RESUMO
We demonstrated direct conversion of benzene into pyridine and aniline, assisted through exact mass measurements (m/z 80.0494, 93.0574, and 94.0651, respectively), through the interaction of benzene with water/nitrogen vapor plasma produced by corona discharge. Systematic analysis using a series of isotopic standards indicated that formation of pyridine and aniline occurred through the reaction between neutral benzene and reactive N+(OH2)2 in water/nitrogen plasma; exact mass measurements of products and intermediates supported this hypothesis. As the proportion of water vapor in plasma increased over time, the reaction proceeded from exclusive formation of protonated pyridine to formation of protonated aniline as the main product; theoretical simulations indicated that the presence of water vapor promoted proton migration to elicit formation of protonated aniline. The reactions we discovered suggest a new mechanism for direct nitrogen fixation.
RESUMO
Wolfiporia cocos is commonly used as a traditional Chinese medicine for its diuretic, tonifying, and invigorating effects on the spleen. However, the epidermis of W. cocos is discarded as scrap during harvesting because of its low price, resulting in a great waste of resources and environmental pollution. In this work, the epidermis of W. cocos was studied and three new lanostane triterpenoids were isolated. The structures were determined using NMR and HRESIMS, with absolute configurations established by comparison of the calculated and experimental ECD spectra. The three new compounds were evaluated for their antimicrobial activities in vitro against Staphylococcus aureus, Escherichia coli, and Saccharomyces cerevisiae. None of the tested compounds showed inhibition against these three strains of indicator microbes at a concentration of 128 µg/ml. This study provides a reference for further medicinal development and the utilization of the epidermis of W. cocos.
