Patent ID: 8729134

Claim:
A compound of formula (IA): wherein R 1 and R 4 are OR 7 , R 2 is H and R 3 is OR 7 ; R 5 is OH or OR 7 and R 6 is H, OH or OR 7 , with the proviso that when R 5 is OH, R 6 is not OH: R 7 is alkyl, aryl or arylalkyl; or pharmaceutically acceptable salt(s) thereof, or a compound of formula (IB): wherein R 1 and R 4 are OR 7 , R 2 is OR 7 and R 3 is H; R 5 and R 6 are independently H, OH or OR 7 , with the proviso that when R 5 is OH, R 6 is not OH: R 7 is aryl or arylalkyl; or pharmaceutically acceptable salt(s) thereof.