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Topic: Simmondsin  (Read 3031 times)

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Offline tashiany

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Simmondsin
« on: October 18, 2017, 04:37:52 PM »

Hi,

We are currently looking at simmondsin,using a spectrophotometric method.  Since commercial standards are extremely expensive, we are looking for a reasonable replacement, which we can use for quantification purposes, mainly for making a calibration curve..
One paper suggested adenosine, but I'm not sure if this will work.
Would be very glad to have your ideas of other simmondsin-like compounds that might work.

Thank you!


Offline Arkcon

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Re: Simmondsin
« Reply #1 on: October 18, 2017, 08:44:43 PM »

Hi,

We are currently looking at simmondsin,using a spectrophotometric method.

I found one reference, for an HPLC method, with optical detection at fairly short wavelengths, 325 nm.  This can be a problem if your samples aren't clear of other components.  But you can address that later.

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Since commercial standards are extremely expensive, we are looking for a reasonable replacement, which we can use for quantification purposes, mainly for making a calibration curve..

You can standardize a secondary standard, using a reasonably pure extract, against these expensive standards.

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One paper suggested adenosine, but I'm not sure if this will work.
Would be very glad to have your ideas of other simmondsin-like compounds that might work.

If that sort of correlation is acceptable to the quality standards you need to adhere to, then you can just follow the procedure in the paper.  Why do you doubt what was written will work?  Also, did you try building a calibration curve of adenosine as was described, and using the curve to check some known samples?

Quote
Thank you!
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline Arkcon

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Re: Simmondsin
« Reply #2 on: October 18, 2017, 08:46:18 PM »
Can you work with some of the information here: https://www.ncbi.nlm.nih.gov/pubmed/8081475
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

Offline tashiany

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Re: Simmondsin
« Reply #3 on: October 19, 2017, 02:28:48 PM »

Thank you very much!

-Why do you doubt what was written will work?
We wanted to try adenosine, but it does not dissolve in methanol, as they did in that paper, for both adenosine and simmondsin: http://www.sciencedirect.com/science/article/pii/S0926669004000536
For this reason we also didn't do a calibration curve...

In the paper you linked they used a simmondsin commercial standard, but maybe the internal standard they mentioned (Phenyl-b-D-galactopyranoside) might work.

Thanks a lot for your help  :)

Offline Arkcon

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Re: Simmondsin
« Reply #4 on: October 19, 2017, 04:03:46 PM »
Working with the reference that you have:

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Abstract

Approximately all simmondsin and oil can be easily removed in one step by repeated extraction with water at 90 °C from ground jojoba seeds. The optimum time and temperature of extraction were respectively 1.5 h and 90 °C. Quantitative analysis of simmondsin was made by HLPC method using adenosine as internal standard.

The adenosine is an internal standard, not a quantification standard.  Also, that is for an HPLC method, not a spectrophotometer method.  Can you write a definition of each of those italicized words?  You seem to lack the basics of analytical chemistry.  What are you trying to do?  What actually can't you do?  Not being able to afford reagents isn't something we can fix for you.
« Last Edit: October 22, 2017, 12:43:58 PM by Arkcon »
Hey, I'm not judging.  I just like to shoot straight.  I'm a man of science.

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