Novel compounds according to formula I
##STR1##
n is 0, 1, 2 or 3;
X represents hydroxamic acid (CONHOH), carboxylic acid, phosphonic acid,
acetylthiomethyl group or a mercaptomethyl group; R2, R10 and R11
independently represent hydrogen or (C.sub.1-8)alkyl, (C.sub.2-6)alkenyl,
(C.sub.3-8)cycloalkyl, aryl(C.sub.0-6)alkyl or heteroaryl(C.sub.0-6)alkyl,
all of which may optionally be substituted; R3 and R4 independently
represent hydrogen, hydroxy or alkoxy; provided that if A, A', Z and R5
are all bonds, and s and t are both 0 (zero), then R6 is different from
hydrogen, and that at least one of R3, R4, R10 and R11 is different from
hydrogen;
or a salt, hydrate or solvate thereof; pharmaceutical compositions
comprising said compound; therapeutical methods comprising administering
said compounds; and
the use of said compounds in the manufacture of medicaments.
