with the proviso that the following are excluded: a compound in which R3 is a benzyl group or an allyl group and A is an oxygen atom, a compound in which R3 is a methyl group, R4 and R9 are a hydrogen atom, Z is a group represented by the formula ???C(???O)???, R7 and R8 are a hydroxy group, R10 is a group represented by formula (V), and A is a group represented by the formula ???NMe-, a compound