The lack of antifungal compounds with reduced side effects highlights the importance of studying natural products for this purpose. Curcumin was a more potent antifungal than fluconazole against P. brasiliensis, the causal agent of the neglected disease paracoccidioidomycosis. Curcumin dramatically inhibited the adhesion of Candida species isolated from AIDS patients to BEC, demonstrating that curcumin is a promising lead compound that warrants further investigation into its therapeutical use in immunocompromised patients.

Key ionic intermediates of the Heck reaction of arene diazonium salts have been intercepted and structurally characterized by ESI‐MS/MS. The use of electrospray ionization enables the ionic species to be transferred smoothly to the gas phase. A catalytic cycle for this reaction involving all the Pd cationic species intercepted has been proposed (see scheme).

Calixarenes, macrocyclic compounds of phenolic units linked by methylene groups at the 2,6-positions, present some of the requirements to serve as platforms for the design and synthesis of biological active compounds. They are also interesting host molecules for chemical biology study purposes. Their basic molecular scaffold has potential ability for molecule recognition; it is promptly synthesized in large amounts, and might be easily modified for maximizing molecular interactions toward relevant guest molecules. Calixarenes present well-defined conformational properties and cavities with molecular dimensions that enable to encapsulate guest drugs. Calixarenes have been shown to have antiviral, antibacterial, antifungal, and anticancer activities (including HIV as target). We provide here an overview of the use of calixarenes either as new chemical entity of distinct biological activities or as host for bioactive guest molecules. The importance of calixarenes for drugs development is discussed. The use of Nuclear Magnetic Resonance (NMR) and Mass Spectrometry (MS) techniques for the study of calixarenes as biological molecule hosts is also described.

Theoretical calculations and gas-phase mass spectrometric studies were performed for the reaction of the naked (NO2+) and monosolvated (CH3NO2.NO2+) nitronium ion with several monosubstituted aromatic compounds. From these studies, we propose a general model for regioselectivity based on the single-electron transfer (SET) mechanism and an alternative mechanistic scheme for electrophilic aromatic nitration. This scheme considers the SET and the polar (Ingold-Hughes) mechanisms as extremes in a continuum pathway, the occurrence and extents of both mechanisms being governed mainly by the ability, or lack of ability, of the aromatic compound to transfer an electron to NO2+.