There is provided a compound of Formula I ##STR00001## wherein each T is independently selected from H, hydrocarbyl, --F--R, and a bond with one of D, E, P or Q, or together with one of P and Q forms a ring; Z is a suitable atom the valency of which is m; D, E and F are each independently of each other an optional linker group, wherein when Z is nitrogen E is other than CH.sub.2 and C.dbd.O; P, Q and R are independently of each other a ring system; and at least Q comprises a sulphamate group.