Consequence of the antioxidant activities and tyrosinase inhibitory effects of various extracts from the fruiting bodies of Pleurotus ferulae

This study was initiated to screen the antioxidant activities, tyrosinase inhibitory effects on the fruiting bodies of Pleurotus ferulae extracted with acetone, methanol and hot water. The antioxidant activities were performed on β-carotene–linoleic acid, reducing power, DPPH, ferrous ions chelating abilities, and xanthine oxidase. In addition to this, phenolic compounds were also analyzed. The methanolic extract showed the strongest β-carotene–linoleic acid inhibition and high reducing power as compared to other extracts. The scavenging effects on DPPH radicals, the acetonic and methanolic extracts were more effective than hot water extracts. The strongest chelating effect was obtained from the methanolic extract as compared to the tested synthetic antioxidant. Gallic acid, protocatechuic acid, caffeic acid, vanillin, ferulic acid, naringin, resveratrol, naringenin, hesperetin, formononetin and biochanin-A were detected from acetonitrile and hydrochloric acid (5:1) solvent extract. Xanthine oxidase and tyrosinase inhibitory activities of acetonic, methanolic, and hot water extracts of P. ferulae increased with increasing concentration. The results suggested that consumption of P. ferulae might be beneficial to the antioxidant, xanthine oxidase, and tyrosinase protection system of the human body against oxidative damage and others complications.     

Biologically active compounds from two members of the Asteraceae family: Tragopogon dubius Scop. and Tussilago farfara L.

Tragopogon dubius and Tussilago farfara are consumed as vegetables and used in folk medicine to manage common diseases. Herein, the chemical compositions and biological activities of different leaf extracts (ethyl acetate, methanol, and water) of T. dubius and T. farfara were evaluated. The antibacterial, antifungal, and antioxidant abilities of the extracts were tested using different assays including free radical scavenging, reducing power, phosphomolybdenum, and metal chelating assays. Enzyme inhibitory potentials were evaluated against cholinesterases, tyrosinase, α-amylase and α-glucosidase. Complexes of bioactive compounds (chlorogenic and rosmarinic acid) were docked into the enzymatic cavity of α-glucosidase and subjected to molecular dynamic calculation, enzyme conformational stability, and flexibility analysis. T. dubius and T. farfara extracts showed remarkable antioxidant potentials. Ethyl acetate extracts of T. dubius and T. farfara were the most potent inhibitors of acetylcholinesterase and butyrylcholinesterase. T. dubius ethyl acetate extract and T. farfara methanolic extract showed noteworthy activity against α-glucosidase. High performance liquid chromatography analysis revealed the abundance of some phenolic compounds including chlorogenic and rosmarinic acids. Ethyl acetate extract of T. dubius showed notable antifungal activity against all strains. Docking studies showed best pose for chlorogenic acid was stabilized by a network of hydrogen bonds with residues Asp1157, Asp1279, whereas rosmarinic acid showed several hydrogen bonds with Asp1157, Asp1420, Asp1526, Lys1460 and Trp1369. This study further validates the use of T. dubius and T. farfara in traditional medicine, as well as act as a stimulus for further studies for future biomedicine development.

Communicated by Ramaswamy H. Sarma     

Chlorogenic acid as an antiherbivore defence of willows against leaf beetles

In the leaves of 13 Finnish willow species, the content of a phenolic, chlorogenic acid, was found to vary from 0 up to 18 mg g^–1 D.W. Effects of pure chlorogenic acid on insect feeding behaviour were tested using four common leaf beetle species which are in the field mainly found on willows with low-chlorogenic acid leaves. One species, Lochmaea capreae L., was invariably deterred by pure chlorogenic acid applied in naturally occurring concentrations on the willow leaves. Accordingly, in 2-choice laboratory feeding trials L. capreae was found to prefer low-chlorogenic acid leaves of four willow species over high-chlorogenic acid leaves of Salix pentandra L. and S. myrsinifolia Salisb. When presented on the leaves of S. phylicifolia L, pure chlorogenic acid inhibited also the feeding by Phratora polaris Sp.-Schn. Instead, chlorogenic acid had no significant effect on Ph. polaris when it was presented on the leaves of another willow S. cinerea L. In laboratory, Ph. polaris did not show general preference for willow species with low chlorogenic acid content in their leaves. Thus, the response of Ph. polaris to chlorogenic acid seems to depend on the plant species. Apparently variation in other traits such as leaf hairyness may easily override the potential effect of chlorogenic acid content on Ph. polaris. To two other leaf beetle species, Galerucella lineola F. and Plagiodera versicolora Laich., chlorogenic acid is an ineffective deterrent even at unnaturally high concentrations. In laboratory, G. lineola and P. versicolora did not prefer willows with low chlorogenic acid content in their leaves. Thus, among four studied leaf beetle species, only L. capreae seems to be clearly affected by this phenolic. Therefore, overall importance of chlorogenic acid as a defence against willow-feeding leaf beetles appears to be very limited.     

Comparative assessment of phytochemical profiles and antioxidant properties of Tunisian and Egyptian anise (Pimpinella anisum L.) seeds

Anis (Pimpinella anisum L.) seeds obtained from two geographic origins Tunisia (TAS) and Egypt (EAS) were studied regarding their biochemical composition and the antioxidant potential of their extracts. The results showed that the highest value of oil was detected with TAS compared to that of EAS ones. Ten (10) fatty acids were identified for the two locations and petroselinic acid was the most prevalent in oil seeds and interestingly, TAS displayed a significantly higher level of this acid than EAS. Besides, TAS exhibited slightly higher essential oil yield than the Egyptian variety and that trans-anethole was the dominant for the two provenances. In both accessions, the highest total phenolic, flavonoid and tannin content was obtained with ethyl acetate fraction. Therefore, TAS exhibited higher chelating and reducing powers than EAS which may be due to a slightly different phenolic composition between the two accession seed extracts. The phenolic compositions of TAS and EAS revealed that ethyl acetate extracts showed higher proportions of naringin, chlorogenic acid and rosmarinic acid. However, ethanol extracts were richer in larcitrin, rosmarinic acid and cirsimartin. The overall results revealed that aniseeds might constitute a novel source of natural antioxidants and could be used as food additive.     

Rosmarinic acid production in hairy root cultures of Agastache rugosa Kuntze

Rosmarinic acid, an important phenolic active compound, is one of the main active constituents of Agastache rugosa Kuntze and has astringent properties, antioxidant capacity, anti-inflammatory activity, antimutagenic ability, antimicrobial capacity, and antiviral properties. To investigate in vitro production of rosmarinic acid, we established a hairy root culture of A. rugosa by infecting leaf and stem explants with Agrobacterium rhizogenes R1000, and tested the growth and rosmarinic acid production of these cultures. Hairy roots were cultured in Murashige and Skoog liquid medium and maximum growth (14.1 g dry wt/l) was attained after 14 days of culture, at which time the content of rosmarinic acid was 116 mg/g dry wt. The present results demonstrate that hairy root culture of A. rugosa is a valuable alternative approach for the production of rosmarinic acid.     

Phytochemical Content,Antidiabetic, Anticholinergic,and Antioxidant Activities of Endemic Lecokia cretica Extracts

The aim of this work was to investigate the enzyme inhibition, antioxidant activity, and phenolic compounds of Lecokia cretica (Lam .) DC. Acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α‐glycosidase enzymes were strongly inhibited by the L. cretica extracts. IC₅₀ values for the three enzymes were found as 3.21 mg/mL, 2.1 mg/mL, and 2.07 mg/mL, respectively. Antioxidant activities were examined in both aqueous and ethanol (EtOH) extracts using CUPRAC, FRAP, and DPPH method. Also, the phenolic compounds of the endemic plant were identified and quantified by using HPLC/MS/MS. According to the results, the extracts have remarkable antioxidant activities. The most abundant phenolic acids of L. cretica in EtOH extract were determined as quinic acid (12.76 mg/kg of crude extract), chlorogenic acid (3.39 mg/kg), and malic acid (2.38 mg/kg).     

Analysis of antioxidant metabolites by solvent extraction from sclerotia of Inonotus obliquus (Chaga)

Introduction – The sclerotia of Inonotus obliquus (Chaga) are effective therapeutic agents to treat several human malignant tumours and other diseases without unacceptable toxic side‐effects. Objective – To investigate solvent effects on metabolic profiles and antioxidant activities of extracts of Chaga. Methodology – Chaga was extracted by petroleum ether, chloroform, ethyl acetate, acetone, ethanol and water. Solvent effects on metabolites in the extracts were assayed by NMR‐based metabolomic analysis. Antioxidant activities were indicated as capacities for scavenging superoxide anion, DPPH and hydroxyl radicals. Results – Petroleum ether and chloroform extracts contained primarily lanostane‐type triterpenoids (LT), whereas the extracts of ethyl acetate, acetone and ethanol were characterised by the predominant presence of hispidin analogues and LT, and water extracts by polysaccharides and phenolic compounds. The ethyl acetate, acetone, ethanol and water extracts revealed remarkable potential for scavenging the tested radicals, while those of petroleum ether and chloroform did not. Polyphenols are the major contributors for quenching the tested free radicals, while in LT only compounds 16 , 17 and 22 participated in scavenging hydroxyl radicals. Conclusion – Polyphenols in Chaga are the principles for quenching free radicals while polysaccharides and a few LT compounds contribute partially in scavenging DPPH and hydroxyl radicals, respectively. NMR‐based metabolomic analysis is a useful method by which to correlate ¹H‐NMR spectra of Chaga extracts with their antioxidant activities, and this allows the prediction of potentials for scavenging free radicals by ¹H‐NMR spectroscopy. Copyright © 2011 John Wiley & Sons, Ltd.     

Changes in composition of phenolic compounds and antioxidant properties of <Emphasis Type="Italic">Vitis amurensis</Emphasis> seeds germinated under osmotic stress

The research focused on the changes of phenolic compounds as well as their antiradical activity and reducing power isolated from Amur grape (Vitis amurensis) seeds during germination under optimal conditions and under osmotic stress. The seeds were found to contain tannins, (+) catechin, (−) epicatechin, and gallic acid (in free, ester- and glycoside-bound forms). Extracts from the seeds were also shown to contain two other phenolic acids: caffeic and p-coumaric acids, in very low levels. During a 3-day seed germination test under osmotic stress (−0.5 MPa), the content of total phenolics, tannins and phenolic acids declined as compared to the control. However, seed germination under stress conditions led to a significant increase in the amount of catechins. Because catechin is the one of the units in condensed tannins, its dynamic increase during seed germination may be involved in metabolism of tannins under osmotic stress. It is also likely that the synthesis of catechins is greater under stress conditions and these compounds may be engaged in the process of acclimatization of grapevines to stress conditions. The content of total phenolic compounds in seed extracts is positively correlated with their antioxidant properties. The extracts from seeds germinated under optimal conditions exhibited strong antiradical properties against the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical as well as reducing power. As regards the extracts from grape seeds germinated under osmotic stress, this capability was much weaker. The research demonstrated that antioxidants could interfere with the oxidation process induced by various stresses by acting as oxygen scavengers, therefore the tolerance to drought stress might be correlated with an increase in the antioxidant potential.     

基于HPLC-ECD研究牡荆叶抗氧化的谱-效关系

为研究牡荆叶指纹图谱与抗氧化活性的谱-效关系，该研究首先建立了18批牡荆叶的高效液相色谱-电化学检测法(HPLC-ECD)指纹图谱，对不同来源牡荆叶药材进行聚类分析，鉴定主要酚类化合物且测定其含量，分析牡荆叶的总酚和总黄酮含量，并采用DPPH自由基清除法、ABTS自由基清除法、氧自由基吸收能力法及铁离子还原能力法考察其体外抗氧化活性，通过皮尔逊相关分析、灰度关联分析及偏最小二乘回归分析法研究牡荆叶的谱-效关系。结果表明：(1)牡荆叶的指纹图谱标定21个共有峰，共指认出10个峰，其含量顺序为绿原酸>异荭草苷>木犀草苷>异牡荆素>异绿原酸A>异绿原酸C>原儿茶酸>荭草苷>异绿原酸B>新绿原酸；不同产地样品间相似性较高，相似度结果为0.816～0.983。(2)系统聚类分析显示，样品含量对分类有一定影响，不同来源样品被分为3类，其中南北方样品存在一定差异。(3)牡荆叶中总酚和总黄酮的含量分别为15.82～61.83 mg·g^-1和27.85～157.65 mg·g^-1,样品均具不同程度的抗氧化活...     

Chemical Characterization and Multidirectional Biological Effects of Different Solvent Extracts of Arum elongatum: in Vitro and in Silico Approaches

Arum elongatum (Araceae) is widely used traditionally for the treatment of abdominal pain, arterial hypertension, diabetes mellitus, rheumatism and hemorrhoids. This study investigated the antioxidant properties, individual phenolic compounds, total phenolic and total flavonoid contents (HPLC/MS analysis), reducing power and metal chelating effects of four extracts obtained from A. elongatum (ethyl acetate (EA), methanol (MeOH), methanol/water (MeOH/water) and infusion). The inhibitory activity of the extracts were also determined against acetylcholinesterase, butyrylcholinesterase, tyrosinase, amylase and glucosidase enzymes. The MeOH/water extracts contained the highest amount of phenolic contents (28.85 mg GAE/g) while the highest total flavonoid content was obtained with MeOH extract (36.77 mg RE/g). MeOH/water demonstrated highest antioxidant activity against DPPH⋅ radical at 38.90 mg Trolox equivalent per gram. The infusion extract was the most active against ABTS⁺⋅ (133.08 mg TE/g). MeOH/water extract showed the highest reducing abilities with the CUPRAC value of 102.22 mg TE/g and the FRAP value of 68.50 mg TE/g. A strong metal chelating effect was observed with MeOH/water extract (35.72 mg EDTAE/g). The PBD values of the extracts ranged from 1.01 to 2.17 mmol TE/g. EA extract displayed the highest inhibitory activity against AChE (2.32 mg GALAE/g), BChE (3.80 mg GALAE/g), α-amylase (0.56 mmol ACAE/g) and α-glucosidase (9.16 mmol ACAE/g) enzymes. Infusion extract was the most active against tyrosinase enzyme with a value of 83.33 mg KAE/g. A total of 28 compounds were identified from the different extracts. The compounds present in the highest concentration were chlorogenic acids, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, isoquercitrin, delphindin 3,5-diglucoside, kaempferol-3-glucoside and hyperoside. The biological activities of A. elongatum extracts could be due to the presence of compounds such as gallic acid, chlorogenic acids, ellagic acid, epicatechin, catechin, kaempferol, 4-hydroxybenzoic acid, caffeic acid, p-coumaric acid, ferulic acid, quercetin, isoquercitrin, and hyperoside. Extracts of A. elongatum showed promising biological activities which warrants further investigations in an endeavor to develop biopharmaceuticals.     

Phenolic compounds and antioxidants from Eucalyptus camaldulensis as affected by some extraction conditions,a preparative optimization for GC-MS analysis

Abstract

Four organic solvents along with water were applied for the conventional extraction of Eucalyptus camaldulensis (Myrtaceae), phenolic contents and antioxidant activities were investigated through variable protocols and correlation coefficients were considered, the phenolic composition was also characterized by Gas chromatography-mass spectrometry (GC-MS). Using solvents with dissimilar polarities affected the phenolic yields extracted from E. camaldulensis and their related antioxidant activities varied significantly among the four investigated plant organs. The leaf extract of acetone 70% contained the highest amount of phenolic compounds (46.56?mg/g dry weight); while the bud-water boiled extract maintained the maximum value of tannins (45.68?mg/g dry weight). Correlation coefficients indicated that phenolic compounds were mostly accountable for the phosphomolybednum antioxidant potentials (0.520), followed by tannins (0.460). Also, both the reducing power activities and hydrogen peroxide scavenging of E. camaldulensis extracts positively correlated with tannins, but at different significance degrees. However, the GC-MS analysis revealed that most of the detected phenolic constituents were more abundant in the plant seed. So, the existence of some other compounds such as organic acids, along with phenolics, may have increased the antioxidant potentials of leaf and bud. Undeniably, the optimization of extraction conditions could stimulate the antioxidant capabilities of the plant extracts of E. camaldulensis.     

3种百合鳞茎中多酚类物质的抗氧化活性分析

以野生百合渥丹、山丹和传统食用的兰州百合为研究对象,对其鳞茎中多酚类物质、11种单体酚的含量及抗氧化活性(ABTS自由基、超氧阴离子、羟自由基的清除能力,铜离子还原能力以及抑制脂质过氧化活性)进行了分析。结果表明:两种野生百合鳞茎中的多酚类物质含量及抗氧化活性均显著高于兰州百合。3种百合鳞茎中单体酚的种类也有所不同,但均含有没食子酸、矢车菊素-3-芸香糖苷、儿茶素、表儿茶素、杨梅酮、芦丁、对香豆酸、山奈酚。相关性分析显示,除对羟自由基的清除力外,各酚类物质总量与不同抗氧化指标之间呈显著正相关关系。试验结果认为,野生百合鳞茎可作为天然抗氧化资源应用于食品和医药业,具有一定的开发应用前景。     

Metabolism of phenolic compounds in <Emphasis Type="Italic">Vitis riparia</Emphasis> seeds during stratification and during germination under optimal and low temperature stress conditions

We studied the alterations in phenolic compounds in grape seeds during their stratification and germination under optimal conditions (+25 °C) and at low temperature (+10 °C). Biological materials in the study were seeds of Vitis riparia. Phenolic compounds were extracted from defatted seeds using 80 % methanol or 80 % acetone. The content of total phenolics was determined with the Folin-Ciocalteau reagent, while the content of tannins was determined by vanillin assay and the protein (BSA) precipitation method. The RP-HPLC method was used to determine phenolic compounds (phenolic acids, catechins) in the extracts. High amounts of tannins, catechins, gallic acid and lesser amounts of p-coumaric acid were found in the seeds. The content of total phenolics in acetone extracts was higher than that obtained using methanol. The amounts of phenolic acids and tannins found in V. riparia seeds after stratification were much lower. It may confirm a possible role of these compounds in dormancy of V. riparia seeds. After 72 h of low temperature treatment, inhibition of grape root growth and biochemical changes in seeds were detected. The chilling stimulated increased accumulation of some phenolic compounds (free gallic acid and catechins) in the seeds. These substances can protect plants against some abiotic stressors.     

Variation of phenolic composition and biological activities in Limoniastrum monopetalum L. organs

Changes in phenolic composition and biological activities were investigated in different Limoniastrum monopetalum L. organs. For that, 80% aqueous acetone extracts were used to estimate total phenolic contents and their antioxidant activities were evaluated using DPPH· and O₂^·− radical scavenging activities and reducing power. The efficiency of organ extracts was tested against human pathogen strains. Ultimately, acid hydrolysis of all organs was subjected to RP-HPLC for phenolic identification. Results showed that flower extracts exhibited the highest polyphenol (65.42 GAE/g DW) and flavonoid (35.36 CE/g DW) contents. Stems were enriched in condensed tannin content (21.4 mg CE/g DW) and displayed the best antiradical activities and the highest reducing power. Besides, stem and gall extracts showed the highest efficiency against pathogenic bacteria as compared with those of flower. Concerning the antifungal test, a slight activity was found in gall extracts. The RP-HPLC showed a difference in phenolic compounds that varied as function of organ. In fact, the major phenolic compound varied as function of organ. Results suggest that L. monopetalum could be a promising source of biomolecules for therapeutic and nutraceutical industries and the difference between organs may be related to their physiological role.     

Studies on the antioxidant activity and phenolic compounds of enzyme-assisted water extracts from Du-zhong (Eucommia ulmoides Oliv.) leaves

Enzyme-assisted water extracts (EWEDL) and ethanol extracts of Du-zhong leaves (EEDL) were evaluated for their antioxidant activities using the DPPH radical-scavenging assay, Fe²⁺-chelating assay, and inhibition ability of the linoleic acid peroxidation assay. In general, the antioxidant activity of Du-zhong leaf extracts increased with increasing concentration. Based on the two extracting methods with different antioxidative reactions, it was shown that the enzyme-assisted water extracting method was more effective for antioxidant extraction from Du-zhong leaves. By HPLC-MS analysis, the main phenolic compounds (geniposidic acid, epicatechin, and chlorogenic acid) identified in EWEDL and EEDL were similar. EWEDL and EEDL had total phenolic contents of 13.84?±?0.11 and 14.72?±?0.14?mg chlorogenic acid equivalents (CAE) in each gram of extract, respectively. However, there was no positive correlation between total phenolic content and antioxidant activities of EWEDL and EEDL measured by the three different assays.     

Cyathuscavins A, B, and C, new free radical scavengers with DNA protection activity from the Basidiomycete Cyathus stercoreus

Three new polyketides, cyathuscavins A (1), B (2), and C (3) were isolated from the mycelium culture of Cyathus stercoreus. The structures of the compounds were elucidated on the basis of NMR and mass spectroscopic data. Antioxidant activities of the compounds were evaluated by the scavenging ability against ABTS⁺, DPPH, and superoxide anion radicals. Cyathuscavins A–C showed significant antioxidant activity comparable to those of reference antioxidants, BHA and Trolox. Cyathuscavins A–C protected supercoiled plasmid DNA from Fe²⁺/H₂O₂-induced breakage.     

Lecanoric acid,a secondary lichen substance with antioxidant properties from <Emphasis Type="Italic">Umbilicaria antarctica</Emphasis> in maritime Antarctica (King George Island)

Eight lichen species, Cetraria aculeata, Cladonia furcata, Pseudephebe pubescens, Sphaerophorus globosus, Stereocaulon alpinum, Umbilicaria antarctica, Usnea antarctica and Usnea aurantiacoatra, were collected from King George Island, maritime Antarctica, for the evaluation of antioxidant activities. Anti-linoleic acid peroxidation activity, free radical scavenging activity, reducing power and superoxide anion scavenging activity were assessed of methanol and acetone extract of the lichens in vitro. Extract of Umbilicaria antarctica, Cladonia furcata, Sphaerophorus globosus and Usnea antarctica were found to have strong in vitro antioxidant properties. In general, acetone extract exhibited stronger activities than methanol extract. The activity-guided bioautographic TLC and HPLC analysis demonstrated that lecanoric acid was the main antioxidant compound in the acetone extract of Umbilicaria antarctica, the most potent antioxidant lichen species among the test species. The results suggested that several Antarctic lichens and their substances can be used as novel bioresources of natural antioxidants.     

Functional constituents of wild and cultivated Goji (L. barbarum L.) leaves: phytochemical characterization,biological profile,and computational studies

Goji (Lycium barbarum L.) leaves are emphasized as a functional tea or as dietary supplements. The phenolic compound profile, antioxidant, enzyme inhibitory, antimicrobial, and antimutagenic activities of leaf extracts from two selected cultivars in comparison with wild-growing plants have been evaluated. HPLC-DAD/ESI-ToF-MS analysis revealed the presence of phenolic acids and flavonoids with chlorogenic acid and rutin being the dominant compounds in the cultivated plants, whereas rutin and kaempeferol-3-O-rutinoside for wild growing ones. In particular, cv. Erma contained the highest amount of chlorogenic acid and showed a strong tyrosinase-inhibitory effect. Staphylococcus aureus, Listeria monocytogenes, and Penicillium funiculosum were the most sensitive strains when exposed to extracts from cultivated plants. Antimutagenic activity was evaluated by Ames' test. The tested extracts provided high protection against mutagenicity induced by 2-anthramine (2-AA) to Salmonella typhimurium strains TA 98 and TA 100 (max. inhibition (%) 88% and 74.2%, respectively). Overall, Goji leaves are a rich source of bioactive compounds with functional properties that need further risk/benefit evaluation when used in foods or health-promoting formulations.     

Survey of Phytochemical Composition and Biological Effects of Three Extracts from a Wild Plant (Cotoneaster nummularia Fisch. et Mey.): A Potential Source for Functional Food Ingredients and Drug Formulations

This study was focused on the analysis of the phenolic content, antioxidant, antibacterial, anti-cholinesterase, anti-tyrosinase, anti-amylase and anti-glucosidase activity of three solvent extracts from Cotoneaster nummularia. Moreover, water extract was tested in terms of mutagenic/anti-mutagenic effects. The antioxidant activities of these extracts were evaluated by DPPH, ABTS, O₂, metal chelating, phosphomolybdenum, β-carotene/linoleic acid, ferric and cupric reducing power assays. Enzyme inhibitory activities were also examined with colorimetric methods. Generally, methanol and water extracts exhibited excellent biological activities. These extracts were rich in phenolic and flavonoid content. Furthermore, Cotoneaster extracts indicated appreciable antibacterial properties against human pathogen strains. HPLC analysis showed that ferulic acid, chlorogenic acid, (-) – epicatechin and (+)-catechin were the major phenolics in extracts tested. These data offer that these extracts from C. nummularia may be considered as a potential source of biological agents for developing functional foods or drug formulations.     

Antioxidant and antimicrobial activities of rosemary extracts linked to their polyphenol composition

Rosmarinus officinalis extracts were investigated by a combination of bioassays and biochemical analysis to identify bioactive compounds. The 2,2-diphenyl-2-picrylhydracyl hydrate (DPPH) radical scavenging method, Folin–Ciocaulteau method and HPLC chromatography were used to study the distribution and levels of antioxidants (AOXs). Antimicrobial activity analysis was carried out using the disk diffusion and broth dilution techniques. A good correlation between the AOX activities and total phenol content in the extracts was found. Although all rosemary extracts showed a high radical scavenging activity, a different efficacy as antimicrobial agent was observed. Methanol extract containing 30% of carnosic acid, 16% of carnosol and 5% of rosmarinic acid was the most effective antimicrobial against Gram positive bacteria (minimal inhibition concentration, MIC, between 2 and 15 μg/ml), Gram negative bacteria (MIC between 2 and 60 μg/ml) and yeast (MIC of 4 μg/ml). By contrast, water extract containing only 15% of rosmarinic acid showed a narrow activity. MIC value of the methanol and water extracts is in a good correlation with the values obtained with pure carnosic acid and rosmarinic acid, respectively. Therefore, our results suggested that the antimicrobial rosemary extracts efficacy was associated with their specific phenolic composition. Carnosic acid and rosmarinic acid may be the main bioactive antimicrobial compounds present in rosemary extracts. From a practical point of view, rosemary extract may be a good candidate for functional foods as well as for pharmaceutical plant-based products.