Abstract: A propionic acid derivative having the following formula (II) and its salt: 1

Abstract: Methods for decreasing visceral fat, inhibiting accumulation of visceral fat and improving the distribution of visceral fat all include the administration of a thiazolidine derivative represented by formula (IV), ##STR1## wherein A.sup.3 represents an optionally substituted phenyl or oxazolyl group.

Abstract: The invention has an object to provide a novel quinoline derivative of the following formula (I) which has no benzyl group in the 5-position and shows hypoglycemic effect, particularly, by oral administration: ##STR1## in which R.sup.1 is hydrogen; an alkyl group of 1-6 carbon atoms, an amino group of the formula of --NR.sup.4 R.sup.5 in which each of R.sup.4 and R.sup.5 independently is hydrogen, alkyl of 1-6 carbon atoms, phenyl, pyridyl, pyrimidyl or benzoyl; or a phenyl group, a naphthyl group, a cycloalkyl group having 3 to 8 carbon atoms, or a 5 to 8 membered heterocyclic group comprising, as ring-constituting atoms, 1 to 2 nitrogens, oxygens or sulfurs and remaining carbon atoms, each of which may have, as a substituent, alkyl of 1-6 carbon atoms, alkoxy of 1-6 carbon atoms, halogen, hydroxyl, halogenoalkyl of 1-6 carbon atoms, halogenoalkoxy of 1-6 carbon atoms, nitro, amino, phenyl, thienyl, furyl, thiazolyl or pyridyl; Z is O, S, C.dbd.O, or CH.sub.