This compounds correspond to the formula (I), where: R1represents and aryl or heteroaryl group optionally substituted by one or moresubstituents selected from the group consisting of halogen atoms, straight orbranched optionally substituted lower alkyl, cycloalkyl, hydroxy, straight orbranched, optionally substituted lower alkoxy, cyano, or -CO2R', wherein R'represents a hydrogen atom or a straight or branched, optionally substitutedlower alkyl group； R2 represents a group selected from: a) a straight orbranched lower alkyl group substituted by one or more carboxylic groups(-COOH) and optionally substituted by one or more halogen atoms； b) acycloalkyl group substituted by one or more carboxylic groups (-COOH) andoptionally substituted by one or more halogen atoms； c) a straight or branchedalkylcycloalkyl or cycloalkylalkyl group substituted by one or more carboxylicgroups (-COOH) and optionally substituted by one or more halogen atoms.Formula (I).
