A compound represented by the general formula I: I wherein R1 represents hydrogen, etc. R.sup.2 represents NHSO.sub.2R.sup.3, etc., provided that R.sup.3 represents C.sub.1-6 alkyl, etc. R.sup.5 represents hydrogen, etc. R.sup.6 and R.sup.7 may be the same or different and each independently represents hydrogen, etc. X represents oxygen, etc. Y represents oxygen, etc. Z.sup.1 to Z.sup.6 each represents carbon, etc. n is an integer of 0 to 6 and ast1 indicates that the carbon atom is asymmetric, and *2, in the case where R.sup.5 is not hydrogen, indicates that the carbon atom is asymmetric or a salt of the compound.