Euglobal-IIIa, a novel acylphloroglucinol-sesquiterpene derivative from Eucalyptus robusta: absolute structure and cytotoxicity

Euglobal-IIIa (1), a novel acylphloroglucinol-sesquiterpene derivative, and a known analogue, have been isolated from leaves of Eucalyptus robusta. The structures was elucidated by extensive spectroscopic data and by comparison with data reported in literature, while the absolute configuration of 1 was determined by the X-ray diffraction analysis. Compound 1 exhibited comparable cytotoxicity with that of cisplatin against five human cancer cell lines HL-60, SMMC-7721, A-549, MCF-7, and SW480 with IC(50) values of 15.7, 15.5, 17.6, 14.3, and 21.8 µM, respectively. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at 10.1007/s13659-011-0021-9 and is accessible for authorized users.