Taxezopidines J, K, and L, new taxoids from Taxus cuspidata inhibiting Ca2+-induced depolymerization of microtubules

Three new taxoids, taxezopidines J (1), K (2), and L (3), have been isolate d from seeds of the Japanese yew Taxus cuspidata Sieb. et Zucc. and the str uctures were elucidated on the basis of spectroscopic data and chemical mea ns. Taxezopidines K (2) and L (3) markedly inhibited Ca2+-induced depolymer ization of microtubules, while taxuspine D (4), a known taxoid from the yew , induced unusual shape change of mitotic spindles like taxol. (C) 1999 Els evier Science Ltd. Ail rights reserved.