Insights into the mechanism of [3+2] cycloaddition reactions between N-benzyl fluoro nitrone and maleimides, its selectivity and solvent effects.

We present a theoretical study of the [3+2] cycloaddition (32CA) reactions of N-benzyl fluoro nitrone with a series of maleimides producing isoxazolidines. We use the Molecular Electron Density Theory at the MPWB1K/6-311G(d) level. We focus on the reaction mechanism, selectivity, solvent, and temperature effects. In addition, we perform topological analyses at the minimal and transition states to identify the intermolecular interactions. Electron Localization Function approach classifies the N-benzyl fluoro nitrone as zwitterionic (zw-) three-atom components (TACs), associated with a high energy barrier. The low polar character of the reaction is evaluated using the Conceptual Density Functional Theory analysis of the reactants, confirmed by the low global electron density transfer computed at the transition states. Computations show that these 32CA reactions follow a one-step mechanism under kinetic control, with highly asynchronous bond formation and no new covalent bond is formed at the TS. Besides, the potential energy surfaces along the reaction pathways in gas phase and in solvent are mapped. The corresponding Gibbs free energy profiles reveal that the exo-cycloadducts are kinetically and thermodynamically more favored than endo-cycloadducts, in agreement with the exo-selectivity observed experimentally. In particular, we found that solvent and temperature did not affect this selectivity and mainly influence the activation energies and the exothermic character of these 32CA reactions.

Mineral Profiling of Twenty Wild and Cultivated Aromatic and Medicinal Plants Growing in Morocco.

Aromatic and medicinal plants (AMPs) have attracted a considerable attention owing to their medicinal and nutritional value. The main research focus in AMPs is devoted to bioactive compounds and related biological activities; however, little is known about their mineral profiling, hence the novelty of this work, which aims at investigating the mineral composition of 20 species of AMPs belonging to 10 botanical families growing in Morocco. Mineral profiling was determined using an inductively coupled plasma optical emission spectrometer in various plant parts depending on each species. Wide variations were found in mineral content among the studied plants. Major elements were K (3987.49 ± 319.01-36,707.01 ± 2936.56 mg/kg), Ca (862.54 ± 69.86-32,836.15 ± 2626.89 mg/kg), P (1065.77 ± 86.33-6328.83 ± 506.32 mg/kg), Mg (986.96 ± 79.66-4935.41 ± 394.82 mg/kg), and Na (28.21 ± 2.23-5792.26 ± 463.38 mg/kg). Fe (62.09 ± 4.96-1636.24 ± 130.89 mg/kg), Mn (10.63 ± 0.85-124.72 ± 9.85 mg/kg), B (5.64 ± 0.45-71.33 ± 5.71 mg/kg), Zn (8.94 ± 0.72-47.01 ± 3.76 mg/kg), and Cu (2.06 ± 0.14-15.12 ± 1.20 mg/kg) were detected at minor levels. Most of the investigated plants were shown to be good sources of minerals. Important correlations were found among different minerals. These outcomes were confirmed by principal component analysis, which separate among studied plants and minerals through the first two principal components. According to obtained results, the studied plants could provide a new promising source of necessary minerals for human diet as well as other various applications.