Hydrolyzed Tannins from Geranium pusillum

The polyphenolic compound 1-O-galloyl-3,6-hexahydroxybiphenyl-D-galactopyranoside (pusilagin) was isolated from the aerial part. The tannin structure was established using acid hydrolysis and IR, PMR, and ¹³C NMR spectral methods.     

Lipase-Catalyzed Solvent-Free Amidation of Phenolic Acids

A series of N-alkyl-substituted amides, based on various phenolic acids, have been synthesized by the condensation of equimolar amounts of phenolic acids with different alkyl amines in the presence of Candida antarctica lipase at 60–90 °C in 16–20 h. The reactions were carried out in a solvent-free system without the use of any activating agents. All the products were obtained in appreciable amounts and the yields for different compounds varied between 75.6% and 83.5%. The synthesized compounds were characterized using spectroscopy techniques, namely infrared and NMR (¹H and ¹³C).     

Thin-Layer Chromatography of Phenolic Acids on Aminopropylsilica

JPC – Journal of Planar Chromatography – Modern TLC - The possibility of using aminopropylsilica TLC plates for determination of phenolic acids has been investigated. Eighteen phenolic...     

Comparison of the Antihypertensive Activity of Phenolic Acids

Phenolic acids, found in cereals, legumes, vegetables, and fruits, have various biological functions. We aimed to compare the antihypertensive potential of different phenolic acids by evaluating their ACE inhibitory activity and cytoprotective capacity in EA.hy 926 endothelial cells. In addition, we explored the mechanism underlying the antihypertensive activity of sinapic acid. Of all the phenolic acids studied, sinapic acid, caffeic acid, coumaric acid, and ferulic acid significantly inhibited ACE activity. Moreover, gallic acid, sinapic acid, and ferulic acid significantly enhanced intracellular NO production. Based on the results of GSH depletion, ROS production, and MDA level analyses, sinapic acid was selected to study the mechanism underlying the antihypertensive effect. Sinapic acid decreases endothelial dysfunction by enhancing the expression of antioxidant-related proteins. Sinapic acid increased phosphorylation of eNOS and Akt in a dose-dependent manner. These findings indicate the potential of sinapic acid as a treatment for hypertension.     

Use of Oligosalicylates in the Preparation of Phenolic Amido Acids

Abstract

A simplified methodology has been developed for preparing salicylamides from the corresponding acids via oligosalicylates which both protect the phenolic group and, at the same time, activate the carboxyl for coupling.     

Anticancer,Cardio-Protective and Anti-Inflammatory Potential of Natural-Sources-Derived Phenolic Acids

Phenolic acids (PAs) are one of the utmost prevalent classes of plant-derived bioactive chemicals. They have a specific taste and odor, and are found in numerous medicinal and food plants, such as Cynomorium coccineum L., Prunus domestica (L.), and Vitis vinifera L. Their biosynthesis, physical and chemical characteristics and structure–activity relationship are well understood. These phytochemicals and their derivatives exert several bioactivities including but not limited to anticancer, cardioprotective, anti-inflammatory, immune-regulatory and anti-obesity properties. They are strong antioxidants because of hydroxyl groups which play pivotal role in their anticancer, anti-inflammatory and cardioprotective potential. They may play significant role in improving human health owing to anticarcinogenic, anti-arthritis, antihypertensive, anti-stroke, and anti-atherosclerosis activities, as several PAs have demonstrated biological activities against these disease during in vitro and in vivo studies. These PAs exhibited anticancer action by promoting apoptosis, targeting angiogenesis, and reducing abnormal cell growth, while anti-inflammatory activity was attributed to reducing proinflammatory cytokines. Pas exhibited anti-atherosclerotic activity via inhibition of platelets. Moreover, they also reduced cardiovascular complications such as myocardial infarction and stroke by activating Paraoxonase 1. The present review focuses on the plant sources, structure activity relationship, anticancer, anti-inflammatory and cardioprotective actions of PAs that is attributed to modulation of oxidative stress and signal transduction pathways, along with highlighting their mechanism of actions in disease conditions. Further, preclinical and clinical studies must be carried out to evaluate the mechanism of action and drug targets of PAs to understand their therapeutic actions and disease therapy in humans, respectively.     

Simultaneous Determination of Phenolic Acids in Water Caltrop by HPLC-DAD

Trapa natans L., or the water caltrop, a native plant of Romania, has not been researched in our country until recently. It has, however, been used for the treatment of the several diseases since ancient times. The objective of this work is to validate the HPLC method to detect and quantify the phenolic acids from Trapa natans L. specie. The HPLC-DAD method was validated for the analysis of 3-O-methylgallic, chlorogenic, caffeic, and ferulic acids in water caltrop roots, leaves, pulp, and hulls. The analysis was conducted on a Zorbax XDB-C18 column with gradient elution of acetonitrile-orthophosphoric acid. The method was validated in terms of linearity, accuracy, precision, limit of detection, quantification, and recovery, and found to be satisfactory. We verified the performance parameters after experimental studies, and we established that the HPLC method can be applied for the determination of phenolic acids in plant materials.     

New Feruloyl Esterases to Access Phenolic Acids from Grass Biomass

In the Sorangium cellulosum strain So ce56 genome, two putative esterase-encoding genes (loci sce1896 and sce8927) were cloned, expressed in Escherichia coli, and the resulting enzymes (designated ScFAE1 and ScFAE2) were used to assess the possible release of ferulic acid (FA) from triticale and wheat brans, and an aqueous fraction of steam-exploded wheat straw. The two polypeptides, sharing only 30% sequence identity, exhibit a typical catalytic Ser-Asp-His triad, a characteristic of α/β-hydrolase fold proteins. Both ScFAE1 (35?kDa) and ScFAE2 (34?kDa) were purified to apparent homogeneity and comparison of their kinetic parameters indicated an apparent higher affinity of ScFAE2 than ScFAE1 towards the various feruloyl substrates. This property was reflected by the observation that ScFAE2 was capable of yielding up to 85% of FA from destarched triticale bran. In the steam-exploded wheat sample, more than 85% yield of FA or p-coumaric acid was also effected by ScFAE2 without the decomposition of valuable chemical such as furfural. The two cloned FAEs represent the first of myxobacterial origin to be characterized and they are classified as new members of the type D family of FAEs.     

Simultaneous Capillary Electrophoretic Analysis of Flavonoids and Phenolic Acids in Plants

An efficient capillary electrophoretic method is described for the simultaneous determination of hydroxylated and methoxylated flavonoids and phenolic acids present in plant extracts. The separation of samples injected in pressure injection mode was carried out using fused silica capillary in boric acid buffer (alkaline pH) containing SDS as pseudostationary phase and methanol as organic modifier with direct UV detection at 220nm.     

Thin-Layer Chromatographic Analysis of Flavonoids,Phenolic Acids,and Amino Acids in Some Croatian Hypericum Taxa

JPC – Journal of Planar Chromatography – Modern TLC - The flowering tops of Hypericum hirsutum, H. montanum, H. perforatum subsp. angustifolium, H. perforatum subsp. perforatum, and H....     

Determination of Phenolic Acids in Danshen Preparations by LC with Chemiluminescence Detection

A simple and sensitive method has been developed for the simultaneous determination of eight phenolic acids in Danshen preparations based on liquid chromatography with chemiluminescence detection. Chemiluminescence parameters including flow rate, buffer pH, the concentration of luminescent and reactive solutions, were optimized. The analytical performance of the optimized luminol-H₂O₂ detection was compared with those of luminol-pyrogallol and UV detection. Under the optimized conditions, the method was validated with respect to linearity, precision, limits of detection and quantification. The method offers an attractive alternative to be used to evaluate the quality of Danshen preparations.     

The Quantitative Determination of some Phenolic Acids In Delphinium Formosum by HPLC

ABSTRACT

Some phenolic acids from the flowers of Delphinium formosum have been determined quantitatively by reversed-phase high-performance liquid chromatography with diode-array detection. A comparative study was performed by extracting the following phenolic acids: p-hydroxy benzoic, p-coumaric, caffeic, protocatechuic and vanillic acids with four different methods. The results were supported with recovery studies.     

HPTLC Determination of Flavonoids and Phenolic Acids in Some Croatian Stachys Taxa

JPC – Journal of Planar Chromatography – Modern TLC - Stachys is a large genus belonging to the family Lamiaceae. In common with many other representatives of this family, the aerial...     

Cocrystals of Praziquantel with Phenolic Acids: Discovery,Characterization, and Evaluation

Solvent-assisted grinding (SAG) and solution slow evaporation (SSE) methods are generally used for the preparation of cocrystals. However, even by using the same solvent, active pharmaceutical ingredient (API), and cocrystal coformer (CCF), the cocrystals prepared using the two methods above are sometimes inconsistent. In the present study, in the cocrystal synthesis of praziquantel (PRA) with polyhydroxy phenolic acid, including protocatechuic acid (PA), gallic acid (GA), and ferulic acid (FA), five different cocrystals were prepared using SAG and SSE. Three of the cocrystals prepared using the SAG method have the structural characteristics of carboxylic acid dimer, and two cocrystals prepared using the SSE method formed cocrystal solvates with the structural characteristics of carboxylic acid monomer. For phenolic acids containing only one phenolic hydroxyl group (ferulic acid), when preparing cocrystals with PRA by using SAG and SSE, the same product was obtained. In addition, the weak molecular interactions that were observed in the cocrystal are explained at the molecular level by using theoretical calculation methods. Finally, the in vitro solubility of cocrystals without crystal solvents and in vivo bioavailability of PRA-FA were evaluated to further understand the influence on the physicochemical properties of API for the introduction of CCF.     

Phenylalanine Increases the Production of Antioxidant Phenolic Acids in Ginkgo biloba Cell Cultures

The aims of this study were to evaluate the antioxidant properties, to investigate the content of major secondary metabolites in Ginkgo biloba cell cultures, and to determine the change in the production of phenolic acids by adding phenylalanine to the culture medium. Three in vitro methods, which depend on different mechanisms, were used for assessing the antioxidant activity of the extract: 1,1-diphenyl-2-picrylhydrazil (DPPH), reducing power and Fe²⁺ chelating activity assays. The extract showed moderate activity both in the DPPH and in the reducing power assays (IC₅₀ = 1.966 ± 0.058 mg/mL; ASE/mL = 16.31 ± 1.20); instead, it was found to possess good chelating properties reaching approximately 70% activity at the highest tested dose. The total phenolic, total flavonoid, and condensed tannin content of G. biloba cell culture extract was spectrophotometrically determined. The phenolic acid content was investigated by RP-HPLC, and the major metabolites—protocatechuic and p-hydroxybenzoic acids—were isolated and investigated by ¹H NMR. The results showed that phenylalanine added to G. biloba cell cultures at concentrations of 100, 150, and 200 mg/150 mL increased the production of phenolic acids. Cultures that were grown for 3 weeks and collected after 4 days of phenylalanine supplementation at high concentration showed maximal content of phenolic acids (73.76 mg/100 g DW).     

葡萄酒中7种酚酸的色谱电化学分析

建立了同时测定葡萄酒中没食子酸、原儿茶酸、丁香酸、p-香豆酸、咖啡酸、绿原酸和阿魏酸等7种生物活性酚酸的反相高效液相色谱电化学分析新方法,并测定了5种国产不同品牌的葡萄酒.采用HypersilODS色谱柱(250mm×4.0mm,5.0μm),流动相为甲醇-4%醋酸,梯度洗脱,流速为0.8mL/min,工作电压为0.7V,柱温为30℃.实验结果表明,电化学法的检出限比紫外法的检出限低4～600倍.     

Chemoselective Esterification of Phenolic Acids in the Presence of Sodium Bicarbonate in Ionic Liquids

Chemoselective esterification of phenolic acids with dialkyl sulphates or alkyl halides in the presence of sodium bicarbonate in 1,3‐dialkylimidazolium ionic liquids is reported in excellent yields and less reaction time as compared to organic solvents.