Isolation and free-radical-scavenging properties of cyanidin 3-O-glycosides from the fruits of Ribes biebersteinii Berl.

Isolation and free-radical-scavenging properties of cyanidin 3-O-glycosides from the fruits of Ribes biebersteinii Berl. The reversed-phase preparative high performance liquid chromatographic purification of the methanol extract of the fruits of Ribes biebersteinii Berl. (Grossulariaceae) afforded five cyanidin glycosides, 3-O-sambubiosyl-5-O-glucosyl cyanidin (1), cyanidin 3-O-sambubioside (2), cyanidin 3-O-glucoside (3), cyanidin 3-O-(2G-xylosyl)-rutinoside (4) and cyanidin 3-O-rutinoside (5). They showed considerable free-radical-scavenging properties in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay with the RC50 values of 9.29 × 10-6, 9.33 × 10-6, 8.31 × 10-6, 8.96 × 10-6 and 9.55 × 10-6 mol L-1, respectively. The structures of these compounds were elucidated by various chemical hydrolyses and spectroscopic means. The total anthocyanin content was 1.9 g per 100 g dried fruits on cyanidin 3-glucoside basis.

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Computational and experimental validation of free radical scavenging properties of high‐performance thin‐layer chromatography quantified phenyl myristate in Homalium nepalense

Journal of Separation Science ◽

10.1002/jssc.201901178 ◽

2020 ◽

Vol 43 (8) ◽

pp. 1566-1575

Author(s):

Satish Kanhar ◽

Partha Pratim Roy ◽

Atish Kumar Sahoo

Keyword(s):

Free Radical ◽

Thin Layer ◽

Thin Layer Chromatography ◽

High Performance ◽

Experimental Validation ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Radical Scavenging Properties ◽

Layer Chromatography

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Effects of Different Extraction Solvent Systems on Total Phenolic, Total Flavonoid, Total Anthocyanin Contents and Antioxidant Activities of Roselle (Hibiscus sabdariffa L.) Extracts

Asian Journal of Chemistry ◽

10.14233/ajchem.2019.22147 ◽

2019 ◽

Vol 31 (11) ◽

pp. 2517-2521

Author(s):

Nguyen Quoc Duy ◽

Huynh Anh Thoai ◽

Tri Duc Lam ◽

Xuan Tien Le

Keyword(s):

Free Radical ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Total Flavonoid ◽

Total Phenolic ◽

Anthocyanin Content ◽

Total Anthocyanin ◽

Antioxidant Power ◽

Ferric Reducing Antioxidant Power ◽

Solvent Systems

This study aims to investigate the variations in total phenolic content, total anthocyanin content, total flavonoid content and the antioxidant capacity of Roselle extracts in various extraction solvents. Extracts produced using three solvent systems (methanol, ethanol and acetone) at three different concentrations (50, 70 and 90 % (v/v)) were compared roselle calyx extract produced using distilled water. The antioxidant capacities of roselle calyx extracts were evaluated using DPPH free radical-scavenging capacity, ferric reducing antioxidant power (FRAP) and reducing power. The extraction efficiencies of phenolics, anthocyanins and flavonoids from roselle calyx varied considerably. The results showed that at 50 %, ethanol was the appropriate solvent for extraction of flavonoids, which achieved 508.64 mg RE/L and phenolics, which achieved 762.11 mg GAE/L, while at 70 %, methanol was the effective solvent for extracting anthocyanins, which achieved 8.404 mg/L. For antioxidant activity, at 50 % for ethanol, 70 % for methanol, 50 and 70 % for acetone were solvents used to obtain the highest DPPH free radical scavenging activities, ranging from 869.47-927.60 μmol TE/L. Thus, at 50 and 70 % for acetone were determined as solvents which gave extracts with the highest ferric reducing antioxidant power FRAP, ranging from 3493.52–3459.22 μmol TE/L.

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Reversed-Phase High Performance Liquid Chromatographic Analysis of Three First Line Anti-Tuberculosis Drugs

Revista de Chimie ◽

10.37358/rc.18.12.6799 ◽

2019 ◽

Vol 69 (12) ◽

pp. 3590-3592

Author(s):

Nela Bibire ◽

Romeo Iulian Olariu ◽

Luminita Agoroaei ◽

Madalina Vieriu ◽

Alina Diana Panainte ◽

...

Keyword(s):

High Performance ◽

Biological Fluids ◽

Gradient Elution ◽

High Performance Liquid Chromatographic ◽

Reversed Phase ◽

Assay Method ◽

Active Pharmaceutical Ingredients ◽

First Line ◽

Pharmaceutical Ingredients ◽

Liquid Chromatographic

Active pharmaceutical ingredients such as isoniazid, pyrazinamide and rifampicin are among the most important first-line anti-tuberculosis drugs. A simple, rapid and sensitive reversed phase-high performance liquid chromatographic assay method for the simultaneous determination of isoniazid, pyrazinamide and rifampicin has been developed. Separation of the interest compounds was achieved in a 10 min chromatographic run in gradient elution mode on a Zorbax SB-C18 stainless steel column (150 � 4 mm, 5 mm) using a guard column containing the same stationary phase. The gradient elution was carried out with a mobile phase of 10% CH3CN aqueous solution for channel A and 50% CH3CN in pH = 6.8 phosphate buffer (20 mM), to which 1.5 mL triethylamine were added for channel B. Quantification of the analyzed substances was carried out spectrophotometrically at 269 nm. Detection limits of 0.48 mg/L for isoniazid, 0.52 mg/L for pyrazinamide and 0.48 mg/L for rifampicin were established for the developed assay method. The present work showed that the proposed analysis method was advantageous for simple and rapid analysis of the active pharmaceutical ingredients in pharmaceuticals and biological fluids.

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Chemical Analysis, Toxicity Study, and Free-Radical Scavenging and Iron-Binding Assays Involving Coffee (Coffea arabica) Extracts

Molecules ◽

10.3390/molecules26144169 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4169

Author(s):

Nuntouchaporn Hutachok ◽

Pimpisid Koonyosying ◽

Tanachai Pankasemsuk ◽

Pongsak Angkasith ◽

Chaiwat Chumpun ◽

...

Keyword(s):

Free Radical ◽

Mononuclear Cells ◽

Radical Scavenging ◽

Free Radical Scavenging ◽

Chemical Compositions ◽

Coffee Bean ◽

Dependent Manner ◽

Roasted Coffee ◽

Instant Coffee ◽

Radical Scavenging Properties

We aimed to analyze the chemical compositions in Arabica coffee bean extracts, assess the relevant antioxidant and iron-chelating activities in coffee extracts and instant coffee, and evaluate the toxicity in roasted coffee. Coffee beans were extracted using boiling, drip-filtered and espresso brewing methods. Certain phenolics were investigated including trigonelline, caffeic acid and their derivatives, gallic acid, epicatechin, chlorogenic acid (CGA) and their derivatives, p-coumaroylquinic acid, p-coumaroyl glucoside, the rutin and syringic acid that exist in green and roasted coffee extracts, along with dimethoxycinnamic acid, caffeoylarbutin and cymaroside that may be present in green coffee bean extracts. Different phytochemicals were also detected in all of the coffee extracts. Roasted coffee extracts and instant coffees exhibited free-radical scavenging properties in a dose-dependent manner, for which drip coffee was observed to be the most effective (p < 0.05). All coffee extracts, instant coffee varieties and CGA could effectively bind ferric ion in a concentration-dependent manner resulting in an iron-bound complex. Roasted coffee extracts were neither toxic to normal mononuclear cells nor breast cancer cells. The findings indicate that phenolics, particularly CGA, could effectively contribute to the iron-chelating and free-radical scavenging properties observed in coffee brews. Thus, coffee may possess high pharmacological value and could be utilized as a health beverage.

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