Patent ID: 7678791

Claim:
A compound of structural formula (I) as defined below: or their pharmaceutically acceptable salt thereof, wherein R 1 is a hydrogen or acetyl group, G is a structure of formula II, III, IV or V: wherein, in formula II, III, IV or V, Q is N— or CR 2 —, which is bonded to a linkage group “L”, which in turn is bonded to a structure and R 2 is a group selected from hydrogen, (C 1 -C 6 )alkyl, aryl, heteroaryl, or heterocycloalkyl group; L is a bond, or a linker group selected from one or a combination of two to five of the following groups: 1) (C 1 -C 6 )alkylene, 2) (C 3 -C 8 )cycloalkylene, 3) arylene, 4) heteroarylene, 5) heterocycloalkylene containing 1 to 3 heteroatoms, 6) —C(═O)—, 7) —C(═N—O—R 3 )—, 8) —C═N—, 9) —O—, 10) —S(O) n —, wherein n is number between 0 and 2, 11) —N(R 4 )—, wherein the carbon or nitrogen atoms of the linker group are unsubstituted or are independently substituted by 1 to 3 substituents selected from (C 1 -C 6 )alkyl, (C 1 -C 6 )alkyl, amino, (C 1 -C 6 )alkylamino, di(C 1 -C 6 )alkylamino, hydroxyl, (C 1 -C 6 )alkoxy or heterocycloalkyl group; R 3 and R 4 are independently a group selected from hydrogen, substituted or unsubstituted (C 1 -C 6 )alkyl, aryl, heteroaryl or heterocycloalkyl group; and structure is a structural formula VI, VII, VIII or IX: wherein Y is a bond which is bonded to linkage group “L”, defined as above; and Z is a carbon (—CR 7 R 8 —), carbonyl (—C(O)—), amide (—C(O)NH—), sulfonamide (—S(O 2 )N—), or a heteroatom selected from N, O, S, SO or SO 2 ; wherein R 5 , R 6 , R 7 , and R 8 are independently a group selected from hydrogen, (C 1 -C 6 )alkyl, aryl, heteroaryl, or heterocycloalkyl group; R 5 and R 6 , R 7 and R 8 can join together to form a five to seven-member ring system optionally containing one to three heteroatoms, and wherein if R 1 is an acetyl group, G is II, Q is N—, and L is —C(═O)—, then is not VIII in which R 5 and R 6 are hydrogen.