Stopped-Flow Kinetic Study of the Aroxyl Radical-Scavenging Action of Catechins and Vitamin C in Ethanol and Micellar Solutions

2008 ◽  
Vol 56 (12) ◽  
pp. 4406-4417 ◽  
Author(s):  
Shuji Mitani ◽  
Aya Ouchi ◽  
Emi Watanabe ◽  
Yu Kanesaki ◽  
Shin-Ichi Nagaoka ◽  
...  
1997 ◽  
Vol 101 (20) ◽  
pp. 3746-3753 ◽  
Author(s):  
Kazuo Mukai ◽  
Wataru Oka ◽  
Keiko Watanabe ◽  
Yoshifumi Egawa ◽  
Shin-ichi Nagaoka ◽  
...  

Author(s):  
Kazuo Mukai ◽  
Wataru Oka ◽  
Keiko Watanabe ◽  
Yoshifumi Egawa ◽  
Shin-ichi Nagaoka ◽  
...  

2021 ◽  
Vol 11 (8) ◽  
pp. 3634
Author(s):  
Teresa Leszczyńska ◽  
Barbara Piekło ◽  
Aneta Kopeć ◽  
Benno F. Zimmermann

This study compares the content of basic nutrients (proteins, fats, digestible carbohydrates, dietary fiber and ash), steviol glycosides, selected antioxidants (vitamin C, total polyphenols) and antioxidant activity in dried leaves of Stevia rebaudiana Bertoni cultivated in Poland, Paraguay and Brazil and available in the direct sale. The basic chemical composition was determined by standard AOAC (Association of Official Analytical Chemists) methods. Content of steviol glycosides was determined by the UHPLC-UV chromatographic method. Total polyphenols content was expressed as gallic acid equivalent (GAE) and catechins equivalent (CE). Antioxidant activity was measured as ABTS●+ free radical scavenging activity. Dried leaves of S. rebaudiana grown in Poland had significantly higher contents of dietary fiber, and lower protein and ash content, compared to those derived from Paraguay and Brazil. The former had, however, considerably higher contents of total steviol glycosides, stevioside and rebaudioside D, compared to the remaining two plants. In the Paraguay-derived dried leaves, the content of rebaudioside A, C, E and rubusoside was found to be significantly lower. Dried leaves of S. rebaudiana Bertoni, cultivated in Poland, contained substantially more vitamin C and a similar content of total polyphenols, compared to those from Brazil and Paraguay. The examined material from Brazil and Paraguay plantations showed similar antioxidant activity, while that obtained from Polish cultivation was characterized by a significantly lower value of this parameter.


2021 ◽  
Vol 2 (5) ◽  
pp. 6608-6618
Author(s):  
Eva Coronel ◽  
Silvia Caballero ◽  
Gabriela Gonzalez ◽  
Miho Sunguino ◽  
Laura Mereles

Los frutos de Anisocapparis speciosa son nativas de la Ecoregión del Gran Chaco, crecen de manera silvestre en todo este territorio, su pulpa y semillas son comestibles y muy apreciadas por las poblaciones indígenas que lo habitan, además de otros usos con propiedades medicinales atribuidas por conocimientos etnobotánicos, pero no se tienen datos sobre la composición de estos frutos regionales y sus potenciales aplicaciones. El objetivo del presente trabajo fue evaluar la composición de la pulpa y semillas de frutos en estado maduro, y el potencial antioxidante en diferentes estadíos de madurez. La composición proximal, el contenido de minerales, vitamina C y solidos solubles se realizaron según metodologías oficiales de la AOAC.  Los fenoles totales se determinaron por el método de Folin Ciocalteau y la capacidad antioxidante total por medio de la inhibición del radical ABTS. Los componentes mayoritarios en pulpa y semillas fueron carhobidratos y fibra alimentaria. La pulpa madura posee un buen contenido de vitamina C (20 mg/100g). El contenido de fenoles y capacidad antioxidante total fue mayor en la pulpa que en la semillas en estados inmaduros. Los frutos de Anisocapparis speciosa pueden representar una buena fuente de carbohidratos, fibra alimentaria, Mg y vitamina C en la dieta. La pulpa y semillas son fuentes de antioxidantes naturales. Estudios futuros sobre métodos postcosecha, almacenamiento y procesamiento serán necesarios para potenciar su uso y re-valorización en el marco de la Seguridad alimentaria en la población regional.   The native Anisocapparis speciosa fruits from Gran Chaco Ecoregion, they grow wild throughout this territory, their edible pulp and seeds are highly appreciated by the indigenous populations that inhabit it, in addition to other uses with medicinal properties attributed by ethnobotanicals knowledge, but there are no data on the composition of these regional fruits and their potential applications. The aims of the present work were to analyze the pulp and seeds composition of fruits in the ripe state, and the antioxidant potential in different stages of maturity. The proximal composition, minerals content, vitamin C and soluble solids were carried out according to official AOAC methodologies. The total phenolics compounds (TPC) by the Folin Ciocalteau method and the total antioxidant capacity by means of the inhibition of the radical ABTS were evaluated. The main components in pulp and seeds were carbohydrates and dietary fiber. The ripe pulp has a good content of vitamin C (20 mg/100g). The content of TPC and total antioxidant capacity (ABTS radical scavenging) was higher in pulp than in the seeds, in immature stages. The Anisocapparis speciosa fruits can represent a good source of carbohydrates, dietary fiber, Mg and vitamin C in the diet of regional populations. The pulp and seeds are sources of natural antioxidants. Future studies on post-harvest, storage and processing methods will be necessary to enhance its use and re-valorization within the Food Security framework.  


2001 ◽  
Vol 6 (8) ◽  
pp. 770-777 ◽  
Author(s):  
Hui-Chun Yeh ◽  
Jinn-Shyan Wang ◽  
Oliver Y. Su ◽  
Wann-Yin Lin

2022 ◽  
Author(s):  
Habibu Tijjani ◽  
Adamu Matinja ◽  
Marwanatu Yahya ◽  
Emmanuel Aondofa ◽  
Akibu Sani

Diarrhea is a common health complaint occurring with mild, temporary conditions to a potentially life-threatening condition. <i>Cucurbita maxima</i> (Cucurbitaceae) seed is reportedly used traditionally for the treatment of diarrheal and thus this study aimed to evaluate the in vitro antioxidants, total tannins, phenolics contents, and antidiarrheal potentials of <i>n</i>-hexane and aqueous <i>C. maxima</i> seed extracts in castor oil induced diarrheal rats. The <i>n</i>-hexane extract mainly contains oils while the aqueous extract was thick, brown solid. The aqueous and <i>n</i>-hexane seed extract of <i>C. maxima</i> expressed significant 2,2, diphenyl-1-picrythdrazyl (DPPH) scavenging activities at 6.25 – 1000 mg/mL with IC<sub>50</sub> values of 104.01 mg/mL, 29.27 mg/mL and 26.78 mg/mL for <i>n</i>-hexane, aqueous and vitamin C respectively. The hydroxyl radical scavenging activities of the <i>n</i>-hexane and aqueous seed extract of <i>C. maxima</i> were significantly lower at higher concentrations compared with that of vitamin C. Furthermore, the total antioxidant capacities of <i>n</i>-hexane (22.08mg/mL) and aqueous seed extract (11.03 mg/mL) of <i>C. maxima</i> were found to be higher than that of vitamin C (134.46 mg/mL). The aqueous extracts (658.33±380.08 mg QE/g) total tannins were not significantly different from the <i>n</i>-hexane extract (468.33±102.55 mg QE/g) while the <i>n</i>-hexane extract contains significantly higher total phenolics (2.93±1.25 mg GAE/g) compared with the aqueous extract (0.19±0.04 mg GAE/g). Percentage inhibition of stooling was found to be 57±22%, 41±16%, and 46±11% for loperamide, <i>n</i>-hexane, and aqueous respectively. The study concludes that aqueous and n-hexane seed extracts of <i>C. maxima</i> (pumpkin) possess in vitro antioxidant activities and antidiarrheal properties.


2016 ◽  
Vol 19 (4) ◽  
pp. 76-83
Author(s):  
Trang Thi Xuan Dai ◽  
Anh Thi Tu Vo

This study was subjected to investigate antimicrobial and antioxidant properties of Eclipta alba extracts (methanol, hexane, chloroform and ethyl acetate extracts). The antioxidant property of the extract was assessed by 2,2- diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. Kirby-Bauer method was used to determine the antibacterial activity against Enterobacter cloacae of the extracts. The extracts of Eclipta alba were tested against E. cloacae. The highest antibacterial potentiality was exhibited by the ethyl acetate extract of E. alba leaves, means of zones of bacterial growth inhibition are 26.3 mm at a concentration of 32 μg/mL. DPPH free radical scavenging effect of the extracts was compared with standard antioxidant vitamin C. The highest antioxidant activity was exhibited by the ethyl acetate extract of E. alba leaves. The result also showed that the DPPH scavenging activity of ethyl acetate extract from leaves of E. alba was high (EC50 = 419.38 μg/mL). However, this result was 18.99 times lower than that of vitamin C (EC50 = 22.08 μg/mL).


Sign in / Sign up

Export Citation Format

Share Document