Preferably, the compound has the Formula II; wherein X is the sulphamate group; A is the first group; R1 and/or R2 is a substituent other than H; wherein R1 and R2 may be the same or different but not both being H; and wherein optionally group A is attached to at least one other carbon atom in ring B. Preferably, group A is additionally attached to the carbon atom at position 1 of the ring B. Pref