Octadeca-9,11 Dienoic Acid - a Measurement of free Radical Activity or a Marker of Infection in the Lung?

1991 ◽  
Vol 81 (s25) ◽  
pp. 17P-17P ◽  
Author(s):  
CIA Jack ◽  
MJ Jackson ◽  
E Ridgeway ◽  
CRK Hind
1994 ◽  
Vol 224 (2) ◽  
pp. 139-146 ◽  
Author(s):  
Catherine I.A. Jack ◽  
Elizabeth Ridgway ◽  
Malcolm J. Jackson ◽  
Charles R.K. Hind

Diabetes ◽  
1992 ◽  
Vol 41 (8) ◽  
pp. 909-913 ◽  
Author(s):  
A. Collier ◽  
A. Rumley ◽  
A. G. Rumley ◽  
J. R. Paterson ◽  
J. P. Leach ◽  
...  

Gerontology ◽  
1992 ◽  
Vol 38 (5) ◽  
pp. 268-274 ◽  
Author(s):  
A.J. Sinclair ◽  
A.J. Girling ◽  
L. Gray ◽  
J. Lunec ◽  
A.H. Barnett

1994 ◽  
Vol 127 (6) ◽  
pp. 1443-1449 ◽  
Author(s):  
Ever D. Grech ◽  
Christopher M. Bellamy ◽  
Malcolm J. Jackson ◽  
Ronald A. Muirhead ◽  
E.Brian Faragher ◽  
...  

2018 ◽  
Vol 1 (3) ◽  
pp. 128-133
Author(s):  
Wahyu Utami ◽  
Muhammad Da’i ◽  
Viesa Rahayu ◽  
Prihantini Kurnia Sari ◽  
Dian Werdhi Kusumanegara ◽  
...  

Penelitian pendahuluan tentang aktivitas antioksidan ekstrak etanol dan ekstrak etil asetat daun dewandaru (Eugenia uniflora L.) menunjukkan potensi anti radikal bebas yang tinggi dari kedua ekstrak. Oleh karena itu telah dilakukan fraksinasi ekstrak etanol dan ekstrak etil asetat daun dewandaru, serta pengujian aktivitas antiradikal dari masing-masing fraksi. Selain itu, penelitian ini juga bertujuan untuk mengetahui apakah ada korelasi antara kandungan fenol dan flavonoid total dalam berbagai fraksi tersebut dengan aktivitas antiradikalnya. Daun dewandaru diekstraksi dengan kloroform, etil asetat, dan etanol secara maserasi bertingkat. Selanjutnya dilakukan fraksinasi terhadap masing-masing ekstrak etanol dan ekstrak etil asetat menggunakan kromatografi kolom gravitasi dengan fase diam silika G60 dan fase gerak campuran perbandingan tertentu antara kloroform, etil asetat, etanol, dan air secara gradien kepolaran. Aktivitas antiradikal diukur secara spektrofotometri dengan pereaksi DPPH (2,2-diphenyl-1-picrylhidrazyl) dan sebagai pembanding digunakan vitamin E. Penentuan kadar fenol dan flavonoid total dalam fraksi secara spektrofotometri menggunakan pereaksi Folin Ciocalteu untuk penetapan kadar fenol total, sedangkan untuk penentuan kadar flavonoid total menggunakan pereaksi AlCl3. Hasil penelitian menunjukkan bahwa fraksi-fraksi dari ekstrak etil asetat dan ekstrak etanol daun dewandaru mempunyai aktivitas antiradikal yang cukup tinggi. Lima fraksi dari ekstrak etanol memiliki aktivitas antiradikal lebih tinggi dibanding vitamin E. Aktivitas antiradikal paling tinggi ditunjukkan dengan nilai ARP (antiradical power) sebesar 3496,5 mg DPPH/mg sampel, sedangkan vitamin E sebesar 1776,20 mg DPPH/mg sampel. Korelasi antara kadar fenol maupun flavonoid total dalam berbagai fraksi tersebut dengan aktivitas antiradikalnya menunjukkan korelasi positif dengan korelasi sebesar 0,55 dan 0,45. Berdasarkan hasil diatas dapat disimpulkan bahwa fraksi-fraksi polar daun dewandaru mempunyai aktivitas antiradikal yang lebih tinggi daripada vitamin E, namun aktivitas tersebut berkorelasi rendah dengan kandungan fenol dan flavonoid totalnya.   Preliminary research on the antioxidant activity of ethanol and ethyl acetate extracts of Dewandaru leaves (Eugenia uniflora L.) showed high anti-free radical potency from both extracts. Therefore fractionation of the ethanol and ethyl acetate extracts of dewandaru leaves was carried out, as well as evaluation of antiradical activity of each fraction. In addition, this study also aimed to determine whether there is a correlation between the phenol and total flavonoid content in various fractions with their anti-inflammatory activity.Dewandaru leaves were extracted by sequentially maceration with chloroform, ethyl acetate and ethanol. Furthermore, the ethanol and ethyl acetate extracts were fractionated  using gravity column chromatography with silica G60 as stationary phase and increasing polarity of mobile phase by  varying the ratio of chloroform, ethyl acetate and ethanol. Anti-free radical activity was determined using spectrophotometer and DPPH (2,2-diphenyl-1-picrylhidrazyl), vitamin E was used as a standard. Determination of total phenol and flavonoid content was determined using spectrophotometer, Folin Ciocalteu reagent was used to determine total phenolic content, meanwhile  ALCl3 reagent was used to determine total flavonoid content.  The results showed that fractions of  ethanol and ethyl acetate extracts of dewandaru leaves showed high anti-free radical activity. Of all fractions, there 5 fractions of ethanol extract showed higher anti-free radical activity as compared to vitamin E.  The highest anti-free radical activity is indicated by ARP (antiradical power) value of 3496.5 mg DPPH/mg sample, meanwhile the ARP value of vitamin E was 1776,20 mg DPPH/mg sample. Correlation between total phenol and flavonoid content of those fractions indicated positive correlation with correlation value of 0.55 and 0.45 respectively. Based on the results, it can be concluded that polar fractions of dewandaru leaves displayed higher anti-free radical activity as compared to vitamin E, however those activitiesdid not have correlation with their total phenolic and flavonoid content


2017 ◽  
Vol 3 (1) ◽  
pp. 91
Author(s):  
Henny Nurhasnawati ◽  
Sukarmi Sukarmi ◽  
Fitri Handayani

Malay apple (Syzygium malaccense L.) is a plant that can be used for treatment. Antioxidants have the activity to reduce free radical compounds which is one of the causes of the emergence of various diseases in humans. The purpose of this study to determine the comparison of methods of maceration and socletation extraction of antioxidant activity of malay apple leaf. Research stages include sampling, plant determination, making of simplisia, maceration extraction and socletation with 70% ethanol solvent and determine the antioxidant activity by UV-Vis spectrophotometry with DPPH (1,1-diphenyl-2-picrylhydrazyl) as free radical. The parameter is IC50 value that is the concentration of antioxidant compound which can cause 50% loss of DPPH free radical activity. Although both methods show very strong antioxidant activity, it can be concluded that the difference in extraction methods has an effect on the antioxidant activity produced. The results of antioxidant activity test showed that socletation methods gave an average IC50 value of 37.67 ppm, this value is higher than maceration methods with an average IC50 value of 47.80 ppm. Malay apple leaf has the potential as a natural antioxidant, although it has a lower IC50 value than vitamin C which is 9.72 ppm.


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