酚酸物质对红松种子萌发及苗木生长和生理特性的影响

Simple SummaryIn the context of international commitments to reduce the environmental impact of herbicides, ecologically more favorable control method approaches must be explored. This is particularly important for allergenic Ambrosia artemisiifolia L., one of the most harmful species in the world. Secondary plant metabolites and, in particular, some phenolic compounds are known to have a strong allelopathic effect on weed growth. In this study we investigated whether phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid) can inhibit the early growth of A. artemisiifolia. Phenolic acids were tested at five different dose levels that were up to 16 times than those naturally occurring in plants. The results show that the suppression of the early growth of A. artemisiifolia is strongly dependent on phenolic acid and its dose. Treating seeds with ferulic acid, vanillic acid, p-coumaric acid, p-hydroxybenzoic acid, or a mixture of all phenolic acids resulted in significantly better inhibition of early growth parameters than other phenolic acids. However, none of the phenolic acids tested were effective as bioherbicides at their naturally occurring doses in plants. Therefore, selected doses of phenolic acids with significantly reduced herbicide doses should be further explored to effectively control A. artemisiifolia.This study aimed to investigate whether different doses of specific phenolic acids (chlorogenic acid, caffeic acid, ferulic acid, gallic acid, protocatechuic acid, p-hydroxybenzoic acid, syringic acid, vanillic acid, and p-coumaric acid), alone or in combination, can inhibit the early growth of the common ragweed (Ambrosia artemisiifolia L., Asterales: Asteraceae). A seed bioassay was performed in Petri dishes and placed in a climate chamber to assess the effects of five dose levels of phenolic acids to radicle and shoot length, as well seedling biomass of A. artemisiifolia. The lowest dose of phenolic acid corresponded to the natural phenolic acid concentration previously reported in dry plant tissue samples from Brassicaceae cover crop plants. Results show that the inhibition of the early growth of A. artemisiifolia depends strongly on phenolic acid. Across different treatments, high doses of phenolic acids significantly shortened shoots and radicles, as well as reduced seedling biomass. Treating seeds with ferulic acid alone, vanillic acid alone, p-hydroxybenzoic acid alone, or a mixture of all phenolic acids significantly reduced all early growth parameters. The estimated effective dose for the 50% inhibition (ED50) of radicle growth in A. artemisiifolia seedlings was 368.39 ± 59.85 × 10−8 mol with ferulic acid, 135.41 ± 17.65 × 10−8 mol with p-coumaric acid, 810.36 ± 134.15 × 10−8 mol with p-hydroxybenzoic acid, and 160.11 ± 12.30 × 10−8 mol with the combination of all phenolic acids.

A strong radical-scavenging activity against a stable radical compound, 1,1-diphenyl-2-picrylhydrazyl (DPPH) was found in the hot water extract of Japanese rice bran. When the extract was treated with ethanol, a dominant radical-scavenging activity was observed in the ethanol-soluble (ES) fraction in a dose-dependent manner, but a weak radical-scavenging activity was detected in the ethanol-precipitable (EP) fraction. Their activities were proportional to the amounts of phenolic substances in each fraction. The phenolic substances in the ES fraction were efficiently separated by Amberlite XAD column chromatography and high performance liquid chromatography using an ODS column. The four major phenolic acids (ferulic, para-coumaric, para-hydroxybenzoic and vanillic acids) and four minor phenolic acids (caffeic, gentisic, protocatechuic and syringic acids) were detected in the HPLC system. Among these phenolic acids, protocatechuic, caffeic, ferulic and gentisic acids showed relatively strong radical scavenging activities (EC50: 8, 9, 29 and 75 microM, respectively) compared with the control antioxidants such as ascorbic acid and alpha-tocopherol (EC50: 93 and 134 microM). Para-coumaric, syringic and vanillic acids exhibited weak but significant radical-scavenging activities (EC50: 780, 2640 and 3250 microM). However, para-hydroxybenzoic acid did not show any significant effects even at 5 mM. Furthermore, a simulated mixture combined with these phenolic acids in comparable amounts in the ES fraction showed slightly weak radical-scavenging activity compared with that of rice bran extract. However, all the phenolic acids detected in the ES fraction did not show significant antioxidant activities against hydroperoxide generation in lipid peroxidation compared with that of a typical antioxidant such as ascorbic acid, which was estimated by the alminum chloride method. These results suggest that Japanese rice bran has a potent radical-scavenging activity against DPPH radical and this activity is associated with some phenolic acids in the ES fraction. The significance of this finding is discussed from the viewpoint of the protective role of rice bran against oxygen radical-induced chronic diseases.

Lignin-related phenolic acids have been implicated in rice sterility problem on peatlands in Southeast Asia. Therefore, a comparison was made of phenolic constituents in peat soils from three zones; tropical Malaysia, temperate Japan and boreal Finland. From peat samples were extracted lignin-derived phenolic acids: 4-hydroxybenzoic, vanillic, syringic, trans-4-hydroxycinnamic and ferulic acids. The amounts of all the phenolic acids were greater in the tropical and temperate peat soils than in the boreal peat. Between the tropical and temperate peats, there was a marked difference in the quantitative distribution of the five phenolic acids. The ratio of the total amount of trans-4-hydroxycinnamic and ferulic acids to that of 4-hydroxybenzoic, vanillic and syringic acids was 0.12 for tropical and 2.7 for temperate peats. The substituted hydroxycinnamic acids, therefore, occurred in a smaller amount in the tropical than in the temperate peat soils. The polymerisation of these phenolic acids may cause rice sterility problem in the tropical peat soils.

The antioxidative properties of p‐hydroxy‐benzoic acid, vanillic acid, syringic acid, 3,4‐dihydroxy‐benzoic acid, p‐coumaric acid, ferulic acid, sinapic acid and caffeic acid in lard autoxidation at 100°C are compared. The effect of phenolic acids is investigated within the concentration range 0.02 – 0.20 wt %. It is proved that the derivatives of the benzoic acid have weaker inhibiting properties than is the case of the corresponding analogues of the cinnamic acid due to the more active participation of the inhibitor in the elementary reactions of propagation and initiation of the radical chain process. The activity (a complex parameter demonstrating the efficiency and strength of the antioxidant) of the phenolic acids investigated decreases in the sequence: caffeic acid >3,4‐dihydroxy‐benzoic acid > sinapic acid > syringic acid>ferulic acid>p‐coumaric acid>vanillic acid. The increase in concentration of the acids investigated is most advisable in the case of sinapic, syringic and ferulic acids which are not consumed in side reactions.

Vanillic acid and syringic acid: Exceptionally robust aromatic moieties for inhibiting in vitro self-assembly of type I collagen

Enzymatic coupling of chloroanilines with syringic acid, vanillic acid and protocatechuic acid

Fresh and sun-dried dates of three native varieties from Oman, namely, Fard, Khasab, and Khalas, were examined for their antioxidant activity and total contents of anthocyanins, carotenoids, and phenolics, as well as free and bound phenolic acids. All results are expressed as mean value +/- standard deviation (n = 3) on a fresh weight basis. Fresh date varieties were found to be a good source of antioxidants (11687-20604 micromol of Trolox equiv/g), total contents of anthocyanins (0.24-1.52 mg of cyanidin 3-glucoside equiv/100 g), carotenoids (1.31-3.03 mg/100 g), phenolics (134-280 mg of ferulic acid equiv/100 g), free phenolic acids (2.61-12.27 mg/100 g), and bound phenolic acids (6.84-30.25 mg/100 g). A significant (p < 0.05) amount of antioxidants and carotenoids was lost after sun-drying of dates, whereas the total content of phenolics and free and bound phenolic acids increased significantly (p < 0.05). Anthocyanins were detected only in fresh dates. Date varieties had different levels and patterns of phenolic acids. Four free phenolic acids (protocatechuic acid, vanillic acid, syringic acid, and ferulic acid) and nine bound phenolic acids (gallic acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, syringic acid, p-coumaric acid, ferulic acid, and o-coumaric acid) were tentatively identified. Of the date varieties studied, Khalas, which is considered to be premium quality, had higher antioxidant activity, total carotenoids, and bound phenolic acids than other varieties. These results suggest that all date varieties serve as a good source of natural antioxidants and could potentially be considered as a functional food or functional food ingredient, although some of their antioxidant constituents are lost during sun-drying.

Phenolic acids are widely distributed in foods and raw materials. They are easily absorbed by humans due to their simplicity. Once they enter the blood plasma, they act as antioxidants. Beer can be a rich source of phenolic acids in the diet. The aim of this study was to determine the concentrations of phenolic acids in two experimental worts and beers as well as in nine market beers (using HPLC-UV). An examination of the total antiradical activities of phenolic acids with in vitro model systems (using ABTS and DPPH free radicals), at the concentrations comparable to those detected in beers, was performed. Only low fractions of the main phenolic acids present in barley malt (ferulic, vanillic and p-coumaric acid) were detected in the experimental worts. Moreover, the concentrations of phenolic acids significantly decreased until the last steps of beer production. The main beer phenolic acids (vanillic and ferulic acid) exerted a lower share of total antiradical activity against both free radicals (calculated as the sum of the individual activities of all acids detected in beer) than the minor phenolic acids (caffeic, chlorogenic, o-coumaric, sinapic or syringic acid). The synergies, between individual phenolic acids in pairs, were also studied with in vitro model solutions using free radicals. The total antiradical activity of the compounds studied in pairs, was at the most as high as the sum of the antiradical activity of the individual phenolic acids, but in most cases it was considerably lower (i.e. no synergy was detected).

BackgroundPhenolic acids are lignin-derived fermentation inhibitors formed during many pretreatment processes of lignocellulosic biomass. In this study, vanillic, p-hydroxybenzoic, and syringic acids were selected as the model compounds of phenolic acids, and the effect of short-term adaptation strategies on the tolerance of S. cerevisiae to phenolic acids was investigated. The mechanism of phenolic acids tolerance in the adapted yeast strains was studied at the morphological and physiological levels.ResultsThe multiple phenolic acids exerted the synergistic inhibitory effect on the yeast cell growth. In particular, a significant interaction between vanillic and hydroxybenzoic acids was found. The optimal short-term adaptation strategies could efficiently improve the growth and fermentation performance of the yeast strain not only in the synthetic media with phenolic acids, but also in the simultaneous saccharification and ethanol fermentation of corncob residue. Morphological analysis showed that phenolic acids caused the parental strain to generate many cytoplasmic membrane invaginations with crack at the top of these sites and some mitochondria gathered around. The adapted strain presented the thicker cell wall and membrane and smaller cell size than those of the parental strain. In particular, the cytoplasmic membrane generated many little protrusions with regular shape. The cytoplasmic membrane integrity was analyzed by testing the relative electrical conductivity, leakage of intracellular substance, and permeation of fluorescent probe. The results indicated that the short-term adaptation improved the membrane integrity of yeast cell.ConclusionThe inhibition mechanism of phenolic acid might be attributed to the combined effect of the cytoplasmic membrane damage and the intracellular acidification. The short-term adaptation strategy with varied stressors levels and adaptive processes accelerated the stress response of yeast cell structure to tolerate phenolic acids. This strategy will contribute to the development of robust microbials for biofuel production from lignocellulosic biomass.

ABSTRACTSimple phenolic acid levels were determined on pooled millstreams of five different classes of Canadian wheat milled to ~75, 80, and 85% extraction. Pooled flours and whole grain were analyzed by reversed‐phase high‐performance liquid chromatography (RP‐HPLC) to establish endogenous levels of insoluble bound, soluble esterified, and free phenolic acids. Only ferulic acid was detected in the insoluble bound category, which accounted for &gt;80% of the total phenolic acids present in every flour. The soluble esterified phenolic acids accounted for up to 17% of the overall total phenolic acid content within a flour. The major constituents were sinapic, ferulic, and vanillic acids, with minor amounts of coumaric, caffeic, and syringic acids. Free phenolic acids accounted for a maximum of 6% of the total phenolic content of any prepared flour. Ferulic acid was the major free phenolic acid, while sinapic acid was not detected in any flour. Significant correlations (r = 0.64–0.97, P &lt; 0.05) were observed between insoluble bound ferulic acid, individual soluble esterified acids, and most free acids with polyphenol oxidase activity, as well as color and ash content for each class.

Influence of dietary phenolic acids on redox status of iron: Ferrous iron autoxidation and ferric iron reduction

Mulberries, Morus spp., grow in different growing regions of Turkey with a high diversity providing an opportunity to select superior accessions. The goal of the study was to determine the differences in phytochemical components and horticultural characteristics between white and black mulberry accessions in the Igdir province. Fruits of black and white mulberries collected from Igdir province were assayed for various horticultural characteristics including berry width, berry length, berry weight, and berry peduncle length. Samples were also assayed for vitamin C, organic acids (citric, tartaric, malic, succinic, and fumaric), sugars (glucose and fructose), phenolic acids (catechin, rutin, quercetin, chlorogenic, ferulic, o-coumaric, p-coumaric, caffeic, syringic, vanillic, and gallic acids), and antioxidant capacity [Trolox equivalent antioxidant capacity (TEAC) assay]. Differences (P &lt; 0.05) were noted between accessions in berry length and berry weight. Malic acid was found to be the predominant organic acid regardless of species. Rutin (for black mulberry) and chlorogenic acid (for white mulberry) were the predominant phenolic acids. Black mulberry had higher glucose and fructose content than white mulberry. Analysis showed that black mulberry had higher content of tartaric acid, malic acid, TEAC, fructose, glucose, catechin, rutin, quercetin, o-coumaric acid, and caffeic acid compared with white mulberry (P &lt; 0.01); however, white mulberry had higher content of succinic acid, vitamin C, chlorogenic acid, ferulic acid, p-coumaric acid, syringic acid, and gallic acid (P &lt; 0.01). Our results provide a reference for further studies of mulberry fruits in detection of organic acids, sugars, antioxidant capacity, and phenolic compounds. Also, it is clear that we need standardized testing, extraction, and analysis protocols to compare genotypes grown in different countries.

Plant phenols may accumulate in end-stage kidney disease. The effect of hemodialysis on their plasma concentration remains poorly determined. Contingent on concentration, health-promoting or noxious effects occur; therefore, we assessed plasma concentration in hemodialyzed patients. In total, 21 maintenance hemodialyzed patients with diuresis < 500 mL per day (with oliguria), nine hemodialyzed patients with diuresis ≥ 500 mL per day (without oliguria) and 31 healthy volunteers were included. Nine phenolic acids were identified with high-performance liquid chromatography and total polyphenol concentration was determined with the Folin-Ciocalteu method in pre- or post-hemodialysis plasma and pre- or intra-hemodialysis dialysate. The concentration of total polyphenols was 27% higher in pre-hemodialysis plasma than in that of controls (0.95 ± 0.18 mmol/L [P < 0.0001]). The concentration of total polyphenols was higher in patients with oliguria (1.01 ± 0.17) than in those without (0.84 ± 0.13 mmol/L), despite the former having more intense hemodialysis (Kt/V 1.29 ± 0.31 and 0.77 ± 0.25, respectively). Pre-hemodialysis phenolic acid concentration in patients undergoing dialysis exceeded reference values by 3 to 34 times (3-hydroxyphenylacetic acid and vanillic acid, respectively), from 0.69 (dihydrocaffeic acid) to 169.3 μmol/L (hippuric acid). The concentration of six phenolic acids (3-hydroxyhippuric, caffeic, dihydrocaffeic, hippuric, homovanillic, and vanillic acid) was 1.1 (homovanillic) to 11.3 (3-hydroxyhippuric) times higher in patients with oliguria than in those without. 4-hydroxyhippuric acid occurred more in the plasma of patients with oliguria than in those without oliguria. A single hemodialysis session decreased total polyphenol concentration by 16% and phenolic acids from 30% (caffeic) to 58% (vanillic and 3-hydroxyphenylacetic acid) and these compounds appeared in the dialysate. The percentage decrease (Δ%) of creatinine concentration correlated with the Δ% of total polyphenols and five phenolic acids (3-hydroxyphenylacetic, dihydrocaffeic, hippuric, homovanillic, and vanillic acid). Urea Δ% and Kt/V correlated only with the Δ% of homovanilic acid. The results demonstrate that phenols accumulate variably in hemodialyzed patients and are differently eliminated during hemodialysis. Residual renal function ensures a lower concentration of plasma phenols.

The present research focused on the analysis of European beech (Fagus sylvatica L.) wood polyphenols in respect to red heartwood formation, which is a significant color and technological defect of the species. For the first time, high-performance liquid chromatography/tandem mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) were applied for the investigation of the structure and the radial distribution of polyphenols. Altogether 125 compounds were characterized by their MSn spectra, of which 71 were tentatively identified, including procyanidins (dimers to pentamers), flavonoids (taxifolin, naringenin, isorhamnetin, (epi)afzelechin), (+)-catechin, (−)-epicatechin) and their glycoside conjugates, phenolic acids (gallic acid, vanillic acid, syringic acid) and their glycosides as well as gallic acid derivatives, many of which were identified for the first time in beech wood. It was found that the concentration of many compounds increased at the color boundary. In situ polyphenol synthesis and metabolism were clearly evidenced at the color boundary. Red heartwood contained only free aglycones (syringic acid, taxifolin, naringenin, isorhamnetin, naringenin, syringic acid). Contrary to earlier assumptions, the MALDI-TOF analysis did not indicate the presence of oxidized high-molecular-weight polymeric polyphenols in the red heartwood tissues. The role of individual compounds in the formation of the red heartwood chromophores are discussed.

Chemical agents in the rhizosphere soils of plants might have an influence on root-rot disease, which therefore might reveal the mechanism of root rot in Panax notoginseng (P. notoginseng). With this hypothesis the alterations of phenolic acids (PAs) in the rhizosphere soils of P. notoginseng after pathogen infection were determined. The effects of PAs on the growth of Fusarium oxysporum (F. oxysporum), a fungal pathogenic factor for P. notoginseng, as well as production of fusaric acid, a wilting agent for the plants, were also examined. The results indicate the presence of five PAs (ferulic acid, syringic acid, p-hydroxybenzoic acid, p-coumaric acid, and vanillic acid) in the rhizosphere soils of P. notoginseng, whose contents in the rhizosphere soils of healthy plants are higher than those of the diseased ones. Further we found that individual PA could inhibit the mycelium growth and spore production of F. oxysporum, but stimulate fusaric acid production as well, disclosing the double-edge sword role of PAs in the occurrence of root rot of P. notoginseng and paving the way for the intervention of P. notoginseng root rot via balancing PAs.