Search results for "FLAVONOIDS"

Influence of solvents on the antioxidant property of flavonoids.

2003

In polyphenols redox systems, the solvent plays a fundamental role in the chemical behaviour of these compounds. Antioxidants can react in different ways with the prooxidant molecules. We have found differences in the antioxidant capacity of flavonoids such as naringin, neohesperidin, neoericitrin, hesperidin, narirutin didymin and the related flavones naringenin, hesperetin eriodictyol and isosakuratenin, when they are in the presence of radicals and solved in water or in an alcohol mixture.

Green extraction approach for the recovery of polyphenols from Croatian olive leaves (Olea europea)

2017

Abstract Pressurized liquid extraction (PLE) is shown as an innovative green technology for the effective extraction of the various phytochemicals from food by-products, therefore the aims of this study were to evaluate the application of PLE to engineer green extracts of Croatian olive leaves ( Olea europaea , cv. Oblica) for potential industrial production (functional foods/pharmaceuticals). PLE was conducted under various cycle numbers (1, 2), temperature (60, 80, 100 °C) and static times (5, 10, 15 min). Obtained extracts were characterized in terms of: (i) total polyphenols (TP); (ii) total flavonoids (TF); hydroxycinnamic acids (HCA); and (iv) flavonols (FLA). Response surface methodo…

Two New Flavonoids fromBonannia graeca: a DFT-NMR Combined Approach in Solving Structures

2007

Two new cyclized C-geranylated flavonoids, the dihydroflavonol bonanniol C (4a) and the flavanone bonannione B (6a), were isolated as minor compounds from the aerial parts of Bonannia graeca (Umbelliferae). Their structures were elucidated by a combined approach of extensive spectroscopic means and quantum mechanical methods. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Approaches to the identification and assay of flavonoids in bee bread extracts by spectrophotometric method

2017

Flavonoids are regarded as key compounds in bee bread. In this paper, quantitative determination of sum of flavonoids and dominating group of flavonoids were carried out by colorimetric aluminum chloride method. The principle of aluminum chloride colorimetric method is that aluminum chloride forms complexes with flavones and flavanols wherein it reacts with the C-4 keto group and hydroxyl groups of the ring C, and/or ring A and/or ring B. In this work 3 samples of bee bread and 5 extracts were investigated. The total contents of flavonoids in the tested extracts ranged from 10 to 166 mg/L. Our study confirmed that complex of quercetin dihydrate with aluminum chloride had the maximum absorpt…

Isolation of anthocyanins from vegetable wastes.

2004

Influence of flavonoids on the transmembrane electron transport:study ex-vivo

2015

The oxidative stress results from a change in the physiological balancebetween oxidant and antioxidant species. This condition induces an chemical change in the redox state of cells.. The function of t-PMET is to cooperate with intracellular redox pairs, like piruvate and lactate, to maintain thecytoplasmatic NAD+/NADH balance. The t-PMET is correlated with the modulation of internal pH and redox homeostasis, as it is able to activate proton release. Thus, t-PMET causes external and internal pH modification, as well as development of an inside negative membrane potential. The aim of this work was evaluate the erythrocytes redox status in a group of health volunteers and then to study whethe…

Effect of extraction solvent on total phenolic content, total flavonoid content and antioxidant activity of Cetraria islandica

2020

Oxidative stress may lead to a number of diseases such as atherosclerosis, nephrotoxicity, liver cirrhosis, cancers, diabetes, and Alzheimer disease. Medicinal plants are an important source of antioxidants. Therefore, the antioxidant potential of Cetraria islandica was evaluated in this work. The coarse powder of leaf of Cetraria islandica was extracted in Soxhlet apparatus, with ethanol (90%) and ethanolic extract of Cetraria islandica (EECI) was further processed for phytochemical screening, total phenol content, total flavonoid content, and various in vitro antioxidant assays. The phytochemicals present in EECI were glycosides, carbohydrates, triterpenoids, proteins and amino acids, gum…

Performance of Host-Races of the Fruit Fly,Tephritis conuraon a Derived Host Plant, the Cabbage ThistleCirsium oleraceum: Implications for the Origin…

2008

The thistle-infesting fruit fly Tephritis conura Loew (Diptera: Tephritidae) forms host races on the melancholy thistle, Cirsium hetewphyllum (L.) Hill (Asterales: Asteraceae) and the cabbage thistle, Cirsium olemceum (L.). Scop. Previous research indicates that the host shift occurred from C. hetewphyllum to C. oleraceum. In this paper we address whether the host shift involved physiological adaptations by studying oviposition acceptance and survival of the two host races on the derived host C. oleraceum. Performance differed significantly between host races. T. conura originating from C. oleraceum produced adults in 75% of all egg-laying trials in contrast to only 6.6% in T. conura origin…

Phytochemical Evaluation of Tinctures and Essential Oil Obtained from Satureja montana Herb

2020

Winter Savory (Satureja montana L.) has been used in traditional medicine and as a spice or natural food preservative in the Mediterranean region for centuries. In this paper, some technological and analytical aspects of the S. montana tinctures development and an evaluation of the essential oil composition are provided. The total phenolic and flavonoid contents and phenolic compounds profile analyzed spectrophotometrically and by high-performance thin-layer chromatography (HPTLC), respectively, were evaluated in the developed tinctures. The results showed that the tinctures prepared from the S. montana herb by maceration or remaceration are rich in polyphenols, and there is an influence of…

Role of Natural Cross Linkers in Resin–Dentin Bond Durability: A Systematic Review and Meta-Analysis

2022

Background: The role of endogenous Matrix Metallo Proteinases in resin dentin bond deterioration over time has been well documented. The present study aimed to systematically review the literature; in vitro and ex vivo studies that assessed the outcomes of natural cross-linkers for immediate and long-term tensile bond strength were included. Methods: The manuscript search was carried out in six electronic databases—PubMed/MEDLINE, LILACS, SciELO, Cochrane, Web of Science and DOAJ, without publication year limits. Only manuscripts in English (including the translated articles) were selected, and the last search was performed in December 2020. The Preferred Reporting Items for Systematic Revi…