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.

Grandisin, 2-methoxy 6,7,2',6'-tetrahydroxy flavanone 6-O-glucoside, from Cassia grandis leaves - antioxidant and cytotoxic activities.

Chemical investigation of Cassia grandis leaves resulted in the isolation of the new 2-methoxy 6,7,2',6'-tetrahydroxy flavanone 6-O-ß-glucoside together with the known flavonol glycosides, kaempferol-3-O-α-rhamnoside, and quercetin 3-O-α-rhamnoside. The structure assign ments were based on conventional analytical methods and confirmed by HRFTESIMS, 1H and 13C NMR, COSY, HSQC and HMBC data. The total phenolic content of the extract was estimated by Folin-Ciocalteu's method. The antioxidant capacity was investigated using DPPH radical scavenging assay. The ethyl acetate and the n-butanol fractions showed poor cytotoxic activity only at high concentrations against the three different cancer cell lines, hepatocellular (HepG-2), breast (MCF-7), and prostate (PC3) by the neutral red uptake assay.

Phenolics from Caesalpinia ferrea Mart.: antioxidant, cytotoxic and hypolipidemic activity.

Nine phenolics were isolated from the aqueous ethanol extract of the leaves of Caesalpinia ferrea. The isolates were characterized for the first time from that plant. The structures of all isolates (1-9) were elucidated by conventional methods, spectroscopic analysis, including 1 D and 2D NMR, and by HR-ESIMS as well. The antioxidant capacities using the ORAC method and the cytotoxic activity using the neutral red assay (NRU) for that extract and three major isolates have been evaluated. In addition, the hypolipidemic activity (in vitro and in vivo) of the extract has been assessed.

Bone mineralization enhancing activity of a methoxyellagic acid glucoside from a Feijoa sellowiana leaf extract.

The capability of an aqueous methanol extract obtained from the leaves of Feijoa sellowiana Berg. on possible prevention and treatment of osteoporosis has been examined by evaluating its stimulating effect on the two human osteoblastic cell lines HOS58 and SaOS-2. The extract was found to increase significantly the mineralization of cultivated human bone cell, whereby a clear increment (15.3 +/- 2.7%) in von Kossa positive area was determined when administering 25 microg/ml leaf extract. A phytochemical investigation of the extract has demonstrated the high phenolic content and led to the isolation and identification of twenty three of them, among which the new 3-methoxyellagic acid 4-O-beta-glucopyranoside was fully identified. All structures were elucidated on the basis of conventional analytical methods and confirmed by FTMS, 1D- and 2D-NMR data. The new compound was found to cause a significant increase of mineralized area at 20 microg/mL, while at lower concentrations the effect was not significant. However, an increase of the number of mineralized spots (nodules) at all tested concentrations of the compound was observed.

Ericifolin: an eugenol 5-O-galloylglucoside and other phenolics from Melaleuca ericifolia.

Ericifolin, an eugenol 5-O-beta-(6'-O-galloylglucopyranoside) possessing the naturally unknown phenolic moiety, 5-hydroxyeugenol, together with the two new phenolics, 2-O-p-hydroxybenzoyl-6-O-galloyl-(alpha/beta)-4C1-glucopyranose and 3-methoxyellagic acid 4-O-rhamnopyranoside have been isolated from the antibacterial leaves extract of Melaleuca ericifolia. In addition, 19 known phenolics were also separated and characterized. All structures were elucidated on the basis of analysis of 1H, 13C NMR, HMQC, HMBC and FTMS spectral data.

Phenolics from extracts of Brahea armata with inhibitory effect against 5alpha-reductase type-II.

Fractions of the aqueous alcohol extracts of the rind and kernel of Brahea aramata fruits have been investigated for their activity against 5alpha-reductase type II, which is expressed predominantly in the prostate. This isozyme represents a major target for drugs against benign prostate hyperplasia (BPH) and prostate cancer. Also, a structural analysis of the phytophenolics, present in both aqueous alcohol extracts as the major constituents, has led to the isolation of five phenolics, including the new natural product, 4',6'-dimethoxy beta,4,2'-trihydroxy chalcone from the rind extract and three phenolics, including the new natural product, 1-p-hydroxybenzoyl glycerol from the kernel extract. All structures were confirmed by ESI-MS and NMR analysis.