Amounts Of Phenolic Acids Research Articles

Distribution of free and combined phenolic acids in wheat internodes

Finely ground residues of mature and maturing wheat internodes after extraction with 80% ethanol were successively extracted with 96% dioxane to give milled lignin (ML 1) and water soluble (MC 1) fractions. The residue was treated with a polysaccharide hydrolase mixture to give a residue (ER 1). Quantitative analyses of phenolic acids were made on each of these fractions. Alkaline nitrobenzene oxidation and alkaline hydrolysis were used to determine the chemical state of the phenolic acids in the fractions. Very low quantities of free phenolic acids were found in the 80% ethanol extracts but significant amounts of esterified and etherified phenolic acids were present. The amounts of phenolic acids in the extract-free residue after alkaline nitrobenzene oxidation at 170° were always higher than those liberated by alkaline hydrolysis at room temperature. In mature internodes, 24% of the total p-coumaric acid (PCA) plus ferulic acid (FA) remained after mild alkaline hydrolysis. PCA is the major ester linked phenolic acid in ML 1, whereas FA is the major ester linked phenolic acid in MC 1. In ER 1 the predominant esterified phenolic acid is PCA, but FA is found both in ester and ether linked forms. The major changes in the ratio of esterified PCA/FA and the increases in etherified FA during maturity coincide with decreases in the digestibility of wheat internodes.

Flavonoids and phenolic acids in adenostoma, a dominant genus of the californian chaparral

The flavonoid and phenolic acid pattern of Adenostoma fasciculatum and A. sparsifolium, two dominant, endemic species of the Californian chaparral, was analysed qualitatively and quantitatively. Adenostoma sparsifolium was found to secrete large amounts of lipophilic, unusually substituted flavonoids onto the leaf surface; A. fasciculatum produces five hydrophilic flavonol 3-O-glycosides of kaempferol, quercetin and isorhamnetin. The phenolic acid pattern differed quantitatively but not qualitatively between the species. The amounts of phenolic acids that could be detected within the leaves, leaf litter and soil beneath the shrubs seem too small to explain allelopathic effects as the main reason for the dominance of the two species.

Influence of Phenolic Acids on Rumen Fungi1

AbstractPhenolic acids are associated with forage fiber, and in the free acid state have been shown to reduce in vitro fiber digestion by rumen bacteria. The objective of the study was to test the effect of free phenolic acids on the colonization and degradation of leaf blades by rumen fungi, which have been shown to attack lignified and other tissues. Colonization of leaf blades of ‘Coastal’ bermudagrass (Cynodon dactylon L. Pers.) by fungi was studied using the light microscope and digestibility was evaluated by dry weight loss. Reduction in the amounts of phenolic acids was determined using ultraviolet spectrophotometry at wavelengths characteristic for the acids. Colonization by rumen fungal populations from a steer (Bos spp.) eating bermudagrass or alfalfa (Medicago sativa L.) was evaluated in the presence of penicillin and streptomycin to inhibit growth of rumen bacteria. The addition of 0.1% p‐coumaric, ferulic, or sinapic acid to media reduced by at least two to three times the number of sporangia developing on the cut edges of leaf blades; the reduction was greater for the alfalfa inocula. Dry weight loss of leaf blade sections in the presence of acids was 25 to 50% of that without acids, and the reduction was greater with alfalfa inocula. No major differences in sporangial numbers or dry weight loss occurred among these acids. Reduction in spectral areas at characteristic wavelengths between uninoculated and inoculated tubes was 14 to 15% for p‐coumaric and ferulic acid, but was 44% for sinapic acid. Phenolic acids similar to those in plant cell walls inhibited the development of sporangia on leaf blades and reduced fiber digestion by rumen fungi.

Organic constituents in atmospheric fallout in the Tokyo area

The non-volatile organic constituents of eight atmospheric fallout (wet plus dry fallout) samples from the Tokyo area were determined. Considerable amounts of total organic carbon were found, ranging from 3.1 to 25 mgCm −2 day −1. n-Alkanes were found in the ranges of carbon chain length from C 12 to C 40 in total amounts between 4.4 and 55 μg m −2 day −1, in addition to an even larger amount of unresolved complex mixed hydrocarbons. Fatty acids were detected between carbon chain lengths of C 8 and C 34, including unsaturated and branched acids. The total content of fatty acids ranged from 26 to 190 μg m −2 day −1. Furthermore, o-, m- and p-hydroxybenzoic, vanillic and p-coumaric acids were identified and the presence of syringic, ferulic and protocatechuic acids and bisphenol A were indicated. The amounts of phenolic acids and bisphenol A were each less than 4.7 /gmg m −2day −1. These organic constituents may influence the composition of organic matter in urban aquatic environments. The major sources of hydrocarbons are considered to be higher plants, and combustion products of fossil fuels. The fatty acids and phenolic acids may be derived from higher plants as well as domestic and industrial sources. Pollens may be a source of plant organic matter. However, loss of more volatile compounds might have occurred during evaporation before analysis.