A compound of formula (I) or a pharmaceutically acceptable salt thereof: ##STR1## in which X represents R.sub.1 OOC-- in which R.sub.1 is C.sub.1-4 alkyl, C.sub.2-4 alkenyl or C.sub.2-4 alkynyl; R.sub.2 O-- in which R.sub.2 is C.sub.1-2 alkyl, C.sub.1 -2 alkylcarbonyl or aminocarbonyl optionally substituted by one or two methyl groups; a group ##STR2## in which Y represents a 3-membered divalent residue completing a 5-membered aromatic ring and comprises one or two heteroatoms selected from oxygen, nitrogen and sulphur, any amino nitrogen optionally substituted by a C.sub.1-2 alkyl group, Y being optionally C-substituted by a methyl group; or a group ##STR3## in which A.sub.1 is oxygen or sulphur, one of A.sub.2 and A.sub.3 is CR.sub.3 and the other is nitrogen or CR.sub.4 where R.sub.3 and R.sub.4 are independently selected from hydrogen and methyl; and each of p and q independently represents an integer of 2 to 4.
化合物的
化学式(I)或其药学上可接受的盐:##STR1## 其中X代表R.sub.1 OOC--,其中R.sub.1是C.sub.1-4烷基,C.sub.2-4烯基或C.sub.2-4炔基; R.sub.2 O--,其中R.sub.2是C.sub.1-2烷基,C.sub.1-2烷基羰基或
氨基羰基,可选择地被一个或两个甲基基团取代的
氨基; 一个基团##STR2## 其中Y代表一个3元二价残基,完成一个5元芳香环,并包含来自氧,氮和
硫的一个或两个杂原子,任何
氨基氮可选择地被C.sub.1-2烷基基团取代,Y可选择地被甲基基团取代; 或一个基团##STR3## 其中A.sub.1是氧或
硫,A.sub.2和A.sub.3中的一个是CR.sub.3,另一个是氮或CR.sub.4,其中R.sub.3和R.sub.4独立地选择自氢和甲基; p和q各自独立地表示2到4的整数。