constitutional isomers of penta-O-allyl-β-D-fructofuranosyl-α-D-glucopyranoside; constitutional isomers of hexa-O-allyl-β-D-fructofuranosyl-α-D-glucopyranoside; constitutional isomers of hepta-O-allyl-β-D-fructofuransoyl-α-D-glucopyranoside