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The contents of chlorogenic acid and baicalin in shuang huanglian aerosol were determined by HPLC. The process of chemical kinetics of the aerosol was studied by constant temperature acceleration tests, and the stability of the drug predicted. The results appeared close to those from the stored sample method. pH changes during degradation of the drug were also observed.
In vitro studies have demonstrated positive effects of bioactive compounds on several functions of the immune system. In the present study, 25 of such compounds were tested for their immune modulating properties on influenza virus specific human B- and T-cell responses in vitro. One of these compounds, N-acetyl-L-cysteine was shown to increase influenza virus specific lymphocyte proliferation and interferon(IFN)-gamma production at a concentration of 1.0 mmol/l. Furthermore, N-acetyl-L-cysteine was found to enhance a specific activity of two influenza specific CD8+ cytotoxic T-lymphocyte clones directed towards HLA-A*0201 and HLA-B*2705 restricted epitopes. A second compound, chlorogenic acid, was shown to enhance antigen specific proliferation of lymphocytes in three out of four donors, at concentrations of 10-50 micromol/l. Neither of the two compounds exhibited a positive effect on the production of influenza virus specific antibodies by human peripheral blood mononuclear cells in vitro.
Four cytochrome P450 genes, CYP6B8, CYP6B9, CYP6B27 and CYP6B28, exist in the Helicoverpa zea genome as two pairs of paralogs that evolved from gene duplication and 5'-polar gene conversion events. RT-PCR gel blot analyses have shown that all of these genes are expressed constitutively in midguts of all larval instars, suggesting that they have primary roles in the detoxification of plant allelochemicals. Among these, CYP6B9 is expressed only in midgut tissue whereas its paralog, CYP6B27, is expressed primarily in midgut and secondarily in fat body and ovary. CYP6B28 is expressed in midgut, fat body and, to lesser extents in ovary and integument whereas its paralog, CYP6B8, is expressed in midgut and to some extent in fat body. Comparison of the expression levels induced by eight plant allelochemicals, one drug (phenobarbital), and an insecticide (alpha-cypermethrin) indicates that, for the most part, the four P450s respond individually to these inducers, with all four induced strongly by chlorogenic acid, a shikimate pathway intermediate and a lignin biosynthesis intermediate present in a wide variety of plants, and indole-3-carbinol, a glucobrassicin breakdown product present in the Brassicaceae. The multiple levels at which these P450 genes are apparently diverging (e.g. transcriptional responses, protein sequences) support the suggestion that gene conversion events facilitate gene evolution by allowing duplicated copies greater time to acquire selectable differences in both coding and promoter sequences.
Colombian Arabica coffee beans were roasted to give light, medium, and dark samples. Their aqueous extracts were analyzed by gel filtration chromatography, UV-visible spectrophotometry, capillary electrophoresis, and the ABTS(*)(+) assay. A progressive decrease in antioxidant activity (associated mainly with chlorogenic acids in the green beans) with degree of roasting was observed with the simultaneous generation of high (HMM) and low molecular mass (LMM) compounds possessing antioxidant activity. Maximum antioxidant activity was observed for the medium-roasted coffee; the dark coffee had a lower antioxidant activity despite the increase in color. Analysis of the gel filtration chromatography fractions showed that the LMM fraction made a greater contribution to total antioxidant activity than the HMM components.
OBJECTIVE: The optimal extraction technology of Fengshitongbi capsule was investigated in this study. METHODS: Orthogonal tests were employed for optimum of extraction technology, the determination of the contents of Chlorogenic acid and Sinomenine were gained by HPLC and TLC-scanning respectively. RESULTS: Six volume of water,extracting 3 times with half an hour each time, and seven volume of 70% ethanol, extracting two times with one and a half hour each time were considered the optimum extraction technology of Flos Lonicerae and Caulis Sinomenii as well as Rhizoma Smilacis Glabrae respectively. CONCLUSION: The considerable extraction rate of active components in the drugs is achieved by applying the selected technology.
In plants, PPO has been related to defense mechanism against pathogens and insects and this role was investigated in coffee trees regarding resistance against a leaf miner and coffee leaf rust disease. PPO activity was evaluated in different genotypes and in relation to methyl-jasmonate (Meja) treatment and mechanical damage. Evaluations were also performed using compatible and incompatible interactions of coffee with the fungus Hemileia vastatrix (causal agent of the leaf orange rust disease) and the insect Leucoptera coffeella (coffee leaf miner). The constitutive level of PPO activity observed for the 15 genotypes ranged from 3.8 to 88 units of activity/mg protein. However, no direct relationship was found with resistance of coffee to the fungus or insect. Chlorogenic acid (5-caffeoylquinic acid), the best substrate for coffee leaf PPO, was not related to resistance, suggesting that oxidation of other phenolics by PPO might play a role, as indicated by HPLC profiles. Mechanical damage, Meja treatment, H. vastatrix fungus inoculation and L. coffeella infestation caused different responses in PPO activity. These results suggest that coffee resistance may be related to the oxidative potential of the tissue regarding the phenolic composition rather than simply to a higher PPO activity.
In the present paper, a quantitative method for determining the main choleretic components (chlorogenic acid, p-hydroxyacetophenone and scoparone) in Artemisia scoparia Waldst. et Kit. by TLC densitometry was developed. The concentrated methanolic extract was spotted on to a home-made silica gel G plate The plate was developed stepwisely, first with chloroform-ethyl acetateformic acid (2:2:1), then with cyclohexane-ethyl acetate (1:1). The three components were well separated. The spots were scanned with a Shimadzu CS-910 TLC scanner, by reflection mode and linear scanning. The linear relationship between the amount of the three components and peak area was obtained, but it did not go through the origin; so a two-point external standard method was used in the determination. Various samples of different collecting seasons and different parts of the plant were assayed.
Modulation of IFN-gamma production from T cells by smokeless tobacco extract (STE) could be a factor in periodontal disease. The major inducer of IFN-gamma from T cells is bioactive IL-12 (p70), a heterodimeric protein composed of p35 and p40 subunits, while homodimeric IL-12 p40 antagonizes bioactive IL-12. Both p70 and p40 are produced by macrophages in response to lipopolysaccharide (LPS), IFN-gamma and/or CD40 ligation. To determine the impact of STE on IL-12 p40, p70 and IFN-gamma, splenic T cells were stimulated with anti-CD3 while splenic macrophages were stimulated with LPS in the presence or absence of STE. Production of IL-12 p40 and p70 from LPS-stimulated splenic macrophages and IL-12 p40, p70 and IFN-gamma from LPS/anti-CD3-stimulated T cells and macrophages was decreased by STE. To determine the impact of STE on macrophage IL-12 production alone, splenic or peritoneal macrophages were enriched and then stimulated. STE significantly diminished production of IL-12 p40 and p70 from LPS-stimulated peritoneal macrophages, LPS/IFN-gamma-stimulated peritoneal and splenic macrophages, but increased production of IL-12 p40 and p70 from IFN-gamma/CD40-stimulated splenic macrophages or IFN-gamma-stimulated peritoneal macrophages. None of the effects of STE on IL-12 was due to nicotine, rutin or chlorogenic acid. In contrast to STE, nicotine at 100 microg/ml significantly elevated production of IL-12 p40 and p70 from splenic macrophages stimulate by IFN-gamma/LPS. The results indicate that STE has a significant overall effect upon IL-12 production. It suppresses p40 and p70 production during responses to LPS or LPS/IFN-gamma but augments p40 and p70 production during responses to IFN-gamma without LPS. This affect could have a major impact on diseases associated with excessive production of IL-12.
Coffee model systems prepared from combinations of chlorogenic acid (CGA), N(alpha)-acetyl-1-arginine (A), sucrose (S), and cellulose (C) were roasted at 240 degrees C for 4 min prior to analysis by UV-visible spectrophotometry, capillary zone electrophoresis (CZE), and the ABTS radical cation decolorization assay. The A/CGA/S/C and A/S/C systems were also fractionated by gel filtration chromatography. Antioxidant activity of the systems showed a positive, nonlinear relationship with the amount of CGA remaining after roasting. Sucrose degradation was a major source of color in the heated systems. There was no relationship between antioxidant activity and color generation.
Coffee consumption has been associated with improved glucose tolerance and a lower risk of type 2 diabetes in diverse populations in the U.S., Europe, and Japan. This review discusses the strength of the evidence, relevant mechanisms, possible implications, and directions for further research. The finding that higher consumption of decaffeinated coffee was associated with a lower risk of type 2 diabetes suggests that coffee constituents other than caffeine play a role. Coffee is a source of several compounds that improved glucose metabolism in animal studies, including the chlorogenic acids and lignans. Further research on phytochemicals in coffee may lead to the identification of novel mechanisms for effects of diet on the development of type 2 diabetes. In addition, knowledge on effects of coffee components may aid in the development or selection of types of coffee with improved health effects. Longer-term randomized intervention studies that test the effects of coffee consumption on glucose tolerance are warranted. Physical activity and weight management should be the mainstay of public health strategies to prevent type 2 diabetes. For individual choices regarding coffee consumption, potential effects of coffee on various health outcomes should be considered.
Kinetic data are reported describing the stability of various classes of polyphenolic antioxidants in an apple juice enriched in these compounds as a function of storage temperature and oxygen concentration. The most thermally sensitive compounds were the various quercetin glycosides and epicatechin, whereas phloridzin and chlorogenic acid were more stable. The quercetin glycosides showed differences in their stability: quercetin galactoside approximately quercetin rhamnoside > quercetin glucoside/rutinoside > quercetin arabinoside. The effect of the presence of oxygen on the degradation rates was clear for only quercetin and to a lesser extent for epicatechin. Accelerated shelf-life testing of enriched apple juice during 4 days at 80 degrees C showed decreases in the antioxidant activity of 20-40%. The parameters obtained were used to predict the stability at different storage conditions. Calculations showed that polyphenolic antioxidants and antioxidant activity of enriched apple juice will be quite stable at ambient or refrigerated storage conditions up to half a year.
Arabic coffee (Qahwa), a traditional beverage widely consumed in the Middle East, has attracted increasing scientific attention due to its distinctive phytochemical composition and associated health effects. This review provides an integrated analysis of Qahwa's nutritional profile, focusing on its key bioactive constituents, including chlorogenic acids, caffeine, diterpenes (cafestol and kahweol), and phenolic compounds. These constituents contribute to a range of biological activities, notably antioxidant, anti-inflammatory, hepatoprotective, and metabolic regulatory effects. The influence of technological variables, including roasting degree, brewing method, and bean origin, on the chemical composition and functional properties is critically examined. Safety concerns, particularly acrylamide formation and mycotoxin contamination, are also discussed. Although emerging data support Qahwa's potential as a functional beverage, further research is required to clarify dose-response relationships, synergistic interactions, and long-term health outcomes. This work highlights Qahwa as a promising candidate for food and nutraceutical applications, warranting standardized compositional profiling and toxicological evaluation.
Three espresso coffee (EC) samples of different botanical varieties and types of roast were prepared in standard conditions using an experimental EC prototype: Arabica coffee, Robusta Natural blend, and Robusta Torrefacto blend (a special roast by adding sugar). The ECs were characterized with regard to the physical parameters, amount of total solids, total solids on filtrate, lipids, caffeine, trigonelline, and chlorogenic acids by HPLC, and sensory descriptive analysis related to foam appearance, taste, and mouthfeel. Principal component analysis (PCA) was applied to differentiate the EC samples. Arabica and Robusta samples were separated successfully by principal component 1 (55.3% of variance) including physicochemical and sensory parameters related to foam and taste of ECs. Torrefacto and Robusta Natural EC samples were separated by principal component 2 (20.7% of total variance) including mouthfeel and other attributes of color foam. Some interesting correlations among sensory and physicochemical variables were found. A very simple discriminate function was obtained by discriminate analysis allowing the classification of each EC sample into its respective group with a success rate of 100%.
The chromatographic fingerprint of Chinese traditional medicine, Yinhuang Oral Liquid together with its original materials Radix Scutellariae and Flos lonicera was established by high performance liquid chromatography (HPLC). At the same time, baicalin and chlorogenic acid in the Yinhuang Oral Liquid were also quantitatively determined. The analysis was performed on a Lichrospher C18 column (250 mm x 4.6 mm i. d. , 5 microm) and with gradient elution. The optimum conditions were explored. The mobile phase A was methanol and the mobile phase B was 0.1% H3PO4 aqueous solution. The wavelength of 254 nm was selected for detection. Finally, the data of fingerprints of 6 samples of Yinhuang Oral Liquid were processed with two different mathematic methods. This proposed method demonstrated good stability for the 6 samples of Yinhuang Oral Liquid. In the comparison of the common peaks in chromatogram of Yinhuang Oral Liquid with those of crude herbs, most of them could be matched well.
Commercially available St. John's wort (Hypericum perforatum) extracts, preparations that are used in the treatment of depression, were examined for the potential to inhibit human cytochrome P450 (CYP) enzyme activities, specifically CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Crude extracts demonstrated inhibition of each of these five enzymes, with CYP2D6, CYP2C9, and CYP3A4 being more sensitive than CYP1A2 and CYP2C19. Extracts were fractionated by HPLC, and each of the fractions was tested for inhibition of these five CYPs to identify individual constituents with inhibitory activity. Several fractions were shown to possess inhibitory activity, including the fractions containing hyperforin (the putative active antidepressant constituent), I3,II8-biapigenin, and hypericin. Hyperforin and I3,II8-biapigenin were isolated from the extract, and inhibition constants for the five CYP activities were measured. In addition, three other constituents, hypericin, quercetin, and chlorogenic acid, were tested for inhibitory activity toward the CYP enzymes. The flavonoid compound I3,II8-biapigenin was shown to be a potent, competitive inhibitor of CYP3A4, CYP2C9, and CYP1A2 activities with K(i) values of 0.038, 0.32, and 0.95 microM, respectively. Hyperforin was a potent noncompetitive inhibitor of CYP2D6 activity (K(i) = 1.5 microM) and competitive inhibitor of CYP2C9 and CYP3A4 activities (K(i) = 1.8 and 0.48 microM, respectively). Hypericin also demonstrated potent inhibition of several CYP activities. These in vitro data indicate that St. John's wort preparations contain constituents that can potently inhibit the activities of major human drug-metabolizing enzymes and suggest that these preparations should be examined for potential pharmacokinetic drug interactions in vivo.
Polyphenol oxidase (PPO) has been extracted from both soluble and particulate fractions of loquat fruit (Eriobotrya japonica Lindl. cv. Algerie). The soluble PPO (20% of total activity) was partially purified 3.3-fold after ammonium sulfate fractionation being in its active state. The particulate PPO fraction (80% of total activity) was purified to homogeneity in a latent form being activable by sodium dodecyl sulfate (SDS). The enzyme was purified 40.0-fold with a total yield of 15.3% after extraction by phase partitioning in Triton X-114 followed by three chromatographic steps. The molecular weight was estimated to be about 59.2 and 61.2 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration chromatography, respectively, indicating that latent PPO is a monomer. Latent PPO catalyzed the oxidation of chlorogenic acid (CA) at a rate 50-fold faster than that of 4-tert-butylcatechol (TBC) but the soluble active counterpart only twice. Both PPOs exhibited similar Km values for TBC but Km for CA was 5-fold higher for the latent than for the active soluble PPO. Other kinetic characteristics, including sensitivity to inhibitors, substrate specificity, thermal stability, temperature, and pH profiles, were quite different between both PPOs. These results provide strong evidences that the soluble active and the particulate latent are different forms of PPO in loquat fruit flesh. The results suggest that the major PPO form for the oxidation of CA, leading to enzymatic browning under physiological conditions, is the latent one.
Tobacco plants over-expressing L-phenylalanine ammonia-lyase (PAL(+)) produce high levels of chlorogenic acid (CGA) and exhibit markedly reduced susceptibility to infection with the fungal pathogen Cercospora nicotianae, although their resistance to tobacco mosaic virus (TMV) is unchanged. Levels of the signal molecule salicylic acid (SA) were similar in uninfected PAL(+) and control plants and also following TMV infection. In crosses of PAL(+) tobacco with tobacco harboring the bacterial NahG salicylate hydroxylase gene, progeny harboring both transgenes lost resistance to TMV, indicating that SA is critical for resistance to TMV and that increased production of phenylpropanoid compounds such as CGA cannot substitute for the reduction in SA levels. In contrast, PAL(+)/NahG plants showed strongly reduced susceptibility to Cercospora nicotianae compared to the NahG parent line. These results are consistent with a recent report questioning the role of PAL in SA biosynthesis in Arabidopsis, and highlight the importance of phenylpropanoid compounds such as CGA in plant disease resistance.
A simple and rapid capillary electrophoresis with direct chemiluminescence method has been developed for the determination of five natural pharmacologically active compounds including rutin, protocatechuic aldehyde, chlorogenic acid, luteolin and protocatechuic acid. The luminol as a component of the separation electrolyte buffer was introduced at the head of the separation capillary. The separation of five compounds was carried out in a fused-silica capillary with 15.0 mmol/L tetraborate, 1.0 mmol/L SDS and 0.42 mmol/L luminol (pH 8.5). The analytes was determined by enhancing the chemiluminescence of luminol with 0.13 mmol/L K3Fe(CN)6 in 0.05 mol/L NaOH, which was introduced at the post-column stage. The voltage applied was 16 kV. Under the optimum conditions, the analytes were separated within 10 min. The excellent linearity was obtained over two to three orders of magnitude with a detection limit (signal:noise = 3) of 0.012-0.055 micromol/L for all five analytes. The method was successfully used in the analysis of pharmaceutical and biological samples, and the assay results were satisfactory.