad absorption band varies depending on the concentration of phenolics.…”

Section: Resultsmentioning

confidence: 99%

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Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

Kurt¹,

Olutaş²,

Avcıoğlu³

et al. 2023

Beilstein J. Nanotechnol.

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The presented study comprises the one-pot synthesis and the characterization of quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles (Ch/Q- and Ch/CA-Ag NPs), and their antibacterial and anticancer activities. The formation of Ch/Q- and Ch/CA-Ag NPs has been confirmed by ultraviolet–visible (UV–vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The characteristic surface plasmon resonance (SPR) absorption band has been found at 417 and 424 nm for Ch/Q- and Ch/CA-Ag NPs, respectively. The formation of a chitosan shell comprising quercetin and caffeic acid, which surround the colloidal core Ag NPs, was confirmed by UV–vis, and FTIR analyses, and monitored by TEM microscopy. The size of nanoparticles has been determined as 11.2 and 10.3 nm for Ch/Q- and Ch/CA-Ag, respectively. The anticancer activity of Ch/Q- and Ch/CA-Ag NPs has been evaluated against U-118 MG (human glioblastoma) and ARPE-19 (human retinal pigment epithelium) cells. Both NPs showed anticancer activity, but Ch/Q-Ag NPs seemed to be more effective on cancer cell lines (U-118 MG) in comparison to healthy ones (ARPE-19). Furthermore, the antibacterial activity of Ch/Q- and Ch/CA-Ag NPs against Gram-negative (P. aeruginosa and E. coli) and Gram-positive (S. aureus and S. epidermidis) bacteria was determined, and dose-dependent antibacterial effects were found.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 3 more Smart Citations

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

Kurt¹,

Olutaş²,

Avcıoğlu³

et al. 2023

Beilstein J. Nanotechnol.

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Functionality and nutritional properties of yellow pea, green lentil, chickpea, and navy bean proteins extracted by different methods

Higa,

House,

Nickerson

2023

Eur Food Res Technol

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Combining Experimental and Computational Methods to Produce Conjugates of Anticholinesterase and Antioxidant Pharmacophores with Linker Chemistries Affecting Biological Activities Related to Treatment of Alzheimer's Disease

Makhaeva,

Kovaleva,

Rudakova

et al. 2023

Preprint

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Effective therapeutics for Alzheimer's disease (AD) are in great demand worldwide. In our previous work, we responded to this need by synthesizing novel drug candidates consisting of 4-amino-2,3-polymethylenequinolines conjugated with butylated hydroxytoluene via fixed-length alkylimine or alkylamine linkers (spacers) and studying their bioactivities pertaining to AD treatment. Here, we report significant extensions of these studies, including the use of variable-length spacers and more detailed biological characterizations. Conjugates were potent inhibitors of acetylcholinesterase (AChE, minimum IC50 15.1±0.2 nM) and butyrylcholinesterase (BChE, minimum IC50 5.96±0.58 nM), with weak inhibition of off-target carboxylesterase. Conjugates with alkylamine spacers were more effective cholinesterase inhibitors than alkylimine analogs. Optimal inhibition for AChE was exhibited by cyclohexaquinoline and for BChE by cycloheptaquinoline. Increasing spacer length elevated potency against both cholinesterases. Structure-activity relationships agreed with docking results. Mixed-type reversible AChE inhibition, dual docking to catalytic and peripheral anionic sites, and propidium iodide displacement suggested the potential of hybrids to block AChE-induced β-amyloid (Aβ) aggregation. Hybrids also exhibited inhibition of Aβ self-aggregation in the thioflavin test; those with a hexaquinoline ring and C8 spacer were the most active. Conjugates demonstrated high antioxidant activity in ABTS and FRAP assays as well as inhibition of luminol chemiluminescence and lipid peroxidation in mouse brain homogenates. Quantum-chemical calculations explained antioxidant results. Computed ADMET profiles indicated favorable blood-brain barrier permeability suggesting CNS activity potential. Thus, the conjugates could be considered promising multifunctional agents for potential treatment of AD.

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Miniaturized Methodologies for Determining the Total Phenol and Flavonoid Concentrations and the Antioxidant Activity

Cited by 6 publications

References 43 publications

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

Quercetin- and caffeic acid-functionalized chitosan-capped colloidal silver nanoparticles: one-pot synthesis, characterization, and anticancer and antibacterial activities

Functionality and nutritional properties of yellow pea, green lentil, chickpea, and navy bean proteins extracted by different methods

Combining Experimental and Computational Methods to Produce Conjugates of Anticholinesterase and Antioxidant Pharmacophores with Linker Chemistries Affecting Biological Activities Related to Treatment of Alzheimer's Disease

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