Abstract: A semiconductor device in which the insulation characteristics of an insulating film of multilayer structure including a lower-layer insulating film and a high-dielectric-constant film formed on the lower-layer insulating film are ensured, and a method for fabricating such a semiconductor device. A silicon oxide film or a silicon oxynitride film is formed on a semiconductor substrate as a lower-layer insulating film and part of the lower-layer insulating film is removed. Then a high-dielectric-constant film the dielectric constant of which is higher than that of the lower-layer insulating film is formed on the exposed semiconductor substrate and the lower-layer insulating film. If the lower-layer insulating film is a silicon oxide film, then a metallic compound not including chlorine is used for forming this high-dielectric-constant film. If the lower-layer insulating film is a silicon oxynitride film, then a metallic chloride can be used for forming this high-dielectric-constant film.

Abstract: Benastatins A and B which are novel and physiologically active substances having the formula ##STR1## wherein R represents --CH.sub.2 --CH.sub.2 -- or --CH.dbd.CH--, exhibit a potent immunomodifier activity, a glutathione transferase inhibition activity and an anti-microorganism activity and are therefore extremely useful for various drugs.