Patent ID: 8748600

Claim:
A compound of formula (I) wherein: R1 is hydrogen or a substituent group; R2 is amino or a substituent group; N* is amino when R 1 is hydrogen or ═NH when R 1 is a substituent group; R3 and R4 are both carbocyclic, heterocyclic or alkyl groups and may be same or different; and R5 is hydrogen, alkyl or a cyclic aryl group, with the proviso that: when R3 and R4 are both alkyl they are linked to form a cycloalkyl group, and R5 is an aromatic or cyclic aliphatic group; and when R3 and R4 are both carbocyclic or heterocyclic groups, R5 is hydrogen, an alkyl group or an aromatic group; or a salt thereof.