Fast analysis of triterpenoids in Ganoderma lucidum spores by ultra‐performance liquid chromatography coupled with triple quadrupole mass spectrometry

A rapid and reliable method was established for simultaneous determination of main triterpenoids in Ganoderma lucidum spores using ultra‐high‐performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC‐TQ‐MS). The established method was validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to determine the contents of 10 main triterpenoids in different batches of G. lucidum spores. The analysis results showed that moderate levels of triterpenoids were found in G. lucidum spores. In addition, a MS full scan with a daughter ion scan experiment was performed to identify the potential derivatives of triterpenoids present in G. lucidum spores. As a result, a total of 22 triterpenoids from different G. lucidum spores were unequivocally or tentatively identified via comparisons with authentic standards and literatures. This method provides both qualitative and quantitative results without the need for repetitive UPLC‐MS analyses, thereby increasing efficiency and productivity, making it suitable for high‐throughput applications. Copyright © 2013 John Wiley & Sons, Ltd.     

Facile Synthesis of Benzotriazines and Indoles by Ring-Scissions of α-Benzotriazol-1-yl Hydrazones

Abstract: α-(Benzotriazol-1-yl)hydrazones 2a-d and 13a-c were prepared by refluxing the corresponding α-(benzotriazol-1-yl)ketones with p-tosyl hydrazide or benzenesulfonyl hydrazide. Treatment of 2a-b with n-butyllithium in the presence of TMEDA gave benzotriazines 6a-b, while lithiation of 13a-c resulted in indole derivatives 16a-c, depending on the structure of the hydrazones.     

Infrared imaging as a means of visually characterizing the thermoacoustic onset process influenced by a Helmholtz resonator

A Helmholtz resonator can be used as a transmission part to connect the thermoacoustic engine (TE) with its load. However, the resonator can significantly influence the performance of the TE. In order to investigate the impact of a Helmholtz resonator on the onset process of a TE, infrared (IR) imaging is firstly used as a visualization method to characterize the onset mechanism. The influence of dimensions of the Helmholtz resonator on the onset process are analyzed experimentally and theoretically. Results show that the Helmholtz resonator reduces the pressure amplitude at the onset moment and increases the onset temperature of the TE, both of which depend on the acoustic power absorbed from the TE. Onset without a sudden increase of pressure amplitude is observed with the Helmholtz resonator at resonance length. This paper shows that IR imaging is an effective way to characterize the temperature distribution in a TE study.     

THEN FILM CELLS BASED ON CuInSe2

Abstract

Using thin film devices of the form CdS(n)/CuInSe₂(p) fabricated on electrodeposited CuInSe₂, electrical and optical measurements have been made. From temperature-dependent I-V measurements, it was observed that the recombination current became progressively more important as the temperature was decreased. Results of dark C-V measurements indicated that CuInSe₂ films with carrier concentrations in the range from 10¹⁵ to 10¹⁷ cm^?3 can be easily prepared using the electrodeposition method. Photoresponse of the devices was also measured, giving an essentially flat region in the range from 0.6 to 1.0 micron. At wavelengths beyond 1 micron, the quantum efficiency decreased continuously with the increase in the wavelength. This continuous decrease in the quantum efficiency could be due to the presence of interface states as suggested by the photo capacitance measurements.     

Studies on Carbohydrates X. A New Method for the Preparation of Isopropylidene Saccharides

Cabohydrates reacting with acetone in the presence of molecular sieve and p—toluene sulfonic acid provided a simple, convenient, high yield and good selective process for preparation of isopropylidene carbohydrates.     

Studies toward the Synthesis of (R)‐(+)‐Harmicine

The study toward the total synthesis of (R)‐(+)‐harmicine is reported in this paper. The enantioselective synthesis of pyrrolidinone, the main backbone of of (R)‐(+)‐harmicine, has been completed by the methodology based on photo‐induced Wolff rearrangement of α‐diazo‐β‐carbonyl compounds.