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PubMed1980

[Obtaining flour and a protein concentrate from seeds of the Helianthus annuus (sunflower) and its addition in cookies].

The objectives of the studies described herein were: 1) to obtain a sunflower flour and protein concentrate for human consumption, and 2) to explore possible ways for their utilization. The Peredovik variety was selected, since it is most abundant in Mexico. The procedure usually followed for the obtention of flours for animal feeds was used with some modifications. The hull was mechanically eliminated with a yield of 51%, with a satisfactory appearance of the almond. In order to facilitate the milling of the almonds, 80% of the oil was extracted by compression (18,000 kg/cm2 for 10 minutes) after steaming during 10 min. Chlorogenic acid ws eliminated with a 70% ethanol solution. The resulting flour could be added to wheat flour in as high a proportion as 65% in weight. Cookies were then prepared which contained 16 g/100 g with a protein of high quality, 80% to 90% in relation to casein, and with adequate sensorial properties.

Amino Acids↗
PubMed1995

Activation of the classical pathway of complement by tobacco glycoprotein (TGP).

Tobacco glycoprotein (TGP), a polyphenol-rich glycoprotein isolated from tobacco leaves, activates the classical complement pathway through a mechanism that appears to involve direct interaction with C1q. A binding site on C1q for TGP can be localized by competitive inhibition with DNA to a region located in the junction between the collagen-like and globular regions of the molecule. A protein with activity similar to TGP has also been isolated from cigarette smoke condensate (TGP-S); it shares a binding site on C1q with TGP and has similar functional activity, with the exception that complement activation does not proceed to formation of a C3 cleaving enzyme. The ability of TGP and TGP-S to activate complement can be partially duplicated using polyphenols associated with tobacco leaf and smoke, i.e., chlorogenic acid and rutin. These polyphenols also compete with TGP for a binding site on immobilized C1q, suggesting that the polyphenol portion of TGP is critical for activation of complement. These results provide an additional mechanism for complement activation by cigarette products that, in vivo, could result in a localized complement depletion, generation of biologically active complement cleavage products, and initiation of an inflammatory response.

Complement Activation↗
PubMed1996

[Polyphenolic composition of the leaf of bilberry].

Dried leaves of 14 harvested batches and one batch from commercial origine of Vaccinium myrtillus L present a similar polyphenolic pattern. The mean levels of the harvested batches and the levels of the commercial batch were respectively: total polyphenol compounds 12.98 and 10.62%, tannins 7.84 and 7.43%, total flavonoid compounds 2.98 and 2.20% (spectrophotometry), 1.41 and 1.16% (HPLC), quercetin 3-glucuronide 1.02 and 0.83%, hyperoside 0.22 and 0.16%, chlorogenic acid 3.66 and 1.58%. The levels were higher in young leaves and lower in old leaves. A specific chromatographic profile of the flavonoid compounds and a determination method of the tannin or the total polyphenol content were proposed in a standardization purpose.

Chromatography, High Pressure Liquid↗
PubMed1998

Inhibition of cholesterol biosynthesis in primary cultured rat hepatocytes by artichoke (Cynara scolymus L.) extracts.

High-dose aqueous extracts from artichoke leaves were found to inhibit cholesterol biosynthesis from 14C-acetate in primary cultured rat hepatocytes in a concentration-dependent biphasic manner with moderate inhibition (approximately 20%) between 0.007 and 0.1 mg/ml and more strong inhibition at 1 mg/ml. Cytotoxic effects detected by lactate dehydrogenase leakage and the 3-[4, 5-dimethylthiazol-2-yl]-2,5-dephenyl tetrazolium bromide-assay were restricted to higher concentrations. Replacement of 14C-acetate by 14C-mevalonate largely omitted the inhibiting effect of artichoke extracts indicating an inhibition at the level of hydroxymethylglutaryl-CoA-reductase. However, no direct inhibition of this enzyme could be detected and no other enzymic steps later in the biosynthetic pathway for cholesterol seemed to be affected. Instead, inhibition was found to occur in a time-dependent manner, to last for several hours even after washing out the extracts by fresh medium and to be fully reversible within 20 hr after removal of the extracts. In addition, the stimulation of HMGCoA-reductase activity by insulin was efficiently blocked by the extracts, although other insulin-dependent phenomena, such as increased lactate production, were not influenced. These results suggest an indirect modulation of hydroxymethylglutaryl-CoA-reductase activity as the most likely inhibitory mechanism of the artichoke extracts. Screening of several known constituents of artichoke extracts revealed that cynaroside and particularly its aglycone luteolin were mainly responsible for inhibition, whereas chlorogenic acid was much less effective and caffeic acid, cynarin and other dicaffeoylquinic acids were without significant influence. Indeed, luteolin also efficiently blocked the insulin effect on cholesterol biosynthesis. In conclusion, these results demonstrate that artichoke extracts may inhibit hepatic cholesterol biosynthesis in an indirect but efficient manner and, thus, may contribute via this action to the recently confirmed hypolipidemic influence of this phytopharmacon in man.

Acetates↗
PubMed1996

Inhibition of metmyoglobin/H2O2-dependent low density lipoprotein lipid peroxidation by naturally occurring phenolic acids.

The ferrylmyoglobin <==> metmyoglobin redox transitions promoted by hydrogen peroxide and dietary phenolic acids and their potential role in the oxidation of LDL were studied. The use of parinaric acid incorporated in LDL as a probe for radicals (detected by fluorescence quenching of the probe) revealed an oxidative stress inside LDL shortly ( < 1 min) after addition of hydrogen peroxide to metmyoglobin in the aqueous phase outside the particle, reflecting an efficient access of the oxidant to LDL lipids. However, the propagation step of peroxidation only occurs after a lag phase, as detected by the kinetics of oxygen consumption. Triton X-100 decreases but does not suppress the lag phase of oxidation. Addition of metmyoglobin (without peroxide) to LDL was not followed by significant oxidation during the time of the experiment, unless Triton X-100 was present in the medium. When dietary phenolic acids were present in the medium before peroxide addition, an inhibition of parinaric acid fluorescence quenching and oxygen consumption was recorded as a function of concentration and substitution pattern on the phenol ring of the phenolic acids. This was associated with a conversion of ferrylmyoglobin to metmyoglobin. The results indicate that the naturally occurring phenolic acids prevent ferrylmyoglobin-dependent LDL oxidation in a way strongly dependent on the substitution pattern on the phenol ring. Among the phenolic compounds studied, the o-dihydroxy derivatives of cinnamic and benzoic acids (caffeic, chlorogenic, and protocatechuic acids), in a molar ratio of 1 to metmyoglobin, efficiently blocked LDL oxidation initiated by ferrylmyoglobin. Replacement of one OH group from catecholic structure with an H (p-coumaric acid) or methoxy group (ferulic acid) decreased the antioxidant activity. Also, the catechol structure fused in heterocyclic rings with adjacent carbonyl groups (ellagic acid) resulted in decreased antioxidant activity. These observations correlate with the efficiency of phenolic acids to reduce ferrylmyoglobin to metmyoglobin. Therefore, the protection of LDL against oxidation is assigned to the reduction of the oxoferryl moiety of the hemoprotein to the ferric form. Additionally, it is suggested that an access constraint of oxidants plays a minor role in the ferrylmyoglobin-induced oxidation against LDL.

Animals↗
PubMed2006

Differential methods of inoculation of plant growth-promoting rhizobacteria induce synthesis of phenylalanine ammonia-lyase and phenolic compounds differentially in chickpea.

Foliar spray and micro-injection of plant growth-promoting rhizobacterial species, viz. Pseudomonas fluorescens and P. aeruginosa on chickpea induced synthesis of phenylalanine ammonia-lyase (PAL) when tested against Sclerotinia sclerotiorum. Induction of PAL was also associated with increased synthesis of phenolic compounds such as tannic, gallic, caffeic, chlorogenic and cinnamic acids. Treatment with P. fluorescens was found to be more effective in inducing phenolic compounds as compared to P. aeruginosa. However, persistence of PAL activity was observed more with P. aeruginosa. Although both the inoculation methods were effective, foliar application was found to be superior to micro-injection in terms of rapid PAL activity leading to the synthesis of phenolic compounds.

Antibiosis↗
PubMed2005

Chlorogenate hydrolase-catalyzed synthesis of hydroxycinnamic acid ester derivatives by transesterification, substitution of bromine, and condensation reactions.

A chlorogenate hydrolase (EC 3.1.1.42) synthesized 2-phenylethyl caffeate (2-CAPE) from 5-chlorogenic acid (5-CQA) and 2-phenylethyl alcohol (2-PA) (by transesterification), from 5-CQA and 2-phenylethyl bromide (2-PBr) (by substitution of bromine), and from caffeic acid (CA) and 2-PA or 2-PBr (by condensation) as well as hydrolysis of 5-CQA. Some reaction conditions including pH, temperature, substrate and solvent concentrates, and reaction time were optimized for the production of 2-CAPE. A maximal molar yield of 50% was achieved by transesterification, 4.7% by substitution of bromine, and 13% by condensation. Among the parameters studied for optimization, the pH of the buffer solution and concentration of 2-PA or 2-PBr affected the production of 2-CAPE. The optimum pH for the hydrolysis reaction was within the neutral range (pH 6.5), whereas the residual three reactions were only catalyzed within the acidic range (pH 3.0-4.0). The optimum concentrations of 2-PA and 2-PBr for three reactions were 5-70 vol% and no 2-CAPE was produced in the 2-PA or 2-PBr solutions containing powdered enzyme. The enzyme may bind to the caffeoyl moiety of 5-CQA or CA to form an enzyme-substrate complex. It then catalyzes four different reactions corresponding to the reaction conditions.

Aspergillus↗
PubMed2003

Flavoring components of raw monsooned arabica coffee and their changes during radiation processing.

Volatile aroma principles, nonvolatile taste constituents (caffeine and chlorogenic and caffeic acids), and glycosidically bound aroma compounds of monsooned and nonmonsooned raw arabica coffee were analyzed using gas chromatography-mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC). Among the most potent odor active constituents known to contribute to the aroma of the green beans, 3-isopropyl-2-methoxypyrazine, 3-isobutyl-2-methoxypyrazine, 4-vinylguaiacol, beta-damascenone, (E)-2-nonenal, trans,trans-2,4-decadienal, phenylacetaldehyde, and 3-methylbutyric acid were detected by GC-MS in both samples. A decrease in content of methoxypyrazines and an increase in 4-vinylguaiacol and isoeugenol resulted in a dominant spicy note of monsooned coffee. These phenolic compounds exist partly as their glycosides, and their release from the bound precursors during monsooning accounted for their higher content in monsooned coffee. A considerable decrease in astringent chlorogenic acid as a consequence of hydrolysis to bitter caffeic acid was noted in monsooned coffee. Radiation processing of nonmonsooned beans at a dose of 5 kGy resulted in an increased rate of monsooning. At this dose a quantitative increase in most of the aroma active components could be observed in all samples studied. Hydrolysis of chlorogenic acid to caffeic acid was noted in radiation-processed monsooned coffee beans irrespective of whether the treatment was carried out before or after monsooning. These changes were, however, not observed in irradiated, nonmonsooned coffee beans, suggesting an enzymatic rather than a radiolytic cleavage of chlorogenic acid. A rationale behind the mechanism of monsooning and radiation-induced enhancement of the monsooning process is discussed.

Caffeic Acids↗
PubMed1983

Protective effects of ellagic acid and other plant phenols on benzo[a]pyrene-induced neoplasia in mice.

The inhibitory effects of three phenolic compounds (ferulic, chlorogenic and ellagic acids) on benzo[a]pyrene- and 7,12-dimethylbenz[a]anthracene-induced neoplasia have been investigated in mice. Ellagic acid was the most potent antagonist of tumorigenesis since this compound is active, by i.p. administration or added in the diet, on benzo[a]pyrene-induced pulmonary adenoma formation in A/J mice and, after topical application, on 7,12-dimethylbenz[a]anthracene-induced skin tumorigenesis in NMRI Swiss mice. If ellagic acid has little or no effect on the number of tumor bearing animals, the incidence of pulmonary tumors per animal is decreased by greater than 50%. Ferulic acid and chlorogenic acid (5 X 100 mg/kg, by i.p. route) were also active, but less than ellagic acid, against the lung carcinogenesis by benzo[a]-pyrene (100 mg/kg, i.p.) but were totally ineffective against the formation of skin tumors by 7,12-dimethylbenz[a]anthracene. These results remarkably paralleled the in vitro antimutagenic effects of these compounds shown by Wood et al. on benzo[a]pyrene. It must be noted that ellagic acid only exerted, by i.p. route, a severe toxicity after four injections of 100 mg/kg, in oil suspension, whereas the oral administration in the diet (a daily dose of 100 mg/kg during 15 days) did not cause any toxicity.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1979

[Influence of food browning on nutrition. III. Effect of brown substances on digestive enzyme activity (author's transl)].

In the present study, we separated and partially purified brown substances from eggplants and examined their inhibitory action on trypsin activity. The following results were obtained: 1. The first half of the elute after passing ethanol-extractable brown substances through DEAE-cellulose column showed no inhibitory action on trypsin, whereas the middle portion of the elute contained a trypsin inhibitor(s). Similar results were obtained after fractionation with Sephadex G-25. The degree of inhibition was increased after purification. 2. Both crude ethanol extracts of eggplant brown substances and acetate buffer extracts from eggplant exocarps showed similarly an enzyme inhibition of competitive type. 3. Both nondialyzable portion of ethanol extracts and purified fraction after Sephadex G-25 passage showed a noncompetitive type of inhibition. DOPA-melanin and chlorogenic acid-melanin as model substances exhibited a similar noncompetitive inhibition. Purified ethanol extracts of eggplant brown substances showed an ultraviolet absorption spectrum similar to that of chlorogenic acid. From these findings it is concluded that both eggplant brown substances and polyphenol substances play an essential role in the inhibition of digestive enzymes.

Melanins↗
PubMed1991

Loss of heterocyclic amine mutagens by insoluble hemicellulose fiber and high-molecular-weight soluble polyphenolics of coffee.

The presence of 2 kinds of components in brewed and instant coffee that could remove and destroy heterocyclic amine mutagens was demonstrated. The component that could remove the mutagens was insoluble fiber composed of hemicellulose. The fiber could tightly adsorb the mutagens Trp-P-1, Trp-P-2, Glu-P-1 and A alpha C, and those generated in roasted coffee beans. The component that could destroy the mutagens was high-molecular-weight soluble polyphenolics. They might be converted into quinone derivatives in the presence of molecular oxygen. The quinone derivatives might destroy the mutagens. The fibers and the polyphenolics in one cup of brewed or instant coffee had the capacity to remove and destroy a substantial amount of the mutagens in pyrolysates of foodstuffs.

Amines↗
PubMed2006

Potential polyphenol markers of phase change in apple (Malus domestica).

In order to identify potential biochemical markers that can be used as indicators for phase change, the dynamics of polyphenolic compounds across apple seedlings (Malus domestica, Jonathan x Golden Delicious) were analyzed in this study by high performance liquid chromatography. Precocious flowering was induced by foliar sprays of plant growth regulators. Qualitative changes in the concentration of polyphenols were observed at node nos. 50, 80 and 120. Spontaneous and induced flowering was found at node nos. 122 and 77. It was reasonable to conclude that node no. 77 represented the point of transition between the juvenile phase and the adult vegetative phase, which was marked by the presence of phloridzin in the buds. The disappearance of myricitrin in the bark and the absence of caffeic acid in the aboveground tissues were qualitative markers of the reproductive phase, which was reached at node no. 122.

Biomarkers↗
PubMed2000

Expression of tryptophan decarboxylase and tyrosine decarboxylase genes in tobacco results in altered biochemical and physiological phenotypes.

The substrate specificity of tryptophan (Trp) decarboxylase (TDC) for Trp and tyrosine (Tyr) decarboxylase (TYDC) for Tyr was used to modify the in vivo pools of these amino acids in transgenic tobacco. Expression of TDC and TYDC was shown to deplete the levels of Trp and Tyr, respectively, during seedling development. The creation of artificial metabolic sinks for Trp and Tyr also drastically affected the levels of phenylalanine, as well as those of the non-aromatic amino acids methionine, valine, and leucine. Transgenic seedlings also displayed a root-curling phenotype that directly correlated with the depletion of the Trp pool. Non-transformed control seedlings could be induced to display this phenotype after treatment with inhibitors of auxin translocation such as 2,3,5-triiodobenzoic acid or N-1-naphthylphthalamic acid. The depletion of aromatic amino acids was also correlated with increases in the activities of the shikimate and phenylpropanoid pathways in older, light-treated transgenic seedlings expressing TDC, TYDC, or both. These results provide in vivo confirmation that aromatic amino acids exert regulatory feedback control over carbon flux through the shikimate pathway, as well as affecting pathways outside of aromatic amino acid biosynthesis.

3-Deoxy-7-Phosphoheptulonate Synthase↗