Isolation and relative stereochemistry of lippialactone, a new antimalarial compound from Lippia javanica

The aerial parts of Lippia javanica were investigated for biologically active chemical compounds present in them. Chromatographic separation of the ethyl acetate extract of the aerial parts yielded a new antimalarial α-pyrone, lippialactone (2). Lippialactone is active against the chloroquinesensitive D10 strain of Plasmodium falciparum with an IC50 value of 9.1 μg/mL, and is also mildly cytotoxic. The relative stereochemistry of lippialactone was determined by molecular modeling based on the determination of the relative configuration by quantum mechanical GIAO 13C chemical shift calculations.National Research Foundation.http://www.elsevier.com/locate/fitotehb201

In Vitro Studies on Antioxidant and AntiParasitic Activities of Compounds Isolated from Rauvolfia caffra Sond

As part of an ongoing study of natural products from local medicinal plants, the methanol extract of stem bark of Rauvolfia caffra Sond was investigated for biological activity. Column chromatography and preparative thin-layer chromatography were used to isolate lupeol (1), raucaffricine (2), N-methylsarpagine (3), and spegatrine (4). The crude extract, fractions and isolated compounds were tested for anti-oxidant, antitrypanosomal and anti-proliferation activities. Two fractions displayed high DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity and reducing power with IC50 (The half maximal inhibitory concentration) and IC0.5 values of 0.022 ± 0.003 mg/mL and 0.036 ± 0.007 mg/mL, and 0.518 ± 0.044 mg/mL and 1.076 ± 0.136 mg/mL, respectively. Spegatrine (4) was identified as the main antioxidant compound in R. caffra with IC50 and IC0.5 values of 0.119 ± 0.067 mg/mL and 0.712 ± 0 mg/mL, respectively. One fraction displayed high antitrypanosomal activity with an IC50 value of 18.50 μg/mL. However, the major constituent of this fraction, raucaffricine (2), was not active. The crude extract, fractions and pure compounds did not display any cytotoxic effect at a concentration of 50 μg/mL against HeLa cells. This study shows directions for further in vitro studies on the antioxidant and antitrypanosomal activities of Rauvolfia caffra Sond

Molecular Networking-Based Metabolome, In Vitro Antidiabetic and Anti-Inflammatory Effects of <i>Breonadia salicina</i> (Vahl) Hepper & J.R.I. Wood

Breonadia salicina (Vahl) Hepper & J.R.I. Wood is widely distributed throughout Africa. It is used ethnobotanically to treat various diseases. However, the metabolic profile of the Breonadia species is not well characterized and the metabolites that are responsible for the bioactivity of this plant remain unknown. Therefore, there is a need to determine the phytochemical and bioactivity profile to identify metabolites that contribute to the antidiabetic, anti-inflammatory and antiproliferation activity, including the genotoxicity and cytotoxic effects, of Breonadia salicina. The study is aimed at exploring the metabolomic profile antidiabetic, anti-inflammatory and antiproliferation activity, as well as the genotoxicity and cytotoxicity effects, of constituents of B. salicina. The compounds in the B. salicina extract were analyzed by ultra-performance liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), and the resultant data were further analyzed using a molecular networking approach. The crude stem bark and root extracts showed the highest antidiabetic activity against α-amylase at the lowest test concentration of 62.5 µg/mL, with 74.53 ± 0.74% and 79.1 ± 1.5% inhibition, respectively. However, the crude stem bark and root extracts showed the highest antidiabetic activity against α-glucosidase at the lowest test concentration of 31.3 µg/mL, with 98.20 ± 0.15% and 97.98 ± 0.22% inhibition, respectively. The crude methanol leaf extract showed a decrease in the nitrite concentration at the highest concentration of 200 µg/mL, with cell viability of 90.34 ± 2.21%, thus showing anti-inflammatory activity. No samples showed significant cytotoxic effects at a concentration of 10 µg/mL against HeLa cells. Furthermore, a molecular network of Breonadia species using UPLC-QTOF-MS with negative mode electrospray ionization showed the presence of organic oxygen compounds, lipids, benzenoids, phenylpropanoids and polyketides. These compound classes were differentially distributed in the three different plant parts, indicating the chemical differences between the stem bark, root and leaf extracts of B. salicina. Therefore, the identified compounds may contribute to the antidiabetic and anti-inflammatory activity of Breonadia salicina. The stem bark, root and leaf extracts of B. salicina yielded thirteen compounds identified for the first time in this plant, offering a promising avenue for the discovery of new lead drugs for the treatment of diabetes and inflammation. The use of molecular networking produced a detailed phytochemical overview of this Breonadia species. The results reported in this study show the importance of searching for bioactive compounds from Breonadia salicina and provide new insights into the phytochemical characterization and bioactivity of different plant parts of Breonadia salicina

Anodization fabrication techniques and energy-related applications for nanostructured anodic films on transition metals

Nanostructured anodic films on transition metals prepared using the electrochemical anodization method have recently attracted particular attention owing to their extraordinary properties and potential use in a variety of applications. Herein, we provide a thorough review of the anodization fabrication of anodic films with different nanostructures, including nanopores, nanotubes, nanoflowers, nanoneedles and nanowires on transition metals, focusing on the growth processes of nanostructured anodic films on three representative transition metals, namely, iron, copper and zinc. Specific consideration is given to the anodization behavior and formed film nanostructures of these transition metals. We conclude that electrolyte composition plays a key role in influencing the final morphologies of anodic films. Fluoride-containing solutions represent universal electrolytes for forming nanostructured anodic films on transition metals. The main applications of the resulting nanostructured anodic films, especially in energy-related fields, such as photoelectrochemical water splitting and supercapacitors, are also presented and discussed. Finally, we indicate the main challenges associated with the fabrication of anodic films with highly ordered nanostructures and the potential future directions of this field are indicated

Bioactive compounds from the endophytic fungus <i>Fusarium proliferatum</i>

<p>The crude extract of an endophytic fungus isolated from <i>Syzygium cordatum</i> and identified as <i>Fusarium proliferatum</i> showed 100% cytotoxicity against the brine shrimp <i>Artemia salina</i> at 100 μg/mL. Seven coloured, biologically active metabolites – including ergosta-5,7,22-trien-3β-ol, nectriafurone-8-methyl ether, 9-<i>O</i>-methyl fusarubin, bostrycoidin, bostrycoidin-9-methyl ether and 8-hydroxy-5,6-dimethoxy-2-methyl-3-(2-oxo-propyl)-1,4-naphthoquinone– were isolated from the extract.</p

Dinemasones A, B and C: New Bioactive Metabolites from the Endophytic Fungus Dinemasporium strigosum

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In Vitro Studies on Antioxidant and Anti-Parasitic Activities of Compounds Isolated from Rauvolfia caffra Sond

As part of an ongoing study of natural products from local medicinal plants, the methanol extract of stem bark of Rauvolfia caffra Sond was investigated for biological activity. Column chromatography and preparative thin-layer chromatography were used to isolate lupeol (1), raucaffricine (2), N-methylsarpagine (3), and spegatrine (4). The crude extract, fractions and isolated compounds were tested for anti-oxidant, antitrypanosomal and anti-proliferation activities. Two fractions displayed high DPPH (2,2-diphenyl-1-picrylhydrazyl) free radical scavenging activity and reducing power with IC50 (The half maximal inhibitory concentration) and IC0.5 values of 0.022 &plusmn; 0.003 mg/mL and 0.036 &plusmn; 0.007 mg/mL, and 0.518 &plusmn; 0.044 mg/mL and 1.076 &plusmn; 0.136 mg/mL, respectively. Spegatrine (4) was identified as the main antioxidant compound in R. caffra with IC50 and IC0.5 values of 0.119 &plusmn; 0.067 mg/mL and 0.712 &plusmn; 0 mg/mL, respectively. One fraction displayed high antitrypanosomal activity with an IC50 value of 18.50 &mu;g/mL. However, the major constituent of this fraction, raucaffricine (2), was not active. The crude extract, fractions and pure compounds did not display any cytotoxic effect at a concentration of 50 &mu;g/mL against HeLa cells. This study shows directions for further in vitro studies on the antioxidant and antitrypanosomal activities of Rauvolfia caffra Sond

Agar Acts as Cathode Microskin to Extend the Cycling Life of Zn//α-MnO2 Batteries

The Zn/MnO2 battery is a promising energy storage system, owing to its high energy density and low cost, but due to the dissolution of the cathode material, its cycle life is limited, which hinders its further development. Therefore, we introduced agar as a microskin for a MnO2 electrode to improve its cycle life and optimize other electrochemical properties. The results showed that the agar-coating layer improved the wettability of the electrode material, thereby promoting the diffusion rate of Zn2+ and reducing the interface impedance of the MnO2 electrode material. Therefore, the Zn/MnO2 battery exhibited outstanding rate performance. In addition, the agar-coating layer promoted the reversibility of the MnO2/Mn2+ reaction and acted as a colloidal physical barrier to prevent the dissolution of Mn2+, so that the Zn/MnO2 battery had a high specific capacity and exhibited excellent cycle stability

Various Tastes of Sugar: The Potential of Glycosylation in Targeting and Modulating Human Immunity via C-Type Lectin Receptors

C-type lectin receptors (CLRs) are important in several immune regulatory processes. These receptors recognize glycans expressed by host cells or by pathogens. Whereas pathogens are recognized through their glycans, which leads to protective immunity, aberrant cellular glycans are now increasingly recognized as disease-driving factors in cancer, auto-immunity, and allergy. The vast variety of glycan structures translates into a wide spectrum of effects on the immune system ranging from immune suppression to hyper-inflammatory responses. CLRs have distinct expression patterns on antigen presenting cells (APCs) controlling their role in immunity. CLRs can also be exploited to selectively target specific APCs, modulate immune responses and enhance antigen presentation. Here we will discuss the role of glycans and their receptors in immunity as well as potential strategies for immune modulation. A special focus will be given to different dendritic cell subsets as these APCs are crucial orchestrators of immune responses in infections, cancer, auto-immunity and allergies. Furthermore, we will highlight the potential use of nanoscale lipid bi-layer structures (liposomes) in targeted immunotherapy