Extraction of Phenolic Compounds from Fresh Apple Pomace by Different Non-Conventional Techniques

Red Delicious apple pomace was produced at laboratory scale with a domestic blender and different non-conventional extraction techniques were performed to isolate phenolic compounds, such as ultrasound-assisted extraction (UAE), ultraturrax extraction (UTE), accelerated solvent extraction (ASE) and pulsed electric field (PEF) extraction pre-treatment. Total phenolic content (TPC) was determined by Folin–Ciocalteu assay. Phloridzin, the main phenolic compound in apples, was determined by chromatographic analysis Q-TOF-LC/MS. The results obtained with these techniques were compared in order to identify the most efficient method to recover polyphenols. The highest value of TPC (1062.92 ± 59.80 µg GAE/g fresh apple pomace) was obtained when UAE was performed with EtOH:H₂O (50:50, v/v), while ASE with EtOH:H₂O (30:70, v/v) at 40 °C and 50% of flush was the most efficient technique in the recovery of phloridzin. The concentration of the main phenolic compounds ranged from 385.84 to 650.56 µg/g fresh apple pomace. The obtained results confirm that apple pomace represents an interesti-ng by-product, due to the presence of phenolic compounds. In particular, phloridzin could be considered a biomarker to determine the quality of numerous apple products. Therefore, this research could be a good starting point to develop a value-added product such as a functional food or nutraceutical.     

Identification and in vitro antioxidant activities of phenolic compounds isolated from Cynoglossum cheirifolium L.

In an extensive search for bioactive compounds from plant sources, the quantitative and qualitative characterisation of the compounds present in Cynoglossum cheirifolium extracts was studied. Total phenolic and flavonoid contents were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined through DPPH^? scavenging activity and Ferric reducing antioxidant power (FRAP). Our study showed that leaves produce more phenolic compounds, followed by flowering aerial part. The butanolic fraction obtained from leaves extract exhibited the highest total phenolics (78.65 ± 3.58 mg GAE/g DW) and flavonoids (22.15 ± 4.66 mg CE/g DW). In contrast, this fraction displayed the highest DPPH^? scavenging ability with IC₅₀ values of 0.06 ± 0.003 mg/mL. The RP-HPLC-PDA analysis of phenolic compounds from leaves of C. cheirifolium lets to identify: rosmarinic acid, ferulic acid, caffeic acid, p-coumaric acid, syringic acid, sinapic acid and rutin. The obtained results indicate that this plant represent a valuable source of natural antioxidants.     

芥子酸及其衍生物对酪氨酸酶抑制作用的电化学研究

采用电化学方法研究了芥子酸、芥子酸甲酯及芥子碱对酪氨酸酶的抑制作用. 结果发现, 酪氨酸酶电极对其底物邻苯二酚有良好的电催化作用, 电流响应在底物1.0×10-7~6.0×10-5 mol/L的浓度范围内呈线性关系, 并具有较高的灵敏度(60.93 nA·L/μmol); 芥子酸及其衍生物都对酪氨酸酶的活性有抑制作用, 抑制能力大小的顺序为芥子酸>芥子酸甲酯>芥子碱. 通过对这3种物质的抑制参数的计算结果表明, 芥子碱是非竞争型抑制, 而芥子酸和芥子酸甲酯是混合型抑制. 这3种物质对酪氨酸酶可能的抑制机理一是抑制物与底物竞争酶的双铜活性中心; 二是抑制物具有抗氧化活性, 因而抑制酶对底物的催化反应.     

Setup of an Ultrasonic-Assisted Extraction to Obtain High Phenolic Recovery in Crataegus monogyna Leaves

Hawthorn leaves are a rich source of phenolic compounds that possess beneficial activities for human health. Ultrasonic-assisted extraction (UAE) is an extraction technique frequently used for the isolation of phenolic compounds in plants. Thus, in this study, a Box–Behnken design was used to optimize UAE conditions such as the percentage of acetone, the extraction time and solvent-to-solid ratio (v/w) in order to obtain the maximum content of total compounds by Folin–Ciocalteu and the maximum in vitro antioxidant activity by DPPH, ABTS and FRAP assays in Crataegus monogyna leaves. The optimum conditions to obtain the highest total phenolic content and antioxidant activities were 50% acetone, 55 min and 1/1000 (w/v). A total of 30 phenolic compounds were identified and quantified in C. monogyna leaf extract obtained at these optimum UAE conditions. HPLC-MS allows the identification and quantification of 19 phenolic compounds and NP-HPLC-FLD analyses showed the presence of 11 proanthocyanidins. According to the results, the most concentrated phenolic compounds in C. monogyna leaf extract obtained at optimum UAE conditions were phenolic acid derivatives such as protocatechuic acid-glucoside, dihydroxy benzoic acid pentoside and chlorogenic acid, flavones such as 2″-O-rhamnosyl-C-hexosyl-apigenin, flavonols such as hyperoside and isoquercetin and proanthocyanidins such as monomer and dimer. As a result, the optimized UAE conditions could be used to obtain an extract of C. monogyna leaves enriched with phenolic compounds.     

Selective Extraction of Sinapic Acid Derivatives from Mustard Seed Meal by Acting on pH: Toward a High Antioxidant Activity Rich Extract

The aim of this paper is to study the effect of the pH on the extraction of sinapic acid and its derivatives from mustard seed meal. Solutions of acidic pH (pH 2), basic pH (pH 12) and distilled water (uncontrolled pH ~ 4.5) were tested at different percentages of ethanol. The maximum extraction yield for sinapic acid (13.22 µmol/g of dry matter (DM)) was obtained with a buffered aqueous solution at pH 12. For ethyl sinapate, the maximum extraction yield reached 9.81 µmol/g _DM with 70% ethanol/buffered aqueous solution at pH 12. The maximum extraction yield of sinapine (15.73 µmol/g _DM) was achieved with 70% ethanol/buffered aqueous solution at pH 2. The antioxidant activity of each extract was assessed by DPPH assay; the results indicated that the extracts obtained at pH 12 and at low ethanol percentages (<50%) exhibit a higher antioxidant activity than extracts obtained at acidic conditions. Maximum antioxidant activity was reached at pH 12 with buffer solution (11.37 mg of Trolox Equivalent/g _DM), which confirms that sinapic acid-rich fractions exhibit a higher antioxidant activity. Thus, to obtain rich antioxidant extracts, it is suggested to promote the presence of sinapic acid in the extracts.     

Solid-State Fermentation as a Strategy to Improve the Bioactive Compounds Recovery from Larrea tridentata Leaves

Chemical composition of Larrea tridentata leaves was determined and elevated content of lignin (35.96 % w/w) was found. The present study was proposed in order to evaluate the extraction of bioactive compounds, particularly phenolic compounds, by solid-state fermentation (SSF) of L. tridentata leaves. The basidiomycete Phanerochaete chrysosporium was used in the experiments due to its ability to degrade lignin. The concentration of total phenolic compounds in the extracts produced by SSF was determined. Additionally, the extracts were characterized regarding the concentration of flavonoids, quercetin, kaempferol, and nordihydroguaiaretic acid and antioxidant activity. SSF was not an efficient process to recover phenolic compounds from L. tridentata leaves. However, this process was very efficient when used as a pretreatment before the plant extraction with organic solvent (methanol). By submitting the plant to SSF and subsequently to extraction with 90 % (v/v) methanol, the recovery of phenolic compounds was improved by 33 % when compared to the results obtained by methanolic extraction of the non-fermented plant. Scanning electron microscopy micrographs revealed a major disorganization and porosity of the plant structure after fermentation, and Fourier transform infrared spectroscopy spectra indicated a possible solubilization of some constituents of lignocellulose fraction after this process, which may have favored the solvent action in the later stage.     

Solid-State Fermentation of Rapeseed Meal with the White-Rot Fungi Trametes versicolor and Pleurotus ostreatus

Rapeseed meal is valuable high-protein forage, but its nutritional value is significantly reduced by the presence of a number of antinutrients, including phenolic compounds. Solid-state fermentation with white-rot fungi was used to decrease the sinapic acid concentration of rapeseed meal. After 7 days of growth of Trametes versicolor and Pleurotus ostreatus, the sinapic acid content of rapeseed meal was reduced by 59.9 and 74.5 %, respectively. At the end of the experiment, sinapic acid concentration of T. versicolor cultures decreased by 93 % of the initial value; in the case of cultures of P. ostreatus, 93.2 % reduction was observed. Moreover, cultivation of white-rot fungi on rapeseed meal resulted in the intensive production of extracellular laccase, particularly strong during the late phases of growth of T. versicolor. The obtained results confirm that both fungal species may effectively be used to decompose antinutritional phenolics of rapeseed meal. Rapeseed meal may also find use as an inexpensive and efficient substrate for a biotechnological production of laccase by white-rot fungi.     

Changes in the Volatile Profile of Wheat Sourdough Produced with the Addition of Cava Lees

The volatile fraction is of great importance for the organoleptic quality and consumer acceptance of bread. The use of sourdough improves the sensory profile of bread, as well as the addition of new ingredients to the fermentation. Cava lees are a sparkling wine by-product formed of dead microorganisms, tartaric acid, and other inorganic compounds, rich in antioxidant compounds as well as β-glucans and mannoproteins. The aim of this study was to evaluate the effect of different concentrations of Cava lees (0–2% w/w) on sourdough volatile compounds to re-valorize this by-product of the wine industry. Headspace solid-phase microextraction (HS-SPME) was optimized to study the volatile fractions of sourdoughs. The parameters selected were 60 °C, 15 min of equilibrium, and 30 min of extraction. It was found that the addition of Cava lees resulted in higher concentrations of volatile compounds (alcohols, acids, aldehydes, ketones and esters), with the highest values being reached with the 2% Cava lees. Moreover, Cava lees contributed to aroma due to the compounds usually found in sparkling wine, such as 1-butanol, octanoic acid, benzaldehyde and ethyl hexanoate.     

Elucidation of Antioxidant Compounds in Moroccan Chamaerops humilis L. Fruits by GC–MS and HPLC–MS Techniques

The aim of this study was to characterize the phytochemical content as well as the antioxidant ability of the Moroccan species Chamaerops humilis L. Besides crude ethanolic extract, two extracts obtained by sonication using two solvents with increased polarity, namely ethyl acetate (EtOAc) and methanol-water (MeOH-H₂O) 80:20 (v/v), were investigated by both spectroscopy and chromatography methods. Between the two extracts, the MeOH-H₂O one showed the highest total polyphenolic content equal to 32.7 ± 0.1 mg GAE/g DM with respect to the EtOAc extract (3.6 ± 0.5 mg GAE/g DM). Concerning the antioxidant activity of the two extracts, the EtOAc one yielded the highest value (1.9 ± 0.1 mg/mL) with respect to MeOH-H2O (0.4 ± 0.1 mg/mL). The C. humilis n-hexane fraction, analyzed by GC–MS, exhibited 69 compounds belonging to different chemical classes, with n-Hexadecanoic acid as a major compound (21.75%), whereas the polyphenolic profile, elucidated by HPLC–PDA/MS, led to the identification of a total of sixteen and thirteen different compounds in both EtOAc (major component: ferulic acid: 104.7 ± 2.52 µg/g) and MeOH-H₂O extracts (major component: chlorogenic acid: 45.4 ± 1.59 µg/g), respectively. The attained results clearly highlight the potential of C. humilis as an important source of bioactive components, making it a valuable candidate to be advantageously added to the daily diet. Furthermore, this study provides the scientific basis for the exploitation of the Doum in the food, pharmaceutical and nutraceutical industries.     

Chemometric Optimization of Biologically Active Compounds Extraction from Grape Marc: Composition and Antimicrobial Activity

The article focuses on the optimization of the extraction process of biologically active compounds (BAC) from grape marc—a by-product of the wine industry. The influence of temperature, specifically 30 °C, 45 °C and 65 °C, and ethanol concentration in solutions, specifically 0–96% (v/v) on the extraction yield of polyphenols, flavonoids, tannins and anthocyanins, were investigated. The composition of individual polyphenols, anthocyanins and organic acids, antioxidant activity (DPPH and ABTS) and CIELab chromatic characteristics of the grape marc extracts (GME), were characterized. The microbiostatic and microbicidal effects in direct contact of GME with pathogenic microorganisms, Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, were determined in vitro. The influence of extraction parameters on the total polyphenol content (TPC), total flavonoid content (TFC), tannin content (TC), total anthocyanin content (TAC) and their interdependencies were studied using information analysis. A mathematical model was developed on cubic spline functions. The analysis of individual compounds showed the presence of a wide range of flavonoids (procyanidin B2, procyanidin B1, hyperoside and quercetin), flavones (catechin), hydroxybenzoic acid derivatives (gallic, protocatechuic, p-hydroxybenzoic acids, m-hydroxybenzoic acid, syringic acid), hydroxycinic acid derivatives and ferulic acid methyl ester. The malvidol-3-glucoside was the main anthocyanin identified in the extract. A high amount of tartaric acid was also found. GME showed significant antimicrobial activity against Gram-positive bacteria and lower activity against Gram-negative bacteria.     

Comparison of the Phenolic Compound Profile and Antioxidant Potential of Achillea atrata L. and Achillea millefolium L.

In the present study, Achillea atrata L. and A. millefolium L. were compared for the first time with regard to their phenolic compound profile and antioxidant activity by applying the 2,2-diphenyl-picryl hydrazyl radical assay. For this purpose, aerial plant parts were consecutively extracted with solvents of increasing polarity (dichloromethane, n-butanol, ethyl acetate), revealing that the A. atrata ethyl acetate fraction showed the highest antioxidant activity with an IC₅₀ value of 12.2 ± 0.29 µg/mL compared to 17.0 ± 0.26 µg/mL for A. millefolium. Both species revealed the presence of luteolin, apigenin, centaureidin, and nevadensin exclusively in this most polar fraction, which are known as effective 2,2-diphenyl-picryl hydrazyl radical scavengers. The antioxidant capacity of the aforementioned fractions strikingly correlated with their total phenolic contents, which was highest in the ethyl acetate fraction of A. atrata. Characterization of the metabolite profiles of both Achillea species showed only marginal differences in the presence of key compounds, whereas the concentrations of individual compounds appeared to be species-specific. Our results suggest that A. atrata, based on its compound pattern and bioactivity characteristics, has similar qualities for phytotherapy as A. millefolium.     

Macrocystis pyrifera Extract Residual as Nutrient Source for the Production of Sophorolipids Compounds by Marine Yeast Rhodotorula rubra

Seaweed processing generates liquid fraction residual that could be used as a low-cost nutrient source for microbial production of metabolites. The Rhodotorula strain is able to produce antimicrobial compounds known as sophorolipids. Our aim was to evaluate sophorolipid production, with antibacterial activity, by marine Rhodotorula rubra using liquid fraction residual (LFR) from the brown seaweed Macrocystis pyrifera as the nutrient source. LFR having a composition of 32% w/w carbohydrate, 1% w/w lipids, 15% w/w protein and 52% w/w ash. The best culture condition for sophorolipid production was LFR 40% v/v, without yeast extract, artificial seawater 80% v/v at 15 °C by 3 growth days, with the antibacterial activity of 24.4 ± 3.1 % on Escherichia coli and 21.1 ± 3.8 % on Staphylococcus aureus. It was possible to identify mono-acetylated acidic and methyl ester acidic sophorolipid. These compounds possess potential as pathogen controllers for application in the food industry.     

Comparison of Different Extraction Solvents for Characterization of Antioxidant Potential and Polyphenolic Composition in Boletus edulis and Cantharellus cibarius Mushrooms from Romania

Edible mushrooms are well-known for their nutritional benefits and low energy density. In addition, mushroom extracts contain various bioactive compounds that account for their antioxidant activity; the applied extraction conditions influence the extraction efficiency of such compounds. Therefore, this study investigates the effects of four extractants on the content of polyphenols and antioxidant properties of Boletus edulis and Cantharellus cibarius mushrooms, aiming to optimize the extraction process. Powders of B. edulis and C. cibarius mushrooms were subjected to extraction with acidic water (10% CH₃COOH), ethanol/water/acetic acid (15:76.5:8.5, v/v/v), hexane, and diethyl ether to measure their total phenolic content (TPC), total flavonoid content (TFC), and Trolox equivalent antioxidant capacity (TEAC). Furthermore, the level of individual polyphenolic compounds in these extracts was quantified using an HPLC-DAD-ESI-MS method. Results showed that the type of solvent significantly influenced the TPC and TEAC of mushroom powder but insignificantly influenced the TFC. A very strong positive correlation was found between TPC and TEAC, but no correlation was found between TFC and TEAC or TPC and TFC. Acidic water extracted the highest amount of polyphenolic compounds from these mushroom powders. Therefore, the aqueous extract showed the highest TPC and strongest antioxidant activity. Thus, acidic water is recommended for polyphenol analysis in B. edulis and C. cibarius mushrooms.     

Metabolomics techniques applied in the investigation of phenolic acids from the agro-industrial by-product of Carapa guianensis Aubl

Processing of Carapa guianensis seeds to obtain oil on an industrial scale generates a significant amount of by-product, approximately 66% w/w, which is called cake and is a potential source of biomolecules, including simple phenolic structures. For this reason, studies were carried out on the chemical profiles of hydrolyzed extract from this agro-industrial by-product through High Performance Thin-Layer Chromatography (HPTLC) and Gas Chromatography coupled to Mass Spectrometry (GC–MS). These techniques were used to detect metabolic classes and/or groups, and to identify, for the first time, thirteen simple phenolic acids in this by-product. The sample antioxidant capacity was determined by methods of 2,2-diphenyl-1-picrylhydrazyl (DPPH)and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS⁺) radicals direct sequestration. The hydrolyzed fraction showed a total of 63.47% in the relative abundance of the total of compounds, standing out: p-hydroxybenzoic acid (39.19%) and protocatechuic acid (3,4-dihydroxybenzoic acid) (5.62%), both from hydroxybenzoic acids and 3-(3,4-dihydroxyphenyl)lactic acid, (7.76%) hydroxycinnamic acids derivatives. In these results, the fraction rich in simple phenolic acids was obtained, attributing the prominent behavior of this matrix antioxidant activity, expressed by (IC₅₀: of 16.42 µg/mL and 6.52 µg/mL for DPPH and ABTS⁺ radicals, respectively). The research demonstrated an alternative to applicability that involves sustainability from agro-industrial. These techniques were used to detect metabolic classes and/or groups, and to identify, for the first time, thirteen simple phenolic acids in this by-product, generating a process capable of converting biomass into a bioproduct, consisting of bioactive compounds, in addition to adding value to the industrial chain.     

Simultaneous Determination of Quercetin, Rutin and Coumaric Acid in Flowers of Rhododendron arboreum by HPTLC1

A simple and fast method was developed for simultaneous quantitative determination of three biologically active phenolic compounds i.e. quercetin, rutin and coumaric acid in flowers of Rhododendron arboreum using high-performance thin-layer chromatography (HPTLC). The separation was performed on TLC aluminium plates precoated with silica gel RP-18 F_254S. Good separation was achieved in the mobile phase of methanol-water-formic acid (40:57:3, v/v/v) and densitometric determination of these compounds was carried out at 280 nm in reflectance/absorbance mode. The linear regression data for the calibration plots showed a good linear relationship with r = 0.9971, 0.9953 and 0.9960 for quercetin, rutin and coumaric acid, respectively. Accuracy of the method was checked by recovery study conducted at two different levels with the average recovery of 99.90%, 99.02% and 99.16% for quercetin, rutin and coumaric acid, respectively. The present method is being reported first time and may be used for routine quality control of the flowers of R. arboreum.     

Phytochemical Profiling,In Vitro Biological Activities,and In Silico Molecular Docking Studies of Dracaena reflexa

Dracaena reflexa, a traditionally significant medicinal plant, has not been extensively explored before for its phytochemical and biological potential. The present study was conducted to evaluate the bioactive phytochemicals and in vitro biological activities of D. reflexa, and perform in silico molecular docking validation of D. reflexa. The bioactive phytochemicals were assessed by preliminary phytochemical testing, total bioactive contents, and GC-MS analysis. For biological evaluation, the antioxidant (DPPH, ABTS, CUPRAC, and ABTS), antibacterial, thrombolytic, and enzyme inhibition (tyrosinase and cholinesterase enzymes) potential were determined. The highest level of total phenolic contents (92.72 ± 0.79 mg GAE/g extract) was found in the n-butanol fraction while the maximum total flavonoid content (110 ± 0.83 mg QE/g extract) was observed in methanolic extract. The results showed that n-butanol fraction exhibited very significant tyrosinase inhibition activity (73.46 ± 0.80) and acetylcholinesterase inhibition activity (64.06 ± 2.65%) as compared to other fractions and comparable to the standard compounds (kojic acid and galantamine). The methanolic extract was considered to have moderate butyrylcholinesterase inhibition activity (50.97 ± 063) as compared to the standard compound galantamine (53.671 ± 0.97%). The GC-MS analysis of the n-hexane fraction resulted in the tentative identification of 120 bioactive phytochemicals. Furthermore, the major compounds as identified by GC-MS were analyzed using in silico molecular docking studies to determine the binding affinity between the ligands and the enzymes (tyrosinase, acetylcholinesterase, and butyrylcholinesterase enzymes). The results of this study suggest that Dracaena reflexa has unquestionable pharmaceutical importance and it should be further explored for the isolation of secondary metabolites that can be employed for the treatment of different diseases.     

Bioactive Compounds from Ephedra fragilis: Extraction Optimization,Chemical Characterization,Antioxidant and AntiGlycation Activities

Response surface methodology (RSM) with a Box–Behnken design (BBD) was used to optimize the extraction of bioactive compounds from Ephedra fragilis. The results suggested that extraction with 61.93% ethanol at 44.43 °C for 15.84 h was the best solution for this combination of variables. The crude ethanol extract (CEE) obtained under optimum extraction conditions was sequentially fractionated with solvents of increasing polarity. The content of total phenolic (TP) and total flavonoid (TF) as well as the antioxidant and antiglycation activities were measured. The phytochemical fingerprint profile of the fraction with the highest activity was characterized by using RP-HPLC. The ethyl acetate fraction (EAF) had the highest TP and TF contents and exhibited the most potent antioxidant and antiglycation activities. The Pearson correlation analysis results showed that TP and TF contents were highly significantly correlated with the antioxidant and antiglycation activities. Totally, six compounds were identified in the EAF of E. fragilis, including four phenolic acids and two flavonoids. Additionally, molecular docking analysis also showed the possible connection between identified bioactive compounds and their mechanisms of action. Our results suggest new evidence on the antioxidant and antiglycation activities of E. fragilis bioactive compounds that may be applied in the treatment and prevention of aging and glycation-associated complications.     

Phytochemical Investigation,Antioxidant Properties and In Vivo Evaluation of the Toxic Effects of Parthenium hysterophorus

Parthenium hysterophorus L. is a poisonous Asteraceae weed. The phytochemical profile, antioxidant activity, total phenolic contents (TPC), total flavonoid contents (TFC), and cytotoxicity of Parthenium hysterophorus L. flower extract were evaluated in this study, and the toxic effects were assessed in rabbits. The HPLC-DAD system was used for phytochemical analysis. The hemolytic and DPPH assays were performed. The effects of orally administering the flower crude extract to rabbits (n = 5) at four different doses (10, 20, 40, and 80 mg/kg) for ten days on hematological and biochemical parameters were investigated. The crude extract of the flower contained phenolic compounds such as Gallic acid, Chlorogenic acid, Ellagic acid, and P Coumaric acid, which were detected at different retention times, according to the HPLC results. With a sample peak of 4667.475 %, chlorogenic acid was abundant. At concentrations of 80 µg, the methanolic extract of flowers had total phenolic contents (89.364 ± 4.715 g GAE/g) and total flavonoid contents (65.022 ± 2.694 g QE/g). In the DPPH free radical scavenging assay, 80 µg of extract had the highest cell inhibition of 76.90% with an IC50 value of 54.278 µg/µL, while in the hemolytic assay 200 µg of extract had the highest cell inhibition of 76.90% with an IC50 > 500. The biochemical and hematological parameters were altered in the flower extract-fed groups as compared to the control (p < 0.05). The toxic effects on the blood, liver, and kidneys were confirmed. The findings also confirmed the presence of phenolic and flavonoid content in the flower extract, both of which contribute to the plant’s antioxidant potential.     

Sambucus Nigra Extracts–Natural Antioxidants and Antimicrobial Compounds

Due to the health-promoting properties of elderberry fruits, which result from their rich chemical composition, this raw material is widely used in herbal medicine and the food industry. The aim of the study was to demonstrate the antibacterial activity of the elderberry fruit extracts. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The research showed that the content of phenolic acids and flavonoids in the extracts determined their antibacterial activity. The following phenolic acids were predominant: chlorogenic acid, sinapic acid, and t-cinnamic acid. Their average content was, respectively, 139.09, 72.84, 51.29 mg/g extract. Rutin and quercetin (their average content was 1105.39 and 306.6 mg/g extract, respectively) were the dominant flavonoids. The research showed that the elderberry polyphenol extracts exhibited activity against selected strains of bacteria within the concentration range of 0.5–0.05%. The following bacteria were the most sensitive to the extracts: Micrococcus luteus, Proteus mirabilis, Pseudomonas fragii, and Escherichia coli. Of the compounds under analysis, apigenin, kaempferol and ferulic, protocatechuic, and p-coumarin acids had the greatest influence on the high antibacterial activity of elderberry extracts. The results of the microbiological and chemical analyses of the composition of the extracts were analyzed statistically to indicate the bioactive compounds of the greatest antimicrobial significance.     

Effect of Elicitation with (+)-Usnic Acid on Accumulation of Phenolic Acids and Flavonoids in Agitated Microshoots of Eryngium alpinum L.

The present work was aimed at studying the potential of elicitation on the accumulation of phenolic compounds in in vitro shoot cultures of Eryngium alpinum L., a protected plant from the Apiaceae family. The study examined the influence of (+)-usnic acid on the biomass growth as well as on the biosynthesis of the desired flavonoids and phenolic acids in the cultured microshoots. The phenolic compound content was determined by HPLC-DAD. The flavonoid of the highest concentration was isoquercetin, and the phenolic acids of the highest amount were rosmarinic acid, caffeic acid and 3,4-dihydroxyphenylacetic acid, both in the non-elicited and elicited biomass. Isoquercetin accumulation was efficiently increased by a longer elicitation with a lower concentration of lichenic compound (107.17 ± 4.67 mg/100 g DW) or a shorter elicitation with a higher concentration of acid (127.54 ± 11.34 and 108.37 ± 12.1 mg/100 g DW). Rosmarinic acid production generally remained high in all elicited and non-elicited microshoots. The highest content of this acid was recorded at 24 h of elicitation with 3.125 µM usnic acid (512.69 ± 4.89 mg/100 g DW). The process of elicitation with (+)-usnic acid, a well-known lichenic compound with allelopathic nature, may therefore be an effective technique of enhancing phenolic compound accumulation in alpine eryngo microshoot biomass.