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PubMed1998

Natural dietary polyphenolic compounds cause endothelium-dependent vasorelaxation in rat thoracic aorta.

This study investigated the possible active principles which support the endothelial nitric oxide-dependent relaxation produced by red wine and other plant polyphenolic compounds in thoracic aorta from male Wistar rats (12-14 wk old). Relaxation experiments were recorded isometrically on vessels precontracted with norepinephrine. Ten different chromatographic fractions (3-18 mg) isolated from red wine polyphenolic compounds (RWPC) and some available defined polyphenols (10-15 mg) were tested. Fractions enriched into either anthocyanins or oligomeric condensed tannins exhibited endothelium-dependent vasorelaxant activity (maximal relaxation in the range of 59-77%) comparable to the original RWPC. However, polymeric condensed tannins elicited a weaker vasorelaxant activity than the original RWPC (maximal relaxation ranged between 20-47%, P < 0.01). Moreover, the representative of either phenolic acid derivatives (benzoic acid, vanillic acid, gallic acid), hydroxycinnamic acid (p-coumaric acid, caffeic acid) or the flavanol [(+)-epicatechin] classes failed to induce this type of response. Among the anthocyanins, delphinidin (maximal relaxation being 89%), but not malvidin or cyanidin, showed endothelium-dependent vasorelaxation. These results show that anthocyanins and oligomeric-condensed tannins exhibited a pharmacological profile comparable to the original RWPC. These compounds may be involved in the reduction of cardiovascular mortality related to the presence of wine, fruits and vegetables in the diet.

Animals↗
PubMed1995

4-coumarate:coenzyme a ligase from loblolly pine xylem. Isolation, characterization, and complementary DNA cloning.

4-Coumarate:CoA ligase (4CL, EC 6.2.1.12) was purified from differentiating xylem of loblolly pine (Pinus taeda L.). The pine enzyme had an apparent molecular mass of 64 kD and was similar in size and kinetic properties to 4CL isolated from Norway spruce. The pine enzyme used 4-coumaric acid, caffeic acid, ferulic acid, and cinnamic acid as substrates but had no detectable activity using sinapic acid. 4CL was inhibited by naringenin and coniferin, products of phenylpropanoid metabolism. Although the lignin composition in compression wood is higher in p-hydroxyphenyl units than lignin from normal wood, there was no evidence for a different form of 4CL enzyme in differentiating xylem that was forming compression wood. cDNA clones for 4CL were obtained from a xylem expression library. The cDNA sequences matched pine xylem 4CL protein sequences and showed 60 to 66% DNA sequence identity with 4CL sequences from herbaceous angiosperms. There were two classes of cDNA obtained from pine xylem, and the genetic analysis showed that they were products of a single gene.

Amino Acid Sequence↗
PubMed1998

4-Coumarate:coenzyme A ligase in hybrid poplar. Properties of native enzymes, cDNA cloning, and analysis of recombinant enzymes.

The enzyme 4-coumarate:coenzyme A ligase (4CL) is important in providing activated thioester substrates for phenylpropanoid natural product biosynthesis. We tested different hybrid poplar (Populus trichocarpa x Populus deltoides) tissues for the presence of 4CL isoforms by fast-protein liquid chromatography and detected a minimum of three 4CL isoforms. These isoforms shared similar hydroxycinnamic acid substrate-utilization profiles and were all inactive against sinapic acid, but instability of the native forms precluded extensive further analysis. 4CL cDNA clones were isolated and grouped into two major classes, the predicted amino acid sequences of which were 86% identical. Genomic Southern blots showed that the cDNA classes represent two poplar 4CL genes, and northern blots provided evidence for their differential expression. Recombinant enzymes corresponding to the two genes were expressed using a baculovirus system. The two recombinant proteins had substrate utilization profiles similar to each other and to the native poplar 4CL isoforms (4-coumaric acid > ferulic acid > caffeic acid; there was no conversion of sinapic acid), except that both had relatively high activity toward cinnamic acid. These results are discussed with respect to the role of 4CL in the partitioning of carbon in phenylpropanoid metabolism.

Amino Acid Sequence↗
PubMed1977

Role of Phenolic Inhibitors in Peroxidase-mediated Degradation of Indole-3-acetic Acid.

7-Hydroxy-2,3-dihydrobenzofuran derivatives, metabolites of a carbamate insecticide carbofuran, and five other phenolic inhibitors of indoleacetic acid (IAA) oxidase interfered with IAA-induced spectral change in the Soret band of horseradish peroxidase (HRP). The onset of IAA degradation required transformed HRP intermediates. The inhibitors, when added before IAA, protected HRP from reacting with IAA, thus preventing formation of highly reactive enzyme intermediates, and consequently, IAA degradation. When added after IAA, the inhibitors quickly reversed the IAA-induced spectral change of HRP and inhibited further IAA degradation.The phenolic inhibitors differed in stability and reactivity. 7-Hydroxy-2,2-dimethyl-2,3-dihydrobenzofuran, 3,7-dihydroxy-2,2-dimethyl-2,3-dihydrobenzofuran, catechol, protocatechuic acid, caffeic acid, ferulic acid, and scopoletin belonged to one group which produced only a temporary inhibition to IAA-induced spectral change of HRP and IAA degradation since the inhibitors were metabolized in the reaction. The length of the lag was dependent on the IAA, inhibitor, and enzyme concentrations. 3-Keto-7-hydroxy-2,2-dimethyl-2,3-dihydrobenzofuran and 3-keto-carbofuran belonged to the other group which produced a persistent inhibition.Degradation of IAA required both the heme group and apoprotein of HRP. Reconstituted enzyme from bovine hemin and apoprotein or HRP after unfolding by urea or guanidine treatment were inhibited by the inhibitors in a way similar to the native HRP. The inhibition was reversible by higher concentrations of IAA, but the plot of 1/v versus 1/s and 1/v versus i were curvilinear, reflecting the complex nature of a competitive inhibition.

Journal Article↗
PubMed2004

Purification, crystallization and preliminary X-ray crystallographic analysis of hydroxycinnamoyl-coenzyme A hydratase-lyase (HCHL), a crotonase homologue active in phenylpropanoid metabolism.

4-Hydroxycinnamoyl-coenzyme A hydratase-lyase (HCHL), also called feruloyl-CoA hydratase-lyase (FCHL), from Pseudomonas fluorescens strain AN103 is an enzyme of the crotonase superfamily that catalyses the one-step conversion of the CoA thioesters of 4-coumaric acid, caffeic acid and ferulic acid to the aromatic aldehydes 4-hydroxybenzaldehyde, protocatechuic aldehyde and vanillin, respectively. The reaction occurs via a hydration followed by a carbon-carbon bond-cleavage reaction. HCHL has been crystallized by the hanging-drop method of vapour diffusion using polyethylene glycol 20 000 Da as the precipitant. The crystals belong to the orthorhombic system, with proposed space group P2(1)2(1)2 and unit-cell parameters a = 154.2, b = 167.5, c = 130.8 A. The V(M) suggests that the asymmetric unit contains four trimers. Single-wavelength data collection has been undertaken and structure determination is under way by molecular replacement using data collected to 1.8 A resolution. Determination of the structure of HCHL will provide insight into the catalytic mechanism of an unusual enzymatic reaction with relevance to the applications of the enzyme in metabolic engineering.

Carbon↗
PubMed1982

In vivo and in vitro activity by diverse chelators against Trypanosoma brucei brucei.

A system of prescreens and screen has been developed to select chelators as potential drugs against Trypanosoma brucei brucei EATRO 110. The chelators tested were nearly all commercially available, low molecular, and having moderate to high affinity for Fe(III). We prescreened 70 compounds showing heme-sparing or inhibitory activity in a Crithidia fasciculata growth system having excess Fe and minimal hemin. Of these, 45 were highly trypanocidal for suspensions of bloodstream T. b. brucei; criteria of activity here were immobilization, lysis, and loss of infectivity. Eighteen of the chelators highly active in the suspension prescreen were tried in T. b. brucei-infected mice. Thirteen of these chelators were curative in mice with 24-h infections, that is, they allowed survival greater than 30 days beyond the untreated controls. 3,4-Dihydroxycinnamic acid (caffeic acid), 2,9-dimethyl-1, 10 phenanthroline (neocuproine), and 2-pyridinecarboxaldehyde-2-pyridyl-hydrazone cured five out of five mice after an i.v dose of 100 mg/kg. Salicylaldehyde thiosemicarbazone cured five out of five mice at an i.p. dose of 500 mg/kg. Lesser activity was shown by several other chelators.

Animals↗
PubMed1988

Characterization of an extracellular lignin peroxidase of the lignocellulolytic actinomycete Streptomyces viridosporus.

Previously we reported production of an extracellular lignin-inducible peroxidase by Streptomyces viridosporus (M. Ramachandra, D.L. Crawford, and A.L. Pometto III, Appl. Environ. Microbiol. 53:2754-2760, 1987). This peroxidase was shown to oxidize 3,4-dihydroxyphenylalanine, 2,4-dichlorophenol, homoprotocatechuic acid, caffeic acid, and N,N,N',N'-tetramethylphenylenediamine and was found in higher than normal levels in strains enhanced for lignocellulose degradation. In the present study, we used a pure extracellular enzyme preparation with high peroxidase isoform P3 activity to oxidize lignin substructure model compounds of both the 1,2-diaryl propane and arylglycerol-beta-aryl ether types and containing C alpha-carbonyl and C alpha-hydroxyl groups. The reactions were monitored by gas chromatography-mass spectrometry and high-pressure liquid chromatography techniques. In the presence, but not the absence, of hydrogen peroxide, the enzyme preparation catalyzed C alpha-C beta bond cleavage in the side chains of the diaryl ethers 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol (I) and 1-(4-hydroxy-3-methoxyphenyl)-2-(2-methoxyphenoxy)propan-1-one (II) and the diaryl ethane 1-(4-methoxyphenyl)-2-(phenyl)ethan-1-one (III). Rapid hydrogen peroxide consumption was observed when the enzyme preparation was added to either milled corn lignin or lignocellulose. Additional characterizations showed that this enzyme is a heme protein (Soret band, 408 nm) and a major component of the ligninolytic system of S. viridosporus T7A. This is the first report of a lignin peroxidase in a bacterium. We have designated this new lignin peroxidase as ALiP-P3.

Biodegradation, Environmental↗
PubMed2002

Cloning and characterization of the ferulic acid catabolic genes of Sphingomonas paucimobilis SYK-6.

Sphingomonas paucimobilis SYK-6 degrades ferulic acid to vanillin, and it is further metabolized through the protocatechuate 4,5-cleavage pathway. We obtained a Tn5 mutant of SYK-6, FA2, which was able to grow on vanillic acid but not on ferulic acid. A cosmid which complemented the growth deficiency of FA2 on ferulic acid was isolated. The 5.2-kb BamHI-EcoRI fragment in this cosmid conferred the transformation activity of ferulic acid to vanillin on Escherichia coli host cells. A sequencing analysis revealed the genes ferB and ferA in this fragment; these genes consist of 852- and 2,127-bp open reading frames, respectively. The deduced amino acid sequence of ferB showed 40 to 48% identity with that of the feruloyl-coenzyme A (CoA) hydratase/lyase genes of Pseudomonas and Amycolatopsis ferulic acid degraders. On the other hand, the deduced amino acid sequence of ferA showed no significant similarity to the feruloyl-CoA synthetase genes of other ferulic acid degraders. However, the deduced amino acid sequence of ferA did show 31% identity with pimeloyl-CoA synthetase of Pseudomonas mendocina 35, which has been classified as a new superfamily of acyl-CoA synthetase (ADP forming) with succinyl-CoA synthetase (L. B. Sánchez, M. Y. Galperin, and M. Müller, J. Biol. Chem. 275:5794-5803, 2000). On the basis of the enzyme activity of E. coli carrying each of these genes, ferA and ferB were shown to encode a feruloyl-CoA synthetase and feruloyl-CoA hydratase/lyase, respectively. p-coumaric acid, caffeic acid, and sinapinic acid were converted to their corresponding benzaldehyde derivatives by the cell extract containing FerA and FerB, thereby indicating their broad substrate specificities. We found a ferB homolog, ferB2, upstream of a 5-carboxyvanillic acid decarboxylase gene (ligW) involved in the degradation of 5,5'-dehydrodivanillic acid. The deduced amino acid sequence of ferB2 showed 49% identity with ferB, and its gene product showed feruloyl-CoA hydratase/lyase activity with a substrate specificity similar to that of FerB. Insertional inactivation of each fer gene in S. paucimobilis SYK-6 suggested that the ferA gene is essential and that ferB and ferB2 genes are involved in ferulic acid degradation.

Amino Acid Sequence↗
PubMed2005

Identification of flavonoids and their glycosides by high-performance liquid chromatography with electrospray ionization mass spectrometry and with diode array ultraviolet detection.

Identification of flavonoids and flavonoid glycosides was carried out on Psidium guajava Linn leaves by means of high-performance liquid chromatography ultraviolet (HPLC-UV) analysis and HPLC mass spectrometry. By using HPLC-UV, two known phenolics (gallic acid and quercetin) and five newly reported ones (procatechuic acid, chlorogenic acid, caffeic acid, kaempferol and ferulic acid) were identified in alcohol guava leaf extract. Structural information about the compounds was obtained from the retention times, the UV spectra and mass spectra without the need to isolate the individual compounds. Two flavonoids (quercetin and kaempferol) and four flavonoid glycosides (three known components, quercetin 3-O-alpha-L-arabinoside, quercetin 3-O-beta-D-glucoside and quercetin 3-O-beta-D-galactoside, along with one novel compound, kaempferol-glycoside) and three other unknown compounds have been identified in the fractions.

Chromatography, High Pressure Liquid↗
PubMed1988

Lipoxygenase products as common intermediates in cyclic AMP-dependent and -independent adrenal steroidogenesis in rats.

Aldosterone secretion from adrenal glomerulosa cells can be stimulated by angiotensin II (AII), extracellular potassium and ACTH. Mitochondria from these cells respond to intracellular factors generated by AII (cyclic AMP (cAMP)-independent steroidogenesis) and ACTH (cAMP-dependent steroidogenesis), suggesting that the two-signal-transduction mechanisms are linked by a common intermediate. We have evaluated this hypothesis by stimulating mitochondria from the unstimulated zona glomerulosa with a subcellular post-mitochondrial fraction (PMF) obtained from the zona glomerulosa after stimulation with AII or from the fasciculata gland after stimulation with ACTH; the subcellular fractions were also tested on mitochondria from fasciculata cells. PMFs obtained after incubation of adrenal zona glomerulosa with or without AII (0.1 microM) or ACTH (0.1 nM) were able to increase net progesterone synthesis 4.5-fold in mitochondria isolated from unstimulated rat zona glomerulosa. AII-pretreated PMFs from the zona glomerulosa also stimulated steroidogenesis by mitochondria from zona fasciculata cells. Separate experiments showed that inhibitors of arachidonic acid release and metabolism (bromophenacyl bromide, nordihydroguaiaretic acid, caffeic acid or esculetin) blocked corticosterone production in fasciculata cells stimulated with ACTH, suggesting that arachidonic acid could be the common intermediate in the actions of AII and ACTH on steroid synthesis. Evidence to support this concept was obtained from experiments in which the formation of an activated PMF by treatment of zona fasciculata with ACTH was blocked by the presence of the same inhibitors. Moreover, the inhibitory effects of these substances on PMF activation by ACTH were overcome by exogenous arachidonic acid and, in addition, arachidonic acid release was stimulated by ACTH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗
PubMed2001

Abatement of the major contaminants present in olive oil industry wastewaters by different oxidation methods: ozone and/or UV radiation versus solar light.

Four different cinnamic acids (caffeic acid, ferulic acid, p-coumaric acid and cinnamic acid) present in olive oil wastewaters, were treated with advanced oxidation methods: ozone and/or UV radiation. Basic and acid media were tested. Differences between all four acids were found, both in the reaction times and the intermediates formed. Based on a careful study of these intermediates and the variation of their concentrations all along the reaction time, a general mechanism for the degradative oxidation of cinnamic acids is proposed. These results are compared with those obtained with solar light, using a pyrylium salt as a catalyst.

Cinnamates↗
PubMedDate not supplied

In vitro antioxidant and in vivo photoprotective effects of a lyophilized extract of Capparis spinosa L buds.

The aim of the present study was to evaluate the in vitro antioxidant and in vivo photoprotective activities of a lyophilized extract of Capparis spinosa L. (LECS) obtained by methanolic extraction from the flowering buds of this plant. For the in vitro experiments, LECS was tested employing three different models: (a). bleaching of the stable 1,1-diphenyl-2-picrylhydrazyl radical (DPPH test); (b). peroxidation, induced by the water-soluble radical initiator 2,2'-azobis(2-amidinopropane) hydrochloride, of mixed dipalmitoylphosphatidylcholine/linoleic acid unilamellar vesicles (LUVs) (LP-LUV test); and (c). UV-induced peroxidation of phosphatidylcholine multilamellar vesicles (UV-IP test). The in vivo antioxidant/radical scavenger activity was assessed by determining the ability of topically applied LECS to reduce UVB-induced skin erythema in healthy human volunteers. From the results obtained in in vitro and in vivo tests, LECS showed a significant antioxidant effect. Furthermore, by chromatographic fractionation and spectroscopic methods, we identified the major constituents of LECS, and particularly some flavonols (kaempferol and quercetin derivatives) and hydroxycinnamic acids (caffeic acid, ferulic acid, p-cumaric acid, and cinnamic acid).

Adult↗
PubMed2002

[Studies on the chemical constituents from herba of Corallodiscus flabellata].

OBJECTIVE: To study the chemical constituents from Corallodiscus flabellata. METHOD: The compounds were isolated with macroporous adsorption resin, silica gel column chromatography and identified on the basis of their physiochemical and spectral data. RESULT: Six compounds were obtained and identified as vanillic acid, 3,4-dihydroxyphenylethyl-8-O-beta-D-glucopyranoside, syringic acid, caffeic acid, isoacteoside, ferulic acid. CONCLUSION: All the compounds were isolated from this plant for the first time.

Gallic Acid↗
PubMed1989

[Polyphenolic substances of Cynara scolymus L. leaves].

From the leaves of Cynara scolymus the following substances where isolated: apigenin, luteolin, luteolin-4'-glucoside, cynaroside, scolimoside, cosmoside, quercetin, rutin, chlorogenic acid, caffeic acid, isochlorogenic acid, luteolin-7-gentiobioside, along with the more uncommon scopoletin, hesperitin, hesperidoside, esculetin-6-O-beta-glucoside; more over maritimein was for the first time isolated and identified in the genus.

Phenols↗
PubMed1980

Inhibitory effects of phenolic compounds on benzo(a)pyrene-induced neoplasia.

The inhibitory effects of 18 synthetic phenolic compounds added to the diet on benzo(a)pyrene-induced neoplasia of the forestomach of female ICR/Ha mice have been determined. Seven of the compounds showed suppression of neoplasia. The most potent inhibitors were p-methoxyphenol, 2-tert-butyl-4-hydroxyanisole [the minor isomer of 2(3)-tert-butyl-4-hydroxyanisole] and 3,5-di-tert-butylcatechol. A second group of compounds with a weaker inhibitory activity consisted of 3,5-di-tert-butylphenol, 3-tert-butyl-4-hydroxyanisole [the major isomer of 2(3)-tert-butyl-4-hydroxyanisole], 2-tert-butylhydroquinone, and 2-tert-butylphenol. In additional experiments, three naturally occurring phenolic derivatives of cinnamic acid, i.e., o-hydroxycinnamic acid, 3,4-dihydroxycinnamic acid (caffeic acid), and 4-hydroxy-3-methyoxycinnamic acid (ferulic acid), were investigated. All three suppressed benzo(a)pyrene-induced neoplasia of the forestomach. Humans ingest a variety of phenols. Data as to the inhibitory capacities of members of this group of compounds are of importance for evaluating the role that they play in determining the reaction to exposure to chemical carcinogens.

Animals↗
PubMedDate not supplied

In vivo effect of dietary factors on the molecular action of aflatoxin B1: role of non-nutrient phenolic compounds on the catalytic activity of liver fractions.

Young adult rats were kept on a synthetic diet containing various food associated phenolic compounds each at 0.5% level. The ability of liver microsomes to catalyze reactions of aflatoxin B1 leading to its activation and DNA adduct formation was measured after an experimental feeding period of 3 weeks. A decrease in both activities was observed with several flavonoids (fisetin, kaempferol, morin, naringin and (+/-)catechin), phenolic acids (caffeic acid and chlorogenic acid), other phenolics (eugenol, vanillin) and synthetic phenolic antioxidants butylated hydroxyanisole and butylated hydroxytoluene. Certain phenolics notably naringin, (+/-) catechin, eugenol, vanillin and butylated hydroxyanisole were also found to induce cytosolic glutathione S-transferase activity that stimulated the formation of specific aflatoxin B1-glutathione conjugate. The results emphasize the role of phenolic compounds in the activation and detoxification processes, and hence in modulating the carcinogenicity of aflatoxin B1.

Aflatoxin B1↗
PubMed1994

Suppression of hydroperoxide-induced cytotoxicity by polyphenols.

A variety of synthetic and dietary polyphenols protect mammalian and bacterial cells from cytotoxicity induced by hydroperoxides, especially hydrogen peroxide (H2O2). Cytotoxicity of H2O2 on Chinese hamster V79 cells was assessed with a colony formation assay. Cytotoxicity and mutagenicity of H2O2 on Salmonella TA104 were assessed with the Ames test. SOS response induced by H2O2 was investigated in the SOS chromotest with Escherichia coli PQ37. The polyphenol-bearing o-dihydroxy (catechol) structure, i.e., nordihydroguaiaretic acid, caffeic acid ester, gallic acid ester, quercetin, and catechin, were effective for suppression of H2O2-induced cytotoxicity in these assay systems. In contrast, neither ferulic acid ester-bearing o-methoxyphenol structure nor alpha-tocopherol were effective, indicating that o-dihydroxy or its equivalent structure in flavonoids is essential for the protection. There are many reports describing that polyphenols act as prooxidants in the presence of metal ions. Our results suggest, however, that they act as antioxidants in the cells, when no metal ions are added to the medium.

Animals↗
PubMed1991

Purification of a new peroxidase catalysing the formation of lignan-type compounds.

A novel peroxidase that catalyses the dimerization of ferulic acid or caffeic acid via oxidative coupling and formation of beta beta'-linkage to the lignan-type compounds 8,8'-bis(caffeic acid) or 8,8'-bis(ferulic acid) respectively was purified from the leaves of Bupleurum salicifolium. The enzyme, for which the name caffeate peroxidase is proposed, was purified 2700-fold. It is a glycoprotein and has an Mr of 38,000 as determined by gel filtration and SDS/PAGE. The Km values for ferulic acid and caffeic acid were 0.24 mM and for H2O2 0.04 mM with caffeic acid and 0.48 mM with ferulic acid. The purified peroxidase does not exhibit activity on other phenylpropanoids tested and has no detectable phenol oxidase or NADPH oxidase activity. The caffeate peroxidase could be involved in the biosynthesis of lignans.

Catalysis↗