The synthesis of decyl-o-phenanthrolinium organic salt and a study of the impact of anion type on in vitro antibacterial activities

According to evidence in the literature, organic salts have an affinity for biological membranes that makes them easily absorbed into cells and capable of having a wide range of biological effects, such as broad antibacterial potential and anticancer activity. The present work describes the preparation of three organic salts with a common decyl-1,10-phenanthrolinium cation ([C22H25N2]+) differing in the anions (Br−, PF6− and (CF3SO2)2N−). The synthesis was confirmed using spectrometry methods (NMR (1H 13C, 19F, 31P), ESI MS, Uv-Vis), CHNSBr elemental and thermal analysis as well as conductivity measurements. In vitro biological activities were tested on two Gram-positive (Staphylococcus aureus (S. aureus), Streptococci pyogenes (S. pyogenes)) and two Gram-negative (Escherichia coli (E. Coli) and Klebsiellae pneumoniae (K. Pneumoniae)) bacteria and compared with a commercial antibiotic (Gentamicin). The salt with the halide anion demonstrated better inhibition activities than the commercially available gentamicin. Their ion-conductivity in ethanol was found to decrease in the order [C22H25N2][PF6], [C22H25N2][(CF3SO2)2N] and [C22H25N2]Br while, their thermal stability was found to increase in the order [C22H29N2]Br, [C22H29N2][PF6], and [C22H29N2][(CF3SO2)2N]. The minimum inhibitory concentration (MIC) values show that the salts could inhibit bacterial growth at concentrations as low as 50 μg/L. Passing the cytotoxicity investigations, these salts can be considered as alternative antibiotics in combating the emerging drug resisting bacteria

Investigation of antioxidant and antimicrobial activities of Euclea schimperi leaf extracts

Abstract Background Bioactive components from medicinal plants are said to be responsible for the antioxidant and antimicrobial effects of plant extracts. It was the main purpose of this paper to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant and antimicrobial activities of leaf extracts of Euclea schimperi. Results Strong evidence was found when a positive correlation was found between TPC or TFC and antioxidant power. To put it differently, TPC of the E. schimperi leaf extracts varied between 748.78 ± 3.11 mgGAE/100 g of dry extract (methanol) and 40.45 ± 0.66 mgGAE/100 g of dry extract (chloroform) while TFC varied from 3.306 ± 0.142 mgQE/100 g of dry extract (methanol) to 0.334 ± 0.002 mgQE/100 g dry extract (chloroform). Similarly, all extracts exhibited significant amount of antioxidant and antimicrobial activities. Ferric reducing power was ranged between 312.145 ± 1.542 mgAAE/100 g extract (methanol) and 48.177 ± 0.286 mgAAE/100 g (chloroform). DPPH radical scavenging activity (%) lied between 83.4% (methanol) and 58.5% (chloroform). The voltammetric analysis of the crude extract gave three different sharp peaks at the oxidation potential side. Finally, the reducing agent capacity of the extracts was further confirmed by synthesizing silver nanoparticles from AgNO3 solution and the plant crude extracts. Crude extracts of E. schimperi leaves showed various degree of antimicrobial activity towards different standard strains with mean zone of inhibition ranging from 0 to 20.67 mm. Both solvent leaf extracts of E. schimperi exhibited MIC ranging from 62.5 to 125 mg/mL towards most bacterial species. Conclusions Euclea schimperi leaf extracts were found to contain high amount of total phenolic and small amount of flavonoid compounds which play a major role in controlling oxidation. In general, therefore, the results prove the effectiveness of the plant for its excellent antioxidant and antimicrobial activities. Accordingly, the positive values of the plant in traditional medicines have been confirmed

Synthesis of N-Tetradecyl-1,10-phenathrolinium-Based New Salts for Biological Applications

New organic salts were synthesized by quaternizing 1,10-phenanthroline using 1-bromotetradecane. The first step yielded an organic salt of formula [C26H37N2]Br. Anion exchange reaction using Li[(CF3SO2)2N] resulted in a more stable salt of formula [C26H37N2][(CF3SO2)2N]. The organic salts were investigated by spectrometry (1H, 13C, 19F NMR, X-ray photoelectron spectroscopy (XPS), UV-Vis, and matrix-assisted laser desorption/ionization mass spectroscopy (MALDI MS), CHNSBr elemental analysis, and thermal analysis (TGA and DSC). The thermal characterization showed the melting and decomposition points of [C26H37N2][(CF3SO2)2N] to be 48°C and 290°C, respectively, which indicates it is an ionic liquid with large liquidus range. The biological activities of the salts were investigated against two Gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and two Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria, and they are found to be active against all of them. They were compared with [Cu(1,10-phenanthroline)2Cl]Cl. They are found more active against the Gram-negative bacteria. The salts demonstrated minimum inhibitory concentration as low as 50 µg/L. These results suggest the synthesized salts can be considered as a better alternative to certain transition metal complex drugs. This minimizes the concern of introducing metal ions into the organism

Geographical origin discrimination of Ethiopian sesame seeds by elemental analysis and chemometric tools

Origin discrimination of sesame seeds is becoming one of the important factors for the sesame seed trade in Ethiopia as it influences the market price. This study was undertaken to construct accurate geographical origin discriminant models for Ethiopian sesame seeds using multi-element analysis and statistical tools. The concentration of 12 elements (Na, Mg, Cr, Mn, Fe, Cu, Co, Ni, Zn, Cd, As and Pb) were determined in 93 samples which were collected from three main sesame seed-producing regions in Ethiopia, Gondar, Humera and Wollega. According to a one-way analysis of variance (ANOVA), the concentration of 10 elements showing a significant difference (p < 0.05) was taken for statistical analysis using principal component analysis (PCA) and linear discriminant analysis (LDA). PCA showed some clustering of samples according to their respective origins. Then, the follow-up LDA resulted in a 100 % correct origin classification rate for all 93 sesame seed samples obtained from three regions in Ethiopia

Removal of cadmium ions from aqueous solution using very small ionic liquids to water ratio without metal chelator and pH modifications

Solvent extraction is an energy-efficient technology which uses two immiscible phases. In this regard, solvents like hydrophobic 1-butyl-3-methylimidazolium hexafluorophosphate based ionic liquids have been used. The hydrophilicity of the metal ions is a challenge to use this method. Coordinating the metal ions by ligands, lowering the pH of the aqueous phase, modifying the ionic liquid itself in such a way that it can coordinate with the metal ions, employment of large ionic liquid to aqueous phase ratio (minimum of 1:1) were also the attempts made to improve the distribution coefficient of the ionic liquids. All these efforts are problematic in hindering the applications of ionic liquids in extraction. In this report, the extraction efficiencies of ionic liquids (C4mim][PF6], [C6mim][PF6] , [C8mim][PF6] and [C10mim][PF6]) from water samples containing Cd2+ using very small ionic liquid to water ratio (1:6 and 1:12) from a solution of concentrations 0.005 mg/L with out using any coordinating agent as an extractant and the need of changing the pH are disclosed. While ionic liquids to aqueous phase ratio 1:12 demonstrated extraction efficiencies of 75%, 83.75%, 87.50% and 100%, respectively; the 1:6 ratio extracted 87.50%, 100%, 100% and 100%, respectively which shows suitability of the later ratio for better extraction. Moreover, the recyclabilities of [C6mim][PF6] and [C8mim][PF6] was investigated and the result showed that they can be used at least for five cycles. A Linear calibration curve with good coefficient of determination was obtained during the analysis for determination of the metal in the extracts.Keywords: Cadmium(II), Ionic Liquids, Extraction, Recyclability, Small Ionic Liquid to Water Rati

Development of biodegradable film from cactus (Opuntia Ficus Indica) mucilage loaded with acid-leached kaolin as filler

Nowadays, substituting petroleum-based plastics with biodegradable polymers made from polysaccharides loaded with various reinforcing materials has recently gained attention due to the impact of conventional plastics wastes. In this study, polysaccharidic mucilage from Ethiopian cactus (Opuntia Ficus Indica) was derived using microwave-assisted extraction technique to develop biodegradable polymers that were inexpensive, readily available, simple to make, and ecofriendly. The effect of microwave power 300–800 W, solid-liquid (cactus-sodium hydroxide solution) ratio 1:5–1:25, sodium hydroxide concentration 0.1–0.8 mol/L, and extraction time 2–10 min on mucilage extraction were studied and the maximum yield of mucilage was attained at optimized parameters of 506 W, 1:20, 0.606 mol/L, and 9.5 min, respectively. Biodegradable polymers made with mucilage alone have poor mechanical characteristics and are thermally unstable. Thus, to overcome the stated problems, glycerol as a plasticizer and acid-leached kaolin crosslinked with urea as a reinforcing material were used. Moreover, the effect of acid-leached kaolin and glycerol on the physico-chemical properties of the films was studied, and a maximum tensile strength of 6.74 MPa with 18.45 % elongation at break, thermally improved biodegradability of 26 %, were attained at 10 % acid-leached kaolin and 20 % glycerol crosslinking with 2 % urea. But the maximum degradability of 53.5 % was attained at 30 % glycerol content. The control and reinforced biodegradable films were characterized using TGA, FTIR, SEM, and XRD to determine the thermal, functional group, morphology, and crystallinity of the bioplastics, respectively. These biodegradable plastics may be used for packaging application

Rapid and simultaneous determination of trigonelline, caffeine, and chlorogenic acid in green coffee bean extract

Abstract A simple, inexpensive, and rapid method for simultaneous determination of trigonelline, caffeine, and chlorogenic acid from green coffee bean extract was proposed based on salting‐out assisted liquid–liquid extraction, using QuEChERS salt and acetonitrile followed by UV‐Vis analysis. The proposed method represents acceptable linearity for trigonelline (0.9978), caffeine (0.9995), and chlorogenic acid (0.9996) with excellent correlation (0.93 and 0.83) for trigonelline and caffeine, respectively, when compared to RP‐HPLC‐DAD. The proposed method could be used in coffee industries for quality control and geographical origin traceability studies of green coffee samples

Chemical Composition of Urtica simensis Grown in Different Regions of Ethiopia

Leaf samples of Urtica simensis collected from different locations of Ethiopia were analyzed for their proximate compositions, total phenolic and flavonoid contents, antioxidant activities, and fatty acid profiles. The proximate analysis results revealed the presence of ash in the range 17.2–24.3%, crude fat 3.19–3.50%, crude protein 3.42–6.38%, crude fiber 9.37–14.0%, and carbohydrate 56.7–63.7%. The determined total polyphenols, flavonoids, and antioxidant activities ranged 2.18–4.84 mg gallic acid, 1.35–4.46 mg catechin, and 1.58–3.36 mg ascorbic acid, respectively, equivalents per gram of dry sample. High variability was observed for polyphenol and flavonoid contents while only random variation was observed for crude fat and carbohydrate among samples from different locations. In addition, the fatty acid profiles of the leaves were analyzed by using gas chromatography coupled with mass spectrometry. A total of 16 different fatty acids were detected in the samples. Linolenic, palmitic, and linoleic acids were the major fatty acids with average compositions of 36.6, 20.7, and 15.5%, respectively, of the total fatty acid. The result of this study revealed that the carbohydrate and ash contents of leaves of Urtica simensis are exceptionally high to make the leaves a significant source of the dietary important chemicals. Additionally, the lipid fraction of the leaves was found to be rich in essential fatty acids (α-linolenic and linoleic acids) that are critically required in the human diet