Classes of compounds that interact with integrins

A method of inhibiting or effecting the activity of an integral receptor which comprises contacting an integrin with a compound of formula I, or a pharmaceutically acceptable salt thereof; General Formula I Wherein the ring may be of any configuration; Z is sulphur, oxygen, CH2, NH, NRA or hydrogen, in the case where Z is hydrogen then R1 is not present, RA is selected from the set defined for R1 to R5, X is oxygen or NRA providing that at least one X of General Formula I is NRA, X may also combine independently with one of R1 to R5 to form an azide, R 1 to R 5 are independently selected from the group comprising H, -(CO)R6 or an alkyl, acyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl substituent of 1 to 20 atoms, which is optionally substituted, and can be branched or linear wherein substituents may optionally be further substituted, wherein R6 is selected from the group comprising an alkyl, acyl, alkenyl, alkynyl, heteroalkyl, aryl, heteroaryl, arylalkyl or heteroarylalkyl