A compound according to any one of claims 2 to 4, a salt of the compound or a hydrate of the foregoing, wherein E is a group represented by the formula ???NR2??? (wherein R2 has the same definition as R2 in claim 2), and Y is an optionally substituted phenyl group, an optionally substituted pyridyl group or a group represented by the formula: (wherein W11 and W12 are each independently an optional