Resveratrol Content
Posted on 09. Jul, 2009 by Raji Jone in Women's Health
Resveratrol is a phytoalexin produced naturally by several plants when under attack by pathogens such as bacteria or fungi. Resveratrol has also been produced by chemical synthesis and is sold as a nutritional supplement derived primarily from Japanese knotweed.
Resveratrol was originally isolated by Takaoka from the roots of white hellebore in 1940, and later, in 1963, from the roots of Japanese knotweed. However, it attracted wider attention only in 1992, when its presence in wine was suggested as the explanation for cardioprotective effects of wine.
Resveratrol (3,5,4′-trihydroxystilbene) is a polyphenolic phytoalexin. It is a stilbene, a derivate of stilbene, and is produced in plants with the help of the enzyme stilbene synthase. Resveratrol content also stayed stable in the skins of grapes and pomace taken after fermentation and stored for a long period.
It exists as two geometric isomers: cis- (Z) and trans- (E), with the trans-isomer shown in the top image. The trans- form can undergo isomerization to the cis- form when exposed to ultraviolet irradiation. Trans-resveratrol in the powder form was found to be stable under “accelerated stability” conditions of 75% humidity and 40 degrees C in the presence of air.
It exists as two geometric isomers: cis- (Z) and trans- (E), with the trans-isomer shown in the top image. The trans- form can undergo isomerisation to the cis- form when exposed to ultraviolet irradiation. Trans-resveratrol in the powder form was found to be stable under “accelerated stability” conditions of 75% humidity and 40 degrees C in the presence of air. Resveratrol content also stayed stable in the skins of grapes and pomace taken after fermentation and stored for a long period.
Both the cis- and trans-isomers of resveratrol were detected in all tested samples. cis-Resveratrol levels were comparable to those of the trans-isomer. They ranged from 0.5 mg/L to 1.9 mg/L in red wines and had a maximum of 0.2 mg/L in white wines. A new report indicates that resveratrol activates Sirtuin 1 (SIRT1) and PGC-1 and improves functioning of the mitochondria. Another research calls into question the theory connecting resveratrol, SIRT1, and calorie restriction.
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