Odontadenia lutea (Vell.) Markgr. (APOCYNACEAE): fitoquímica, citotoxicidade e ação inseticida das folhas

Abstract

Bioactivity research on natural products from plants found in the Cerrado can contribute significantly to the country's public health. This work aimed to isolate and identify the bioactive compounds of the leaves of Odontadenia lutea (Vell.) Markgr., to evaluate the in vitro cytotoxic activity of the extract, fractions and isolated compounds in HL-60, PC-3 and HCT-116 tumor cell lines and to evaluate the in vitro insecticidal activity of the extract and fractions on worker ants Atta sexdens rubropilosa. The chemical constituents were isolated by chromatographic techniques and the structural elucidation by IR, 1D and 2D NMR and ESI-MS techniques. The cytotoxic potential on tumor cell lines was evaluated by the MTT method. The insecticidal activity was verified by the percentage of mortality and the median survival of the ants after the daily intake of the test compounds for 25 days. The hexane fraction (OLFEH) provided the T-1 mixture, in which α-amyrin, β-amyrin and lupeol were identified. Rutin was isolated from the methanolic and ethyl acetate fractions. The methanolic fraction still provided 3-O-(9,12,15-octadecatrienoyl)-glyceryl-β-D-galactopyranoside and linolenic and palmitic acids. The compounds tested were non-toxic against HCT-116 and HL-60. The crude ethanolic extract (OLFE), dichloromethane (OLFED), ethyl acetate (OLFEA) and methanolic (OLFEM) fractions at 50 μg.mL-1 and rutin at 25 μg.mL-1 exhibited low toxicity on PC-3, while OLFEH at 50 μg.mL-1 was moderately toxic, exhibited a percentage of cell growth inhibition of 52.08%. In the evaluation of the insecticidal activity, there was only significant mortality at the end of OLFEH treatments, the others did not show 100% mortality at any of the concentrations tested. OLFEH at 2 mg.mL-1 decreased the median survival of the ants from sixteen to six days, there was 98% mortality on day 14 and 100% at the end of the experiment. The substances rutin, β-amyrin, 3-O-(9,12,15-octadecatrienoyl)-glyceryl-β-D-galactopyranoside, linolenic acid and palmitic acid are reported for the first time for the genus Odontadenia. It is suggested that T-1 contributes to the moderate cytotoxic activity of OLFEH over PC-3. It is suggested that T-1 also contributes to the insecticidal activity of OLFEH in A. sexdens rubropilosa. The hexane fraction of O. lutea leaves may be a potential source for the isolation of substances with insecticidal activity in A. sexdens rubropilosa.