Patent ID: 8492370

Claim:
A compound of formula (I) or a pharmaceutically acceptable salt thereof: wherein: R 1 represents H, OH, or OMe; R 2 represents H or Me; R 3 represents H or CONH 2 ; R 4 and R 5 both represent H; R 6 represents H, F, OH, OMe, Br, Cl, CF 3 , CH 3 , SH, CH 2 CH 3 or NR 10a R 11a ; R 7 represents H, F, OH, OMe, Br, Cl, CF 3 , CH 3 , SH, CH 2 CH 3 or NR 10b R 11b ; R 8 represents H, F, Br, Cl, CF 3 , CH 3 , SH, CH 2 CH 3 or NR 10c R 11c ; R 9 represents H, F, OH, OMe, Br, Cl, CF 3 , CH 3 , SH, CH 2 CH 3 or NR 10d R 11d ; R 10a , R 11a , R 10b , R 11b , R 10c , R 11c , R 10d , R 11d independently represent H, CH 3 or CH 2 CH 3 ; provided however that: (i) when R 7 represents OH, R 8 represents H and R 9 represent H, then R 6 does not represent H, OH or OMe; (ii) when R 7 represents OMe, R 8 represent H and R 9 represents H, then R 6 does not represent OMe; (iii) when R 6 represents H, OH, or OMe, R 7 represents H and R 8 represents H, then R 9 does not represent OH, Cl or NH 2 ; (iv) when R 6 represents H, OH, or OMe, R 8 represents H and R 9 represents H, then R 7 does not represent NH 2 ; and (v) when R 6 represents H or OH, then R 7 , R 8 and R 9 do not all represent H.