Glycine derivatives and medicinal compositions thereof

A compound of formula (I):

• wherein:
• R1 is —H, or linear or branched (C1-C10)alkyl, (C2-C6)alkenyl, aryl, (C3-C8)cycloalkyl, (C5-C10)heterocycloalkyl, aryl(C1-C6)alkyl, or heteroaryl, each of which may be optionally substituted by one or more substituents selected from the group consisting of a halogen atom, —OH, oxo (═O), —SH, —NO2, —N(R5)(R8), —CN, —CON(R5)2, —NHCO(R5), —COR5, —CO2R5, (C1-C10)alkylsulfanyl, (C1-C10)alkylsulfinyl, (C1-C10)alkylsulfonyl, (C1-C10)alkyl, (C1-C10)alkylcarboxyl, (C1-C10)alkoxy, aryl, aryloxy, and heteroaryl;
• G is —OC(O)—, —SO2—, or —C(O)—;
• R2 is —H or (C1-C10)alkyl or aryl(C1-C6)alkyl, each of which may be optionally substituted by one or more substituents selected from the group consisting of a halogen atom, —OH, oxo (═O), —SH, —NO2, —N(R5)2, —CN, —CON(R5)2, —NHCO(R5), —CO(R5), —CO2(R5), (C1-C10)alkylsulfanyl, (C1-C10)alkylsulfinyl, (C1-C10)alkylsulfonyl, (C1-C10)alkyl, (C1-C10)alkylcarboxyl, (C1-C10)alkoxy, aryl, aryloxy, and heteroaryl;
• R3 is —H or (C1-C10)alkyl, aryl, (C3-C8)cycloalkyl, heteroaryl, aryl(C1-C6)alkyl, or heteroaryl(C1-C6)alkyl, each of which may be optionally substituted by one or more substituents selected from the group consisting of a halogen atom, —OH, oxo (═O), —SH, —NO2, —N(R5)2, —CN, —CON(R5)2, —NHCO(R5), —CO(R5), —CO2(R5), (C1-C10)alkylsulfanyl, (C1-C10)alkylsulfinyl, (C1-C10)alkylsulfonyl, (C1-C10)alkyl, (C1-C10)alkylcarboxyl, (C1-C10)alkoxy, aryl, aryloxy, aryl(C1-C10)alkylenoxy, and heteroaryl;
• R6 is a group of formula (i):
• wherein
• A− is a physiologically acceptable anion;
• R4 is a group of formula (Y):
• —(CH2)p-P—(CH2)q-W (Y)
• wherein
• p is 0 or an integer from 1 to 4;
• q is 0 or an integer from 1 to 4;
• P is absent or is —O—, —S—, —SO—, —SO2—, —C(O)—, —N(R5)-, —CH═CH—, —N(R5)(SO2)—, —N(R5)(COO)—, —N(R5)(C(O))—, —S(O2)N(R5)-, —CO(O)N(R5)-, or —C(O)N(R5)-;
• W is —H, or linear or branched (C1-C10)alkyl, (C2-C6)alkenyl, aryl, (C3-C8)cycloalkyl, (C5-C10)heterocycloalkyl, aryl(C1-C6)alkyl, or heteroaryl, each of which may be optionally substituted by one or more substituents selected from the group consisting of a halogen atom, —OH, oxo (═O), —SH, —NO2, —N(R5)2, —CN, —CON(R5)2, —NH(COR5), —CO(R5), —CO2(R5), (C1-C10)alkylsulfanyl, (C1-C10)alkylsulfinyl, (C1-C10)alkylsulfonyl, (C1-C10)alkyl, (C1-C10)alkylcarboxyl, (C1-C10)alkoxy, aryl, aryloxy, and heteroaryl;
• R5 and R8 are each independently —H, or (C1-C10)alkyl, (C1-C10)alkoxy, (C2-C6)alkynyl, (C2-C6)alkenyl, (C3-C7)cycloalkyl, (C3-C7)cycloalkyl-(C1-C10)alkyl, heteroaryl, (C1-C10)alkyl-heteroaryl, or aryl, each of which may be optionally substituted by one or more substituents selected from the group consisting of a halogen atom, —OH, oxo (═O), —SH, —NO2, —CN, —CONH2, (C1-C10)alkylsulfanyl, (C1-C10)alkylsulfinyl, (C1-C10)alkylsulfonyl, (C1-C10)alkyl, (C1-C10)alkylcarboxyl, (C1-C10)alkoxy, aryl, aryloxy, and heteroaryl;
• or a pharmaceutically acceptable salt thereof.