A compound of the following formula or a tautomer, enantiomer, stereoisomer thereof, or a solvate, or a pharmaceutically acceptable salt thereof for use in treating and/or preventing obesity, or obesity-induced diabetes; or inhibiting high blood pressure or hypoxia induced cardiomyopathy thereby increasing heart function; wherein A is -C(=O)-, -C(=S)-, -NH-, -O- or -S-; when A is -NH-, -O- or -S-, X is -C(=O)- or -C(=S)-; or when A is -C(=O)- or -C(=S)-, X is - NH-, -O- or -S-; Y is absent or -C-, -N -, -O- or -S-, R is hydrogen or C 1-6 alkyl; when Y is absent, Z is -NH-, -O- or -S-; or when Y is -C-, -N -, -O- or -S-, Z is -C- or -C(=O)-; R 1 and R 2 are taken together with their intervening atoms to form an oxolane (tetrahydrofuran) ring, a dioxolane ring, a tetrahydrothiophene ring, a thiophene ring, an oxazole ring, a pyrrolidine ring, a pyrroline ring or a pyrazolidine ring, wherein the ring is unsubstituted or substituted by one or more substituents selected from C 1-6 alkyl, hydroxy, amino, nitro, halogen, C 1-6 haloalkyl, C 1-6 alkoxy or aryl; R 3 and R 4 are taken together with their intervening atoms to form: (i) a fused cyclopentane ring, a fused cyclohexane ring or a fused cycloheptane ring; the fused ring is unsubstituted or substituted by NH 2, NO 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl; or (ii) a fused benzene ring, a fused pyrrole ring, a fused furan ring, a fused thiophene ring, a fused pyridine ring, a fused benzofuran ring, a fused isobenzofuran ring, a fused indole ring, a fused isoindole ring or a fused benzothiophene ring; the ring is unsubstituted or substituted by NH 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl, aryl or heteroaryl; and R 5 is H, halogen, -OH, -NO 2, C 1-6 alkyl, aryl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl. A is -C(=O)-, -C(=S)-, -NH-, -O- or -S-; when A is -NH-, -O- or -S-, X is -C(=O)- or -C(=S)-; or when A is -C(=O)- or -C(=S)-, X is - NH-, -O- or -S-; Y is absent or -C-, -N -, -O- or -S-, R is hydrogen or C 1-6 alkyl; when Y is absent, Z is -NH-, -O- or -S-; or when Y is -C-, -N -, -O- or -S-, Z is -C- or -C(=O)-; R 1 and R 2 are taken together with their intervening atoms to form an oxolane (tetrahydrofuran) ring, a dioxolane ring, a tetrahydrothiophene ring, a thiophene ring, an oxazole ring, a pyrrolidine ring, a pyrroline ring or a pyrazolidine ring, wherein the ring is unsubstituted or substituted by one or more substituents selected from C 1-6 alkyl, hydroxy, amino, nitro, halogen, C 1-6 haloalkyl, C 1-6 alkoxy or aryl; R 3 and R 4 are taken together with their intervening atoms to form: (i) a fused cyclopentane ring, a fused cyclohexane ring or a fused cycloheptane ring; the fused ring is unsubstituted or substituted by NH 2, NO 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl; or (ii) a fused benzene ring, a fused pyrrole ring, a fused furan ring, a fused thiophene ring, a fused pyridine ring, a fused benzofuran ring, a fused isobenzofuran ring, a fused indole ring, a fused isoindole ring or a fused benzothiophene ring; the ring is unsubstituted or substituted by NH 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl, aryl or heteroaryl; and (i) a fused cyclopentane ring, a fused cyclohexane ring or a fused cycloheptane ring; the fused ring is unsubstituted or substituted by NH 2, NO 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl; or (ii) a fused benzene ring, a fused pyrrole ring, a fused furan ring, a fused thiophene ring, a fused pyridine ring, a fused benzofuran ring, a fused isobenzofuran ring, a fused indole ring, a fused isoindole ring or a fused benzothiophene ring; the ring is unsubstituted or substituted by NH 2, halogen, hydroxy, C 1-6 alkyl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl, aryl or heteroaryl; and R 5 is H, halogen, -OH, -NO 2, C 1-6 alkyl, aryl, C 1-6 haloalkyl, C 1-6 hydroxyalkyl, C 1-6 alkoxy, C 1-6 alkoxyC 1-6 alkyl, C 2-6 alkenyl or C 2-6 alkynyl.