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PubMedDate not supplied

Enhancement effect of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide and cationic surfactant on the chemiluminescence of poly(3, 4, 5-trihydroxybenzoate ester)dendrimers.

In the presence of l-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC), the chemiluminescence (CL) intensities of poly(3, 4, 5-trihydroxybenzoateester)dendrimers, 1 and 2, having 1,2-pyrocatechol and 1,3,5-trihydroxybenzene as core molecules and also six and nine gallic acid units in the periphery, were respectively 7.4- and 2.4-fold stronger than those of 1 and 2 in the absence of EDC. Similarly, the CL intensities of 1 and 2 in the presence of cetyltrimethylammonium bromide (CTAB) were respectively 4- and 1.7-fold stronger than those of 1 and 2 in the absence of CTAB.

Ethyldimethylaminopropyl Carbodiimide↗
PubMed2003

Quantitative analysis of aglycone quercetin in mulberry leaves (Morus alba L.) by capillary zone electrophoresis.

A capillary zone electrophoresis method was established for analysis of aglycone quercetin in mulberry leaves (Morus alba L.). The influence of, e.g., background electrolyte concentrations and pH, surfactant concentrations, organic solvents, temperature, and voltage on the separation of aglycone quercetin, rutin, quercitrin, kaempferol, catechin, and gallic acid was systematically investigated. The optimum condition providing baseline separation of all compounds within 16.5 min was obtained in 150 mM boric acid (pH 10.0) using a fused-silica capillary with an effective length of 42.5 cm (50 microm inner diameter), temperature of 32 degrees C, and voltage of 15 kV. Method assessment was performed by standard addition method using rutin as an internal standard. Linearity of the method was excellent (r(2) > 0.999) over the concentration tested (40-160 microg/mL). The relative standard deviations (%RSDs) from injection, intraday, and interday precision were less than 2.5%. Recoveries were good (asymptotically equal to 100.0%,%RSD = 0.8%) with a limit of detection (LOD) and limit of quantitation (LOQ) of 0.86 and 3.16 microg/mL (%RSD = 1.8%), respectively. The aglycone quercetin found in the mulberry leaves was 0.452 g/100 g (%RSD = 0.6%) on dry weight.

Electrophoresis, Capillary↗
PubMed2006

A simple light-emitted diode-induced fluorescence detector using optical fibers and a charged coupled device for direct and indirect capillary electrophoresis methods.

We constructed a simple fluorescence detector for both direct and indirect CE methods using a blue light-emitted diode (470 nm) as excitation source, a bifurcated optical fiber as a waveguide, and a CCD camera as a detector. The connection of all the components is fairly easy even for nonexperts and the use of a CCD camera improves the applicability of this detector compared to the others using PMTs because it permits the recording of 2-D electropherograms or phosphorescence measurements. This detector provides a compact, low cost, and rapid system for the determination of native fluorescence compounds which have high quantum yields by CE with direct fluorescence detection, showing an LOD of 2.6 x 10(-6) M for fluorescein; the determination of fluorescence derivative compounds by CE with direct fluorescence detection, showing an LOD of 1.6 x 10(-7) M for FITC-labeled 1,6-diaminohexane; and nonfluorescence compounds by CE with indirect fluorescence detection with an LOD of 2.7 x 10(-6) M for gallic acid.

Electrophoresis, Capillary↗
PubMed2004

Characterisation of embalming materials of a mummy of the Ptolemaic era. Comparison with balms from mummies of different eras.

Gas chromatography-mass spectrometry has been used to determine the nature of organic materials used in mummification balms. A comparative analysis of samples taken from Egyptian mummies is developed. The results are given in two parts. First, it is shown that the chemical composition of the balm is practically independent of the part of the mummy from which it is taken. This study was done on a Ptolemaic mummy (circa 100 BC from the Guimet Museum in Lyon). Fats, beeswax, and diterpenic resins were the main components: they were found everywhere. Castor oil was also very often detected (in half of the samples). This particular fat is present in the balm inside the thorax but not in the skull. Moreover it is shown that a vegetable tannin was employed. Components indicative of vegetable tannin input (gallic acid and inositols) were found in seven samples out of eighteen, particularly close to the body and on the canopic pack of the heart. Secondly, some conclusions from a comparative study of the composition of balms from mummies of various social levels as well as of different Egyptian periods are reported. It is shown that beeswax was used as from very early times (XVIIIth dynasty). The mixture of beeswax, fats, and diterpenoid resins would appear to be more recent. The balms of three mummies dating from more recent Egyptian periods (XIXth to XXVth dynasty) were analysed. No evidence of a resin, gum-resin, or plant gum could be found. Some mummies would appear to have been embalmed with fats or beeswax. Finally, the entrails canopic pack said to belong to Ramses II undoubtedly shows an embalming process with a triterpenic resin of the mastic type. The adopted analytical methodology enabled us to achieve simultaneous detection of four components of the balm of the Ptolemaic mummy. Analysis of the other five mummies revealed far less complex chemical compositions for the balms. This may be an indication of different embalming processes, although we should bear in mind the question of organic matter preservation through the ages.

Castor Oil↗
PubMed2004

Determination of hydrolyzable tannins in the fruit of Terminalia chebula Retz. by high-performance liquid chromatography and capillary electrophoresis.

A RP-HPLC method for determining fourteen components (gallic acid, chebulic acid, 1,6-di-O-galloyl-D-glucose, punicalagin, 3,4,6-tri-O-galloyl-D-glucose, casuarinin, chebulanin, corilagin, neochebulinic acid, terchebulin, ellagic acid, chebulagic acid, chebulinic acid, and 1,2,3,4,6-penta-O-galloyl-D-glucose) in the fruit of Terminalia chebula Retz. is described. The separation was achieved within 80 min using a binary gradient with mobile phases consisting of a pH 2.7 phosphoric acid solution and an 80% CH3CN solution. Capillary electrophoretic analyses were also attempted, and it was found that CZE (25 mM Na2B4O7, 5 mM NaH2PO4, pH 7.0) was an efficient method for the separation of gallotannins, while an MEKC method (25 mM Na2B4O7, 5 mM NaH2PO4, 20 mM SDS, pH 7.0, and 10% acetonitrile) provided a better separation for most of the tannins examined. The HPLC and CE methods developed were both successfully applied to the assay of tannins in commercial samples of Chebulae Fructus.

Calibration↗
PubMed2004

Antioxidant activity of plant extracts on the inhibition of citral off-odor formation.

Grape seed, pomegranate seed, green tea, and black tea extracts were used to inhibit the off-odor from citral degradation. A 0.1 M citrate buffer (pH 3), containing 100 ppm citral and 200 ppm gallic acid equivalent plant extract, was incubated at 40 degrees C. The reaction mixtures were analyzed by high-performance liquid chromatography (HPLC) at days 0, 6, 10, 13, and 16 to monitor degradation of citral and formation of alpha, p-dimethylstyrene, p-cymene-8-ol, and p-methylacetophenone. The addition of plant phenolic extracts could not inhibit citral degradation, however, all four plant extracts significantly inhibited p-methylacetophenone formation. The samples, with the addition of plant extracts, exhibited higher concentrations of alpha, p-dimethylstyrene and p-cymene-8-ol than the control. This is presumed to be due to the oxygen-scavenging effect of plant extracts blocking the pathway from p-cymene-8-ol to p-methylacetophenone. Our results suggest that these plant extracts act as general antioxidants inhibiting the generation ofp-methylacetophenone regardless of the types of water-soluble phenolic compounds existing in the plant extracts.

Acyclic Monoterpenes↗
PubMed1997

Comparative toxicity of allelochemicals and their enzymatic oxidation products to maize fungal pathogens, emphasizing Fusarium graminearum.

A series of stable quinones and their precursors, and enzymatic oxidation products of plant allelochemicals were tested for their effect on maize fungal pathogens, primarily Fusarium graminearum. Benzoquinone was typically significantly more toxic than hydroquinone, while 1,2-naphthoquinone was typically significantly more toxic than 1,2-dihydroxynaphthalene. Aspergillus flavus was the most resistant fungus to these compounds, while Phoma medicaginis was the most susceptible. Applying tyrosinase in conjunction with several phenolic compounds only increased the toxicity of gallic acid to Fusarium graminearum. Applying peroxidase generally increased toxicity of all compounds tested to this fungus in a dose-dependent fashion. Ferulic acid was generally the most toxic compound, both alone and when combined with peroxidase and H2O2, followed by coumaric acid. These results suggest that enzymatic oxidation of plant allelochemicals may result in the generation of products that either are directly toxic to maize pathogens, or indirectly inhibitory due to their ability to tie up nutrients.

Analysis of Variance↗
PubMedDate not supplied

Identification of hydrolysable tannins in the reaction zone of Eucalyptus nitens wood by high performance liquid chromatography--electrospray ionisation mass spectrometry.

The first detailed analysis of the phenolic constituents of the reaction zones (tissue of antimicrobial defence) from the sapwood of a Eucalyptus spp. is presented. Plantation-grown Eucalyptus nitens trees with stem decay resulting from pruning wounds were sampled and extracts were prepared from healthy sapwood and from reaction zone tissue. Analysis by HPLC with ESI-MS revealed that a diverse range of hydrolysable tannins are present in both healthy sapwood and in reaction zone extracts, including over 30 gallotannins, ellagitannins and phenols. Eight tannins were unequivocally identified, including the gallotannins tri-O-galloyl-beta-D-glucose, tetra-O-galloyl-beta-D-glucose and penta-O-galloyl-beta-D-glucose, and the ellagitannins pedunculagin, tellimagrandin I, casuarinin, casuarictin and tellimagrandin II. The phenols gallic acid, ellagic acid and catechin were also identified. The ellagitannins (particularly pedunculagin) are considerably more abundant in the reaction zone than in the healthy sapwood and may contribute to the effectiveness of the reaction zone as an antimicrobial barrier.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Comparison of extraction methods for secologanin and the quantitative analysis of secologanin from Symphoricarpos albus using 1H-NMR.

In order to develop an efficient large-scale extraction of secologanin from Symphoricarpos albus, different methods have been compared. Ultrasonication with organic solvents and water, microwave-assisted extraction and hot water extraction methods were evaluated for their efficiencies. Among the methods tested, ultrasonication with methanol showed the highest yield of secologanin (3.35 +/- 0.24 mg/g fresh weight). For reliable quantification of secologanin a 1H-NMR method was developed. The experiment was performed by the analysis of the integral of the signal of H-9, which was well separated in the range delta 7.4-7.5 in the 1H-NMR spectrum. The quantity of the compound was calculated from the relative ratio of intensity of the target peak to the known amount of internal standard, 200 microg of gallic acid. This method allows rapid and simple quantification of secologanin in 5 min without any pre-purification steps.

Chemistry Techniques, Analytical↗
PubMedDate not supplied

Chemical identification of the sources of commercial Fructus Chebulae.

Twenty-eight commercial samples of Fructus Chebulae were collected from local herbal markets in Taiwan and were determined to have been derived from Terminalia chebula Retz. and Terminalia chebula Retz. var. parviflora Thwaites, which differ markedly in external appearance. Ten tannin-related constituents [gallic acid (1), chebulic acid (2), punicalagin (4), chebulanin (7), corilagin (8), neochebulinic acid (9), ellagic acid (11), chebulagic acid (12), chebulinic acid (13) and 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (14)] were identified and quantified by HPLC. Samples derived from T. chebula. var. parviflora, which are typically round-shaped, generally contained higher concentrations of 13 and 14 but lower levels of 12 compared with those from T. chebula, which are largely oval-shaped. The ratio of the concentration of 14 to that of 4 may serve as a potential parameter for differentiating samples from the two origins (T. chebula, ratio 0.6 +/- 0.3; T. chebula. var. parviflora, ratio 3.4 +/- 2.2). Levels of the three major bioactive constituents 12-14 were found to provide good references for the quality assessment of Fructus Chebulae. The ratio of the concentration of 12 to that of 14 may offer a guideline for determining quality as well as origin of the drug (lower-grade T. chebula, ratio 12.4 +/- 6.0; medium-grade T. chebula, ratio 8.8 +/- 7.9; higher-grade T. chebula, ratio 3.2 +/- 0.8; T. chebula var. parviflora, ratio 1.6 +/- 0.7).

Carboxylic Acids↗
PubMed2003

Antiprotozoal activity of the constituents of Rubus coriifolius.

Extraction of the aerial parts of Rubus coriifolius, a medicinal plant used by the Maya communities in Southern Mexico to treat bloody diarrhoea, resulted in the isolation of seven known compounds (-)-epicatechin, (+)-catechin, hyperin, nigaichigoside F1, beta-sitosterol 3-O-beta-d-glucopyranoside, gallic acid and ellagic acid. All compounds were tested for their antiprotozoal activity against Entamoeba histolytica and Giardia lambia. Epicatechin was the main responsible for the antiprotozoal activity of the extract against both protozoa, its activity was comparable to emetine, but no exceeded that of metronidazole.

Animals↗
PubMed2003

Cytotoxicity and antimicrobial activity of goniothalamin isolated from Bryonopsis laciniosa.

The cytotoxicity and antimicrobial activity of goniothalamin isolated from Bryonopsis laciniosa was investigated. Goniothalamin showed potent cytotoxicity with LC50 values (5.03 microg/mL) comparable with the reference standard agent, gallic acid. It also showed weak antibacterial and significant antifungal activity against a wide range of gram positive and gram negative bacteria and fungi. The antibacterial (minimum inhibitory concentration) effect against Bacillus cereus and Shigella shiga was found to be 64 microg/mL.

Animals↗
PubMed2005

In vitro antioxidant studies and free radical reactions of triphala, an ayurvedic formulation and its constituents.

The aqueous extract of the fruits of Emblica officinalis (T1), Terminalia chebula (T2) and Terminalia belerica (T3) and their equiproportional mixture triphala were evaluated for their in vitro antioxidant activity. gamma-Radiation induced strand break formation in plasmid DNA (pBR322) was effectively inhibited by triphala and its constituents in the concentration range 25-200 microg/mL with a percentage inhibition of T1 (30%-83%), T2 (21%-71%), T3 (8%-58%) and triphala (17%-63%). They also inhibited radiation induced lipid peroxidation in rat liver microsomes effectively with IC(50) values less than 15 microg/mL. The extracts were found to possess the ability to scavenge free radicals such as DPPH and superoxide. As the phenolic compounds present in these extracts are mostly responsible for their radical scavenging activity, the total phenolic contents present in these extracts were determined and expressed in terms of gallic acid equivalents and were found to vary from 33% to 44%. These studies revealed that all three constituents of triphala are active and they exhibit slightly different activities under different conditions. T1 shows greater efficiency in lipid peroxidation and plasmid DNA assay, while T2 has greater radical scavenging activity. Thus their mixture, triphala, is expected to be more efficient due to the combined activity of the individual components.

Animals↗
PubMed2005

Bioactive compounds from Rhodiola rosea (Crassulaceae).

The methanol extract of the underground part of Rhodiola rosea was found to show inhibitory activity against Staphylococcus aureus. Bioactivity-guided fractionation of a 95% ethanol extract from the stems of R. rosea led to the isolation of five compounds: gossypetin-7-O-L-rhamnopyranoside (1), rhodioflavonoside (2), gallic acid (3), trans-p-hydroxycinnamic acid (4) and p-tyrosol (5). Their structures were elucidated by UV, IR, MS and NMR data, as well as by comparison with those of the literature. Compounds 1 and 2 were evaluated for their antibacterial and antiprostate cancer cell activities. Compounds 1 and 2 exhibited activity against Staphylococcus aureus with minimum inhibitory concentrations of 50 microg/mL and 100 microg/mL, respectively. Cytotoxicity studies of 1 and 2 also displayed activity against the prostate cancer cell line with IC(50) values of 50 microg/mL and 80 microg/mL, respectively.

Anti-Bacterial Agents↗
PubMed2006

Antioxidant flavonol glycosides from Schinus molle.

Chromatographic separation of aqueous MeOH extract of the leaves of Schinus molle L. has yielded two new acylated quercetin glycosides, named isoquercitrin 6''-O-p-hydroxybenzoate (12) and 2''-O-alpha-L-rhamnopyranosyl-hyperin 6''-O-gallate (13), together with 12 known polyphenolic metabolites for the first time from this species, namely gallic acid (1), methyl gallate (2), chlorogenic acid (3), 2''-alpha-L-rhamnopyranosyl-hyperin (4), quercetin 3-O-beta-D-neohesperidoside (5), miquelianin (6), quercetin 3-O-beta-D-galacturonopyranoside (7), isoquercitrin (8), hyperin (9), isoquercitrin 6''-gallate (10), hyperin 6''-O-gallate (11) and (+)-catechin (14). Their structures were established on the basis of chromatographic properties, chemical, spectroscopic (UV, 1H, 13C NMR) and ESI-MS (positive and negative modes) analyses. Compounds 4-9 and 11 exhibited moderate to strong radical scavenging properties on lipid peroxidation, hydroxyl radical and superoxide anion generations with the highest activities shown by 6 and 7 in comparison with that of quercetin as a positive control in vitro.

Anacardiaceae↗
PubMed2004

Characterization of gallotannins and benzophenone derivatives from mango (Mangifera indica L. cv. 'Tommy Atkins') peels, pulp and kernels by high-performance liquid chromatography/electrospray ionization mass spectrometry.

Polyphenolics were extracted from peels, pulp and kernels of mango fruits (Mangifera indica L. cv. 'Tommy Atkins') and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. In the peel 18 gallotannins and five benzophenone derivatives were detected which were tentatively identified as galloylated maclurin and iriflophenone glucosides. Twenty-one and eight gallotannins were found in the kernels and pulp, respectively, whereas no evidence for the presence of benzophenone derivatives was obtained. Gallotannins quantified by the rhodanine assay amounted to 1.4 mg/g dm in the peels (expressed as gallic acid), while only small amounts (0.2 mg/g dm) were found in the pulp. In contrast, mango kernels contained 15.5 mg/g dm and thus proved to be a rich source of gallotannins.

Benzophenones↗
PubMed1997

Inhibition of peroxynitrite-mediated tyrosine nitration by catechin polyphenols.

Peroxynitrite is a cytotoxic species generated by the reaction between superoxide and nitric oxide. The ability of catechins and their gallate esters to decrease peroxynitrite-induced nitration of tyrosine and to limit surface charge alteration of low density lipoprotein (LDL) was investigated. All compounds tested were found to be potent peroxynitrite scavengers preventing the nitration of tyrosine. The ability of the catechin polyphenols at 10 microM to minimise tyrosine nitration induced by peroxynitrite (500 microM) was ECG (38.1 +/- 3.6%) approximately EGCG (32.1 +/- 7.5%) approximately gallic acid (32.1 +/- 1.9%) > catechin (23.9 +/- 5.4%) approximately epicatechin (22.9 +/- 3.3%) approximately EGC (19.9 +/- 2.0%). Trolox (10 microM) was used as the standard for comparative purposes and was found to be less effective than the polyphenols in inhibiting tyrosine nitration (13.6 +/- 2.9%). The catechin polyphenols were also found to offer protection from peroxynitrite-induced modification of critical amino acids of apolipoprotein B-100 of LDL which contribute towards its surface charge.

Catechin↗
PubMed2000

Artifacts in cell culture: rapid generation of hydrogen peroxide on addition of (-)-epigallocatechin, (-)-epigallocatechin gallate, (+)-catechin, and quercetin to commonly used cell culture media.

There is considerable current interest in the possible beneficial health effects of quercetin, catechins, epigallocatechins, epigallocatechin gallates, and related phenolic compounds found in teas, wines, and other plant products. As a result, many laboratories are studying the effects of these compounds on cells in culture. The present paper shows that addition of these compounds to commonly used cell culture media leads to generation of substantial amounts of hydrogen peroxide (H(2)O(2)). Dulbecco's modified Eagle medium gives the highest H(2)O(2) level for all the compounds tested, with levels reaching >400 microM within 2 h for addition of 1 mM concentrations of gallic acid, epigallocatechin gallate, and epigallocatechin. Catechin and quercetin produced lower, but still significant, levels of H(2)O(2). McCoy's 5A and RPMI 1640 media also promoted H(2)O(2) production from the above phenolic compounds. This rapid generation of H(2)O(2) could account for some or all of the reported effects of phenolic compounds on cells in culture.

Artifacts↗