The present study describes the structure elucidation of the new β-lapachone type naphthoquinone isolated from the roots of Distictella elongata. Its structure, according to the molecular formula C16H16O6, was identified as 4,7-dihydroxy-10-methoxy-2,2-dimethyl-3,4-dihydro-2H-benzo[h]chromene-5,6-dione. The structure was assigned by spectrometric methods [HRESIMS, 1D NMR (¹H and 13C), and 2D NMR (g-DQF-COSY, g-HMQC and g-HMBC]. Root chloroform extract of D. elongata showed significant inhibition of the growth of SK-MEL (melanoma) and SK-OV-3 (ovary adenocarcinoma) cells with IC50 values of 40 µg mL-1 and 56 µg mL-1, respectively. However, the naphthoquinone was not responsible for the cytotoxic activity exhibited by the extract.
cerrado; naphthoquinone; Bignoniaceae; Distictella elongata
