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.     

Components and antioxidant activity of fruits of Cirsium palustre and C. rivulare

In the hexane extract of C. palustre and C. rivulare fruits, fatty acids, sterols, triterpenes, and volatile compounds were analyzed by the GC-MS-FID method. In the methanolic extracts, total phenol content was estimated. The antioxidant activity of both extracts was measured with DPPH assay and expressed in % scavenged DPPH.     

Antimicrobial,DPPH scavenging and tyrosinase inhibitory activities of Thymus vulgaris,Helichrysum arenarium and Rosa damascena mill. ethanol extracts by using TLC bioautography and chemical screening methods

Antimicrobial, DPPH scavenging and tyrosinase inhibitory activities of Thymus vulgaris, Helichrysum arenarium and Rosa damascena Mill. ethanol extracts by using TLC bioautography and chemical screening methods. The ethanol extracts of Thymus vulgaris (Tv), Helichrysum arenarium (Ha) and Rosa damascena Mill. (Rm) (red) were screened for their antimicrobial, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and tyrosinase inhibitory activities. The test microorganisms included bacteria of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). Thin Layer Chromatography (TLC) - bioautography, disk diffusion and well diffusion methods were used for the antimicrobial activity assays. Rosa damascena Mill. extract was effective against E. coli and all plant extracts showed antimicrobial activity against S. aureus. The phenolic acids in the structure of the extracts were also identified by LC-MS analysis. Human blood agar well diffusion method and TLC-DPPH assays were used to identify the hemolytic and antioxidant activity of plant extracts, respectively, along with 10 compounds including phenolic acids as a standard. Among these compounds, caffeic acid (Rf = 0.68) was detected in all extracts while vanillic acid (Rf = 0.75), and gallic acid (Rf = 0.51) was found in Tv extract. Kojic acid (Rf = 0.36), on the other hand, was detected in Rm extract as a tyrosinase inhibitor. All plant extracts presented tyrosinase inhibitory activities on TLC-bioautography assay.     

An in vitro evaluation of the antibacterial activity of the non-volatile phenolic fraction from rosemary leaves

In this study, the aim was to evaluate the antimicrobial action of the non-volatile phenols of rosemary leaves against two Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and two Gram-positive bacteria (Staphylococcus aureus and Staphylococcus epidermidis). Three extracts with different phenolic compositions were tested. By the agar disc diffusion method, Gram-positive bacteria were more sensitive to the extracts, and S. epidermidis showed the highest inhibition zones. Overall, all the extracts tested by the broth dilution method showed higher activity than results from the agar disc diffusion method. The minimal bactericidal concentration values indicated that E. coli was the most susceptible strain. This study demonstrated that the flavonoidic fraction of rosemary leaves does not play a crucial role as antimicrobial agents against these microorganisms. The most active extract was characterised by the highest amount of non-volatile terpenoidic compounds.     

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.     

Phytochemical composition,in vitro antioxidant activity and antibacterial mechanisms of Neolamarckia cadamba fruits extracts

Aqueous extracts of Neolamarckia cadamba fruits prepared at different maturity stages were used for the analysis of various phytochemicals, and their antioxidant and antibacterial activities were determined. Ripe fruit extract had highest phenolics (3.14 mM GAE/ g fruit extract) with caffeic acid, tannic acid, syringic acid and quercetin as major phenolic compounds. The ripe fruit extract showed lowest IC₅₀ values in DPPH radical scavenging assay (231.33 μg fruit extract/ mL), and highest ABTS radical scavenging activity (111.18 μM TEAC/g). Immature fruit extract showed lowest minimum inhibitory concentration against tested bacteria, and the antibacterial activity was probably due to membrane permeation, as was evident by leakage of genetic material and reduction in propidium iodide uptake by bacterium; and by inhibition of sugar and amino acid uptake. The appreciable amount of phenolic compounds and biological activities in the aqueous extracts of N. cadamba fruits suggests it's potential application as natural preservative.     

Phenolic Contents,Organic Acids,and the Antioxidant and Bio Activity of Wild Medicinal Berberis Plants- as Sustainable Sources of Functional Food

Wild fruits have increasingly been investigated as part of recent searches for food products with a high antioxidant activity. In this study, wild edible berberis Berberis vulgaris collected from three different provinces (Jilin, Heilongjiang, and Liaoning) were investigated for their phenolic contents, organic acid contents, mineral contents, antioxidant activity as well as their antimicrobial potential against a range of common food borne pathogens. In addition, a physiochemical and mineral analysis of the fruits was also performed. The methanol extracts of berberis fruit collected from Jilin province were highly active against all the studied food borne bacterial pathogens, i.e., S. aureus and L. monocytogenes, E. coli, P. fluorescens, V. parahaemolyticus, and A. caviae while the berberis extracts from Heilongjiang and Liaoning showed activity only against Gram-negative bacteria. The phenolic content and antioxidant activity were determined by the HPLC separation method and β-carotene bleaching methods, respectively. Four organic acids such as malic acid, citric acid, tartaric acid, and succinic acid were identified while a variety of phenolic compounds were detected among which catechin, chlorogenic acid, and gallic acid were found to be the predominant phenolic compounds in all three of berberis fruit samples. The berberis fruit from Jilin was found to be superior to the Heilongjiang and Liaoning fruit regarding desired physiochemical analysis; however, there were no significant differences in the mineral contents among the three samples. Overall, the berberis fruit from Jilin was ranked as the best in term of the nutritional, physiochemical, antimicrobial, and antioxidant properties. This study confirms the various useful characteristics and features of berberis at a molecular level that can be used as a sustainable source for their potential nutritional applications for making functional foods in different food industries.     

A new fatty acid ester from an edible mushroom Rhizopogon luteolus

Phytochemical investigation of the Rhizopogon luteolus Fr. led to the isolation of one new fatty acid ester, 3-hydroxy-2,4-dimethylheptacosyl acetate (1) together with two known compounds tetracosanoic acid (2) and ergosterol (3). 1D and 2D NMR, and MS techniques were used for structural elucidation. Phenolic and fatty acid compositions were identified using HPLC–DAD and GC–MSD, respectively. Fumaric acid was the major phenolic acid, whereas linoleic, stearic and oleic acids were the most abundant fatty acids. Antioxidant and anticholinesterase activities of the extracts and compounds (1–3) were tested spectrophotometrically. Among the extracts, hexane extract showed the highest activity in all tests, particularly in β-carotene-linoleic acid assay (IC₅₀: 16.65 ± 1.12 μg/mL). Furthermore, compound 3 exhibited higher antioxidant and anticholinesterase activities. The study indicates that R. luteolus can be used in food, cosmetic and pharmaceutical industries.     

Evaluation of antioxidant activities of the edible and medicinal Acacia albida organs related to phenolic compounds

This study compared phenolic contents and antioxidant activity in different organs of Acacia albida (leaves and bark) and focuses on identification of phenolic compounds of leaves by HPLC-DAD. The analysed organs exhibited differences in total polyphenol contents (100 and 59.5 mg GAE g^? 1 DW). Phenolic contents of leaves were two times higher than those in bark. Ethanolic extracts exhibited good antioxidant activities with IC₅₀ = 26 μg mL^? 1 for DPPH and EC₅₀ = 50 μg mL^? 1 for FRAP. Identification by HPLC-DAD revealed the presence of nine phenolic compounds known for their high antioxidant activity. The results suggested that this species can be used as source of natural antioxidants.     

Phenolic profiles and antioxidant capacities of crude extracts and subsequent fractions from Potentilla fruticosa L. leaves

This work aimed to further investigate the phenolic profiles and antioxidant capacities of the crude extracts and the subsequent fractions of Potentilla fruticosa leaves. Result showed that P. fruticosa leaves contained high amounts for hyperoside, ellagic acid and (+)-catechin contents, and the highest amount being registered for hyperoside (17.67 mg g^?1). Nine sub-fractions were obtained after column chromatographic separation. EF-3, EF-4, EF-5 and BF-2 presented higher values for their total phenolic or flavonoid, (+)-catechin, ellagic acid and hyperoside content. Besides, EF-3, EF-4, BF-2 and BF-3 showed significant in vitro antioxidant capacities and protective effects on Escherichia coli under peroxide stress. The correlation between chromatograms and antioxidant activity showed that (+)-catechin, ellagic acid and hyperoside may play crucial roles in the antioxidant capacities of P. fruticosa and could be used as chemical markers for its quality assessment. Moreover, this is the first time P. fruticosa leaves have been systematically studied.     

In Vitro Cultures of <Emphasis Type="Italic">Schisandra chinensis</Emphasis> (Turcz.) Baill. (Chinese Magnolia Vine)—a Potential Biotechnological Rich Source of Therapeutically Important Phenolic Acids

The contents of free phenolic acids and cinnamic acid were determined using an HPLC method in methanolic extracts from biomass of Schisandra chinensis (Turcz.) Baill. (Chinese magnolia vine) at different stages of organogenesis, cultured in vitro on a few variants of Murashige and Skoog (MS) medium, containing different concentrations of plant growth regulators 6-benzylaminopurine (BAP) and 1-naphthaleneacetic acid (NAA) (from 0.1 to 3.0 mg/l) and in extracts from overground parts of plants growing in vivo. Six of 12 analysed compounds were detected in all extracts: chlorogenic, p-coumaric, p-hydroxybenzoic, protocatechuic, salicylic and syringic acids. Total contents of the examined metabolites in biomass of shoot-differentiating callus culture cultivated on six MS medium variants were dependent on concentrations of growth regulators in the media and ranged from 14.90 to 60.05 mg/100 g d.w. Total contents of the compounds in biomass extracts from undifferentiating callus culture maintained only on two of six MS medium variants were higher and amounted to 74.54 and 78.24 mg/100 g d.w. Maximum total contents of phenolic acids in both types of in vitro cultures were greater than in fruits (55.73 mg/100 g d.w.) and leaves (4.55 mg/100 g d.w.) of plants gowning in vivo. Chlorogenic acid and salicylic acid were the main compounds identified in biomass extracts of shoot-differentiating callus cultures (max 22.60 and 21.17 mg/100 g d.w., respectively), while chlorogenic acid (max 38.43 mg/100 g d.w.) and protocatechuic acid (max 20.95 mg/100 g d.w.) prevailed in the extracts from undifferentiating callus cultures. Other compounds dominated in fruits, namely p-coumaric acid (23.36 mg/100 g d.w.) and syringic acid (14.96 mg/100 g d.w.). This is the first report on biochemical potential of cells from S. chinensis in vitro cultures to produce the biologically active phenolic acids. These are the first results on the analysis of this group of metabolites in overground parts of plants growing in vivo, too.     

In vitro biological activities and fatty acid profiles of Pistacia terebinthus fruits and Pistacia khinjuk seeds

This study reports in vitro anticholinesterase, antioxidant and antimicrobial effects of the n-hexane, dichloromethane, ethanol and ethanol–water extracts prepared from Pistacia terebinthus L. fruits and Pistacia khinjuk Stocks seeds as well as their total phenolic and flavonoid contents, and fatty acid compositions. Ethanol and ethanol–water extracts of both species exhibited higher anticholinesterase activity than galanthamine. Among ABTS, DPPH and CUPRAC assays, the highest antioxidant capacity of the extracts was found in the last one. P. terebinthus ethanol extract being rich in flavonoid content showed the best cupric reducing effect. All extracts possessed no antimicrobial activity. The main fatty acid in P. terebinthus fruits (52.52%) and P. khinjuk seeds (59.44%) was found to be oleic acid. Our results indicate that P. terebinthus fruits and P. khinjuk seeds could be a good source of anticholinesterase compounds, and could be phytochemically investigated.     

Chemical composition,antioxidant and cytotoxic activities of extracts from the leaves of Smilax brasiliensis Sprengel (Smilacaceae)

The antioxidant and cytotoxic activities of petroleum ether and methanol extracts, fatty acids and methyl esters from leaves of Smilax brasiliensis were evaluated, and the composition of the extracts was determined. Palmitic, linoleic and linolenic acids were major components of the extracts. For antioxidant activity, all samples exhibited IC₅₀ values lower than BHT (2,6-di-tert-butyl-4-methylphenol). The extracts, fatty acids and methyl esters from S. brasiliensis presented no toxicity to larvae of the brine shrimp, Artemia salina. Among the purified substances, only methyl linolenate showed toxicity (LD₅₀ = 21.47 μg/mL). This study showed, for the first time, the composition of petroleum ether and methanol extracts from S. brasiliensis leaves, as well as the antioxidant and cytotoxic activities of extracts, fatty acids and methyl esters.     

Correlations Between FAS Elongation Cycle Genes Expression and Fatty Acid Production for Improvement of Long-Chain Fatty Acids in Escherichia coli

Microorganisms have been used for biodiesel (fatty acid methyl ester) production due to their significant environmental and economic benefits. The aim of the present research was to develop new strains of Escherichia coli K-12 MG1655 and to increase the content of long-chain fatty acids by overexpressing essential enzymes that are involved in the fatty acid synthase elongation cycle. In addition, the relationship of β-ketoacyl-acyl carrier protein (ACP) synthase (fabH), β-ketoacyl-ACP reductase (fabG), β-hydroxyacyl-ACP dehydrase (fabZ), and β-enoyl-ACP reductase (fabI) with respect to fatty acid production was investigated. The four enzymes play a unique role in fatty acid biosynthesis and elongation processes. We report the generation of recombinant E. coli strains that produced long-chain fatty acids to amounts twofold over wild type. To verify the results, NAD⁺/NADH ratios and glucose analyses were performed. We also confirmed that FabZ plays an important role in producing unsaturated fatty acids (UFAs) as E. coli SGJS25 (overexpressing the fabZ gene) produced the highest percentage of UFAs (35 % of total long-chain fatty acids), over wild type and other recombinants. Indeed, cis-9-hexadecenoic acid, a major UFA in E. coli SGJS25, was produced at levels 20-fold higher than in wild type after 20 h in culture. The biochemically engineered E. coli presented in this study is expected to be more economical for producing long-chain fatty acids in quality biodiesel production processes.     

Flavonoid and phenolic acid profile by LC-MS/MS and biological activity of crude extracts from Chenopodium hybridum aerial parts

Extracts from leaves and stems of Chenopodium hybridum were characterised for the presence and quantity of flavonoids and phenolic acids by LC-ESI-MS/MS. Five flavonoids and eight phenolic acids were detected for the first time in aerial parts of this plant species, the most abundant compounds being rutin (2.80 μg/g DW), 3-kaempferol rutinoside (2.91 μg/g DW), 4-OH-benzoic (1.86 μg/g DW) and syringic acids (2.31 μg/g DW). Extracts were tested for anti-inflammatory/antiarthritic, antihyaluronidase and cytotoxic activities against human prostate cancer (Du145, PC3) and melanoma cell lines (A375, HTB140 and WM793) of different malignancy. None of the extracts protected bovine serum albumin from heat-induced denaturation. Antihyaluronidase effect at the tested concentration was higher than standard naringenin. Cytotoxic activity was generally low with an exception of the extract from the leaves, which was found most effective against prostate Du145 cell line with 98.28 ± 1.13% of dead cells at 100 μg/mL.     

In vitro antimicrobial activity of extracts and compounds isolated from Cladonia uncialis

Heptane (Hep), diethyl ether (Et₂O), acetone (Me₂CO) and methanolic (MeOH) extracts, as well as ( ? )-usnic acid and squamatic acid, were obtained from thallus of Cladonia uncialis (Cladoniaceae). The antimicrobial activities of these extracts, ( ? )-usnic acid and squamatic acid, were tested against reference strains: Staphylococcus aureus, Escherichia coli and Candida albicans. In addition, Me₂CO extract was analysed against 10 strains of Methicillin-resistant S. aureus (MRSA) isolated from patients. All extracts exerted antibacterial activity against the reference strain S. aureus, comparably to chloramphenicol [minimum inhibitory concentration (MIC) = 5.0 μg/mL]. The Me₂CO extract exhibited the strongest activity against S. aureus (MIC = 0.5 μg/mL), higher than ( ? )-usnic acid, whereas squamatic acid proved inactive. The Me₂CO extract showed potent antimicrobial activity against MRSA (MIC 2.5–7.5 μg/mL). Also no activity of C. uncialis extracts against E. coli and C. albicans was observed.     

Determination of Phenolic Compounds and the Antioxidant Capacity of Ximenia parviflora Benth. var. parviflora (Olacaceae) Fruit by High-Performance Liquid Chromatography with Diode Array Detection

The total phenolic and flavonoid content, phenolic composition, and in vitro antioxidant capacity of ethanolic extracts of Ximenia parviflora Benth. var. parviflora fruits collected at Zinaparo, Michoacan (in central Mexico) were determined. Fruit extracts present a high scavenging activity of 2,2-diphenyl-1-picrylhydrazyl and 2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid] radicals (71.49?±?0.11% and 85.00?±?1.29% inhibition, respectively). The four phenolic compounds identified in fruit extracts by high-performance liquid chromatography with diode array detection were gallic acid, chlorogenic acid, caffeic acid, and quercetin. X. parviflora fruits may be used as a starting material for the extraction of high value antioxidant phenolic compounds with potential applications in the pharmaceutical and dietary supplement industries.     

Phenolic Composition and Biological Properties of Wild and Commercial Dog Rose Fruits and Leaves

Rosa canina L. (dog rose) is a rich source of phenolic compounds that offer great hope for the prevention of chronic human diseases. Herein, wild and commercial samples of dog rose were chemically characterized with respect to their phenolic composition by liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI/MS). Furthermore, in vitro antioxidant properties and antibacterial activity of dog rose fruits and leaves hydromethanolic extracts and infusions were also evaluated. The results revealed that wild and commercial fruits of dog rose are similar in terms of l(+)-ascorbic acid, total phenolics (TPC), total flavonoids (TFC) and total phenolic acids (TPAC) content, individual phenolic constituents and antioxidant activity. Moreover, the fruits had lower levels of phenolic compounds and also revealed lower biological activity than the leaves. On the other hands, the highest content of TPC, TFC, TPAC, individual phenolic constituents, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging activity and FRAP (ferric reducing antioxidant power) were found in the leaf’s infusions. They were also the only ones to show antibacterial activity. Overall, these finding confirmed usefulness of R. canina L. leaves and fruits as a rich source of bioactive phenolic compounds with potential use in food, pharmaceutical, and cosmetic industries.     

Antiviral and Antibacterial Effect of Honey Enriched with Rubus spp. as a Functional Food with Enhanced Antioxidant Properties

The aim of this study was to investigate the effect of blackberry and raspberry fruits (1 and 4%) and leaves (0.5 and 1%) on the biological activities of rape honey. Honey and plant material extracts were analyzed regarding total phenolic, flavonoid, anthocyanin contents, HPTLC and HPLC polyphenol profiles, as well as antioxidant activity. The antiviral potential was analyzed against bacteriophage phi 6—a coronavirus surrogate—whereas antimicrobial was tested against S. aureus and E. coli. Blackberry extracts were more abundant in antioxidants than raspberry extracts, with better properties found for leaves than fruits and for cultivated rather than commercial plants. The addition of both Rubus plant additives significantly increased the antioxidant potential of honey by four-fold (for 4% fruits additive) to five-fold (for 1% of leaves). Honey with the addition of fruits possessed higher antiviral potential compared with raw rape honey (the highest for 4% of raspberry fruit and 1% of blackberry leaf additive). Honey enriched with Rubus materials showed higher antibacterial potential against S. aureus than rape honey and effectively inhibited S. aureus biofilm formation. To summarize, honey enriched with Rubus fruit or leaves are characterized by increased pro-health value and can be recommended as a novel functional food.     

Chemical Profile of Lipophilic Fractions of Different Parts of Zizyphus lotus L. by GC-MS and Evaluation of Their Antiproliferative and Antibacterial Activities

Zizyphus lotus L. is a perennial shrub particularly used in Algerian folk medicine, but little is known concerning the lipophilic compounds in the most frequently used parts, namely, root bark, pulp, leaves and seeds, which are associated with health benefits. In this vein, the lipophilic fractions of these morphological parts of Z. lotus from Morocco were studied by gas chromatography–mass spectrometry (GC–MS), and their antiproliferative and antimicrobial activities were evaluated. GC–MS analysis allowed the identification and quantification of 99 lipophilic compounds, including fatty acids, long-chain aliphatic alcohols, pentacyclic triterpenic compounds, sterols, monoglycerides, aromatic compounds and other minor components. Lipophilic extracts of pulp, leaves and seeds were revealed to be mainly composed of fatty acids, representing 54.3–88.6% of the total compounds detected. The leaves and seeds were particularly rich in unsaturated fatty acids, namely, (9Z,12Z)-octadeca-9,12-dienoic acid (2431 mg kg⁻¹ of dry weight) and (9Z)-octadec-9-enoic acid (6255 mg kg⁻¹ of dry weight). In contrast, root bark contained a high content of pentacyclic triterpenic compounds, particularly betulinic acid, accounting for 9838 mg kg⁻¹ of dry weight. Root bark extract showed promising antiproliferative activity against a triple-negative breast cancer cell line, MDA-MB-231, with a half-maximal inhibitory concentration (IC₅₀) = 4.23 ± 0.18 µg mL⁻¹ of extract. Leaf extract displayed interesting antimicrobial activity against Escherichia coli, methicillin-sensitive Staphylococcus aureus and Staphylococcus epidermis, presenting minimum inhibitory concentration (MIC) values from 1024 to 2048 µg mL⁻¹ of extract. Our results demonstrate that Zizyphus lotus L. is a source of promising bioactive components, which can be exploited as natural ingredients in pharmaceutical formulations.