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In the present study we report the isolation of a phenylpropanoid glucoside, plantamajoside, together with rosmarinic acid, chlorogenic acid and luteolin-7-O-monoglucoside. This is the first report of these compounds from Plantago lagopus.
Ellagic acid, a commonly occurring plant phenol, was shown to be a potent in vitro inhibitor of GSH-transferase(s) activity. Other plant phenols such as ferrulic acid, caffeic acid and chlorogenic acid also showed a concentration dependent inhibition of GSH-transferase(s) activity. The I50 values of ellagic acid, caffeic acid, chlorogenic acid and ferrulic acid were 8.3 X 10(-5)M, 14.0 X 10(-5)M, 20.0 X 10(-5)M and 22.0 X 10(-5)M respectively, suggesting that ellagic acid is the most potent inhibitor of all the four studied plant phenols. At 55 microM concentration of ellagic acid, a significant inhibition (35-47%) was observed on GSH-transferase activity towards CDNB, p-nitrobenzyl chloride and 1,2-epoxy-3-(p-nitrophenoxy)propane as substrates. Ellagic acid inhibited GSH-transferase(s) activity in a non-competitive manner with respect to CDNB while with respect to GSH it inhibited the enzyme activity in a competitive manner. Other phenolic compounds purpurogallin , quercetin, alizarin and monolactone also showed a concentration dependent inhibition of the enzyme activity with a I50 of 0.8 X 10(-5)M, 1.0 X 10(-5)M, 8.0 X 10(-5)M and 16.0 X 10(-5)M respectively. These inhibitors of GSH-transferase(s) activity should be useful in studying the in vitro enzyme mediated reactions of exogenous and endogenous compounds.
In Ethiopia inflammatory skin diseases are among the most common health problems treated with traditional remedies which mainly comprise medicinal plants. In the present work, the anti-inflammatory and anti-nociceptive activities of Cheilanthes farinosa (Forsk.) Kaulf (Adianthaceae), a fern used in many parts of Ethiopia to treat inflammatory skin disorders, were studied using in vivo models of inflammation and pain. The results of the study showed that the fronds Cheilanthes farinosa possess strong anti-inflammatory and anti-nociceptive properties. It was further demonstrated that the active ingredients of the fern reside mainly in the methanol fraction from which three compounds viz. the flavonol glycoside rutin, and the natural cinnamic acids, caffeic acid and its quinic acid derivative chlorogenic acid have been isolated. The methanol extract was also shown to potentiate the anti-inflammatory activity of acetyl salicylic acid. At the tested concentrations, the methanol extract displayed a better anti-nociceptive activity than that of ASA in both the early and late phases of formalin induced nociception in mice. However, the activity of the extract was more pronounced in the late phase, which is commonly associated with inflammatory pain. Evaluation of the pharmacological properties of the compounds isolated from the active fractions pointed out that chlorogenic acid possesses strong anti-inflammatory and anti-nociceptive activities while caffeic acid and rutin were inactive. Moreover, on molar basis chlorogenic acid was proved to be superior in its anti-inflammatory action to acetyl salicylic acid. It was therefore concluded that chlorogenic acid contributes, in full or in part, to the anti-inflammatory and anti-nociceptive activities of Cheilanthes farinosa. Both the methanolic extract and pure chlorogenic acid failed to display anti-nociceptive activity when tested by the tail-flick test indicating that the plant is not a centrally acting analgesic but instead exerts its analgesic activity by way of its antinflammtory action.
An open microwave-assisted extraction system was used to extract gallic acid, protocatechuic acid, chlorogenic acid and caffeic acid from Eucommia ulmodies. The effect of extraction variables, especially solvent, on the recoveries of these polyphenolic compounds was investigated using factorial design. As extracting solvent for these compounds, methanol produced a higher recovery than pure water. For straight chain alcohol solvents, the lower the carbon number, the higher the recoveries of the polyphenolic acids. The optimal ratio of methanol:water:glacial acetic acid in the solvent mixture used in microwave-assisted extraction was 2:8:0.3 (v/v) and this solvent could be directly used as the mobile phase in HPLC separation without additional intermittent treatment as reported in literature. The extraction under the condition of 50% microwave power and 30 s irradiation at a solvent:sample ratio of 10 (mL/g) was found to be the most advantageous. The repeatability test of extraction and chromatographic analysis was satisfactory for the analysis of these polyphenolic compounds.
A fast and reliable HPLC method for the determination of caffeic acid derivatives (caftaric acid, chlorogenic acid, caffeic acid, cynarin, echinacoside and cichoric acid) in various species of the genus Echinacea has been developed. Extraction of root samples by magnetic stirring with 80% methanol aqueous solution at room temperature allowed the complete recovery of all compounds of interest. Root extracts were analysed on a reversed-phase column with gradient elution and photodiode array detection. Caffeic acid derivatives showed differential qualitative and quantitative distributions in Echinacea species. The total amount of phenolic compounds ranged from 33.95 to 0.32 mg/g. The highest contents of caffeic acid derivatives were found in E. paradoxa var. paradoxa, E. paradoxa var. neglecta and E. purpurea, followed by E. angustifolia var. angustifolia, E. simulata, E. pallida and E. laevigata, whilst E. tennesseensis, E. sanguinea and E. atrorubens had low amounts of phenolic compounds. The radical scavenging activities of methanolic extracts of roots of Echinacea species was evaluated in vitro using the DPPH* radical scavenging method. The EC50 values of the samples ranged from 122 to 1223 microg/mL. The radical scavenging activities of the root extracts were correlated with the content of phenolic compounds, with a correlation coefficient (r2) of 0.923.
Phenolic acids were extracted from black carrot roots (Daucus carota ssp. sativus var. atrorubens Alef.) and a black carrot juice concentrate, and characterized by high-performance liquid chromatography/electrospray ionization mass spectrometry. Most of the compounds detected were identified as depsides composed of p-coumaric, caffeic and ferulic acids. Additionally, three hydroxybenzoic acid derivatives and one quercetin glycoside were detected. 5-O-Caffeoylquinic acid (chlorogenic acid) represented the predominant compound amounting to 657 mg/kg in the roots and 5815 mg/kg in the concentrate. The specific fragmentation patterns of mono- and dihydroxycinnamoylquinic acids allowed the distinction of several stereoisomers. The presence of 4-O-caffeoylquinic acid and several further hydroxycinnamic acid esters, together with compounds not belonging to the depside type, is reported for the first time. The present study reveals that the phenolic profile of black carrots is even more complex than hitherto assumed and may contribute to pigment stability of extracts derived from the roots.
Simon extracts are vitamin K(1)-rich food materials extracted from the leaves of the Simon sweet potato. Although vitamin K is known to stimulate bone formation, we postulated that Simon extracts also contain unknown biological compounds having the ability to regulate bone resorption. Here we prepared the vitamin K-free fraction from the Simon extracts and investigated the ability of this fraction on the differentiation of osteoclasts. A remarkable inhibitory effect of osteoclastogenesis was observed when osteoclast precursors were treated with this fraction in rat bone marrow culture systems as well as in a pure differentiation system using murine osteoclast precursor cell line. The vitamin K-free Simon extracts markedly suppressed severe bone destruction mediated by abundant osteoclasts associated with adjuvant-induced arthritis in rats. High performance liquid chromatography (HPLC) analysis revealed that the vitamin K-free Simon extracts contained three types of low molecular weight inhibitors for osteoclastogenesis; caffeic acid, chlorogenic acids and isochlorogenic acids. Among these substances, caffeic acid showed the most powerful inhibitory effects on osteoclastogenesis. Caffeic acid significantly suppressed expression of NFATc1, a key transcription factor for the induction of osteoclastogenesis. Our current study enlightened a high utility of the Simon extracts and their chemical components as effective regulators for bone resorption accompanied with inflammation and metabolic bone diseases.
Cell-suspension cultures of maize ( Zea mays L.) released soluble extracellular polysaccharides (SEPs) into their medium. Some or all of the SEPs had feruloyl ester groups. Pulse-labelling with [(3)H]arabinose was used to monitor changes in the SEPs' M(r) (estimated by gel-permeation chromatography) with time after synthesis. Newly released (3)H-SEPs were 1.3-1.6 MDa, but between 2 days and 3 days after radiolabelling (in one experiment) or between 5 days and 6 days (in another), the (3)H-SEPs abruptly increased to approximately 17 MDa, indicating extensive cross-linking. The cross-linking involved both [(3)H]xylan and [(3)H]xyloglucan components of the SEPs. The cross-links could be cleaved by alkali, returning the SEPs to their original M(r). In 0.1 M NaOH at 37 degrees C, 58% cleavage was effected within 24 h. The requirement for such prolonged alkali treatment indicates that ester-bonded (e.g. diferuloyl) groups were not solely responsible for the cross-linking. Bonds cleaved only by relatively severe alkali could include benzyl ether linkages formed between sugar residues and oxidised phenolics that had quinone methide structures. The ability of alkali to cleave the cross-links was independent of the age of the (3)H-SEP molecules. Cross-linking of (3)H-SEPs in vivo was delayed (up to approx. 7 days after radiolabelling) by exogenous sinapic acid, chlorogenic acid or rutin-agents predicted to compete with the oxidative coupling of feruloyl-polysaccharides. The cross-linking was promoted by exogenous ferulic acid or l-tyrosine, possibly because these compounds acted as precursors for polysaccharide feruloylation, thus providing additional partner substrates for the oxidative coupling of previously formed (3)H-SEPs. The ability of certain phenolics to prevent the cross-linking of (3)H-SEPs supports the idea that the cross-linking involved phenolic oxidation.
We analyzed phenolic compounds and other elements in leaf extracts and compared morphology of three species of the Phytolaccaceae family found in South Korea. To test allelochemical effects of the three Phytolacca species, we also examined seed germination and dry weight of seedlings of Lactuca indica and Sonchus oleraceus treated with leaf extracts. The concentrations of total phenolic compounds were exotic Phytolacca esculenta (3.9 mg/l), native Phytolacca insularis (4.4 mg/l), and exotic Phytolacca americana (10.2 mg/l). There was no significant difference in concentrations between P. esculenta and P. insularis, but the concentration of total phenolics in P. americana was two times higher than either P. esculenta or P. insularis. Analysis of aqueous extracts by HPLC showed seven phenolic compounds (gallic acid, protocatechuic acid, chlorogenic acid, caffeic acid, m-hydroxybenzoic acid, p-coumaric acid, and cinnamic acid). Total phenolics in P. americana were eight to 16 times higher than either P. esculenta or P. insularis, respectively. P. americana inhibited seed germination and dry weight of the two assay species. The phytotoxic effects of the two Phytolacca species were different, despite the fact that P. esculenta and P. insularis had similar levels of total phenolic compounds. We also found that P. americana had invaded Ullung Island, which suggested that P. americana had excellent adaptability to the environment. The three species of Phytolaccaceae in South Korea can be distinguished by their different allelopathic potentials and morphologies.
The interaction between phenolic compounds and the food-borne carcinogenic mycotoxin, aflatoxin B1 (AFB1), was examined. 6 phenolic compounds (gallic acid, chlorogenic acid, caffeic acid, dopamine, p-hydroxybenzoic acid and salicylic acid) inhibited AFB1-induced mutagenesis in Salmonella typhimurium strain TA98 in a suspension assay in the presence of rat-liver microsomes (S9). The inhibitory effect was observed when the phenolic compound and the mutagen (AFB1 plus S9) were administered concurrently, but not when exposure to the mutagen was followed by the phenolic compound. The concentrations of the phenolic compounds used were not mutagenic to S. typhimurium strain TA98 and had no effect on the survival of the bacteria. The inhibition of AFB1 metabolism was studied using high-pressure liquid chromatography. Increasing the concentration of all 6 phenolic compounds resulted in a dose-dependent reduction of both major AFB1 metabolite peaks. The results are consistent with the hypothesis that the phenolic compounds do not react covalently with AFB1, and the inhibitory effect of phenolic compounds on AFB1-induced mutagenesis may be due to the inhibition of the activation enzymes.
Two phenylpropanoid glycosides, a new one, lamalboside (2R-galactosylacteoside) and the known acteoside, the flavonol p-coumaroylglucoside, tiliroside, 5-caffeoylquinic acid (chlorogenic acid), along with rutoside and quercetin and kaempferol 3-O-glucosides were isolated from the flowers of Lamium album. Esters of glycosides were obtained as mixtures of trans/cis isomers. The presence of flavonoid p-coumaroylglucosides links Lamium to other members of the subfamily Lamioideae.
Three flavonoid glycosides: luteolin 7-glucoside and two luteolin 7-diglucosides were isolated from dandelion flowers and leaves together with free luteolin and chrysoeriol in the flower tissue. The hydroxycinnamic acids, chicoric acid, monocaffeyltartaric acid and chlorogenic acid were found throughout the plant and the coumarins, cichoriin and aesculin were identified in the leaf extracts. This represents the first report of free chrysoeriol (luteolin 3'-methyl ether) in Taraxacum officinale agg. An earlier provisional identification of chicoric acid, chlorogenic acid, cichoriin and aesculin in a phenolic survey of the tribe Cichorieae is confirmed. Chicoric acid and the related monocaffeyltartaric acid were found to be the major phenolic constituents in flowers, roots, leaves and involucral bracts and also in the medicinal preparations tested.
BACKGROUND: Epidemiological evidence points to a cancer protective role of green-yellow-orange vegetables and fruits. The involvement of teas as a protective factor in carcinogenesis has not received the attention it seems to merit. To gain relevant information, attempts were made to stimulate in vitro those conditions to which human groups are actually exposed. METHODS: The inhibitory effects of infusions of Chinese, Japanese, and Ceylonese teas were examined by adding them to a nitrosation mixture consisting of 0.8 mg sodium nitrite and 340 mg equivalent of a widely consumed salt-preserved fish (Pak Wik) and estimating the frequency of mutants in TA 1535 strain of Salmonella typhimurium. RESULTS: The tea samples exhibited a strong inhibitory effect at concentrations that are actually ingested by man. A comparable inhibition was obtained by several tea phenolics. A second series of experiments dealt with the formation of nitrosoproline (NPRO) which can be strongly inhibited in vitro by the tea infusions and tea phenolics. The effects of the tea infusions and caffeic acid on the endogeneous formation of NPRO in man were examined by having volunteers ingest 300 mg sodium nitrate and 30 min later 300 mg proline, collecting urine samples over a 24-hr period, and estimating the excreted NPRO. The tested teas, at doses regularly consumed, again exerted a strong inhibitory effect on endogeneous NPRO formation in humans. Comparable inhibitory effects were obtained by ingesting caffeic acid, chlorogenic acid, or ferulic acid with the nitrosation mixture. CONCLUSIONS: These results indicate that the simultaneous intake of teas with food products that are being nitrosated within the stomach of human subjects should exert a protective, beneficial effect.
Plant components with bio-antimutagenic activity were screened on UVC (254 nm)-induced mutagenesis using E. coli B/r WP2. The components with a pyrogallol moiety including gallic acid, (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) reduced the mutation induction, but other components such as caffeic acid, chlorogenic acid and quercetin did not. The above compounds with a pyrogallol moiety were also effective on UVAB (295-400 nm)-induced mutagenesis, while they showed little effect on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenesis. As this bio-antimutagenic effect was not seen in the DNA excision-repair-deficient strains WP2s and ZA159, the activity by the above plant components might be based on the promotion of the excision-repair system in E. coli B/r WP2.
It is well established that phenols interfere with many routine protein assays and a number of protocols have been developed to overcome this. One such method is based on the differences in response obtained with the Lowry assay in the presence and absence of copper. This assumes that the phenol response with the Lowry assay is not affected by copper. However ortho-diphenols such as catechol, methylcatechol, caffeic acid, chlorogenic acid, and phaselic acid show decreased responses in the presence of copper. Three methods of estimating protein were compared for their accuracy in measuring proteins in the presence of covalently bound ortho-diphenols; the Lowry assay, the modified Lowry assay, and a new method including a calculation to take into account differences in ortho-diphenol response in the presence and absence of copper. The ortho-diphenols were caffeic acid and phaselic acid, which were bound to bovine serum albumin and red clover protein either chemically or enzymatically. For all assays, the new method gave values within 4 to 8% of control values for protein (without bound phenols) as determined by the modified Lowry method. Values for the Lowry and modified Lowry methods varied by 20-50% from control protein values. The new method also gave a good approximation of protein-bound phenol content.
Three extracts of Calendulae officinalis flos (Asteraceae): heptane, ethyl acetate and methanol were introduced to a human skin fibroblast (HSF) cells culture and a culture of human breast cancer cells (T47D), cell culture collection ECACC number 85102201. The ethyl acetate but not the heptane and methanol extracts in concentrations above 25 microg/mL, can stimulate cell proliferation and cellular metabolism by increase of mitochondrial dehydrogenase activity. However, concentrations exceeding 75 microg/mL are toxic for cells. The second part of the study concerned elaborating of optimal chromatographic systems for quantitative analysis of these extracts by the use of HPTLC with densitometry. Oleanolic acid, beta-amyrin, beta-amyrin acetate, rutin, narcissin, 3-glucoside of isorhamnetin, quercetin, isoquercitrin, vanillic acid, caffeic acid, chlorogenic acid, protokatechuic acid, p-coumaric acid and syringic acid were all identified.
High-performance liquid chromatography coupled with photo diode array detection and evaporative light scattering detection (HPLC/DAD/ELSD) was established to simultaneously determine nine ingredients in Qingkailing injection. Four wavelengths at 240, 254, 280 and 330 nm, respectively, were chosen as the monitoring wavelength to determine two nucleosides (uridine and adenosine), geniposide, baicalin and two organic acids (chlorogenic acid and caffeic acid), and an evaporative light scattering detector combined was employed to determine three steroids (cholic acid, ursodeoxycholic acid and hyodeoxycholic acid). This assay was fully validated in respect to precision, repeatability and accuracy. The proposed method was successfully applied to quantify the nine ingredients in 19 different Qingkailing injection samples and by principal component analysis (PCA) and hierarchical clustering analysis (HCA), it demonstrated significant variations in the content of these compounds in the samples from different manufacturers and preparation procedures. This method could be readily utilized as a quality control method for traditional Chinese medicine (TCM).
The newly established hyphenated instrumentation of LC/DAD/SPE/NMR and LC/UV/(ESI)MS techniques have been applied for separation and structure verification of the major known constituents present in Greek Hypericum perforatum extracts. The chromatographic separation was performed on a C18 column. Acetonitrile-water was used as a mobile phase. For the on-line NMR detection, the analytes eluted from column were trapped one by one onto separate SPE cartridges, and hereafter transported into the NMR flow-cell. LC/DAD/SPE/NMR and LC/UV/MS allowed the characterization of constituents of Greek H. perforatum, mainly naphtodianthrones (hypericin, pseudohypericin, protohypericin, protopseudohypericin), phloroglucinols (hyperforin, adhyperforin), flavonoids (quercetin, quercitrin, isoquercitrin, hyperoside, astilbin, miquelianin, I3,II8-biapigenin) and phenolic acids (chlorogenic acid, 3-O-coumaroylquinic acid). Two phloroglucinols (hyperfirin and adhyperfirin) were detected for the first time, which have been previously reported to be precursors in the biosynthesis of hyperforin and adhyperforin.