The invention relates to new compounds, being 3-phenylpropionic acid derivatives of formula I wherein W represents COOH group or its bioisosters, or —COO—C1-C4-alkyl group; Y represents NH, N—C1-C10-alkyl, O, or S; Z represents NH, N—C1-C10-alkyl, N-aryl, N-heteroaryl, S, or O; X represents O, S, NH, N—C1-C10-alkyl, N-aryl, NSO2—C1-C10-alkyl, N—SO2-aryl, or N—SO2-heteroaryl; R, to R8 each independently represent hydrogen atom or a substituent defined in the description; A is as defined in the description; n represents an integer from 0 to 4, inclusive; and pharmaceutically acceptable salts thereof. The compounds are the ligands of PPAR-gamma receptor and are useful as medicaments.