Antifungal activity and phytochemical screening of extracts from Phoenix dactylifera L. cultivars

In this study, the rachis extracts of eight date palm Phoenix dactylifera L. cultivars were analysed by phytochemical screening and bioautography on Fusarium oxysporum f. sp. albedinis (Foa). The choice of cultivars was based on their reaction to Foa (resistant, tolerant and sensitive). Phytochemical screening was realised for flavonoids, tannins, alkaloids and coumarins. Antifungal effects were mostly represented by dichloromethanic extracts (seven out of nine inhibition zones). The best results were represented by the dichloromethanic extract of the cultivar 'Bent-Cherk' rachis (6.50?±?1.41?mm) and the ethyl acetate extract of the cultivar 'Rotbi' rachis (6.00?±?1.41?mm). The date palm cultivars presented some similarities concerning phytochemical screening results related to their resistance or sensibility to Foa. From the correlation between phytochemical screening and bioautography, it was observed that the majority of bioactive compounds against Foa seem to be polyphenols. Thus, the natural defence mechanism in vivo against Foa is probably related to the action of polyphenols. The difference between resistant, tolerant and sensitive cultivars is related to their mechanism of action.     

Chiral Separation of 4-Iminoflavan Derivatives on Several Polysaccharide-Based Chiral Stationary Phases by HPLC

The HPLC enantiomeric separation of seven 4-iminoflavans was successfully accomplished in the normal phase mode using six polysaccharide-based chiral stationary phases namely, Chiralcel^®OD-H, Chiralcel^®OD, Chiralcel^®OJ, Chiralpak^®AD, Chiralpak^®IA and Chiralpak^®IB under normal and polar organic phase modes. The resolution depended on nature and concentration of alcoholic modifier. The results demonstrate clearly that the chromatographic system based on the coated and immobilized type Chiralpak^®IB and Chiralcel^®OD-H CSPs provide a powerful analytical tool for enantiomeric separation of all the 4-iminoflavans used in this study.     

In vitro effect of wheat bran (Triticum aestivum) extract on calcium oxalate urolithiasis crystallization

Urolithiasis can lead to the loss of renal function in some cases. In this study, we tested the inhibiting effect of wheat bran (Triticum aestivum L) extract on calcium oxalate crystallization in a turbidimetric model, by FTIR spectroscopy, and polarized microscopy. The results show that this plant extract has a major inhibitory effect on calcium oxalate crystallization.     

Achiral and chiral separation and analysis of antifungal drugs by HPLC and CE: A comparative study: Mini review

The chromatographic and electrophoretic methods developed for the chiral and achiral analyses if antifungal agents are reviewed. The aim of this review is to compare different methodologies of analytical methods and to explore still the existing analytical problems. Last decade is characterized by dynamic development of instrumental methods that results in advance and diversity of applied analytical procedures. The enantiomeric separation of several compounds, including an antifungal drug and several of its precursors, using high-performance liquid chromatography (HPLC) and capillary electrophoresis (CE) is described in this work. The main focus was given to HPLC, the technique of choice in the analysis of most of the pharmaceutical formulations and biological samples. The columns used were based on polysaccharide derivatives. However, the results show that most of the separations obtained by CE are better, in terms of high resolution and short analysis time. The review discusses the chromatographic analysis of the following triazole antifungal drugs: fluconazole, itraconazole, and terconazole from the first generation and posaconazole, voriconazole, ravuconazole, isavuconazole, and albaconazole from the second generation in their pharmaceutical formulations and biological samples.     

Impact of the Synthesis Method on Electrochemical Performance of La0.5Sr0.5MnO3 Perovskite Oxide as a Cathode Material in Alkaline Fuel Cells

Russian Journal of Electrochemistry - The present research investigates the sol–gel route using Pechini, citrate and alkoxide methods in order to obtain strontium doped lanthanum manganite...     

Effect of Co substitution for Fe in Sr2FeMoO6 on electrocatalytic properties for oxygen reduction in alkaline medium

Double perovskites Sr₂Fe_1???x Co _x MoO₆ (x?=?0, 0.25, 0.5, 0.75 and 1) have been investigated as cathode material for oxygen reduction reaction (ORR) in 0.5 M NaOH at 25 °C using the rotating disk electrode. The electrocatalytic powders were prepared by a solid-state process and characterised by X-Ray powder diffraction, scanning electron microscopy and infrared spectroscopy. The electrochemical techniques considered are linear voltammetry, steady-state polarization and impedance spectroscopy. The electrocatalysts Sr₂Fe_1???x Co _x MoO₆/C consisting of the double perovskite oxides and carbon (Vulcan XC-72) were mixed and spread out into a thin layer on a glassy carbon substrate. The electrocatalytic activity was strongly influenced by the Co substitution at room temperature. The relation between catalytic performance and the degree of Co content was examined. The Co-containing catalysts exhibited lower activity attributed to their high resistivity, and the highest activity toward oxygen reduction was observed for Sr₂CoMoO₆.     

Chiral Separation of 4-Iminoflavan Derivatives on Several Polysaccharide-Based Chiral Stationary Phases by HPLC

The HPLC enantiomeric separation of seven 4-iminoflavans was successfully accomplished in the normal phase mode using six polysaccharide-based chiral stationary phases namely, Chiralcel^®OD-H, Chiralcel^®OD, Chiralcel^®OJ, Chiralpak^®AD, Chiralpak^®IA and Chiralpak^®IB under normal and polar organic phase modes. The resolution depended on nature and concentration of alcoholic modifier. The results demonstrate clearly that the chromatographic system based on the coated and immobilized type Chiralpak^®IB and Chiralcel^®OD-H CSPs provide a powerful analytical tool for enantiomeric separation of all the 4-iminoflavans used in this study.