Natural product isolated from Nocardiopsis sp.; specifically induces apoptosis in transformed tumor cells. Isoln, properties and bioactivity: J. W. Kim et al., J. Antibiot. 50, 628 (1997). Structure: Y. Hayakawa et al., J. Am. Chem. Soc. 120, 3524 (1998). Partial synthesis: J. Schuppan et al., Tetrahedron Lett. 41, 621 (2000); K. C. Nicolaou et al., Chem. Commun. 2000, 307. Review of synthetic methods: P. T. Daniel et al., Angew. Chem. Int. Ed. 45, 872-893 (2006).