Three samples of b-carboxyethylgermanium sesquioxide (Ge-132) have been prepared with different methods. Their IR, Raman, XPS, TG-DTA and fast-atom-bombardment mass spectra are quite different and indicate that they have different d.p. and mol. structures. In the aqueous solution, all of them interact strongly with fructose, but not with polypeptides such as GSH and GSSG. This fact may be important in understanding the bioactivity of Ge-132.

Key words: BIOLOGICAL ACTIVITY, INFRARED SPECTROPHOTOMETRY, PROTON MAGNETIC RESONANCE SPECTROMETRY, GLUTATHIONE, PHOTOELECTRON SPECTROSCOPY, CARBOXY GROUP, SUBSTRATE, GERMANIUM OXIDE, FRUCTOSE, RAMAN SPECTROMETRY