RKS-1778, a new mammalian cell-cycle inhibitor and a key intermediate of the [11]cytochalasin group.
In the course of screening for the mammalian cell-cycle inhibitors, we have isolated a new [11]cytochalasin, RKS-1778 (1), and epoxycytochalasin H (2) from a fungus, Phoma sp. SNF-1778. The structure of 1 was determined to be 21-acetoxy-18-hydroxy-10-phenyl-5,6,16,18- tetramethyl[11]cytochalasa-6,13,19-trien-1-one, one the basis of spectroscopic methods, including 1H- and 13C-2D NMR techniques, RKS-1778 (1) may be a precursor of 2 and the key direct product of a proposed biosynthetic intramolecular Diels-Alder reaction. Both 1 and 2 completely arrested the cell-cycle progression of tsFT210 cells in the M phase at concentrations of 2.1 and 2.0 microM, respectively.
Kakeya
H
H
Antibiotics Laboratory, Institute of Physical and Chemical Research (RIKEN), Saitama, Japan.
Morishita
M
M
Onozawa
C
C
Usami
R
R
Horikoshi
K
K
Kimura
K
K
Yoshihama
M
M
Osada
H
H
D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D002453:Cell Cycle / Q000187:drug effects*; D003572:Cytochalasins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology*; D051379:Mice; D003904:Mitosporic Fungi / Q000737:chemistry; D015394:Molecular Structure; D013057:Spectrum Analysis; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D003572:Cytochalasins; C107709:RKS 1778