| abstract |
The present invention is a compound of formula (I) useful as a pharmaceutical agent such as an antitumor agent. Wherein R 2 represents hydrogen or methyl, R 11 and R 18 are the same or different and represent hydroxy, substituted or unsubstituted lower alkoxy or substituted or unsubstituted lower alkanoyloxy, R 17 represents hydrogen, Benzenoid ansamycin derivative represented by hydroxy, substituted or unsubstituted lower alkoxy or substituted or unsubstituted lower alkanoyloxy) or a pharmacologically acceptable salt thereof as an active ingredient (Hsp90) family protein inhibitors and the like are provided. |