The present invention relates to compounds of the formula I ##STR00001## wherein R.sup.3 is C.sub.1-6-alkyloxy, C.sub.1-6-acyloxy or aroyloxy; R.sup.6 is hydrogen or C.sub.1-6-alkyloxy; R.sup.7 is C.sub.1-6-alkyloxy, C.sub.1-6-acyloxy, aroyloxy or arylacyloxy; R.sup.8 is hydrogen or C.sub.1-6-alkyloxy; or R.sup.7 and R.sup.8 form together a group O-L-O with L being (CR.sup.1R.sup.2).sub.n, with R.sup.1 and R.sup.2 being independently from each other hydrogen or C.sub.1-5-alkyl and n being an integer from 1 to 3; R.sup.10 is hydrogen or N--C.sub.1-4-acyl, N--C.sub.1-5-alkyl-x-C.sub.x-alkyl with x being an integer from 1 to 5, for use as medicament for the treatment of a disorder connected to impaired glucose metabolism and impaired insulin action such as syndrome X and diabetes type 1 and 2, especially for the treatment of (non-autoimmune) diabetes type 2. The present invention is also directed to dietary compositions such as (fortified) food, beverages, (fortified) feed, food additives, beverage additives, feed additives, clinical nutrition, dietary supplements, functional food, functional feed and nutraceuticals and to pharmaceutical compositions containing such compounds, to methods of treating a disorder connected to impaired glucose metabolism and impaired insulin action in mammals including humans and to the compounds of the formula I themselves. Another object of the present invention is the use of such compounds for the manufacture of a composition for the treatment of a disorder connected to impaired glucose metabolism and impaired insulin action.