Compounds that may have anti-inflammatory activity have the general formula (I): Wherein R 1 , R 2 , R 3 are each independently H or a C 1-4 alkyl group or a C 2-4 acyl group; R 4 and R 5 are each independently H or a group of formula -SO 3 R 6 , wherein R 6 is H or a C 1-4 alkyl group or a C 2-4 acyl group; with the proviso that at least one of R 4 and R 5 is a group of formula -SO 3 R 6 , or a pharmaceutically acceptable salt thereof.