In vitro study on the competitive reactions between arsenite and selenite with glutathione.

Exposure to arsenic can cause various biological effects by increasing the production of reactive oxygen species (ROS). Selenium acts as a beneficial element by regulating ROS and limiting heavy metal uptake and translocation. There are studies on the interactive effects of As and Se in plants, but the antagonistic and synergistic effects of these elements based on their binding to glutathione (GSH) molecules have not been studied yet. In this study, we aimed to investigate the antagonistic or synergistic effects of As and Se on the binding mechanism of Se and As with GSH at pH 3.0, 5.0, or 6.5. The interaction of As and Se in Se(SG)2 + As(III) or As(SG)3 + Se(IV) binary systems and As(III) + Se(IV) + GSH ternary system were examined depending on their ratios via liquid chromatography diode array detector/electrospray mass spectrometry (LC-DAD/MS) and liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). The results showed that the formation of As(GS)3 was not detected in the As(III) + Se(SG)2 binary system, indicating that As(III) did not affect the stability of Se(SG)2 complex antagonistically. However, in the Se(IV) + As(SG)3 binary system, the addition of Se(IV) to As(SG)3 affected the stability of As(SG)3 antagonistically. Se(IV) reacted with GSH, disrupting the As(SG)3 complex, and consequently, Se(SG)2 formation was measured using LC-MS/DAD. In the Se(IV) + GSH + As(III) ternary system, Se(SG)2 formation was detected upon mixing As(III), Se(IV), and GSH. The increase in the concentration of As(III) did not influence the stability of the Se(SG)2 complex. Additionally, Se(IV) has a higher affinity than As(III) to the GSH, regardless of the pH of the solution. In both binary and ternary systems, the formation of the by-product glutathione trisulfide (GSSSG) was detected using LC-ESI-MS/MS.

Phenolic Compound Composition of Sambucus nigra L. Wild-Growing Plants from Kosovo.

Objectives: The aim of this study was to determine the phenolic components in the flowers and leaves of wild-growing Sambucus nigra L. Materials and Methods: Plant materials were collected from eleven localities in Kosovo. Before LC-DAD-ESI-MSn analysis, an ultrasonic-assisted method with 70% methanol for 30 min extraction was used. Results: In total, 34 and 37 phenolic compounds were identified in flower and leaf extracts, respectively, with a total content of 61321.82-85961.64 mg/kg dry weight (DW) and 36136.62-93890.37 mg/kg DW. In all of the analyzed extracts, 15 phenolic acids, 20 flavonoids, one lignan, and one coumaroyl iridoid were detected. The major components were flavonoids, especially flavonols (quercetin-3-rutinoside, caffeoyl-kaempferol, and isorhamnetin-3-rutinoside), followed by phenolic acids (dicaffeoylquinic acid isomer, caffeic acid derivative, dicaffeoylquinic acid isomer, and dicaffeoylquinic acid isomer). Conclusion: In general, the methanolic extracts of flowers have shown higher polyphenolic content than those found in leaves. The multivariate statistical analysis of the phenolic content of the samples resulted in PLS-DA models with appropriate correlation coefficients of 0.903 and 0.921 for flower and leaf extracts, respectively. The models revealed distinctive clustering patterns, and the loading scatter plots depicted the unique phenolic compounds specific to each sample group.

Elucidation and quantification health-promoting phenolic compounds, antioxidant properties and sugar levels of ultrasound assisted extraction, aroma compositions and amino acids profiles of macroalgae, Laurencia papillosa.

Currently, sustainability is one of the most critical issues confronting society today. The growing of macroalgae in ocean farms appears more sustainable than agriculture on land due to it does not require any fresh water, chemical fertiliser, or soil. Macroalgae have been shown to be a sustainable marine source of amino acids, novel bioactive phenolic and aroma compounds that can be exploitation in food, cosmetic, nutraceuticals, pharmacological applications. Despite starting the huge cultivation of macroalgae in world, bioactive compounds in the edible macroalgae have not been well characterized. Ultrasound assisted extraction (UAE) and conventional extraction (CE) techniques were compared and red macroalgae, L. papillosa extracts were characterized. The highest amount of amino acid was glutamic acid (GLU) and composed of 35% was essential amino acids. UAE at 10% amplitude for 15 min showed significantly highest (p < 0.05) phenolic (212.03±3.03 mg gallic acid equivalent/100 g) as well as antioxidant activity determined by DPPH (105.69±3.02 µmol Trolox/100 g), ABTS (238.69±2.23 µmol Trolox/100 g) radical assay and FRAP value (72.47±3.13 µmol Trolox/100 g) when in comparison with CE. Furthermore, bioactive compounds in extracts were indicated as phlorotannins, flavonoids, phenolic acids and other polyphenols using liquid chromatography coupled to diode array detection and electrospray ionisation tandem mass spectrometry (LC-DAD-ESI-MS/MS). This result confirmed higher antioxidant capacity detected with the UAE. A total of 46 volatile organic compounds were identified and quantified by GC-FID/MS with HS-SPME system. This study emerges as first report to novel extraction method used and deeply characterization of L papillosa. The results seem that significant potential application in the functional food, active packaging and nutraceuticals industry.

Complexing the Marine Sesquiterpene Euplotin C by Means of Cyclodextrin-Based Nanosponges: A Preliminary Investigation.

Euplotin C is a sesquiterpene of marine origin endowed with significant anti-microbial and anti-tumor properties. Despite the promising functional profile, its progress as a novel drug candidate has failed so far, due to its scarce solubility and poor stability in aqueous media, such as biological fluids. Therefore, overcoming these limits is an intriguing challenge for the scientific community. In this work, we synthesized ß-cyclodextrin-based nanosponges and investigated their use as colloidal carriers for stably complex euplotin C. Results obtained proved the ability of the carrier to include the natural compound, showing remarkable values of both loading efficiency and capacity. Moreover, it also allowed us to preserve the chemical structure of the loaded compound, which was recovered unaltered once extracted from the complex. Therefore, the use of ß-cyclodextrin-based nanosponges represents a viable option to vehiculate euplotin C, thus opening up its possible use as pharmacologically active compound.

Antioxidant Activities of Bioactive Compounds Isolated from Rheum emodi Wall (Himalayan Rhubarb) Based on LC-DAD-ESI/MS and Preparative LC/MS System.

Natural compounds are a good substitute for synthetic antioxidants. Attempts have been made to characterize the antioxidant capacity of natural resources (e.g., medicinal plants). Thus, the Rheum emodi Wall was evaluated using liquid chromatography with diode array detection and electrospray ionization-mass spectrometry. Three antioxidant compounds (i.e., myricitrin, myricetin-3-galloyl rhamnoside, and myricetin) were isolated, identified, and used to screen the antioxidant capacity of the new compounds. 2,2-Diphenyl-1-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), and superoxide dismutase assay results are presented in the half-maximal inhibitory concentration values ranging 1.50∼28.46, 102.01∼137.55, and 4.06∼15.74 µg/mL, respectively. Myricetin had the highest antioxidant activity among the other compounds. A significantly positive correlation was noted between the ethyl acetate fraction and the antioxidant compound. In a partial least squares-discriminant analysis model, identified antioxidant compounds were shown to play a role in the structure of the compound and its contents based on the antioxidant activity. The study suggests that myricetin from R. emodi possesses the most potent antioxidant activity, and thus is the most efficient in extracting antioxidant contents.

Determination of the Phenolic Profile by Liquid Chromatography, Evaluation of Antioxidant Activity and Toxicity of Moroccan Erica multiflora, Erica scoparia, and Calluna vulgaris (Ericaceae).

This study aimed to investigate the phenolic profile and selected biological activities of the leaf and aerial extracts of three Ericaceae species, namely Erica multiflora, Erica scoparia, and Calluna vulgaris, collected from three different places in the north of Morocco. The phenolic composition of all extracts was determined by LC coupled with photodiode array and mass spectrometry detection. Among the investigated extracts, that of E. scoparia aerial parts was the richest one, with a total amount of polyphenols of 9528.93 mg/kg. Up to 59 phenolic compounds were detected: 52 were positively identified and 49 quantified-11 in C. vulgaris, 14 in E. multiflora, and 24 in E. scoparia. In terms of chemical classes, nine were phenolic acids and 43 were flavonoids, and among them, the majority belonged to the class of flavonols. The antioxidant activity of all extracts was investigated by three different in vitro methods, namely DPPH, reducing power, and Fe2+ chelating assays; E. scoparia aerial part extract was the most active, with an IC50 of 0.142 ± 0.014 mg/mL (DPPH test) and 1.898 ± 0.056 ASE/mL (reducing power assay). Further, all extracts were non-toxic against Artemia salina, thus indicating their potential safety. The findings attained in this work for such Moroccan Ericaceae species, never investigated so far, bring novelty to the field and show them to be valuable sources of phenolic compounds with interesting primary antioxidant properties.

NMR, LC-MS Characterization of Rydingia michauxii Extracts, Identification of Natural Products Acting as Modulators of LDLR and PCSK9.

Rydingia michauxii (Briq.) Scheen and V.A.Albert (Lamiaceae) is used in Iranian traditional medicine to treat malaria, diabetes, hyperlipidemia, rheumatism and cardiovascular diseases. NMR and LC-DAD-MSn analyses were used to establish extract composition and phenylethanoid, flavonoid glycosides, lignans, labdane diterpenes and iridoids were identified and quantified. The main constituents were isolated, and structures were elucidated based on NMR, polarimetric and MS measurements. A new natural compound, ent-labda-8(17),13-dien-18-glucopyranosyl ester-15,16-olide is described here. The effects of ent-labda-8(17),13-dien-18-oic acid-15,16-olide (1), ent-labda-8(17),13-dien-18-glucopyranosyl es-ter-15,16-olide (2), antirrhinoside (3), echinacoside (4), verbascoside (5), and apigenin 6,8-di-C-glucoside (6), on the low-density lipoprotein receptor (LDLR) and proprotein convertase subtilisin/kexin type 9 (PCSK9), were studied in the human hepatocarcinoma cell line Huh7. Among the six constituents, (3) showed the strongest induction of the LDLR (3.7 ± 2.2 fold vs. control) and PCSK9 (3.2 ± 1.5 fold vs. control) at a concentration of 50 µM. The in vitro observations indicated a potential lipid lowering activity of (3) with a statin-like mechanism of action.

HPLC-DAD-ESI/MS profiles of bioactive compounds, antioxidant and anticholinesterase activities of Ephedra alata subsp. alenda growing in Algeria.

Ephedra (Ephedraceae) is used in medicine for various purposes as having, antioxidant, anticarcinogen, antibacterial, anti-inflammatory hepatoprotective, anti-obesity, antiviral and diuretic activities. In this study the aim was to investigate chemical constituents of Ephedra alata and understand the possible effects of those constituents in antioxidant activity and alzheimer's disease essay. For this purpose, natural compounds from E.alata were characterized by LC-DAD-ESI-MS/MS using negative and positive ionization modes, while the bioactivity was assessed by acetylcholinesterase (AChE) inhibition study and determining of antioxidant activity; DPPH radical scavenging and ß-carotene bleaching assays were used to assess the antioxidant potential. The proposed method of spectrometry provided tentative identification of 27 compounds including alkaloids and phenolic compounds as flavonoids. The methanolic extract showed high contents of total phenolic and exhibited an important antioxidant potential and demonstrated a potent inhibitory effect against acetylcholinesterase (IC50: 11,25 ± 0,25 µg/mL). The results showed that the plant possesses a therapeutic effect.

Studies related to the chemical composition, biological activities and toxicity of methanolic extracts of noni (Morinda citrifolia) fruits and leaves.

Morinda citrifolia is a plant that grows in Brazilian northeast and presented a wide range of therapeutic, industrial and technological applications. Based on this, the aim of this work was to study the chemical composition, main biological activities and potential toxicity of its extracts, aiming their industrial application. Important compounds were identified in the methanolic extracts obtained by ultrasonic and Soxhlet extractions from leaves and fruits. GC × GC allowed for the identification of phytosterols, fatty acids and methyl esters, besides others (scopoletin, hydrocarbons, alcohols, terpenes). By HPLC-DAD, compounds like catechin, rutin, quercetin could be also identified and quantified. Their content of polyphenols and flavonoids was considered between the international standards. The extracts showed high antioxidant activities (EC50 ∼ 300 µg mL-1, using DPPH assay) compared with those from the literature. The extracts did not show toxicity or mutagenicity, but presented cytotoxicity, which can indicate their use safely in phytotherapic or nutritional applications.

Comparative analysis of five Salvia species using LC-DAD-QToF.

Several Salvia species, commonly known as sage plants, are an integral part of various culinary and folklore preparations for the perceived wide range of effects from organoleptic to psychological. As a result, many of these species are an integral part of botanical drug applications, highlighting the need for accurate identification and quality control for consumer's safety. Five closely related Salvia species (S. officinalis, S. miltiorrhiza, S. divinorum, S. mellifera, and S. apiana) within a same botanical family were analyzed and differentiated using LC-QToF. Accurate mass measurement (<5 ppm) of protonated and deprotonated molecules together with resulting fragments and product ions allowed unequivocal or tentative identification of more than 180 compounds either by comparison with reference standards or literature data. The leaf part were identified based on various phenolic acids, flavonoids as well as di- and tri-terpenoids. Polyphenolics, viz., salvianolic A/B and rosmarinic acids in S. officinalis, lipophilic diterpenoids, viz., tanshinones in S. miltiorrhiza, abietatriene diterpenes and triterpenoids (ursane-/olean-type) in S. mellifera, and S. apiana were identified as characteristic, significant components. In comparison, salvinorins and divinorins representing a class of neoclerodane diterpenoids were detected only in S. divinorum. The presented methodology can successfully be applied to qualitatively assess sage-based ingredients in various finished products and formulations.

Occurrence and chemotaxonomical analysis of amatoxins in Lepiota spp. (Agaricales).

About 95% of fatal mushroom poisonings worldwide are caused by amatoxins and phallotoxins mostly produced by species of Amanita, Galerina, and Lepiota. The genus Lepiota is supposed to include a high number of species producing amatoxins. In this study, we investigated 16 species of Lepiota based on 48 recently collected specimens for the presence of amatoxins by liquid chromatography coupled to a diode-array detector and mass spectrometry (UHPLC-QTOF-MS/MS). By comparing the retention times, UV absorptions, and diagnostic MS fragment ions with data obtained from the benchmark species Amanita phalloides, we detected α-amanitin and γ-amanitin in Lepiota subincarnata, α-amanitin and amaninamide in Lepiota brunneoincarnata, and ß-amanitin and α-amanitin in Lepiota elaiophylla. Phallotoxins have not been detected any of these species. Two possibly undescribed amatoxin derivatives were found in Lepiota boudieri and L. elaiophylla, as well as one further non-amatoxin compound in one specimen of L. cf. boudieri. These compounds might be used to differentiate L. elaiophylla from L. xanthophylla and species within the L. boudieri species complex. No amatoxins were detected in L. aspera, L. castanea, L. clypeolaria, L. cristata, L. erminea, L. felina, L. fuscovinacea, L. lilacea, L. magnispora, L. oreadiformis, L. pseudolilacea, L. sp. (SeSa 5), and L. subalba. By combining the occurrence data of amatoxins with a phylogenetic analysis, a monophyletic group of amatoxin containing species of Lepiota is evident. These chemotaxonomic results highlight the relevance of systematic relationships for the occurrence of amatoxins and expand our knowledge about the toxicity of species of Lepiota.

Antioxidant, Antigenotoxic and Cytotoxic Activity of Essential Oils and Methanol Extracts of Hyssopus officinalis L. Subsp. aristatus (Godr.) Nyman (Lamiaceae).

Hyssopus officinalis L. is a well-known aromatic plant used in traditional medicine and the food and cosmetics industry. The aim of this study is to assess the antioxidant, genotoxic, antigenotoxic and cytotoxic properties of characterized hyssop essential oils and methanol extracts. Chemical composition was analyzed by gas chromatography - mass spectrometry (GC-MS) and liquid chromatography with diode array detection and mass spectrometry (LC-DAD-MS), respectively. Antioxidant activity was examined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing/antioxidant power (FRAP) tests; genotoxic and antigenotoxic activity were examined by the comet assay, while cytotoxicity was evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide dye (MTT) test against tumor cell lines (SW480, MDA-MB 231, HeLa) and non-transformed human lung fibroblast cell lines (MRC-5). The essential oils were rich in monoterpene hydrocarbons (e.g., limonene; 7.99-23.81%), oxygenated monoterpenes (1,8-cineole; 38.19-67.1%) and phenylpropanoids (methyl eugenol; 0.00-28.33%). In methanol extracts, the most abundant phenolics were chlorogenic and rosmarinic acid (23.35-33.46 and 3.53-17.98 mg/g, respectively). Methanol extracts expressed moderate to weak antioxidant activity (DPPH IC50 = 56.04-199.89 µg/mL, FRAP = 0.667-0.959 mmol Fe2+/g). Hyssop preparations significantly reduced DNA damage in human whole blood cells, induced by pretreatment with hydrogen peroxide. Methanol extracts exhibited selective and potent dose- and time-dependent activity against the HeLa cell line. Results of the current study demonstrated notable H. officinalis medicinal potential, which calls for further investigation.

Development of comprehensive liquid chromatography with diode array and mass spectrometric detection for the characterization of (poly-)phenolic and flavonoid compounds and application to asparagus.

The main objective of the present work was to develop a method for the simultaneous and comprehensive analysis of (poly-)phenolic and flavonoid compounds with liquid chromatography with diode array and mass spectrometric detection and its application to green asparagus samples. To this end, a representative set of polyphenols was used to develop the method. A through method validation was carried out with these. The method was applied to asparagus samples known as a healthy vegetable being rich in bioactive compounds. Polyphenol contents of asparagus samples were determined by carrying out quantitative and qualitative analyses by LC-DAD-ESI/MS. In this context asparagus sample extracts were obtained using solvents of different polarity. The results were evaluated statistically and showed that rutin is the major phenolic compound in asparagus. This demonstrates the versatility of this rapid and sensitive method for the simultaneous analysis of (poly-)phenolic and flavonoid compounds which was successfully applied to asparagus samples.

Industrial Fruits By-Products and Their Antioxidant Profile: Can They Be Exploited for Industrial Food Applications?

Fruit by-products have a low economic value and have proven biological activities, such as antioxidant capacity due to the presence of active compounds. The main objective of this study was to obtain and determine the antioxidant capacity, through DPPH radical assay and ß-carotene bleaching assay, of three food grade extracts from apple, lemon, and orange industrial by-products. Furthermore, the extracts were characterized by ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS/MS). LC with diode array detector (LC-DAD) was used for the quantification of the main polyphenols. Lemon extract presented the highest inhibition percentage of DPPH radical (51.7%) and the highest total phenolics content (43.4 mg GAE/g) from the by-products studied. Orange by-product was that with the higher number of polyphenols while lemon extract was that with the highest content of individual phenolics. The by-product obtained from the lemon was that with higher amounts of hydroxycinnamic acids (407 µg/g of by-product), mainly chlorogenic acid (386.7 µg/g), followed by the apple by-product (128.0 µg/g of by-product), which showed higher amounts of rosmarinic and chlorogenic acids. These industrial by-products have great potential as a source of natural antioxidants to be used directly as food additives or to be incorporated in packaging to produce active food packaging.

LC-DAD/ESI-MS/MS characterization of phenolic constituents in Rosa canina L. and its protective effect in cells.

In an aim to prove the efficiency of polyphenols of Rosa canina fruits in promoting human health. A methanolic extract of R. canina fruits was prepared by successive maceration with solvents of increasing polarity. The polyphenol composition was analyzed by HPLC-DAD-ESI-MS. The biological activity of this extract on SH-SY5Y cells and HepG2 cells was then studied. The antioxidant activity was tested by various in vitro tests such as DPPH-radical-scavenging activity, FRAP assay, hydroxyl radical scavenging assay and total antioxidant capacity. The subacute toxicity of R. canina was tested on female rats by repeated intraperitoneal administration of various doses. The phenolic profiles showed 25 antioxidants distributed into three classes of phenolic compounds: glycosylated and agglomerated flavonoids/isoflavonoids, tannins and phenanthrenes. Qualitative phytochemical analyses showed that this extract lacks alkaloids. The methanolic extract of R. canina fruits has a total antioxidant capacity of 82.69 ± 1.18 µg EAA/mg of methanol extract and the IC50 of the methods used is in the following increasing order: FRAP assay (61.88 µg/ml), then hydroxyl radical scavenging assay (67.45 µg/ml) and then DPPH radical-scavenging activity (129.81 µg/ml). The extract of R. canina did not cause any phenotypic signs of toxicity or mortality during and after treatment. The LD50 was >5,000 mg/kg, hence, R. canina was considered nontoxic. An in vivo study proved the protective effect of R. canina against cardiac and hepato-renal toxicities. These results drew the importance of a healthy diet, where diets rich in R. canina fruits can be used as a rich natural source of antioxidants and anticarcinogenic phenolic compounds.

Alternative Isolation Protocol for Desulfo and Zwitterionic Cylindrospermopsin Alkaloids and Comparison of Their Toxicity in HepG2 Cells.

The term cylindrospermopsins (CYNs) refers to a structurally related class of cyanobacterial metabolites comprised of a tricyclic guanidine group and a hydroxymethyluracil moiety. Most reports in environmental aquatic samples refer to cylindrospermopsin (CYN), and reports on other CYN alkaloids are scarce, due, in part, to a lack of versatile isolation protocols. Thus, using commercially available solid phase extraction (SPE) cartridges, we optimized an isolation protocol for the complete recovery of CYN, 7-deoxy-cylindrospermopsin (7D-CYN) and 7-deoxy-desulfo-cylindrospermopsin (7D-desulfo-CYN) from the same aliquot. The isolation protocol was adaptable depending on the nature of the sample (solid biomass, culture broth or environmental water sample) and tolerates up to 4 L of dense culture broth or 400 mg of lyophilized biomass. To quantitate the CYN alkaloids, we validated an LC-DAD-MS2 method, which takes advantage of the UV absorption of the uracil group (λ 262 nm). Using electrospray ionization (ESI) in a positive ion mode, the high-resolution MS1 data confirms the presence of the protonated alkaloids, and the MS2 fragment assignment is reported as complementary proof of the molecular structure of the CYNs. We isolated three CYN alkaloids with different water solubility using the same lyophilized sample, with a purity that ranged from 95% to 99%. The biological activity of the purified CYNs, along with a synthetic degradation product of CYN (desulfo-cylindrospermopsin), was evaluated by assessing necrosis and apoptosis in vitro using flow cytometry. CYN's lethal potency in HepG2 cells was greater than the other analogs, due to the presence of all four functional groups: guanidine, uracil, C-7 hydroxyl and the sulfate residue.

Viola cornuta and Viola x wittrockiana: Phenolic compounds, antioxidant and neuroprotective activities on Caenorhabditis elegans.

Different Viola species are known for their traditional use as analgesic, antitussive, febrifuge, hipnotic, analgesic and anti-inflammatory medicinal agents. Additionally, they are considered edible flowers in certain cultures. Thus, the aim of this work was to characterize the phenolic composition and to assess the neuroprotective properties of Viola cornuta and Viola x wittrockiana using in vitro and in vivo methodologies with Caenorhabditis elegans as model. The identification of the phenolic compounds was carried out with a LC-DAD-ESI/MSn. The antioxidant activity of the extracts was determined in vitro using Folin- Ciocalteu, DPPH and FRAP assays and in vivo with a juglone-induced oxidative stress in C. elegans. The neuroprotective properties were evaluated measuring the ability to inhibit CNS enzymes (MAO A, AChE), and the capability to avoid paralyzing the C. elegans CL4176, an Alzheimer disease model. The phenolic content was higher in V. x wittrockiana, being quercetin-3-O-(6-O-rhamnosylglucoside)-7-O-rhamnoside the predominant compound in the extract, which also exhibited a stronger antioxidant capacity in vitro and a higher response to lethal oxidative stress on C. elegans than V. cornuta. Only V. x wittrockiana showed inhibitory effect on CNS enzymes, such as acetylcholinesterase and monoamine oxidase A, but both had protective effect against the paralysis of C. elegans. These findings suggest that the studied V. cornuta and V. x wittrockiana could be interesting candidates for age related neurodegenerative disorder associated with oxidative stress.

Polyphenol Characterization, Antioxidant and Skin Whitening Properties of Alnus cordata Stem Bark.

In this study, we investigated the phenolic composition of the crude extract (MeOH 80 %) of Alnus cordata (Loisel.) Duby stem bark (ACE) and its antioxidant and skin whitening properties. RP-LC-DAD analysis showed a high content of hydroxycinnamic acids (47.64 %), flavanones (26.74 %) and diarylheptanoids (17.69 %). Furthermore, ACE exhibited a dose-dependent antioxidant and free-radical scavenging activity, expressed as half-maximal inhibitory concentration (IC50 ): Oxygen radical absorbance capacity (ORAC, IC50 1.78 µg mL-1 )>Trolox equivalent antioxidant capacity (TEAC, IC50 3.47 µg mL-1 )>2,2-Diphenyl-1-picrylhydrazyl (DPPH, IC50 5.83 µg mL-1 )>ß-carotene bleaching (IC50 11.58 µg mL-1 )>Ferric reducing antioxidant power (FRAP, IC50 17.28 µg mL-1 ). Moreover, ACE was able to inhibit in vitro tyrosinase activity (IC50 77.44 µg mL-1 ), l-DOPA auto-oxidation (IC50 39.58 µg mL-1 ) and in an in vivo model it exhibited bleaching effects on the pigmentation of zebrafish embryos (72 h post fertilization) without affecting their development and survival. In conclusion, results show that A. cordata stem bark may be considered a potential source of agents for the treatment of skin disorders due to its bleaching properties and favorable safety profiles, associated to a good antioxidant power.

Bioaccumulation of selected macro- and microelements and their impact on antioxidant properties and accumulation of glucosinolates and phenolic acids in in vitro cultures of Nasturtium officinale (watercress) microshoots.

The study evaluated bioaccumulation capacity of macro- and microelements, their impact on the production of glucosinolates and phenolic acids and antioxidant properties in a microshoot culture model of Nasturtium officinale. Elements: calcium, chromium, copper, iron, lithium, magnesium, selenium and zinc were supplemented in different salt concentrations to culture media. Bioaccumulation of elements [mg/100 gDW] varied from 1.24 (Li,1 mg/l) to 498.62 (Cr,50 mg/l) and was dependent on the type of element and its concentration. The bioconcentration factor (BCF) ranged from 11.37 (Li,25 mg/l) to 4467.00 (Ca,1 mg/l). The total glucosinolate contents [mg/100gDW] varied from 108.11 (Cr,1 mg/l) to 172.90 (Ca,1 mg/l). The presence of four phenolic acids was confirmed in the microshoots. Their total contents [mg/100gDW] ranged from 19.35 (Mg,10 mg/l) to 139.21 (Fe,50 mg/l). The highest antioxidant activity [nM trolox/mgDW], as evaluated by CUPRAC and QUENCHER-CUPRAC methods, was equal to 55.50 (Cu,1 mg/l) and 161.10 (Li,5 mg/l), respectively. The results proved good correlations between all studied parameters.

A Comprehensive View on (-)-7-Oxo-ent-kaur-16-en-19-oic Acid, the Major Constituent of Xylopia sericea Leaves Extract: Complete NMR Assignments, X-Ray Crystallographic Structure, in Vitro Antimalarial Activity and Cytotoxicity.

Bioguided fractionation of Xylopia sericea antiplasmodial dichloromethane leaves extract led to the isolation of (-)-7-oxo-ent-kaur-16-en-19-oic acid (C20 H28 O3 ) that was identified by a combination of 1D and 2D NMR experiments (COSY, HMBC, HSQC, HSQC-TOCSY, HSQC-NOESY and NOESY) and by X-ray crystallography. A feature to be pointed out is its (4R) configuration that was inferred from the NOE experiments (HSQC-NOESY and NOESY) and X-ray crystallography. In vitro evaluation of this rare diterpene acid against the chloroquine-resistant strain Plasmodium falciparum W2 by the PfLDH method showed it disclosed a low antiplasmodial activity and was not cytotoxic to HepG2 cells (CC50 862.6±6.7 µm) by the MTT assay. The unequivocal NMR signals assignments, the X-ray crystallographic structure, the assessment to the bioactivities and the occurrence this diterpene in X. sericea are reported here for the first time.