Freitas, Giovana C.Batista, Joao M. [UNESP]Franchi, Gilberto C.Nowill, Alexandre E.Yamaguchi, Lydia F.Vilcachagua, Janaina D.Favaro, Denize C.Furlan, Maysa [UNESP]Guimaraes, Elsie F.Jeffrey, Christopher S.Kato, Massuo J.2014-12-032014-12-032014-01-01Phytochemistry. Oxford: Pergamon-elsevier Science Ltd, v. 97, p. 81-87, 2014.0031-9422http://hdl.handle.net/11449/111458The EtOAc extract from the leaves of Piper carniconnectivum C. DC. was subjected to chromatographic separation to afford two non-aromatic B-ring flavanone compounds: 5-hydroxy-2-(1'-hydroxy-4'-oxo-cyclohex-2'-en-1'-yl)-6,7-dimethoxy-2,3-dihydro-4H-chromen-4-one (1) and 5-hydroxy-2-(1',2'-dihydroxy-4'-oxo-cyclohexyl)-6,7-dimethoxy-2,3-dihydro-4H-chromen-4-one (2). The absolute configuration of (+)-1 was unambiguously determined as 2S,1'R by electronic circular dichroism (ECD) spectroscopy and comparison to simulated spectra that were calculated using time-dependent density functional theory (TDDFT). This methodology allowed the assignment of the absolute configuration of (+)-2 also as 2S,1'R, except for the stereogenic center at C-2', which was assigned as R because of the evidence drawn from high resolution NMR experiments. The cytotoxic activity of both compounds and 3 (hydrogenated B-ring derivative of 1) was evaluated on twelve human leukemia cell lines, and the IC50 values (<10 mu M) indicated the activity of 1 against seven cell lines. (C) 2013 Elsevier Ltd. All rights reserved.81-87engPiper carniconnectivumPiperaceaeNon-aromatic B-ring flavanoneCytotoxicArtigo10.1016/j.phytochem.2013.10.012WOS:000330144600010Acesso restrito1308042794786872