Individual Phenolic Acids Research Articles

Determination of phenolic acids and tannins in soil water extracts using the technicon autoanalyzer ii system

Abstract A manual colorimetric procedure for determination of phenolic compounds in food samples was modified for automated analysis of soil water extracts using the Technicon Autoanalyzer II (AA II). The Folin Denis color reagent consists of a mixture of molybdic and tungstic complexes which are reduced to oxides by phenolic acids. The oxides form blue salts under alkali conditions. This reaction was assumed to be specific to the hydroxy and methoxy bonds of phenolic acids. EDTA was added to complex calcium and magnesium in the sample extracts, which otherwise would have interfered with the colorimetric reaction. The method was useful for tracing the disappearance of 11 individual phenolic acids added to soil samples. Accurate measurement of the total concentration of mixed phenolic acids was not possible because of variation in the degree of color development between phenolic acids. The method was sensitive to tannic acid in soil water extracts.

Phenolic acid content of soils from wheat-no till, wheat-conventional till, and fallow-conventional till soybean cropping systems

Soil core (0-2.5 and/or 0-10 cm) samples were taken from wheat no till, wheat-conventional till, and fallow-conventional till soybean cropping systems from July to October of 1989 and extracted with water in an autoclave. The soil extracts were analyzed for seven common phenolic acids (p-coumaric, vanillic,p-hydroxybenzoic, syringic, caffeic, ferulic, and sinapic; in order of importance) by high-performance liquid chromatography. The highest concentration observed was 4 μg/g soil forp-coumaric acid. Folin & Ciocalteu's phenol reagent was used to determine total phenolic acid content. Total phenolic acid content of 0- to 2.5-cm core samples was approximately 34% higher than that of the 0- to 10-cm core samples. Phenolic acid content of 0- to 2.5-cm core samples from wheat-no till systems was significantly higher than those from all other cropping systems. Individual phenolic acids and total phenolic acid content of soils were highly correlated. The last two observations were confirmed by principal component analysis. The concentrations were confirmed by principal component analysis, tions of individual phenolic acids extracted from soil samples were related to soil pH, water content of soil samples, total soil carbon, and total soil nitrogen. Indirect evidence suggested that phenolic acids recovered by the water-autoclave procedure used came primarily from bound forms in the soil samples.

Changes in phenolic acid levels in wheat leaves expressing resistance to Puccinia recondita f. sp. tritici

Levels of individual phenolic acids were examined in primary leaves of wheat ( Triticum aestivum) after inoculation with avirulent and virulent strains of the leaf rust fungus ( Puccinia recondita f. sp. tritici) at stages when previous work had shown fungal and host cells to be affected by expression of the Lr20 or Lr28 alleles for resistance. The predominant phenolic acid, ferulic acid, as well as p-coumaric and syringic acids were detected in primary leaves in both unbound and bound forms. They were not detected in germinating urediniospores of either rust strain. Levels of unbound phenolic acids changed little in response to infection. In Lr28-bearing leaves inoculated with an avirulent strain, increased concentrations of bound phenolic acids and three other unidentified compounds were observed about 4 h after many single or small groups of cells had undergone hypersensitive collapse. In an Lr20-bearing cultivar, levels of bound phenolic acids fell in leaves inoculated with either a virulent or avirulent rust strain. Coniferyl aldehyde and coniferyl alcohol were not detected in healthy or inoculated leaves of either wheat cultivar. Attempts to affect expression of resistance by application of inhibitors of phenylalanine ammonia-lyase were not successful and both wheat cultivars remained resistant to avirulent rust strains. The bound phenolic acids which accumulate in cells undergoing a hypersensitive response may play a role in resistance of Lr28-bearing wheat to the leaf rust fungus.

Effects of mixtures of phenolic acids on phosphorus uptake by cucumber seedlings

To determine how individual phenolic acids in a mixture might affect phosphorus (P) uptake, 15-day-old cucumber seedlings grown in solution culture were treated with ferulic, vanillic,p-coumaric, or equimolar mixtures of these phenolic acids. Phenolic acid and P uptake were determined by solution depletion. The joint action of the mixtures of these phenolic acids on P uptake was primarily additive. Thus, as the number of phenolic acids increased in the mixture, the concentrations of the individual phenolic acids in the mixture required to bring about a given response declined. Seedling uptake of individual phenolic acids from solution mixtures of phenolic acids was reduced when compared to the uptake of phenolic acids from single phenolic acid solutions. The magnitude of the reduction varied with phenolic acid and concentration. The dose required for 50% inhibition of P uptake was approximately two to three times higher for vanillic acid (6.73 mM) than for ferulic (2.27 mM) andp-coumaric acids (3.00 mM) when dose was based on the initial treatment concentrations. The dose required for 50% inhibition of P uptake was not significantly different for the three phenolic acids (42 ± 5 μmol/g root fresh weight) when dose was based on phenolic acid uptake. Potential reasons for these differences are discussed.

EFFECT OF CONTROLLED ATMOSPHERE STORAGE ON PEACH QUALITY.

Peaches stored in air for 40 days at OC developed severe internal breakdown and poor quality after transferring them to 20C to ripen. Comparable fruit stored under controlled atmosphere (1% O2 + 5% CO2) and then ripened at 20C had no breakdown and retained good quality. Fruit stored under CA had less reducing sugars but more sucrose than air stored fruit. Fruit pH increased and titratable acidity decreased over a 40 day storage period. Citric acid increased slightly while malic acid decreased during storage. Little or no differences in overall acidity and individual organic acids existed between CA and air storage. Little or no change in individual phenolic acid content occurred during storage or between CA and air storage. Internal color darkened and became redder with storage. CA stored fruit was significantly firmer than air stored fruit. Sensory evaluation indicated CA stored fruit was more acidic, sweeter, and had better overall flavor than air stored fruit.

Effects of mixtures of phenolic acids on leaf area expansion of cucumber seedlings grown in different pH portsmouth A1 soil materials

Cucumber seedlings growing in A1horizon Portsmouth soil material adjusted to pH 5.2, 6.0, or 6.9 were treated with 0, 0.25 or 0.5, μmol/ g soil ferulic acid,p-coumaric acid, vanillic acid, or an equal mixture (0.5 μmol/g total) of two acids every other day. A total of five treatments was given starting with day 7 from seeding. Absolute rates of leaf expansion were determined for seedlings. The experiment was terminated when seedlings were 17 days old. All three phenolic acids inhibited leaf expansion. The dose required for 50% inhibition of absolute rates of leaf expansion increased as pH of the soil systems increased. The order of toxicity based on 50% dose and relative potency were as follows: ferulic acid > vanillic acid =p-coumaric acid. Effects of mixtures of phenolic acids on absolute rates of leaf expansion, when compared to the effects of individual phenolic acids, were found to be antagonistic for the ferulic-vanillic acid mixture and the ferulic-p-coumaric acid mixture in the pH 5.2 soil systems. Several phenolic acid treatments were required before antagonistic effects of mixtures were evident. In all other instances, when treatment effects were significant, the effects of individual phenolic acids were additive.

Microbial populations and phenolic acids in soil

Populations of bacteria, fungi and actinomycetes in Portsmouth A 1- and B,-soil material were affected in different ways by repeated enrichment with ferulic, p-coumaric, p-hydroxybenzoic or vanillic acids. Responses varied with type of soil material and phenolic acid, phenolic acid concentration, and inorganic nutrient status of the soil. Populations changed more frequently in B 1- than in A 1-soil material. Phenolic acids were readily metabolized by microorganisms, sometimes without detectable population changes, when adequate mineral nutrients were present. Induction of enzymes or selection of organisms capable of degrading individual phenolic acids were clearly evident. Results imply that microbial activity in bioassay systems should be defined for allelopathic studies, particularly when results from various bioassay systems are to be compared

Effect of American and French Oak Barrels on the Phenolic Composition and Sensory Quality of Seyval blanc Wines

Seyval blanc wine was aged in new American, Nevers, and Limousin oak barrels to measure differences in individual free phenolic acids during a time period of 12 weeks. HPLC separated at least 33 different compounds from ethanol extracts of wine. Six were tentatively identified and quantified as gallic, protocatechuic, vanillic, caffeic, syringic, and p -coumaric acids. Aging resulted in an increase in gallic acid for all oak-aged wines. The increase in gallic acid represented 7% of the total increase in nonflavonoid phenols. The results suggested that aging in different types of oak affects primarily the quantitative rather than the qualitative composition of the wine for those compounds having absorbance at 280 nm. The free phenolic acids under study appeared to have little effect on differences in sensory quality of oak-aged wines.

Stoffwechsel phenolischer Verbindungen in gesunden und Braunrost‐infizierten Gersten‐ und Weizenvarietäten

Abstract Metabolism of phenolic compounds in healthy and brown rust‐infected barley and wheat varieties Infections with Puccinia isolates cause an accumulation of phenolic compounds both in resistant and susceptible isogenic lines of barley and wheat seedlings. The increased de novo biosynthesis of hydroxy‐cinnamic and ‐benzoic acids is catalysed by the enzyme phenylalanine‐ammonia‐lyase (PAL) whose activity seems to be controlled not only by the substrate (phenylalanine) but also by the formed products (phenols). Depending on its actual physiological state every plant species shows as a reaction upon infection a typical behaviour. It is remarkable that healthy and rust‐infected plants contain the same percentage of individual phenolic acids. An infection does not lead to an increase of individual hydroxycinnamic‐ or benzoic acids. There are only differences in quantity but no differences in quality. The pattern of phenolic acids seems to be largely genetically determined and formed according to the developmental stage of the plants. The hydroxycinnamic and ‐benzoic acids formed during the host‐parasit‐interactions seem to be, at least for the analysed combinations, more the consequence than the cause of resistance.

Changes in Phenolic Acids in Groundnut Leaves Infected with Rust

AbstractQuantitative changes of individual phenolic acids in rust‐infected groundnut leaves were studied at various stages of disease development. There was no qualitative change in the phenolic acids. However, the concentration of the phenolic compounds increased due to infection more particularly of chlorogenic and trans and cis caffeic acids.

Plant growth inhibitory activity of extracts of raw and treated pig slurry

AbstractStrong acid extracts from raw and treated pig slurries were highly inhibitory to the germination and root growth of barley and wheat. While the activity of the extracts reflected the level of phenolic acids therein, the possibility of other substances contributing to this activity cannot be excluded. Tests with pure compounds showed that certain individual phenolic acids identified in pig slurries inhibited germination and root growth but at higher concentrations than previously reported. Of the treatment systems studied, aeration of pig slurry was the most effective in removing the inhibitory activity associated with extracts.

Behavior of phenolic substances in the decaying process of plants

Abstract Phenolic compounds in the soils collected from plow layers of arccnhousc and field cultures were surveyed quantitatively by ps chromatopphy. The results are as follows: 1) p-Coumaric|fcrulic, salicylic, p-hydroxybenzoic, vanillic, syrinaic, and protocatechuic acids were detected in all upland soils, as in the case of paddy and forest soils reported previously. Amona these phenolics, p-coumaric acid was present in the laraest quantity in most of the upland soils up to 29.0 ppm. 2) The total amounts of individual phenolic acids in the upland soils ranged from 9.5 to 62.0 ppm (average 26.0 ppm). Also, the amounts were less than 0.18% (averaae 0.10%) of the total soil organic matter. The averaae values in the upland soils were higher than those in the paddy soils. but were lower than those in the forest soils. 3) In upland soils, the concentrations of p-hydroxybenzoic, vanillic, syringic, p-coumaric, and ferulic acids, which have no chelatm, ability. were considerably related to the carbon content of soil, but the concentrations of protocatechuic and salicylic acids, which are chelatina agents, were not related to that of soil. These relationships agreed with those found in paddy and forest soils.

Behavior of phenolic substances in the decaying process of plants

Abstract Phenolic compounds in the soils collected from 6 paddy fields and 9 forests were surveyed quantitatively by gas chromatography. The results are as follows: 1) p-Coumaric, ferulic, vanillic, p-hydroxybenzoic, syringic, salicylic, and protocatechuic acids were detected in all soils. Among these acids, p-coumaric acid was present in the largest quantity in most of the soils. Gallic, caffeic, and sinapic acids, resorcinol, and phloroglucinol were not detected. 2) The total amounts of individual phenolic acids in the forest soils (34-632 ppm) were markedly higher than those in the paddy soils (10-26 ppm). p-Coumaric acid content went up to 188 ppm in the forest soils and up to 7 ppm in the paddy soils. The average concentration of total phenolic acids per weight of organic matter in the forest soils was about 2 times as high as that in the paddy soils. 3) In the paddy soils, the concentrations of p-hydroxybenzoic, vanillik, syringic, p-coumarie, and ferulic acids, which have no chelating ability, were considerably related to the pH and the carbon content of the soil, but the concentrations of protocatechuic and salicylic acids, which are chelating agents, were not related to those of the soil. Also in A horizons of forest soils, the concentrations of many phenolic acids were related to carbon content, but not to pH. 4) In a forest soil surveyed, the concentrations of individual phenolics decreased with increasing depth. However, the ratios of the amounts of individual phenolics to the carbon content increased with depth.

Behavior of phenolic substances in the decaying process of plants

Abstract Phenolic compounds in the soils collected from 6 paddy fields and 9 forests were surveyed quantitatively by gas chromatography. The results are as follows: 1) p-Coumaric, ferulic, vanillic, p-hydroxybenzoic, syringic, salicylic, and protocatechuic acids were detected in all soils. Among these acids, p-coumaric acid was present in the largest quantity in most of the soils. Gallic, caffeic, and sinapic acids, resorcinol, and phloroglucinol were not detected. 2) The total amounts of individual phenolic acids in the forest soils (34-632 ppm) were markedly higher than those in the paddy soils (10-26 ppm). p-Coumaric acid content went up to 188 ppm in the forest soils and up to 7 ppm in the paddy soils. The average concentration of total phenolic acids per weight of organic matter in the forest soils was about 2 times as high as that in the paddy soils. 3) In the paddy soils, the concentrations of p-hydroxybenzoic, vanillik, syringic, p-coumarie, and ferulic acids, which have no chelating ability, were...

Quantitative analysis for phenolic acids by thin-layer chromatography

A method is described by which phenolic acid compounds occurring in plant material can be separated on a polyamide column after suitable hydrolysis. The mixture of phenolic acids was also separated on silica gel G thin-layer plates, and the individual phenolic acids were determined spectrophotometrically. Phenolic acid compounds were hydrolysed by a technical enzyme or by treatment with 1% barium hydroxide solution, followed by 1% sulphuric acid. The method was applied successfully to fruit and vegetables.

Behavior of phenolic substances in the decaying process of plants

Abstract The changes in amount of ether-extractable phenolic substances, individual phenolic adds, organic matter content, and pH value in the decaying process of rice straw were compared at 10, 30, and 50°C under moist and flooded conditions for 70 days. 1) The changes in pH value with time varied markedly according to temperature and water conditions. 2) Phenolic substances in the ether-extractable fraction obtained from the acidified solution of alkaline methanol extract contained undetected phenolic compounds in amounts larger than the phenolic adds detected by gas chromatography. pH value during incubation was hardly attributable to these phenolic substances because of their small quantity. 3) The changes in amount of the ether-extractable phenolic substances with time was mainly due to phenolic compounds other than phenolic acids, and influenced largely by the temperature and water conditions. Their formation and degradation took place rapidly at high temperatures under flooded conditions. 4) From the plots of individual phenolic acids vs. time, it was tentatively concluded that phenolic acids contalned in non-decayed straw were rapidly degraded in the earlier stage, and some of them were newly produced from ether-unextractable precursors in the later stage. These reactions occurred rapidly at high temperatures, especially under flooded conditions. 5) The content of p-hydroxybenzolc acid increased simultaneously with a rapid decrease in p-coumaric acid during the incubation ot straw. The relationship between vanillic acid and ferulic acid was the same.

Alkanes and fatty acids in humic substances

Straight-chain fatty acids are shown to occur in natural humic acids and fulvic acids to a substantially greater extent than has previously been estimated. The amounts chemically bonded to the substrate usually exceed those physically adsorbed. Quantities of individual fatty acids and phenolic acids in typical samples have been estimated.