Kabushiki Kaisha Yakult Honsha

Daiichi Seiyaku Co., Ltd.

Daiichi Pharmaceutical Co., Ltd.

Hiroaki Tagawa

Akio Ejima

Hirofumi Terasawa

Satoru Ohsuki

Masamichi Sugimori

Minoru Furukawa

Takeshi Hayano

Masahiro Arimoto

A novel hexa-cyclic compound, a derivative of camptothecin, of the general formura: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound through Friedlaender reaction. It has an excellent antitumour activity and a high degree of safety, and can be applied as an antitumour medicine for curing tumors of various kinds.

Hexa-cyclic compound

A novel hexa-cyclic compound, a derivative of camptothecin, of the general formula: ##STR1## The compound is prepared from an aminoketone compound and a pyranoindolizine compound through Friedlaender reaction. It has an excellent antitumor activity and a high degree of safety, and can be applied as an antitumor medicine for curing tumors of various kinds.

Hexa-cyclic camptothecin derivatives

Novel cephalosporin derivatives and salts thereof are disclosed. These compounds exhibit excellent antimicrobial activity against a wide variety of Gram-negative and Gram-positive bacteria and also have other excellent characteristics as a medicine such as stability and low toxicity. These compounds can be administered in a form of subcutaneous, intravenous or intramuscular injections.

Cephalosporin derivatives and salts thereof

A pyranoindolizine derivative represented by the following general formula (I): ##STR1## wherein R means a hydrogen atom or hydroxyl group and Q denotes &gt;C.dbd.O or ##STR2## with a proviso that Q is other than &gt;C.dbd.O when R is a hydrogen atom. Its preparation process is also described.

Certain pyrano (3,4-f)-indolizine derivatives

Novel cephalosporin derivatives and physiologically acceptable salts thereof which are useful as antibacterial agents against gram-negative and gram-positive bacteria, and a process for preparing these compounds are disclosed.

Growing community of inventors

Tokyo, Japan

Hiroaki Tagawa