31 replies to this topic

[Hedgehog]

Hi Everybody.

People seem like they are really curious about the quality of res they are taking. I would be willing to test peoples resveratrol if they are willing to send me about a 100mg sample. I would also be curious in testing resveratrols OVI (Organic Volatile Impurities) status. Nobody has really talked about that. If anybody has information on either purification of synthesis of the 99% pure resveratrol that would be helpful. This would give an even better overall purity value. Basically all the sellers state they have x amount of trans-resveratrol. that maybe true when you are ONLY look at cis to trans ratios. But there could other impurities (OVI's) such as a large amount EtOH.

1st sample I will do for free and another sample will be 30 bucks. I will not give a CoA to anybody but this is just for informational purposes ONLY. If anybody has any info about the synthesis or purification schemas of resveratrol please send them or post.





Regards,

[Anthony_Loera]

That is really great hedgehog_info!

Kudos on the service, I think many will seriously consider your offer!

A

[drmz]

i have some relentless res. Just PM me and i will sent it. (from the Netherlands)

[Hedgehog]

Hi Everybody.

People seem like they are really curious about the quality of res they are taking. I would be willing to test peoples resveratrol if they are willing to send me about a 100mg sample. I would also be curious in testing resveratrols OVI (Organic Volatile Impurities) status. Nobody has really talked about that. If anybody has information on either purification of synthesis of the 99% pure resveratrol that would be helpful. This would give an even better overall purity value. Basically all the sellers state they have x amount of trans-resveratrol. that maybe true when you are ONLY look at cis to trans ratios. But there could other impurities (OVI's) such as a large amount EtOH.

For OVI I have only found purification methods with:
chloroform, methanol, EtOH

There seems like there are a number of ways to synthesize this stuff and because ppl have been PM'ing me if you could help me out and see if your sample was synthesized or extracted from a plant source. If it was synthesized it would be great if you could get the method they used or at least the last two (wash or synthesis steps including reagents and compounds). Otherwise I have no idea what I should look for when trying to do the OVI

[maxwatt]

Hi Everybody.

People seem like they are really curious about the quality of res they are taking. I would be willing to test peoples resveratrol if they are willing to send me about a 100mg sample. I would also be curious in testing resveratrols OVI (Organic Volatile Impurities) status. Nobody has really talked about that. If anybody has information on either purification of synthesis of the 99% pure resveratrol that would be helpful. This would give an even better overall purity value. Basically all the sellers state they have x amount of trans-resveratrol. that maybe true when you are ONLY look at cis to trans ratios. But there could other impurities (OVI's) such as a large amount EtOH.

For OVI I have only found purification methods with:
chloroform, methanol, EtOH

There seems like there are a number of ways to synthesize this stuff and because ppl have been PM'ing me if you could help me out and see if your sample was synthesized or extracted from a plant source. If it was synthesized it would be great if you could get the method they used or at least the last two (wash or synthesis steps including reagents and compounds). Otherwise I have no idea what I should look for when trying to do the OVI

I have a source who claims they clean and chop the roots from Polygonum cuspidatum, then ferment them to get enough ethanol to extract, then further purify via HPLC. Two passes through a stainless steel HPLC column for 98 or 99%, and a couple of washes; they don't say much about some of the steps, but insist only material from the plants is used, no other chemicals. The tests I've had done show the slightest trace of emodin. There may be some residual anthocyanins from the roots.

[Hedgehog]

This is what people are sending me

Biotiva (only 50:50 trans:cis), Revgenetics 99% Trans, Vital Prime, Megaresveratrol



Would like to get

Longevinex and anybody else on the list that Anthony has provided as a supplier. If you have a capsule I can use that for the cis/trans HPLC test.






This will be a quick simple cis/trans test and would like to run all samples at one time.

Edited by hedgehog_info, 10 January 2008 - 11:44 PM.

[edward]

As I mentioned I will send you a sample of the new Vital Prime supposed 99% trans when I get it (I ordered it last night). Also I will enclose a sample of Mega-Resveratrol as well in the same package... Just have to wait on the Vital Prime people, hopefully their shipping is quicker than some of my experiences with start up Resveratrol suppliers.

~E

edit: clarity

Edited by edward, 10 January 2008 - 11:35 PM.

[Hedgehog]

This is what people are sending me

Biotiva, Revgenetics, "some relentless res"



Would like to get

Longevinex, Megaresveratrol and anybody else on the list that Anthony has provided as a supplier. If you have a capsule I can use that for the cis/trans HPLC test.






This will be a quick simple cis/trans test and would like to run all samples at one time.

[Hedgehog]

This is what a CoA SPEC should look like for Resveratrol. This is if you want PURITY and not quantity. RRT's stands for Relative Rentention Time, or unknown. Also notice this

The actual value may exceed 100 % due to the inherent standard deviation of the method Emodin (HPLC assay, external calibration calculated on dry matter)

Physical data:
Appearance:	off white to slightly yellow-brownish powder
Solubility:	fairly soluble in alcohols, almost insoluble in water

Tests:	Limits:	Methods:
trans-Resveratrol (HPLC purity)	min. 98%	NQ R 05
Total impurities (HPLC, area %)	max. 2.0 %	NQ R 05
cis-Resveratrol	max. 0.2 %	NQ R 05
trans-Resveratrol-3-O-glucoside	max. 1.0 %	NQ R 05
cis-Resveratrol-3-O-glucoside	max. 0.2 %	NQ R 05
Impurity A, unidentified (RRT 1.08)	max. 0.4 %	NQ R 05
Impurity B, unidentified (RRT 1.11)	max. 0.2 %	NQ R 05
Impurity C, unidentified (RRT 1.27)	max. 0.2 %	NQ R 05
Impurity D, unidentified (RRT 1.36)	max. 0.3 %	NQ R 05
Impurity E, unidentified (RRT 1.37)	max. 0.5 %	NQ R 05
Impurity F, unidentified (RRT 1.38)	max. 0.3 %	NQ R 05
Impurity G, unidentified (RRT 1.47)	max. 1.0 %	NQ R 05
Impurity H, unidentified (RRT 1.49)	max. 0.2 %	NQ R 05
Any other unidentified impurity	max. 0.1 %	NQ R 05
trans-Resveratrol (HPLC assay, external calibration, calculated on dry matter)	96-104 % (w/w) **	NQ R 05
** Note: The actual value may exceed 100 % due to the inherent standard deviation of the method
Emodin (HPLC assay, external calibration calculated on dry matter)	below LOQ***	NQ R 05
Emodin glucoside (HPLC assay, external calibration as emodin, calcul. on dry matter)	below LOQ***	NQ R 05
*** LOQ = limits of quantification, 0.1 mg emodin/g sample (0.01 %)
Ethanol (GC):	max. 5000 ppm****	Ph.Eur 5th Ed.<2.2.28>, NQ R05
**** No solvents other than ethanol and water were used in the manufacturing process and none are present above their LOQ
Loss on drying (105 °C):	max. 4.0 %	Ph.Eur 5th Ed. <2.2.32>
Heavy metals:	max. 0.002 %	Ph.Eur 5th Ed. <2.4.8>
As	max. 2 ppm	by ICP-MS
Pb	max. 2 ppm	by ICP-MS
Cd	max. 1 ppm	by ICP-MS
Hg	max. 1 ppm	by ICP-MS
Microbiological tests:
Total aerobic microbial count:	max. 10 000 cfu/g	Ph.Eur 5th Ed. 2005, <2.6.12>
Combined yeast and molds count:	max. 100 cfu/g	Ph.Eur 5th Ed. 2005, <2.6.12>
Escherichia coli in 1 g:	absent	Ph.Eur 5th Ed. 2005, <2.6.13>
Salmonella in 10 g:	absent	Ph.Eur 5th Ed. 2005, <2.6.13>
Staphylococcus aureus in 1 g:	absent	Ph.Eur 5th Ed. 2005, <2.6.13>
The specification is established according to the ICH Q3A / Q6A guidelines.
Storage conditions: Keep in dark, up to 25°C
Shelf life: 3 years

Edited by hedgehog_info, 14 January 2008 - 06:19 AM.

[maxwatt]

Interesting about the

trans-Resveratrol (HPLC assay, external calibration, calculated on dry matter) 96-104 % (w/w) **

So a sample that measures 96% on one run, could measure 101% on another run, for instance?

And a sample that measured say 6.1% emodin could measure five percent on another run? The accuracy of HPLC is only +/-8%! Sounds like a lot depends on the discrimination of the tester.

[Hedgehog]

Interesting about the

trans-Resveratrol (HPLC assay, external calibration, calculated on dry matter) 96-104 % (w/w) **

So a sample that measures 96% on one run, could measure 101% on another run, for instance?

And a sample that measured say 6.1% emodin could measure five percent on another run? The accuracy of HPLC is only +/-8%! Sounds like a lot depends on the discrimination of the tester.

Hi Maxwatt,

Yes there is instrument variability (however, using your instrument needs to run a system suitability before you can start your HPLC run, system suitability usually includes a RSD of few injections and also a resolution check of your column, if your RSD, Resolution, and retention times are all with in spec then you can say my instrument is working) and also weighing variability. The FDA typically recognizes 98-102% purity. The values are based on a number of things and most importantly on the weight of the standard. You also notice that it is calculated anhydrous, meaning they also factored in the water content values.

So a sample that measures 96% on one run, could measure 101% on another run, for instance

? If this happened the sample should be re-run because either the analyst didn't weigh the sample correctly or the RSD is probably bad.

The most I have ever seen my run is differ is 0.2% and normally runs are like 98.125% and 98.134% if you weigh two samples. I guess what I’m trying to say is that it is all about how good you are about weighing and dissolving your substance, and not so much about the HPLC.

[Hedgehog]

Hi Everybody.

People seem like they are really curious about the quality of res they are taking. I would be willing to test peoples resveratrol if they are willing to send me about a 100mg sample. I would also be curious in testing resveratrols OVI (Organic Volatile Impurities) status. Nobody has really talked about that. If anybody has information on either purification of synthesis of the 99% pure resveratrol that would be helpful. This would give an even better overall purity value. Basically all the sellers state they have x amount of trans-resveratrol. that maybe true when you are ONLY look at cis to trans ratios. But there could other impurities (OVI's) such as a large amount EtOH.

1st sample I will do for free and another sample will be 30 bucks. I will not give a CoA to anybody but this is just for informational purposes ONLY. If anybody has any info about the synthesis or purification schemas of resveratrol please send them or post.

So this is how it is going to work for everybody's samples. I have contacted a few labs that have tested some of the samples that I'm going to test. Based on talking with one of them I will assume they did their test correctly and will use it as my Reference standard.

Basically the output will be a list of vendors with area counts for CIS and Trans peaks. With the peak area counts we should be able to see which vendor has the highest purity with regards to the other vendors. And if we assume that vendor is above 98% purity then we can do all the calculations we need. It will be a little tricky because it will also be based on the weights. There is no way that I can weigh out everybody's samples at the same weight and is why we have to take this into consideration. The scale I will be using goes down 0.001mg which or 0.000001g's

Another test that I'm going to run is called FT-IR. I have a reference standard spectrum from Sigma-Aldrich. I will use it for finger printing the molecule or powder. For example, if the reference standard spectrum and the sample spectrum look the same then you have ID your sample. ID is different then quantitating which will be done with HPLC.

Know having that said. I have no control over how the samples are shipped or if I can't rule out if they are subjected to light. So having that said the results are only as good as the sample that comes to me.

Once again sample size I will need is about 100mg and HAS to be shipped in a light protecting package.

Edited by hedgehog_info, 14 January 2008 - 09:22 PM.

[Anthony_Loera]

Hedge,

Your help with the lab tests sounds great.
I have recently gotten a different lab test completed that maybe you can look at as well.


We will send this out on Thursday to folks outside of this forum (simple press release), but wanted forum members get a preview. I am not sure how this will affect our company, but my folks are pushing for price changes to be done Thursday...

I am still on the fence on that one. Cheers!
A

From: Mark Engleka < engleka@biomol.com>
Date: Jan 11, 2008 4:36 PM
Subject: <Edited>
To: Anthony Loera <anthony@revgenetics.com>

Anthony Loera,

Please find attached the results from the SIRT1 activity tests comparing the RevGenetics resveratrol with our own (Cat. # FR-104). In summary, your resveratrol performed as good or better than ours in stimulating the activity of SIRT1.


Method:

8 concentrations of resveratrol, 0-500µM, were tested for stimulation of SIRT1 enzyme activity using the Fluor de Lys Drug Discovery Assay (Cat. # AK-555) described in detail in the attached file (ak555.doc). Specifically, assays were performed with 0.5 µg SIRT1 (Cat. # SE-239), 25 µM peptide substrate (Fluor de Lys-SIRT1, Cat. # KI-177) and 25 µM NAD+ 37°C, per well and incubated for 20minutes at 37°C.


Results:




The source data for the graphs, the raw fluorescence data and calculations are included in the attached excel file. Due to the fact that the SIRT1 specific activity with no resveratrol was, coincidentally, almost exactly 1 pmol/min/µg, the specific activity (full concentration series graph) and the fold activation numbers (bar graph) are very similar.

I hope that you find the results useful. Please let us know if you have any questions or if we can be of further service.

Best regards,


Mark Engleka, Ph.D.
Technical Service
BIOMOL International, L.P.
E-mail: Engleka@BIOMOL.com
Phone: 800-942-0430 Ext. 233
Fax: 610-941-9252

www.biomol.com

SIRT1 Fluorimetric Drug Discovery Kit
RevGenetics SIRT1 Assays

Edited by Anthony_Loera, 14 January 2008 - 09:40 PM.

[Hedgehog]

Hedge,

Your help with the lab tests sounds great.
I have recently gotten a different lab test completed that maybe you can look at as well.


We will send this out on Thursday to folks outside of this forum (simple press release), but wanted forum members get a preview. I am not sure how this will affect our company, but my folks are pushing for price changes to be done Thursday...

I am still on the fence on that one. Cheers!
A

From: Mark Engleka < engleka@biomol.com>
Date: Jan 11, 2008 4:36 PM
Subject: <Edited>
To: Anthony Loera <anthony@revgenetics.com>

Anthony Loera,

Please find attached the results from the SIRT1 activity tests comparing the RevGenetics resveratrol with our own (Cat. # FR-104). In summary, your resveratrol performed as good or better than ours in stimulating the activity of SIRT1.


Method:

8 concentrations of resveratrol, 0-500µM, were tested for stimulation of SIRT1 enzyme activity using the Fluor de Lys Drug Discovery Assay (Cat. # AK-555) described in detail in the attached file (ak555.doc). Specifically, assays were performed with 0.5 µg SIRT1 (Cat. # SE-239), 25 µM peptide substrate (Fluor de Lys-SIRT1, Cat. # KI-177) and 25 µM NAD+ 37°C, per well and incubated for 20minutes at 37°C.


Results:




The source data for the graphs, the raw fluorescence data and calculations are included in the attached excel file. Due to the fact that the SIRT1 specific activity with no resveratrol was, coincidentally, almost exactly 1 pmol/min/µg, the specific activity (full concentration series graph) and the fold activation numbers (bar graph) are very similar.

I hope that you find the results useful. Please let us know if you have any questions or if we can be of further service.

Best regards,


Mark Engleka, Ph.D.
Technical Service
BIOMOL International, L.P.
E-mail: Engleka@BIOMOL.com
Phone: 800-942-0430 Ext. 233
Fax: 610-941-9252

www.biomol.com

SIRT1 Fluorimetric Drug Discovery Kit
RevGenetics SIRT1 Assays

Is this your formulated Resveratrol or just your pure 99% resveratrol. If it is just pure I'm guess you might have a higher purity than Biomol which is a good thing.

[Anthony_Loera]

I popped open one of the X1000 bottles from our inventory, and sent them some capsules. I knew we sell a pretty good product, might as well check the SIRT1 gene activation on it. It's the one test we opted to do, instead of the consumer labs testing which doesn't measure the trans-resveratrol content...

I think we picked the right test to do in the end, what do you think Hedge?

A

Edited by Anthony_Loera, 14 January 2008 - 10:03 PM.

[docmaas]

I will send you a cap of Biotivia transmax 500 98-99% purity. I need an address. My email is docmaasATyahooDOTcom.

thanks,

MIke

Edited by Michael, 21 July 2009 - 10:21 AM.
Trim quote

[Hedgehog]

I popped open one of the X1000 bottles from our inventory, and sent them some capsules. I knew we sell a pretty good product, might as well check the SIRT1 gene activation on it. It's the one test we opted to do, instead of the consumer labs testing which doesn't measure the trans-resveratrol content...

I think we picked the right test to do in the end, what do you think Hedge?

A

yes it does look good. As for gene activation it works just as well and a little bit better then their purified Res product. Well you already have a lab testing your product consumer lab or whatever lab is fine. However, I did email consumer lab just to see how they tested resveratrol and this is what they had to say.

fromEvelyn Delgado <evelyn.delgado@consumerlab.com>to
dateJan 14, 2008 8:10 AMsubjectRE: question about Resveratrol Testing
hide details 8:10 AM (6 hours ago)
Reply
Thank you for your question. Quantitation for all compounds is done from individual external calibration standards and curves.

[zawy]

My revgenetics 300 mg (50%) does not taste bitter like my 100 mg country life or 37.5 mg NSI. The Country Life was 33% grape seed and the NSI was 50% grapeseed. Neither are as bitter as pure grape seed, so it seems clear all the bitterness is from grape seed. Maybe someone with 99% could confirm there is no bitterness. I wonder how much the grape seed could be the cause of several of the symptoms. In particular, laxative and caffiene-like sensations, if not tendinitis. All three of them are a brownish color. The weight of the R300 was accurrate. I thought maybe my chihuaha would like the revgenetics better since it's less bitter and doesn't burn my nose as much in smelling it, so i tried 2 mg RESV/g blueberries again (0.2% of diet by food weight, 3 times more than fish study) . Still, she's too frightened of it. However, she did eat yesterday's sample sometime during the night. I eat about 1 pound food a day (dry weight) and 1 gram RESV/day at 50% which puts me at RESV being 0.5% of my food intake. Heck, 10% of my dry food weight is already in supplements (5 g vit C, 2 g niacin, 4 gram lysine (cholesterol binding ala Pauling), 1 g B-complex, 2 g fish-flax oil, 1 g glucosamine, cinamin, curcumin, magnesium, etc). Years ago i decided the calcium fad was hogwash and upped my vit D instead and ate more greens. I was glad to get rid of those massive calcium pills. And research these days seems to indicate i was right. But I have to draw the line somewhere. RESV will kick something out and i need a better gruel to mix the supplements in so at least there's some hope of absorption. If you call yeast (protein) a supplement, my fat burning days consist of 70% food-by-supplements. I still wonder why calcium was the only supplement approved by doctors back in the day. Hadn't they at least heard of selenium pills reducing all-cause cancer by 50% in two major studies? They've almost caught up with where pauling was back in 1983 (including his recommendations of 200 mcg selenium and 800 mcg vit D), but the good nurses are still ahead of the senior doctors when it comes to supplements. I supposed it has to do with who can write prescriptions which leads to where the funding comes from.

Edited by zawy, 14 January 2008 - 11:01 PM.

[ilanso]

deleted as redundant

Edited by ilanso, 15 January 2008 - 10:18 AM.

[ilanso]

hedgehog_info: I have contacted a few labs that have tested some of the samples that I'm going to test. Based on talking with one of them I will assume they did their test correctly and will use it as my Reference standard.

I would consider a synthetic source (I know some people here still have stashes of the original Indian Orchid group purchase - someone may be willing to mail you a tiny sample) a better candidate for a ref. standard: http://www.imminst.o...o...st&p=207343
Oh, and BTW, I assume you've already seen this: http://www.resvinatr...olstability.pdf

Edited by ilanso, 15 January 2008 - 10:17 AM.

[Hedgehog]

hedgehog_info: I have contacted a few labs that have tested some of the samples that I'm going to test. Based on talking with one of them I will assume they did their test correctly and will use it as my Reference standard.

I would consider a synthetic source (I know some people here still have stashes of the original Indian Orchid group purchase - someone may be willing to mail you a tiny sample) a better candidate for a ref. standard: http://www.imminst.o...o...st&p=207343
Oh, and BTW, I assume you've already seen this: http://www.resvinatr...olstability.pdf

Thanks, There is actually a 6-7 minute method that has been published. However, it looks at only 1 wavelength. Which is right in-between the Cis/Trans absorbance. My detector can measure 2 wavelengths at a time. So I might use that… The other option would with be to calculate a respose factor for the Cis isomer. For example it is probably something like 1.2. I'll try to use ur paper to calculate a response factor. If anybody else calculates it please post what you got. This could also add the purity from some labs to be extra high. based on the report you posted, cis-res doesn't absorb at the wavelength that most methods use to calculate trans-purity. IF this is the case like the paper suggested you have to have a response factor in your calculation.




Thanks for the paper.

[Hedgehog]

This response factor thing is new to me. We rarely use it at work if at all. Most of HPLC runs we know exactly what could be in the run because of the systhesis. However, with a plant extract you have a wide range of compounds to look at. I haven't seen any documentation in the liturature that this has been done or calculated for cis/trans res or even emodin.

Based on the paper that was posted Trans resveratrol absorbs almost three times more at 308 then cis, thus given you an artificially high value.

A relative response factor is a like a normalization constant you can use to adjust for poor absorption of a substance at a certain wavelength. For example Cis and Trans Resveratrol have different absorbtion max's. Cis around 286, trans is around 306-310 and emodin is 430. So if you look at an area count and don't normalize you get an artificial high value of either cis trans depending on what wavelength you view.

RFF = (Ac x Cis)/(Ais x Cc)

where, RRF = Relative response factor Ac = Area of the target analyte Ais = Area of the corresponding internal standard Cis = Concentration of the corresponding internal standard Cc = Concentration of the target analyte

However, using this calculation you can get a Cis-Resveratrol reference standard. You simply can't buy this stuff.

So do you think this methodology will work? Lets assume I will do three hplc runs per sample I get each at the molecules max absorbance and then could use the total area to determine the %. I wonder if many vendors or sites that test for purity do anything like this.

My data might look like this, assuming I can also see emodin with the same HPLC conditions.

Molecule	Cis	Trans	Emodin
Area Count	23400	210600	600
%	9.97	89.77	0.26
UV Wavelength Max	286	308	430
Total Area	234600

Our we could usec = A/e Where C= concentration A= absorbance and e is written in the posted paper. However, emodin doesn't have a published e value that I could find. So Emodin concentration would have to be based on an external standard or on a total area count.

Edited by hedgehog_info, 16 January 2008 - 05:42 AM.

[ilanso]

All the more reason to use a synthetic ref. standard.
Have you called the fellows at the U. of California at Davis? Things must have evolved since 1996.

[docmaas]

Hedge,

You should received a cap of Biotivia today or tomorrow. I mailed it Wed.

Best,

Mike

[Hedgehog]

For anybody who has are is sending me a sample. Please include the Lot#, expiration date, and vendor. This information should be on the container that it was packaged in.

[Hedgehog]

Was messing around with a published method for separating all impurities and it appears like this method also might separate cis trans. However, I think there is a method that will do it in about 8mins.

As you can see by these results you can dramatically skew the results if you only look at one wavelength and don't use a correction factor.



Using Wavelength 325

• Cis-Resveratrol RT 21.193 Area 106171 %Area 4.02
• Trans-Resveratrol RT 21.041 Area 2533065 % Area 95.86

Using Wavelength 286

• Cis-Resveratrol RT 21.038 Area 205015 %Area 9.92
• Trans-Resveratrol RT 21.192 Area 1841141 % Area 89.12
• Plus 5 other impurities that added up to remaining 100%

Attached Files

•  Trans_Cis_325.JPG   11.31KB   59 downloads

[Hedgehog]

I just did a test on the Trans-Max sample... I didn't find any hint of another ingrediant at the wavelengths I looked at. The rentention time was identical to the Revgentics test sample.

AN=Area Normalization

• AN% @ 286 = 97.76%
• AN% @ 325 = 99.23%

No Emodin or Cis-Resveratrol

Hopefully next week or later this week I can go ahead and do test on all samples.

Edited by hedgehog_info, 30 January 2008 - 05:22 PM.

[Anthony_Loera]

I just did a test on the Trans-Max sample... I didn't find any hint of another ingrediant at the wavelengths I looked at. The rentention time was identical to the Revgentics test sample.

AN=Area Normalization

• AN% @ 286 = 97.76%
• AN% @ 325 = 99.23%

No Emodin or Cis-Resveratrol

Hopefully next week or later this week I can go ahead and do test on all samples.

Hedge and Docmass,

James is stating that this test did not test the "Bio-enhanced version of Transmax". I figured it did because of the date it was tested (Feb 2008) compared to the bioenhanced advertising that started in November of 2007, but I could be completely wrong.

So what was tested? I am just trying to get some simple clarification as I am confused now.
A

Edited by Anthony_Loera, 19 May 2008 - 07:16 PM.

[Ken_winemaker]

I make WINE at home, mainly from KITS, and would like to know how much RESVERATROL is present in (red) kit wines.

-- Do you know where I could find some information on this?

-- Have you tested for resveratrol in any wine samples?

-- You offered to test a sample for free, then $30 a sample - would this apply to samples of wine?

Thank you for your consideration. Cheers!

[Hedgehog]

Hi Ken,

I have moved out of the lab and have convenient access to HPLC instruments. There are some literature sources out there describing how to analyze and quatitate resveratrol in wine with a HPLC mass spec.

you can try searching for "analytical testing" or something of that nature.

Maybe a school like UC DAVIS can engineer grapes to over produce resveratrol.

I make WINE at home, mainly from KITS, and would like to know how much RESVERATROL is present in (red) kit wines.

-- Do you know where I could find some information on this?

-- Have you tested for resveratrol in any wine samples?

-- You offered to test a sample for free, then $30 a sample - would this apply to samples of wine?

Thank you for your consideration. Cheers!