eg, hydroscopic reactions, reactions with PE/PP/PET (as it IS packaged in plastic), etc
ROWANSCI
AND MOST OF ALL, REACTIONS WITH ALL THE REACTIVE OXYGEN SPECIES AND REACTIVE NITROGEN AND REACTIVE SULFUR SPECIES [INCLUDING MG, INCLUDING THE ALDEHYDES, INCLUDING HO- AND H2O2]
All this makes a non-trivial difference in whether or not it sticks to certain proteins in your body/brain. It may be a roundable error, but if AGI/ASI is coming soon (it exponentially amplifies any difference), there’s always the chance that one of those differences will be amplified in your output SOMEDAY and that can matter.
Plus it makes chemistry funner (and more motivating to learn), BECAUSE CHEMISTRY IS MORE INTERESTING WHEN YOU TAKE A RAPAMYCIN-FIRST VIEW TOWARDS IT (JUST ASK MATT KAEBERLEIN!) in the near-future, it may be possible to create a guide to learning chemical reactions JUST from rapamycn (and reverse-synthesis/retrosynthesis will help us synthesize in case the FDA restricts import)
Also, mapping out all the possible oxidation/decay pathways is important for figuring out halflife in a wide variety of temperatures/pressures/humidities/environments (esp if people travel with it in space)
After all, rapamycin is a GIANT molecule where MANY possible sites can attach to