1,3-Oxazoline- and 1,3-oxazolidine-2-thiones as substrates in direct modified Stille and Suzuki cross-coupling

1,3-Oxazoline- (OXT) and 1,3-oxazolidine-2-thiones (OZT) can undergo direct Stille and Suzuki cross-coupling reactions under microwave activation to produce 2-aryloxazoles and 2-aryloxazolines in reasonable to good yields.     

Structural Polymorphism in MnGa2Se4

The polymorphic behaviour of the adamantane-type compound MnGa₂Se₄ is reinvestigated by X-ray powder diffraction and electron microscopy techniques carried out on annealed and quenched samples. The low-temperature modification (γ-phase) is confirmed to crystallize in the defect tetragonal thiogallate structure (space group I4-) with lattice parameters a = 5.677(1) Å and c = 10.761(2) Å. Samples quenched from high temperature (750 °C) show the coexistence of two ternary phases both having the MnGa2Se₄ composition but different crystal structures: the main phase is still tetragonal with slightly different lattice parameters (γ′-phase); the secondary phase exhibits an orthorhombic cell with approximate dimensions a = 13.5 Å, b = 8.0 Å, c = 6.5 Å and possible space group Pna2₁ (ε-phase). This latter polymorph is identified as the β-ZnAl2S₄-type form of MnGa₂Se₄. TEM analyses performed on the ε-phase show the presence of ferroelastic twins, confirmed by electron diffraction. The connections among the three structures are shortly discussed.     

Chemical and Bioactive Characterization of the Essential Oils Obtained from Three Mediterranean Plants

Cupressus sempervirens L., Juniperus communis L. and Cistus ladanifer L. are Mediterranean arboreal and shrub species that possess essential oils (EO) in their leaves and branches. This study aimed at characterizing the EOs obtained by steam distillation from the three species collected in different locations from Spain (Almazán, Andévalo, Barriomartín, Cerezal, Ermitas and Huéscar). For this purpose, volatiles composition was determined by GC-MS, and different bioactivities were evaluated. The highest content in terpenes was observed in C. sempervirens (Huéscar origin) followed by J. communis (Almazán origin), corresponding to 92% and 91.9% of total compounds, respectively. With exception of C. ladanifer from Cerezal that presented viridiflorol as the most abundant compound, all the three species presented in common the α-pinene as the major compound. The EOs from C. ladanifer showed high antibacterial potential, presenting MIC values from 0.3 to 1.25 mg/mL. Concerning other bioactivities, C. ladanifer EO revealed an oxidation inhibition of 83%, while J. communis showed cytotoxicity in the MCF-7 cell line, and C. sempervirens and C. ladanifer EOs exhibited the highest potential on NCI-H460 cell lines. Nevertheless, some EOs revealed toxicity against non-tumoral cells but generally presented a GI₅₀ value higher than that of the tumor cell lines.