نتایج جستجو برای: روش تیتراسیون dpph

تعداد نتایج: 378589  

Journal: :Molecules 2010
Vania Urias-Orona Joselina Huerta-Oros Elizabeth Carvajal-Millán Jaime Lizardi-Mendoza Agustin Rascón-Chu Alfonso A Gardea

A pectin (CAP) was extracted from the husk of Cicer arietinum L. Monosaccharide analysis of CAP revealed the dominance of galacturonic acid and smaller amounts of galactose, arabinose, rhamnose, glucose, xylose and mannose. Viscosimetric analysis showed that the intrinsic viscosity ([η]) and the molecular weight (MW) of CAP were 296 mL/g and 105 kDa, respectively. The degree of esterification (...

Journal: :Food chemistry 2013
Fatima Abderrahim Silvia M Arribas M Carmen Gonzalez Luis Condezo-Hoyos

A new microplate-adapted DPPH rapid assay was developed to assess the antioxidant capacity of pure compounds and foods. The assay was carried out in buffered medium (methanol: 10mmol/l Tris buffer pH 7.5, 1:1 v/v) and reaction was completed at 10min. The scavenging capacity index (SCI), a theoretical antioxidant parameter directly related to the antioxidant capacity of samples, was calculated. ...

2015
Natasha C. Moroney Michael N. O’Grady Sinéad Lordan Catherine Stanton Joseph P. Kerry

The anti-oxidative potential of laminarin (L), fucoidan (F) and an L/F seaweed extract was measured using the DPPH free radical scavenging assay, in 25% pork (longissimus thoracis et lumborum (LTL)) homogenates (TBARS) (3 and 6 mg/mL) and in horse heart oxymyoglobin (OxyMb) (0.1 and 1 mg/mL). The DPPH activity of fresh and cooked minced LTL containing L (100 mg/g; L100), F100 and L/F100,300, an...

2012
SILVIA ROBU ANA CLARA APROTOSOAIE ANCA MIRON OANA CIOANCĂ URSULA STĂNESCU MONICA HĂNCIANU

The antioxidant activity of five samples of Lavandulae flowers (L. angustifolia ssp. angustifolia, L. hybrida, L. angustifolia spp. pyrenaica, L. angustifolia spp. angustifolia cv. Munstead and cv. Hidicote Blue) harvested from Romania was investigated using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging and ferrous ion chelating assays. Total polyphenolic content (mg/g dried extract) ...

2011
IVA T. TODOROVA DANIELA I. BATOVSKA BISTRA A. STAMBOLIYSKA STOYAN P. PARUSHEV

Sixteen hydroxychalcones were synthesized in sufficient purity by the Claisen–Schmidt condensation between appropriate acetophenones and aromatic aldehydes. All the compounds were evaluated for their ability to scavenge the stable free 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical. Important structure–activity relationships were observed that strongly contribute to the knowledge for the design o...

Journal: :Bioscience, biotechnology, and biochemistry 2004
Akira Hirota Miyuki Inaba Yu-Chi Chen Naoki Abe Shoji Taki Masamichi Yano Satoru Kawaii

We isolated from soybean miso 8-hydroxyglycitein and 6-hydroxydaidzein as DPPH-radical scavengers, and elucidated their chemical structures by mass spectrometric, and (1)H- and (13)C-NMR spectrosopic analyses. These compounds showed DPPH-radical scavenging activity as high as that of alpha-tocopherol, 8-hydroxygenistein and 8-hydroxydaidzein. This is the first report of the isolation of 8-hydro...

ژورنال: :تحقیقات آب و خاک ایران 2014
مصطفی عبدالله پور رسول راهنمایی ملیحه طالبی فاطمه آقامیر

ذرات کلوئیدی خاک به دلیل داشتن بار سطحی الکتریکی بر بسیاری از واکنش های شیمیایی و فیزیکی خاک اثر می گذارند. با توجه به اهمیت این موضوع، هم از دیدگاه کشاورزی و هم از دیدگاه زیست محیطی، رفتار باری یک نمونه کائولینایت (کائولینایت سمیرم)، که یکی از انواع ذرات کلوئیدی خاک است، مطالعه شد. بدین منظور، بار سطحی کائولینایت در دامنة ph 4 تا 10 و در سه غلظت 005/0، 05/0، و 5/0 مولار الکترولیت کلرید سدیم به...

2016
Xiao Ruan Li Yang Wen-Xia Cui Men-Xing Zhang Zhao-Hui Li Ben Liu Qiang Wang

Supercritical fluid extraction (SFE) was used to extract total alkaloids, peimisine, peimine and peiminine from the bulb of Fritillaria thunbergii Miq. The antioxidant capacity of the extracts was evaluated by DPPH radical scavenging activity (DPPH-RSA), ABTS radical scavenging activity (ABTS-RSA) and ferric reducing capacity (FRAP) assay. A central composite design (CCD) with four variables an...

Journal: :Molecules 2010
Yu Chen Hua Fan Guang-Zhong Yang Yan Jiang Fang-Fang Zhong Hong-Wu He

Garcinia xanthochymus has been widely used in traditional Chinese medicine for expelling worms and removing food toxins. Bioassay-guided fractionation of an EtOAc-soluble extract of G. xanthochymus stem bark led to the isolation of six new xanthones. Their structures were elucidated by spectroscopic methods, especially 2D-NMR techniques. Free-radical-scavenging activities of the isolated compou...

Journal: :Bioscience, biotechnology, and biochemistry 2005
Chun Xie Hiroyuki Koshino Yasuaki Esumi Shunya Takahashi Kunie Yoshikawa Naoki Abe

While screening for bioactive compounds from edible mushrooms, a new potent antioxidant, vialinin A (1), together with a known compound, ganbajunin B (2), and a mixture of ganbajunins D (3) and E (4), were isolated from the dry fruiting bodies of Thelephora vialis. The structure of 1, 5',6'-bis(phenylacetoxy)-1,1':4',1''-terphenyl-2',3',4,4''-tetraol, was elucidated by spectroscopic and chemica...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید