The internet- a wonderful medium to exchange information, and a wonderful medium for people who have no clue as to what they are talking about.
If for some bizarre reason you are under the impression that R-Lipoic Acid comes from potatoes- it does not. Like many urban legends, there was a seed from which this probably started:
Lipoic acid was found to be part of a potato growth medium before it was ever isolated, when it was discovered that is was the "X" (unknown) factor essential for metabolic function. It was never isolated or synthesized from potatoes, the first isolation in the 1950's was actually from liver, but that extraction was never done again, due the amount of liver that was necessary to extract a only tiny amount.
All lipoic acid is made synthetically in a laboratory and has nothing whatsoever to do with potatoes.