Number Of Phenolic Acids Research Articles

Content of Phenolic Acids in the Grain of Selected Polish Triticale Cultivars and Its Products.

The triticale grain has high nutritive value and good technological suitability. Triticale flour can be a valuable raw material for bread-making. The aim of this work was to determine the profile of phenolic acids in triticale grain of selected Polish cultivars and its products. Ultra-high-performance liquid chromatography (UPLC-PDA-MS/MS) was applied for separation and identification of these constituents. The grain of the examined triticale cultivars contained 13 phenolic acids, of which ferulic acid was determined in the largest amount and was constituted from 42–44% of the total content of phenolic acids in the grain. In addition, due to the large amounts of ferulic, di-ferulic, and sinapic acids, composition of the phenolic acids fraction in triticale grain of the tested cultivars varied in comparison with that of wheat and rye cultivars. In triticale flour, the number of phenolic acids was nearly 4 times lower than in the grain, as phenolic acids were removed along with bran, in which their proportion was almost 9 times higher than in the grain intended for grinding. The application of bran in the bread recipe resulted in a 3.5-fold increase in the fraction of phenolic acids compared to the bread produced from triticale flour without bran addition.

Binding mechanism and antioxidant capacity of selected phenolic acid - β-casein complexes.

Phenolic acids are added to some dairy products as functional ingredients. The molecular interactions between the phenolic acids and milk proteins impacts their functional performance and product quality. In this study, the interactions between a milk protein (β-casein) and a number of phenolic acids was investigated: 3,4-dihydroxybenzoic acid (DA); gallic acid (GA); syringic acid (SA); caffeic acid (CaA); ferulic acid (FA); and, chlorogenic acid (ChA). The structural characteristics of the phenolic acids, such as type, hydroxylation, methylation, and steric hindrance, affected their binding affinity to β-casein. The strength of the binding constant decreased in the following order: CaA>ChA>FA>SA>GA>DA. Cinnamic acid derivatives (CaA, FA, and ChA) exhibited a stronger binding affinity with β-casein than benzoic acid derivatives (DA, GA, and SA). Hydrophobic forces and electrostatic interactions dominated the interactions of β-casein with benzoic acid and cinnamic acid derivatives, respectively. The number of hydroxyl groups on the phenolic acids enhanced their binding ability, while steric hindrance effects reduced their binding ability. The influence of methylation depended on phenolic acid type. After binding with phenolic acids, the conformation of the β-casein changed, with a loss of random coil structure, an increase in α-helix structure, and a decrease in surface hydrophobicity. Furthermore, the presence of β-casein decreased the in vitro antioxidant capacities of the phenolic acids, especially for gallic acid. These findings provide some useful insights into the structure-activity relationships of the interaction between β-casein and phenolic acids.

UPLC-QTOF-MS analysis of a carbonic anhydrase-inhibiting extract and fractions of Luffa acutangula (L.) Roxb (ridge gourd).

Luffa acutangula (L.) Roxb, commonly known as ridge gourd (cucurbitaceae), is a common vegetable cultivated in India. It is also a well-used medicinal plant in Indian traditional medicine. To analyse the phenolics content of the most potent carbonic anhydrase-inhibiting fraction from an extract of L. acutangula. An aqueous ethanol extract of dried fruits of L. acutangula was successively fractionated into petroleum ether, dichloromethane and ethyl acetate. The extract and subsequent fractions were assessed for carbonic anhydrase-inhibitory activity and the enzyme inhibition kinetics were determined for the most active fraction. Total phenolic and flavonoid content of the extract and subsequent fractions were determined spectrophotometrically. Ultra-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF-MS) analysis was used to tentatively identify the major phenolics in the most active fraction. The concentration of total phenolics and total flavonoids in the extract and each fraction thereof correlated with the level of carbonic anhydrase inhibition activity. The ethyl acetate fraction of the aqueous ethanol extract of L. acutangula had the highest carbonic anhydrase inhibition activity. The enzyme kinetics analysis indicated a mixed mode of inhibition. UPLC-QTOF-MS analysis of the ethyl acetate fraction indicated a number of phenolic acids, hydroxycoumarins, flavones, flavanones, and flavonoids. The correlation of total phenolic content with carbonic anhydrase inhibition suggested further research that might confirm that phenolic compounds of L. acutangula offer potential therapeutic benefits against carbonic anhydrase-related disorders.

Evaluation of α-Amylase and α-Glucosidase Inhibitory Activity of Flavonoids

A number of phenolic acids and flavonoids were screened for inhibitory activity against rat intestinal α-glucosidase and porcine pancreatic α-amylase. The phenolic acids were not inhibitory to both enzymes at 1 mM. Inhibition of α-amylase by flavonoids mirrored the inhibition of α-glucosidase in that both baicalein and myricetin inhibited the enzyme most strongly, but differs in that spectrum of flavonoid inhibition for α-amylase only restricted to these two flavonoids while it was more wide spread for the inhibition of α-glucosidase. Baicalein inhibited α-amylase and α-glucosidase activity by 41.1±2.6% and 56.9±1.7% at 1 mM, respectively. Myricetin inhibited α-amylase and α-glucosidase activity by 35.9±3.8% and 47.7±2.4% at 1 mM, respectively. The IC50 (concentration required for 50% reduction activity) of baicalein (0.713±0.034 mM) and myricetin (1.030±0.026 mM) confirmed that baicalein is the most potent flavonoid inhibitor against α-glucosidase in the flavonoid series studied.

Antioxidant Properties of Greek O. dictamnus and R. officinalis Methanol and Aqueous Extracts—HPLC Determination of Phenolic Acids

This study determined the total phenol, phenolic acid content, the free radical scavenging activity, and ferric reducing antioxidant properties of methanol and aqueous extracts of R. officinalis and O. dictamnus species (Crete, Greece). The methanol extracts showed higher radical scavenging activity (P < 0.05) than the aqueous extracts (mean EC50 value: 0.33 and 0.38 mg/mL, respectively). Rosemary was superior in activity to dittany (mean EC50 value: 0.26 and 1.04 mg/mL, respectively). A number of phenolic acids were also tested for comparison reasons and showed stronger radical scavenging activity than the synthetic antioxidant BHT (mean EC50 value: 0.0821 mg/mL). In the contrary, the aqueous extracts showed significantly higher ferric reducing antioxidant properties (P < 0.05) than the methanol extracts did (mean EC50 value: 0.028 and 0.038 mg/mL, respectively). Rosemary was superior in reducing activity to dittany (mean EC50 value: 0.035 and 0.107 mg/mL, respectively). Caffeic and rosmarinic acids were found to be stronger reducing agents (mean EC50 value: 0.0034 and 0.0021 mg/mL, respectively) than the other phenolic acids as strong as ascorbic acid (mean EC50 value: 0.0033 mg/mL). The aqueous plant extracts contained significantly higher total phenol (P < 0.05) than the methanol extracts did (mean value: 7.55 and 4.07 mg/g dry leaf). Rosemary was a better source of total phenol than dittany (mean value: 5.14 and 3.35 mg/g dry leaf). Rosmarinic and caffeic acids were identified in all the plant extracts and rosmarinic acid was the predominant phenolic acid ranging from 5574.6 to 7542.9 mg/kg dry leaf. The aqueous plant extracts were significantly higher in phenolic acid content than the methanol extracts (P < 0.05) (mean value: 9631.2, 7796.4 mg/kg dry leaf, respectively). Dittany was the highest source of phenolic acid content (P < 0.05) compared to rosemary (mean value: 9134.9 and 8292.7 mg/kg dry leaf, respectively). A positive linear correlation was found between total phenol content, radical scavenging activity and ferric reducing antioxidant properties of dittany extracts (r2 = 0.9998).

Phenolic acids suppress adipocyte lipolysis via activation of the nicotinic acid receptor GPR109A (HM74a/PUMA-G)

Phenolic acids are found in abundance throughout the plant kingdom. Consumption of wine or other rich sources of phenolic acids, such as the "Mediterranean diet," has been associated with a lower risk of cardiovascular disease. The underlying mechanism(s), however, has remained unclear. Here, we show that many phenolic acids, including those from the hydroxybenzoic and hydroxycinnamic acid classes, can bind and activate GPR109A (HM74a/PUMA-G), the receptor for the antidyslipidemic agent nicotinic acid. In keeping with this activity, treatment with a number of phenolic acids, including cinnamic acid, reduces lipolysis in cultured human adipocytes and in fat pats isolated from wild-type mice but not from mice deficient of GPR109A. Oral administration of cinnamic acid significantly reduces plasma levels of FFA in the wild type but not in mice deficient of GPR109A. Activation of GPR109A by phenolic acids may thus contribute to a cardiovascular benefit of these plant-derived products.

The bioavailability of raspberry anthocyanins and ellagitannins in rats

The fate of anthocyanins and ellagitannins in rats was monitored following ingestion of raspberry juice. After 1 h low nM concentrations of unmetabolised anthocyanins were present in plasma but these declined by 2 h and after 4 h they were no longer detectable. For the first 2 h there was an almost full recovery of anthocyanins as they passed from the stomach through the duodenum/jejunum and into the ileum. After 3 h less than 50% were recovered, and the levels declined rapidly thereafter. Excretion of raspberry anthocyanins in urine over a 24 h period was equivalent to 1.2% of the amount ingested. Trace quantities of anthocyanins were detected in the caecum, colon and faeces and they were absent in extracts of liver, kidneys and brain. Urine also contained a number of phenolic acids but most were present in quantities well in excess of the 918 nmol of anthocyanins present in the ingested juice. These findings indicate that raspberry anthocyanins per se are poorly absorbed, probably prior to reaching the ileum, and that substantial amounts pass from the small to the large intestine where they are degraded by colonic bacteria. Ellagitannins disappeared in the stomach without accumulation of ellagic acid.

Decomposition of Allelopathic Plants in Soil

AbstractHigher plants with strong allelopathic properties are commonly incorporated into soil for weed‐control purposes. To understand the phytotoxic variation in the soil, which can be utilized for weed control through the use of allelopathic plants, the decomposition of alfalfa (Medicago sativa L. cv. Rasen) and kava (Piper methysticum L.) after soil amendment were evaluated. Both alfalfa and kava strongly inhibited barnyardgrass and monochoria growth for up to 10 days (80–100 % weed control). After 20–25 days, the magnitude of inhibition was drastically reduced, but was still effective (50 % weed control). A number of phenolic acids were detected in the soil even 50 days after incorporation in low concentration, but their concentrations reached a maximum after 10–15 days and were efficacious until 20–25 days. Phenolic acids varied between alfalfa and kava. The variations in electrical conductivity (EC) and osmotic pressure (OP) were strongly related to chemicals and toxic compounds exuded into the soil during decomposition and were proportional to the magnitude of inhibition observed, whereas pH did not appear to be correlated with inhibition. The decomposition of several unknown inhibitors present in kava was also analysed and assessed. Our findings indicate that these growth inhibitors were almost disintegrated in soil after 10 days, but strong inhibition was detected until 25 days after amendment. Results from this study demonstrate that chemicals released from allelopathic plants incorporated into soil are toxic and cause inhibition of certain species and could be exploited as a biological tool for weed management.

Identification of the Polyphenols in Barley and Beer by HPLC/MS and HPLC/Electrochemical Detection

Barley polyphenols were isolated using acetone/water (70/30) followed by Sephadex LH-20 chromatography. HPLC/Electrospray mass spectrometry showed the presence of proanthocyanidin dimers, trimers, tetramers, and pentamers. HPLC/electrochemical detection was used to survey the contents of these compounds in a range of barley varieties. Principal components analysis showed that the naked barley varieties Morrell, and to a lesser extent Namoi, were different from the other barley varieties. Beer polyphenol extracts were prepared using Sephadex LH-20 chromatography. A large number of proanthocyanidin dimers and trimers could be detected using HPLC/MS. HPLC/electrochemical detection was used to survey a range of beer types. Compounds detected included catechin, epicatechin, gallocatechin, epigallocatechin, a number of proanthocyanidin dimers and trimers, and a number of phenolic acids. The peaks removed by PVPP have been determined. Principal components analysis was used to identify those compounds which distinguished the beer types. The first principal component was due to prodelphinidin B3, catechin, gallocatechin and two unidentified compounds which were removed by PVPP and the second principal component was due to phenolic acids. Efforts to identify the compounds removed by PVPP have commenced.

Antibacterial constituents of Alchornea cordifolia leaves

AbstractAlchornea cordifolia (Euphorbiaceae), a traditional African medicinal plant, is widely distributed in West Africa. A number of phenolic acids, notably gallic acid, protocatechuic acid, quercetin, quercetin arabinose and galactose glycosides, together with triisopentenyl guanidine were isolated from a methanolic extract of the leaves. The first two, and last one of these compounds showed considerable antibacterial activity.