Ricerc@Sapienza

Mineral evolution is concerned with the timing of mineral occurrences, such as the earliest reported occurrences in the geologic record. Minerals containing essential Li have not been reported from rocks older than ca. 3000 Ma, thus the lithian tourmaline (fluor-elbaite) and mica (lepidolite) assemblage from a pegmatite near Zishineni associated with the ca. 3000 Ma Sinceni Pluton presents unusual interest. Fluor-elbaite (0.75-0.98 F per formula unit) forms green crystals up to 50 trim long. Spindle stage measurements give omega = 1.652(1), epsilon = 1.627(1) (589.3 nm).

Tourmalines form the most important boron rock-forming minerals on Earth. They belong to the
cyclosilicates with a structure that may be regarded as a three-dimensional framework of octahedra ZO6
that encompass columns of structural “islands” made of XO9, YO6, BO3, and TO4 polyhedra. The overall
structure of tourmaline is a result of short-range and long-range constraints resulting, respectively on the
charge and size of ions. In this study, published data are reviewed and analyzed to achieve a synthesis

The new mineral isselite, Cu6(SO4)(OH)10(H2O)4·H2O, has been discovered in the Lagoscuro mine, Monte Ramazzo mining complex, Genoa, Eastern Liguria, Italy. It occurs as sprays of blue acicular crystals, up to 0.1 mm long, associated with brochantite and posnjakite. Streak is light blue and the lustre is vitreous. Isselite is brittle, with irregular fracture and good cleavage on {001} and {100}. Measured density is 3.00(2) g/cm3. Isselite is optically biaxial (-), with α = 1.599(2), β = 1.633(2) and γ = 1.647(2) (determined in white light). The measured 2V is 63.6(5)°.

Leishmania mexicana is an obligate intracellular protozoan parasite that causes the cutaneous form of leishmaniasis affecting South America and Mexico. The cysteine protease LmCPB is essential for the virulence of the parasite and therefore, it is an appealing target for antiparasitic therapy. A library of nitrile-based cysteine protease inhibitors was screened against LmCPB to develop a treatment of cutaneous leishmaniasis. Several compounds are sufficiently high-affinity LmCPB inhibitors to serve both as starting points for drug discovery projects and as probes for target validation.

Chalcogensemicarbazones are condensation products between semicarbazide and its sulphur and selenium isosters with carbonyl compounds with a broad spectrum of biological activities [1-3]. In this work the X-ray structural investigation of library of six chalcogensemicarbazones has been complemented with computational study of their global and local reactive properties, within the framework of density functional theory (DFT). Among other information, DFT calculations helped us to locate the most reactive sites of studied molecules and to identify their sensitivity towards the oxidation.

A third crystalline form of the title compound, C9H10O4, crystallizing in the centrosymmetric monoclinic space group P21/c, has been identified during screening for co-crystals. The asymmetric unit comprises a non-planar independent mol­ecule with a synplanar conformation of the OH group. The sterically bulky o-meth­oxy substituents force the carb­oxy group to be twisted away from the plane of the benzene ring by 74.10 (6)°. The carb­oxy group exhibits the acidic H atom disordered over two sites between two O atoms.

Fungal laccases have great potential as biocatalysts oxidizing a variety of aromatic compounds using oxygen as co-substrate. Here, the crystal structure of 7D5 laccase (PDB 6H5Y), developed in Saccharomyces cerevisiae and overproduced in Aspergillus oryzae, is compared with that of the wild type produced by basidiomycete PM1 (Coriolopsis sp.), PDB 5ANH. SAXS showed both enzymes form monomers in solution, 7D5 laccase with a more oblate geometric structure due to heavier and more heterogeneous glycosylation.