Androstane‐Type Steroidal Glycoside from the Roots of Asparagus curillus Buch.‐Ham. ex Roxb.

The novel androstane‐type steroidal glycoside 1 was isolated from the roots of Asparagus curillus Buch .‐Ham . ex Roxb . Its structure was elucidated as (2α,3β,5α,17β)‐17‐(1‐methoxyethoxy)‐17‐methylandrostane‐2,3‐diol 3‐(β‐D ‐digitoxopyranoside) by means of chemical and advanced spectral analysis.     

Electrochemical synthesis of copper nanowires in anodic alumina membrane and their impedance analysis

Copper (Cu) nanowires having 20 nm diameter were fabricated by electrodeposition within the pores of anodic alumina membrane (AAM) by using template synthesis method. The morphology and composition of nanowires was characterized by scanning electron microscope (SEM) and energy dispersive X-ray fluorescence (EDXRF). X-ray diffraction (XRD) was utilized for structural characterization. Impedance of nanowires was measured at room temperature by leaving the nanowires embedded in the insulating template membrane and small decrease in impedance was found at higher frequency above 10 kHz.     

Liquid–liquid–liquid microextraction of degradation products of nerve agents followed by liquid chromatography–tandem mass spectrometry

Alkyl alkylphosphonic acids (AAPAs) are important environmental markers of nerve agents. A simple hollow fiber-based liquid–liquid–liquid microextraction (HFLLLME) technique has been developed to enrich the AAPAs from water. AAPAs were extracted from acidified aqueous phase to organic phase present in pores of the hollow fiber, and then back extracted into the alkaline acceptor phase present in the lumen of the hollow fiber. Variables affecting the HFLLLME process were optimized using a Plackett–Burman design and a Doehlert design. Optimal experimental conditions were: organic solvent, 1-octanol; pH of acceptor phase, 14; extraction time, 60 min; pH of donor phase, 1; and NaCl concentration, 10% (w/v). Depending upon the alkyl substituent, lower limits of detection varied from 0.1 to 100 ng mL⁻¹ (S/N ≥ 5). Repeatability of the method was observed with relative standard deviation of 1.49–9.83% (n = 3). After validation, the method was applied to detect AAPAs present in the water sample provided by the Organization for Prohibition of Chemical Weapons (OPCW) during the 23rd official proficiency test. The added advantage of this method is that several successive extractions of AAPAs from the same water sample can be performed.     

A mild and convenient one-pot two-step synthesis of hydroxy- iminodihydrobenzofurans mediated by silica gel under microwave activation conditions

A convenient one-pot two-step procedure for the synthesis of hydroxyiminodihydrobenzofurans assisted by microwave irradiation in presence of silica gel is described herein. Cyclic 1,3-dicarbonyl compounds reacted smoothly with various nitroolefins to furnish hydroxyiminodihydrobenzofuran derivatives as the mixture of E and Z isomers. Clean reaction conditions, no work-up procedure, easy isolation and good yields of the products are the salient features of the methodology.     

Neutral Ni(II) complexes based on keto-enamine salicylideneanilines active for selective dimerization of ethylene

Single component organonickel(II)phosphino neutral complexes from salicylideneaniline based ligands bearing N–O chelate sites, were synthesized, which were found efficient in dimerizing ethylene selectively to various butene products.     

Palladium catalyzed atom-efficient cross-coupling reactions of triarylbismuths with aryl iodides and aryl triflates

The atom-efficient cross-coupling of triarylbismuths with aryl iodides or aryl triflates using catalytic Pd(OAc)₂/PPh₃ and K₃PO₄ as base in DMF at 90 °C to afford the corresponding functionalized biaryls in high yields is reported.     

An extension of Matkowski’s and Wardowski’s fixed point theorems with applications to functional equations

Aequationes mathematicae - In this paper, we prove a fixed point theorem for a system of maps on the finite product of metric spaces. Our result generalizes the result of Matkowski (Bull Acad Pol...