title: GEX1 compounds, novel antitumor antibiotics related to herboxidiene, produced by Streptomyces sp. I. Taxonomy, production, isolation, physicochemical properties and biological activities.
abstract: Six structurally related antitumor antibiotics named GEX1 compounds were isolated from a culture broth of Streptomyces sp. GEX1A was identified as a known herbicide, herboxidiene, structurally interested by the tetrahydropyran moiety and the side chain including a conjugated diene. GEX1Q1 to approximately Q5 were determined as novel compounds related to herboxidiene. All GEX1 compounds showed cytotoxicity with IC50 values of 0.0037 to approximately 0.99 microM against human tumor cell lines in vitro, but were not active against both gram-positive and -negative bacteria. Though GEX1A/herboxidiene exhibited antitumor activity in murine tumor-planted mouse models, both GEX1Q3 and GEX1Q5 did not.
authors.affiliation: Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., 3-6-6 Asahimachi, Machida-shi, Tokyo 194-8533, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sakai
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Yoshida
authors.forename: Keiko
authors.initials: K
authors.lastname: Ochiai
authors.forename: Youichi
authors.initials: Y
authors.lastname: Uosaki
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Saitoh
authors.forename: Futoshi
authors.initials: F
authors.lastname: Tanaka
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Akiyama
authors.forename: Shiro
authors.initials: S
authors.lastname: Akinaga
authors.forename: Tamio
authors.initials: T
authors.lastname: Mizukami
mesh_terms: D000818:Animals; D000903:Antibiotics, Antineoplastic / Q000302:isolation & purification* / Q000627:therapeutic use; D005285:Fermentation; D006801:Humans; D051379:Mice; D008826:Microbial Sensitivity Tests; D013302:Streptomyces; D013329:Structure-Activity Relationship; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000903:Antibiotics, Antineoplastic