LONGECITY

Hi guys,

I am seeing this rear it's ugly head lately around the web, so I am posting some items here for discussion regarding stability of resveratrol. In my opinion if res is protected from UV light and remains solid (such as a powder, or inside a powder capsule), it should be pretty stable. :


From a 1996 study:
Resveratrol: Isomeric Molar Absorptivities and Stability
-Brent C. Trela and Andrew L. Waterhouse

Resveratrol has attracted interest as a wine constituent that may reduce heart disease. Published
data on the molar absorptivity and chemical stability of cis- and trans-resveratrol have varied greatly.
Accurate values for UV absorbance for trans-resveratrol [UV ìmax (EtOH) nm () 308 (30 000)] and
cis-resveratrol [UV ìmax (EtOH) nm () 288 (12 600)] were determined and are used to improve
chromatographic quantitation methods. Trials conducted under a variety of commonly encountered
laboratory conditions show that trans-resveratrol is stable for months, except in high-pH buffers,
when protected from light. cis-Resveratrol was stable only near pH neutrality when completely
protected from light.

From a 2002 study regarding UV light:
"Capillary Electrophoresis Determination, Synthesis, and Stability of Resveratrol and Related 3-O-â-D-Glucopyranosides"
- VINCENZO BRANDOLINI,* ANNALISA MAIETTI,PAOLA TEDESCHI,ELISA DURINI, SILVIA VERTUANI, AND STEFANO MANFREDINI*

we have developed a specific protocol to identify and separate
resveratrol isomers and their corresponding glycosides, piceids,
from synthetic as well as natural sources. Furthermore, a study
on UV irradiation of trans-polydatin, aimed at obtaining the
corresponding cis isomer, has been also conducted, leading to
90% final conversion.

From a 2002 study regarding protection from light, while at room temperature:
An LC-MS Method for Analyzing Total Resveratrol in Grape Juice, Cranberry Juice, and in Wine
- YAN WANG,† FLORENTINA CATANA,† YANAN YANG,† ROBIN RODERICK,‡ AND RICHARD B. VAN BREEMEN*

The stability of resveratrol under different conditions was also examined. For
example, resveratrol was stable for up to 5 days at 4 °C in the dark but was not stable at room
temperature without protection from light. Resveratrol was detected in grape, cranberry, and wine
samples. Concentrations ranged from 1.56 to 1042 nmol/g in Concord grape products, and from
8.63 to 24.84 ímol/L in Italian red wine. The concentrations of resveratrol were silmilar in cranberry
and grape juice at 1.07 and 1.56 nmol/g, respectively."

From a 2006 study:
Resveratrol and Its Glycon Piceid Are Stable Polyphenols
- Jiri Prokop, Petr Abrman, Allen L. Seligson, and Milos Sovak

Solid trans-resveratrol and/or trans-piceid (resveratrol-3-
O-glucoside) were tested under accelerated stability condi-
ions for up to 4 years and under ambient conditions in a
mixture with other grape polyphenols for 2 years. As pre-
viously reported about resveratrol in grape pomace,
27 no significant decay in the content of resveratrol or piceid was ob-
served in the presence of atmospheric oxygen and humidity.
n addition, no by-products attributable to the stilbenoid
degradation, i.e., trans–cis isomerism or oxidation, were de-
ected.

Liquid resveratrol products may need better protection.

Cheers
A

Lonegivex has added a new micro-encapsulation process and micronization. Still 100mg dose though. Also has added D3.

Hmm...

I guess we need to test it under an electron microscope.
It's my understanding that the formula hasn't changed because of Pfizer supplying the capsules and res, only the marketing. We will check it out.

Having said that, while testing our micronization samples, I have to say that there is quite a difference between 10um and 1.5um resveratrol in plain water. If Bill's 50% Res tests out at 100um, it will still be much larger than what we are bringing to market.

A
Edited by Anthony_Loera, 22 April 2008 - 06:43 PM.

FYI:
You can compare our current 99% powder size, against one of our micronization samples below:

X1000 powder:


One of our Micronization finalists:



The final pics will be used a a future date, and I believe one or two surprises are yet to come out of this...

A

when we do the experiment to make sure the stability of resveratrol ,we found that it is stable under 45-50 degree centigrade,but it is decomposed when 55-60degree centigrade.