Modulation of the activity of the insulin receptor, enhancement of glucose uptake by cells, and other effects significant in the control and management of diabetes are accomplished using compounds of the formula ##STR00001## wherein each A is independently a proton-accepting substituent; each R is independently a noninterfering substituent; n is 0, 1, or 2; and each linker is independently an isostere of --NHCONH-- or of --N.dbd.N-- or of --NHCO--.Compounds in the genus of Formula (1) can also be used for structure activity studies to identify features responsible for the relevant activities.