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.

Beta vulgaris subspecies cicla var. flavescens (Swiss chard): flavonoids, hepatoprotective and hypolipidemic activities.

The novel flavonoids, 2",2"'-di-O-α-rhamnopyranosyl-vicenin II, a di-C-glycosyl flavone, and herbacetin 3-O-ß-xylopyranosyl- (1"' --> 2")-O-ß-glucopyranoside, were isolated from the leaves of Beta vulgaris subspecies cicla L. var. flavescens, an edible plant which is consumed in the Mediterranean areas, additional to the known flavonoids, 6-C-glucosyl isoscutellarein, vitexin-(1"' --> 2")-O-ß-xylopyranosyl, vitexin-(1'" --> 2")-O-α-rhamnopyranosyI and vitexin. All metabolites were established by conventional methods of analysis and their structures were confirmed by spectroscopic analysis, including 1 D and 2D-NMR and by HR-ESIMS, as well. The extract of the plant leaves shows hepatoprotective effects in rats intoxicated by administration of acetaminophen and exhibits hypolipidemic activity in rats with high-fat-diet induced hypercholesterolemia. The evaluation was done through measuring the liver function enzymes (aspartate and alanine aminotransferases and alkaline phosphatase, the lipid profile (total cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol and triglycerides) and histopathological analysis of liver slides.

Phenolic profiling of an extract from Eugenia jambos L. (Alston)--the structure of three flavonoid glycosides--antioxidant and cytotoxic activities.

Phenolic metabolite profiling and identification using high performance liquid chromatography (HPLC) coupled to high resolution accurate mass spectrometry (HR-ESI-MS) with detection of negative ions was used for assaying the complex mixture of phenolics of an aqueous ethanol leaf extract of Eugeniajambos L. (Myrtaceae). Eight known polyphenolics were tentatively identified, and, in addition, three hitherto unknown flavonol-O-glycosides were detected in the extract. These unknowns were taken as the targets and isolated by means of consecutive polyamide S6, MCI gel and repeated Sephadex LH-20 column fractionation. The isolation and purification were monitored by HPLC/ESI-MS. The isolates were subsequently identified as quercetin 3-O-xylosyl-(1"' --> 2")-O-xyloside, myricetin 7-methylether 3-O-xylosyl-(1"' --> 2")-rhamnoside and myricetin 3',5'-dimethyl ether 3-O-xylosyl-(1"'-->* 2")-O-rhamnoside. All known metabolites were also separated by applying the same chromatographic techniques. ESI-MS, ¹H and ¹³C NMR spectra were then recorded, completely interpreted and confirmed by HR-ESI-MS and 2D NMR spectroscopy. In order to get information about biological activities of E. jambos the extract was tested for radical scavenging activity by DPPH and ORAC assay. In addition, its cytotoxicity was assessed by the neutral red assay against non-tumorigenic HaCaT keratinocytes and the human bladder carcinoma cell line 5637.

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.

Polyphenols in Ammania auriculata: structures, antioxidative activity and cytotoxicity.

Chemical and biological investigations of the extract of Ammania auriculata (Lytheraceae) resulted in the identification of eight polyphenols (1 - 8) for the first time from this plant, including the gallotannin, 2,3,6-tri-O-galloyl-(α,ß)-4C1-glucopyranose (8), for which 1D and 2D-NMR spectra were recorded and assigned for the first time. The structures of all isolates (1 - 8) were elucidated by conventional methods, spectroscopic analysis, including 1D and 2D NMR, and by HR-ESIMS as well. All of the isolated compounds were evaluated for their antioxidant activities, determined by the DPPH and ORAC methods and for their cytotoxicity against the keratinocyte cell line HaCaT using the neutral red assay (NRU) and cell cycle analysis. Compounds 1, 3, 4, 5, and 6 significantly inhibited reactive oxygen species production with ED50 values between 3.22 and 9.79 µg/ml. Compounds 1, 3, 4, and 5 showed cytotoxic activity against HaCaT cells with IC50 values between 30.7 and 84.1 µg/ml. The new galloyl glucose (8) was found not cytotoxic. Ellagitannins, 2,3-hexahydroxy-((α/ß)-glucopyranose (1) and 1 -0-galloyl 2,3-hexahydroxy-(α)-glucopyranose (5) possess remarkable antioxidative and comparably weak cytotoxic activity.

Aphyllin, the first isoferulic acid glycoside and other phenolics from Tamarix aphylla flowers.

The first glycosylated isoferulic acid, isoferulic acid 3-O-beta-glucopyranoside, together with the new phenolics, tamarixetin 3,3'-di-sodium sulphate and dehydrodigallic acid dimetyl ester have been characterized from a flower extract of Tamarix aphylla. The structures were established on the basis of spectral data. The extract exhibited a distinct radical scavenging effect and to improve the viability of human keratinocytes (HaCaT cells). Also, the known isoferulic acid and ferulic acid which have been determined to be the major components of the investigated extract by HPLC/ESI mass spectrometric screening have been separated, characterized and evaluated as active antioxidants and as cell activity stimulating agents as well.

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.

Unusual phenolic glycosides from Cotoneaster orbicularis.

The whole plant of Cotoneaster orbicularis contains the novel di-C-glycosylflavone, 4",4"'-di-O-beta-glucopyranosyl-vicenin II, or 6,8-di-C-beta-Cellobiosylapigenin, as well as the hitherto unknown natural phenolic glucoside, gentisic acid 2-O-beta-glucopyranoside, or orbicularin. Further phenolics are protocatechuic, anisic, caffeic, p-coumaric acids, catechin, epicatechin, 2"-O-alpha-rhamnopyranosylvitexin, vitexin, rutin, isoquercetrin, hyperin and naringenin. All structures were determined by routine methods of analysis and confirmed mostly by 1H- and 13C-NMR.

An unique n-propyl sesquiterpene from Eryngium creticum L. (Apiaceae).

The unique 1-n-propyl-perhydronaphthaline 1,2,4a,5,6,7,8,8a-octahydro-4-methyl-1-propyl-naphthalene-7-carbaldehyde, a compound which possesses an unusual sesquiterpene carbon skeleton, was isolated and identified, together with the new natural methyl ketone eicos-8,11 -dien-18-ol-2-one, from the hexane: ether extract of the aerial parts of Eryngium creticum growing in Sinai, Egypt. The structures were established by conventional methods of analysis and confirmed by DEPT, COSY, HMQC and HMBC.