It might be a bit of a stretch, but if "アセト" is acetoacetic, I don't see why "シアト" couldn't be cyanoacetic.
Onee-sama...haaAcetum
a dilute solution of acetic acid that is used as a solvent (e.g. for a drug)Shiato
I presume it's a sort of chemical, but can't find the English word for it.