A coumarin with an unusual structure from Cuphea ignea, its cytotoxicity and antioxidant activities.

Phenolic metabolite profiling using two dimensional paper chromatographic analysis (2 DPC) was used for assaying the complex mixture of phenolics of an aqueous ethanol aerial part extract of Cuphea ignea (Lytheraceae). A coumarin with a rare structure, namely, 7-hydroxy 3-methoxy coumarin 5-O-ß-glucopyranoside was isolated from the investigated extract. The structure was elucidated by conventional methods and spectral analysis, including one and two dimensional NMR (1D and 2D NMR), as well as by interpretation of the spectra obtained by high resolution electrospray ionization mass technique (HRESIMS). The rare coumarin significantly inhibited reactive oxygen species production with an ED50 value of 6.31±1.64 µg/ml and 5.78±0.66 µg/ml as determined by the the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the oxygen radical absorption capacity (ORAC) assay respectively. The isolated coumarin presented a cytotoxic activity assessed by using the neutral red assay (NRU) against lung cancer cell line (H23) with IC50 of 40.38±2.75 µg/ml.

A cytotoxic flavonol glycoside from Melaleuca leucadendra leaves extract with immunostimulant activity.

Leaves of Melaleuca leucadendra contain the novel flavonol glycoside, myricetin 3-O-ß-4C1-galactopyranuronoid. In addition, known fifteen phenolics were identified. All isolates are characterized for the first time from this plant. Structures were established by conventional methods and confirmed by spectral methods of analysis, including one and two-dimensional nuclear magnetic resonance spectroscopy (1D and 2D-NMR) and high resolution electro-spray ionization mass spectrometry (HRESIMS), as well. Assessment of some immunological and biological efficacy, of the extract in combination with a parallel cytotoxicity evaluation, using the method of cellular reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) technique was carried out. Besides, evaluation of the antioxidant effectiveness, using the free radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) and the oxygen radical absorption capacity (ORAC) methods was performed. In addition, the cytotoxicity against liver (Huh-7), breast (MCF-7) and prostate (PC-3) cancers using the neutral red assay (NRU) technique for the extract and the new flavonol glycoside also, was assessed.