Is there actual evidence that lipoic acid denatures?

[smokinghawk]

It's been said, but never substantiated (that I could find). Is that a rumor, or reality, that ALA denatures when exposed to air?

 

[smokinghawk]

Okay, I've searched medical websites, goggle, and searchengines for every combination of terms I can think of:

lipoic acid
+
oxygen
oxidizes
air
denature
degenerate
decompose

and nothing suggests that ALA "denatures" when exposed to air.