Comment · Fri, May 28, 2021 · ND Owner
L-theanine vs D-theanine
Original post in this thread
intern6 · 4 points
Years ago I bought L-Theanine from one of the more trusted bulk suppliers.
Even now, still having the powder (I assume it is still good, no reason to think otherwise) and I get no benefit whatsoever, probably even the opposite of the assumed effects.
On the other hand, I previously tried L-theanine from Suntheanine and actually had some good results.
They claim that it is hard (or was at the time) to purify only the L-isomer alone, without the d-isomer. They also claim that the d-isomer can block the l-isomer absorption. And that is is also hard to distinguish between the two when testing the end product for purity. Perhaps nowadays the situation is different, but I somewhat believe that low-end suppliers might still sell non-L-isomer products unintentionally (assuming the whole issue is/was real)
What is NDs stance about the issue?
\* I do believe you actually sell the L-isomer, but perhaps you could elaborate/debunk the idea.
What they were answering
Direct reply to the original post — see the thread post above.
u/MisterYouAreSoDumb · ND Owner
The whole Suntheanine issue was a real thing way back. However, that was 10 years ago. Back then they had one of the only processes for making enantiopure L-theanine. Things have changed massively since then. Suntheanine (Taiyokagaku Co.) owns a single patent to make enantiopure L-theanine using fermentation. Other Chinese researchers have different patents for other syntheses that create enantiopure L-Theanine. Here is another. Here is a synthetic purification process in another Chinese patent. However, if you listened to Suntheanine's marketing, you would think they had the only patent to make enantiopure L-theanine. That's just not true. There are many processes for making 100% pure L-theanine now.
As for our L-theanine, we test every single batch in the lab using our polarimeter. We do this for all our products that we claim are enantiopure. You can take a look at Suntheanine's own spec sheet to get the specs..
Specific Rotation +7.7 ̊ - +8.5 ̊
Here is the scan of our L-theanine: https://imgur.com/a/OHXK2
Specific rotation of our L-theanine: 7.980 ̊. That's just the pic I already had from way back. I could get you the most recent one if you wanted to see. However, we always ensure that any product of ours that we are making a stereochemistry claim on is validated in the lab on the polarimeter. It's not hard to distinguish between the isomers if you have the proper equipment. It's just very few places have the proper equipment. We do, and we test every single batch of any product that is supposed to be in L or D form.