Molluscicidal activity of methomyl and cardenolide extracts from Calotropis procera and Adenium arabicum against the land snail Monacha cantiana

In this work, we have evaluated the molluscicidal activity of two cardenolide extracts from Adenium arabicum Balf f. [the benzene (B) and methanol (M) extracts], one cardenolide extract from Calotropis procera (Aiton) W.T. Aiton (extract C), and methomyl against the harmful land snail Monacha cantiana (Montagu). The contact LD?? values for the above mentioned plant extracts were 12.62, 34.63, and 34.35 mg·kg?1 of body weight, respectively, while the LD?? for methomyl was 116.62 mg·kg?1, that is, the plant extracts were 9.24, 3.37, and 3.4 times more toxic than methomyl. In addition, a simple colorimetric method, based on Kedde reagent, was modified to determine cardenolide concentrations in plant extracts. Thin layer chromatography analysis (TLC) showed several cardiac glycosidal compounds in each plant extract. The results proved that cardiac glycosides are promising candidate compounds that could be used to control land snails, or exploited to develop new, effective, and environmentally friendly molluscicides.     

Volumetric Properties and Refractive Indices for Binary Mixtures of 1-Propyronitrile-3-hexylimidazolium Bromide + Ethanol at Temperatures from 293.15 to 323.15 K

Densities and refractive indices have been measured for binary mixtures of 1-propyronitrile-3-hexylimidazolium bromide + ethanol in the temperature range 293.15–323.15 K. From the experimental data the excess molar volume V ^E, refractive index deviation Δn _D, and the coefficient of thermal expansion α were calculated and fitted to fifth- and third-order Redlich–Kister type equations, respectively. Using the measured densities, the apparent molar volumes (V _ϕ ), limiting apparent molar volumes (V_f⁰V_{\phi}^{0}) and limiting apparent molar expansivities (E_f ⁰E_{\phi} ^{0}) were also determined and the details are discussed.     

Selective Spectrofluorimetric Method with Enhanced Sensitivity for Determination of Silodosine in Dosage Form and Human Plasma. Application to Stability Studies and Content Uniformity Testing

A novel, sensitive and selective spectrofluorimetric method has been developed and validated for determination of silodosine (SLD) in its dosage form and human plasma. The method is based on nucleophilic substitution reaction of SLD with 5-(dimethylamino) naphthalene-1-sulfonyl chloride (dansyl chloride) in presence of 5.0 × 10^?4 M sodium carbonate (pH 10.50) to yield a highly fluorescent derivative that was measured at 435 nm after excitation at 347 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence-concentration plot was rectilinear over the range 30.0–200.0 ng ml^?1, with a correlation coefficient of 0.9979. The limits of detection (LOD) and quantification (LOQ) were found to be 5.44 and 16.47 ng ml^?1, respectively. The proposed method was validated according to ICH guidelines, and successfully applied to the assay of commercial capsules as well as content uniformity testing. The high sensitivity of the proposed method allowed its successful application to the analysis of SLD in spiked human plasma with % recovery of 92.88 ± 1.05–100.73 ± 0.75%, (n = 6). The application of the proposed method was further extended to stability studies of SLD after exposure to different forced degradation conditions, such as acidic, alkaline and oxidative conditions, according to ICH guidelines, where this work describe the first attempt for selective spectrofluorimetric determination of silodosine in plasma and in the presence of its oxidative degradation.     

Epigenetic Modifiers Affect the Bioactive Compounds Secreted by an Endophyte of the Tropical Plant Piper longum

Seven endophytic fungi were isolated from the tropical medicinal plant Piper longum L. After preliminary screening, Phomopsis heveicola was selected for the epigenetic activation treatments. The antibacterial, antifungal, and antioxidant potentials of crude extracts obtained from the treatments (with and without epigenetic modifiers) were analyzed in vitro. The extracts inhibited growth of the human pathogens Pseudomonas aeruginosa, Shigella sonnei, Streptococcus pyogenes, and Salmonella typhi, as well as the phytopathogens Puccinia recondita, Rhizoctonia solani, Phytophthora infestans, and Botrytis cinerea. Furthermore, DPPH-scavenging activity was higher in valproic acid treated extracts. Volatile chemicals with known biological activities (measured with GC-MS/MS), were released in the valproic acid treatment. The antimicrobial potentials of the extracts were confirmed using MRM/MS analysis. The experiments revealed a new promising endophytic fungus, P. heveicola, to be utilized in biological plant protection and in biomedical applications.     

Development and validation of TLC–densitometric method for simultaneous determination of two binary antihypertensive mixtures containing felodipine in fixed dose combinations

A new densitometric thin‐layer chromatographic method has been developed for simultaneous determination of two binary mixtures containing felodipine in combination with either metoprolol (mixture I) or ramipril (mixture II). The two mixtures were quantitatively separated on 60 F254 silica gel plates using toluene–ethyl acetate–methanol–ammonia as mobile phase with UV detection at 233 and 229 nm for mixtures I and II, respectively. The studied drugs were satisfactorily resolved with retention factor (R_f) values of 0.34 ± 0.03 and 0.65 ± 0.03 for metoprolol and felodipine, respectively, in mixture I and 0.35 ± 0.03 and 0.74 ± 0.03 for ramipril and felodipine, respectively, in mixture II. Linearity ranges were 2000–7000 and 200–700 ng/band for metoprolol and felodipine, respectively, in mixture I and 1500–4000 ng/band for both ramipril and felodipine in mixture II. Correlation coefficient (r) values were 0.9968 for both metoprolol and felodipine in mixture I and 0.9993 for ramipril and 0.9989 for felodipine in mixture II. The method has been validated according to International Conference on Harmonization guidelines and has been successfully applied for determination of the studied drugs in their dosage forms without interference from commonly encountered excipients. Copyright © 2015 John Wiley & Sons, Ltd.