Doc:Antioxidant

From Metabolomics.JP
(Difference between revisions)
Jump to: navigation, search
m
Line 1: Line 1:
 
{{Flavonoid/Header}}
 
{{Flavonoid/Header}}
 
=={{Bilingual|フラボノイドの抗酸化能|Antioxidant Activity of Flavonoid}}==
 
=={{Bilingual|フラボノイドの抗酸化能|Antioxidant Activity of Flavonoid}}==
 +
 +
==={{Bilingual|単離した場合|In vitro study}}===
 
{{Twocolumn|
 
{{Twocolumn|
 
The reactivity of an antioxidant is determined by its reactivity as a hydrogen or electron-donating agent, the fate of the resulting radical (unpaired electron), its reactivity with other antioxidant, and its metal-chelating potential.
 
The reactivity of an antioxidant is determined by its reactivity as a hydrogen or electron-donating agent, the fate of the resulting radical (unpaired electron), its reactivity with other antioxidant, and its metal-chelating potential.
Line 33: Line 35:
 
}}
 
}}
 
<references/>
 
<references/>
 +
 +
==={{Bilingual|食べた場合|In vivo study}}===
 +
{{Twocolumn|
 +
Although antioxidant activities of flavonoids are several times higher than vitamin C or E in vitro, their plasma and intracellular concentration after intake is 100-1000 times lower than vitamin C. The antioxidant function in vivo is therefore considered negligible<ref>Frei B, Higdon JV (2003) "Antioxidant activity of tea polyphenols in vivo: evidence from animal studies" ''J Nutr'' 133(10):3275S-3284S</ref>.
 +
|
 +
試験管内ではフラボノイドの抗酸化能はビタミンCやEの数倍あるのですが、摂取後の血中濃度はビタミンCの100から1000倍も低くなります。そのため、体内における抗酸化作用は殆ど無いと考えられます。
 +
}}
 +
  
 
{| class="wikitable"
 
{| class="wikitable"

Revision as of 19:57, 30 September 2010

Flavonoid Top Molecule Index Author Index Journals Structure Search Food New Input

Antioxidant Activity of Flavonoid

In vitro study

The reactivity of an antioxidant is determined by its reactivity as a hydrogen or electron-donating agent, the fate of the resulting radical (unpaired electron), its reactivity with other antioxidant, and its metal-chelating potential. The reactivity can be assessed by applying the chromogenic redox indicator ABTS+(radical cation of 2,2'-azino-bis (3-ethylbenzthiazoline 6-sulphonic acid) relative to Trolox (water-soluble vitamin E analogue).

The strength of antioxidant activities is ordered as:

  • the ortho 3',4'-dihydoroxy moiety in the B-ring,
  • the meta 5,7-dihydroxy moiety in the A-ring, and
  • the 2,3-double bond together with both 4-keto and 3/5-hydroxy group in the C-ring.
Glycosylation decreases the activity. Metal chelation is achieved by the first and the third items above.

For example, quercetin is a more effective photoprotectant and anti-oxidant than kaempferol. [1] [2]

  1. Ryan KG, Swinny EE, Markham KR, Winefield C (2002) "Flavonoid gene expression and UV photoprotection in transgenic and mutant Penunia leaves" Phytochem 59:23-32 PMID 11754940
  2. Li J, Ou-Lee T-M, Raba R, Amundson RG, Last RL (1993) "Arabidopsis flavonoid mutants are hypersensitive to UV-B irradiation" Plant Cell 5: 171-179 PMID 12271060

In vivo study

Although antioxidant activities of flavonoids are several times higher than vitamin C or E in vitro, their plasma and intracellular concentration after intake is 100-1000 times lower than vitamin C. The antioxidant function in vivo is therefore considered negligible[1].


Relative total antioxidant activities[2]
Antioxidant Sources Activity* (mM)
Vitamins
Vitamin C fruit and vegetables 1.0 ± 0.02
Vitamin E grains, nuts and oils 1.0 ± 0.03
Anthocyanins
Oenin black grapes/red wine 1.8 ± 0.02
Cyanidin grapes, raspberries and strawberries 4.4 ± 0.12
Delphinidin aubergine skin 4.4 ± 0.11
Flavonols
Quercetin onion, apple skin, berries, black grapes, tea and broccoli 4.7 ± 0.10
Kaempferol endive, leek, broccoli, grapefruit and tea 1.3 ± 0.08
Flavones
Rutin onion, apple skin, berries, black grapes, tea and broccoli 2.4 ± 0.12
Luteolin lemon, olive, celery and red pepper 2.1 ± 0.05
Chrysin fruit skin 1.4 ± 0.07
Apigenin celery and parsley 1.5 ± 0.08
Flavan 3-ols
(Epi)catechin black grapes/red wine 2.4 ± 0.02
Epigallocatechin teas 3.8 ± 0.06
Epigallocatechin gallate teas 4.8 ± 0.06
Epicatechin gallate teas 4.9 ± 0.02
Flavanones
Taxifolin citrus fruit 1.9 ± 0.03
Naringenin 7-rutinoside citrus fruit 0.8 ± 0.5
Naringenin citrus fruit 1.5 ± 0.05
Hesperetin 7-rutinoside orange juice 1.0 ± 0.03
Hesperetin orange juice 1.4 ± 0.08
Teaflavins
Teaflavin black tea 2.9 ± 0.08
Teaflavin 3-gallate black tea 4.7 ± 0.16
Teaflavin 3'-gallate black tea 4.8 ± 0.19
Teaflavin digallate black tea 6.2 ± 0.43
Hydroxycinnamates
Caffic acid white grapes, olive, cabbage and asparagus 1.3 ± 0.01
Chlorogenic acid apple, pear, cherry, tomato and peach 1.3 ± 0.02
Ferulic acid grains, tomato, cabbage and asparagus 1.9 ± 0.02
p-Coumaric acid white grapes, tomato, cabbage and asparagus 2.2 ± 0.06
* ... Measured as the Trolox equivalent antioxidant activity (TEAC) - the concentration of Trolox with the equivalent antioxidant activity of a 1 mM concentration of the experimental substance
  1. Frei B, Higdon JV (2003) "Antioxidant activity of tea polyphenols in vivo: evidence from animal studies" J Nutr 133(10):3275S-3284S
  2. Rice-Evans C, Miller N, Paganga G (1997) "Antioxidant properties of phenolic compounds" Trends Plant Sci 2(4):152-159
Personal tools
Namespaces

Variants
Actions
Navigation
metabolites
Toolbox