Kabushiki Kaisha Yakult Honsha

Sony Group Corporation

Atsuhiro Abe

Fujio Kobayashi

Seigo Sawada

Hideaki Shimizu

Hiroshi Nagata

Takashi Yaegashi

Takanori Ogawa

Hiroshi Kodaira

It is intended to provide a novel compound that has an excellent &#x3b3;-secretase inhibitory effect and specifically inhibits A&#x3b2; production. The present invention provides a compound of the following formula (1) or a pharmaceutically acceptable salt thereof: wherein Rrepresents a linear or branched alkyl group having 1 to 4 carbon atoms or a phenyl group; Rrepresents a linear or branched alkyl group having 1 to 4 carbon atoms which may be substituted by one or more phenyl or halogenophenyl groups; Rrepresents a linear or branched alkyl group having 1 to 4 carbon atoms which may be substituted by one or more hydroxyl groups; Rrepresents a linear or branched alkyl group having 1 to 4 carbon atoms; and the symbol '*' represents a chiral center. 

&#x3b3;-secretase inhibitor

A method for preparing a novel crystalline polymorphic irinotecan hydrochloride which is excellent in the solubility in water and reduced in the content of impurities is provided. A method for preparing c-type crystals of irinotecan hydrochloride having diffraction peaks (2&#x3b8;) at 9.15&#xb0;, 10.00&#xb0;, 11.80&#xb0;, 12.20&#xb0;, 13.00&#xb0; and 13.40&#xb0; in the powder X-ray diffractometry characterized by mixing irinotecan with one or more solvents selected from the group consisting of acetone, acetonitrile and tetrahydrofuran, adding hydrochloric acid, and collecting the formed crystals.

Method for preparing polymorphism of irinotecan hydrochloride

The present invention relates to taxane derivatives each represented by the following formula (1):

Taxane derivatives

Taxane derivatives and drugs containing the same

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Minato-ku, Japan

Atsuhiro Abe