Abstract: Presented is a novel quinolonecarboxylic acid derivative of the formula I and its pharmaceutically acceptable salt: ##STR1## wherein R.sub.1 is hydrogen, halogen or lower alkoxy, R.sub.2 is hydrogen, lower alkyl, lower alkoxy, --NH.sub.2, --NHCOCH.sub.3 or halogen,R.sub.3 is lower alkyl, and z is a group represented by the formula II or III: ##STR2## wherein R.sub.4 and R.sub.5 are identical or different and are hydrogen or lower alkyl. A method of preparation of these compound and a method of treatment of diseases caused by bacterial infection are also presented.

Abstract: This invention provides a novel steroid derivative having the structure of an ester between the carboxyl group of a quinolonecarboxylic acid and the alcoholic hydroxyl group in 21-position of asteroid compound, which has the following formula (I) (wherein R is a hydrogen atom, a methyl group or a hydroxyl group) or a pharmacologically acceptable salt thereof. ##STR1## The compound of this invention has high antibacterial activity and antiinflammatory activity.

Abstract: A hypotensive agent and antiglaucoma agent which comprise a compound represented by the following formula: ##STR1## (wherein R.sub.1 is hydrogen, or a lower alkyl or lower alkoxy group; R.sub.2 is an isopropylamino, tert-butylamino, 2-(2-methoxyphenyl)ethyl-1-amino, 4-(2-methoxyphenyl)!-1-piperazinyl or 4-piperonyl-1-piperazinyl group, provided however that in the case of R.sub.1 being hydrogen, R.sub.2 is neither isopropylamino nor tert-butylamino group) or its pharmacologically acceptable salt.

Abstract: A method of lowering lipids is disclosed wherein a patient is administered a lipid metabolism improving composition characterized by comprising a compound of the following formula: ##STR1## wherein R.sub.1 represents a hydrogen atom or a lower alkyl group; R.sub.2 and R.sub.3 are the same or different and each represents a hydroxyl group, a lower alkoxy group or an amino group, or a pharmacologically acceptable salt thereof as an active ingredient.Since the compound of the present invention lowers blood triglyceride, cholesterol and .beta.-lipoprotein levels, it is of value for ameliorating hyperlipidemia in arteriosclerotic diseases, e.g. myocardinal infarction, angina pectoris, cerebral infarction, cerebral arteriosclerosis, etc., nephrosis, hypertension, diabetes, obesity and other diseases, and prevention of various circulatory diseases.