抄録
Secondary metabolic substances of Usuea diffracta were studied by means of high performance liquid chromatography as well as column chromatography, thin-layer chromatography and microcrystal tests. Natural thalli of Usuea diffracta contain diffractaic acid, barbatic acid and usnic acid as major secondary metabolic substances. In addition to them, baeomycesic acid, squamatic acid, atranorin and gyrophoric acid have been detected for the first time as minor chemical substances. Colorless long linear crystals in GE solution, which are a characteristic of U. diffracta subsp. Subdiffracta, were also detected in a chromatographic fraction of U. diffracta subsp. Diffracta, when ma-jor chemical substances were removed in large quantity.
