7,8-Dihydroxyflavone Reduces Sleep During Dark Phase and Suppresses Orexin A but not Orexin B in Mice [2015]

I've had it for so long, and spent thousands now on testing. Our supply matches THT and TLR's samples. However, none of them match Sigma Aldrich's reference material.

Take a look at the spectrum. The red is ours and the green is Sigma Aldrich's material run on the same machine.

I even sent it to Colmeric, and he ran an HPLC and NMR. The HPLC retention times matched, but it was only 92.2%. Then the NMR did not have the correct amount of protons. So I have been racking my brain over it. I think the issue is that the sample is not 7,8-DHF Hydrate, like we were told, and like Sigma Aldrich carries. I think it is non-anhydrous 7,8-DHF. That would explain why the retention times on HPLC match, but it only comes up as 92.2%, but the FTIR and NMR do not match.

7,8-DHF Hydrate has a molar mass of 254.24 g/mol. Water has a molar mass of 18.01 g/mol. 18.01/254.24 equals 7.08%. So if we add 7.08% to the 92.2% HPLC we got, that leaves us with 99.28%. Since the FTIR and NMR would be seeing the lack of water as a change in structure, they would differ a lot. However, the HPLC would see the retention peak from the 7,8-DHF, and treat the water as an impurity. So that is what I am leaning toward at the moment.

I will no okay it for sale until I am 100% sure it is correct and pure, though. So we are working on doing some more testing to get final confirmation.