Gas chromatography was performed with a Delsi IGC 120 FL Model, the column used was 3% SP 2100 on 120-140 mesh, Chromosorb G, 1.50 m. Liquid chromatography was performed on silica gel 60 (Merck, 0.063-0.200 mm) on a 15 X 150 mm column. PE and TBAB (Fluka) D, L-threitol (Aldrich), and a-methyl glucoside (Janssen) were dried before use (60" C under reduced pressure).