نتایج جستجو برای: ciocalteu method

تعداد نتایج: 1630456  

2011
Nunzia Cicco Vincenzo Lattanzio

During the Folin Ciocalteu (F-C) micro-assay for the determination of phenolics in the presence of methanol, fine solids can form. In a previous paper, we hypothesized that the interference from alcohol on the F-C reaction can be minimized depending on the particular procedure used to reach the alkalinity condition. In order to demonstrate our hypothesis we studied, by spectrophotometrically mo...

Journal: :Advanced pharmaceutical bulletin 2012
Wenqiong Mai Dongfeng Chen Xican Li

PURPOSE The paper tried to systematically investigate the in vitro antioxidant activity of Rhizoma Cibotii (RC) for the first time. METHOD The methanol extract from RC (MERC) was prepared then systematically investigated by various antioxidant assays, including: DPPH• (1, 1-diphenyl-2-picrylhydrazyl radical), ABTS•(+) (3-ethylbenzthiazoline-6- sulfonic acid diammonium salt radical), •O2- (sup...

2014

Regarding the tea quality, the International Organization for Standardization (ISO) has established recently the levels of minimum concentrations of total polyphenols in tea. Because of this standard, the commercial exploitation of tea demands the investigation of the levels of total polyphenols. However, it is quite difficult for most producers and traders to implement because this test is lab...

2015
Yi-ru Chen Bao-sheng Li

Purpose: To investigate the phytochemical profile and antihyperplasic effect of ethanol extract of Fructus hordei. G (FHE) on hyperplasia of mammary gland (HMG) in rats. Methods: The Fructus hordei. G extract (FHE) was obtained by a rotary vacuum evaporator. The total flavonoids, total alkaloids and total phenolic compounds in FHE were assayed by aluminum chloride colorimetric method, acid-dye ...

Journal: :Antioxidants 2014
Márcia O Souza Cátia S Branco Juliane Sene Rafaela DallAgnol Fabiana Agostini Sidnei Moura Mirian Salvador

Polyphenols are natural products with recognized potential in drug discovery and development. We aimed to evaluate the polyphenolic profile of Araucaria angustifolia bracts, and their ability to scavenge reactive species. The antioxidant and antigenotoxic effects of A. angustifolia polyphenols in MRC5 human lung fibroblast cells were also explored. The total polyphenol extract of A. angustifoli...

2015
Marina D. Topuzovic Ivana D. Radojevic Milan S. Dekic Niko S. Radulovic Sava M. Vasic Ljiljana R. Comic Braho Z. Licina

Plants are an abundant natural source of effective antibiotic compounds. Phytomedical investigations of certain plants haven't still been conducted. One of them is Najas minor (N. minor), an aquatic plant with confirmed allelopathy. Research conducted in this study showed the influence of water and ethyl acetate extracts of N. minor on microorganisms, in the view of chemical profiling of volati...

Journal: :Analytical and bioanalytical chemistry 2002
Jan W Schoonen M Goreti F Sales

A new flow-injection analytical procedure is proposed for the determination of the total amount of polyphenols in wines; the method is based on the formation of a colored complex between 4-aminoantipyrine and phenols, in the presence of an oxidizing reagent. The oxidizing agents hexacyanoferrate(III), peroxodisulfate, and tetroxoiodate(VII) were tested. Batch trials were first performed to sele...

Journal: :Molecules 2012
Hasan A Alzahrani Rashid Alsabehi Laïd Boukraâ Fatiha Abdellah Yuva Bellik Balkees A Bakhotmah

In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin-Ciocalteu method and the free radical scavenging activi...

2012
Ivana D. Radojevic Milan S. Stankovic Olgica D. Stefanovic Marina D. Topuzovic Ljiljana R. Comic Aleksandar M. Ostojic

This paper deals with the antioxidant and antimicrobial activity, total phenolic content and concentrations of flavonoids of Equisetum telmateia extracts. Total phenolic content was determined with Folin-Ciocalteu reagent and it ranged between 129.0 to 262.7 mg GA/g. The concentration of flavonoids in various extracts of E. telmateia was determined using spectrophotometric method with aluminum ...

2009
Ljiljana Stanojevic Mihajlo Stankovic Vesna Nikolic Ljubisa Nikolic Dusica Ristic Jasna Canadanovic-Brunet Vesna Tumbas

The antioxidant activity of water, ethanol and methanol Hieracium pilosella L. extracts is reported. The antioxidative activity was tested by spectrophotometrically measuring their ability to scavenge a stable DPPH(•) free radical and a reactive hydroxyl radical trapped by DMPO during the Fenton reaction, using the ESR spectroscopy. Total phenolic content and total flavonoid content were evalua...

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