Tomato and Olive Bioactive Compounds: A Natural Shield against the Cellular Effects Induced by β-Hexachlorocyclohexane-Activated Signaling Pathways

The β-isomer of hexachlorocyclohexane (β-HCH) is a globally widespread pollutant that embodies all the physicochemical characteristics of organochlorine pesticides, constituting an environmental risk factor for a wide range of noncommunicable diseases. Previous in vitro studies from our group disclosed the carcinogenic potential of β-HCH, which contributes to neoplastic transformation by means of multifaceted intracellular mechanisms. Considering the positive evidence regarding the protective role of natural bioactive compounds against pollution-induced toxicity, micronutrients from olive and tomato endowed with the capability of modulating β-HCH cellular targets were tested. For this purpose, the solution obtained from a patented food supplement (No. EP2851080A1), referred to as Tomato and Olive Bioactive Compounds (TOBC), was administered to the androgen-sensitive prostate cancer cells LNCaP and different biochemical and cellular assays were performed to evaluate its efficiency. TOBC shows a dose-dependent significant chemoprotection by contrasting β-HCH-induced intracellular responses such as STAT3 and AhR activation, disruption of AR signaling, antiapoptotic and proliferative activity, and increase in ROS production and DNA damage. These experimental outcomes identified TOBC as a suitable functional food to be included in a diet regimen aimed at defending cells from β-HCH negative effects, recommending the development of tailored enriched formulations for exposed individuals.     

Copper-Catalyzed Ring-Opening Reactions of Alkyl Aziridines with B2pin2: Experimental and Computational Studies

The possibility to form new C–B bonds with aziridines using diboron derivatives continues to be a particularly challenging field in view of the direct preparation of functionalized β-aminoboronates, which are important compounds in drug discovery, being a bioisostere of β-aminoacids. We now report experimental and computational data that allows the individuation of the structural requisites and of reaction conditions necessary to open alkyl aziridines using bis(pinacolate)diboron (B₂pin₂) in a regioselective nucleophilic addition reaction under copper catalysis.     

Synergic Interplay Between Halogen Bonding and Hydrogen Bonding in the Activation of a Neutral Substrate in a Nanoconfined Space

The principle of amplified halogen bonding (XB) in a small space is exploited as a catalytic tool for the activation of an XB acceptor substrate in a nanoconfined environment. The inner cavity of the resorcinarene capsule has been equipped with an XB catalyst bearing an ammonium unit acting as a Trojan horse to drive the catalyst inside the capsule. In the presence of a specific XB catalyst, the capsule is able to catalyze a Michael reaction between N‐methylpyrrole and methyl vinyl ketone. In the bulk medium in absence of the resorcinarene capsule, the XB catalyst is catalytically ineffective. Quantum‐mechanical investigations highlight that the Michael reaction proceeds through the activation of the carbonyl group by synergistically enhanced halogen/hydrogen‐bonding interactions and takes place in an open pentameric capsule.     

In vivo Electrochemical Monitoring of Signaling Transduction of Plant Defense Against Stress in Leaves of Aloe vera L.

In situ recording of the voltammetric response of Aloe vera L. leaves using graphite and platinum microelectrodes inserted in the subcuticular region is described. The plant response against the mechanical stress results in changes of the voltammetric signals associated to signal transduction compounds salicylic and jasmonic acids and hydrogen peroxide, which were separately monitored. A kinetic model is proposed to describe the time variation of the respective voltammetric signatures, denoting the possibility of in vivo electrochemical monitoring of biochemical processes in plants. The obtained results suggest that two defense pathways with different participation of ROS are operative.     

Solvent-free Brønsted acid catalysed alkylation of arenes and heteroarenes with benzylic alcohols

A simple and efficient alkylation of aromatic and heteroaromatic compounds via the direct S_N1-type nucleophilic substitution of benzylic alcohols in the presence of catalytic amounts of the strong Brønsted acid o-benzenedisulfonimide under neat conditions is herein reported. A library of di- and triaryl (and heteroaryl) methanes was prepared in good yields and high regioselectivity. The observed reactivity was shown to be in agreement with Mayr's nucleophilicity and electrophilicity scales.