Kabushiki Kaisha Yakult Honsha

Other

Hisao Hagiwara

Tadashi Miyasaka

Seigo Sawada

Masahiko Mutai

Kenichiro Nokata

Takahiro Ideguchi

Tadashi Yoshimoto

Kunio Kado

Daisuke Tsuru

Shuko Shincho

An exhaust heat exchanger with catalyst to be used in an exhaust system of an internal combustion engine is provided. A catalyst chamber is disposed within a water chamber which a cooling water flows through. An exhaust gas having passed through the catalyst chamber in contact with a catalyst makes an indirect heat exchange with the cooling water before it is discharged outside. The water chamber is formed surrounded by an inner trunk and an outer trunk, and the catalyst chamber is formed by a cylindrical body disposed coaxially with the inner and outer trunks and housing the catalyst. A spiral passage for the exhaust gas is formed between the inner trunk and the cylindrical body. A plurality of heat transmitting pipes are arranged within the water chamber surrounding the inner trunk circumferentially at regular intervals. The exhaust gas having passed through the catalyst flows within the spiral passage and the heat transmitting pipes in turn to make a heat exchange with the cooling water. The cylindrical body is surrounded by a heat shielding cylindrical body with a thin adiabatic gas layer lying between.

Exhaust heat exchanger with catalyst

An anti-amnestic agent which comprises as an active ingredient thereof at least one prolinal derivative of the general formula: ##STR1## wherein A is a protective groups for amino group in the field of amino acid chemistry and X is a residue of an amino acid, in a pharmacologically active amount together with an exipient. This agent is less toxic and can be safely administered to patients orally or intravenously for the remedy of memory disorder.

Anti-amnestic agent

New camptothecin derivatives possessing either or both of high anti-tumor activity and slight toxicity, represented by the general formula: ##STR1## wherein X is H, CH.sub.2 OH, COOH, an alkyl group, an aralkyl group or the grouping CH.sub.2 OR.sup.1 or COOR.sup.2 wherein R.sup.1 is an alkyl group or an acyl group and R.sup.2 is a lower alkyl group, Y is H, OH or the grouping OR.sup.3 wherein R.sup.3 is a lower alkyl group or an acyl group, and Z is H or an acyl group, with the proviso that when X is CH.sub.2 OH, an alkyl group or an aralkyl group, both Y and Z are H, that when X is the grouping CH.sub.2 OR.sup.1 or COOR.sup.2, Y is H, that when Y is OH, both X and Z are H, and that when Y is the grouping OR.sup.3, X is H, and water-soluble alkali metal salts thereof. These camptothecin derivatives are prepared by treating camptothecin with sulfuric acid and a persulfate or with sulfuric acid and a peroxide, if necessary, with an organic compound corresponding to the organic moiety of the substituent to be introduced directly into camptothecin, in an aqueous medium in the presence or absence of a transition metal ion, and optionally treating the resultant products, if necessary, after oxidation of the introduced substituent, with an alkylating agent or an acylating agent.

Camptothecin derivatives

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Tokyo, Japan

Hisao Hagiwara