Inspecting the structure-activity relationship of protein kinase CK2 inhibitors derived from tetrabromo-benzimidazole

CK2 is a very pleiotropic protein kinase whose high constitutive activity is suspected to cooperate to neoplasia. Here, the crystal structure of the complexes between CK2 and three selective tetrabromo-benzimidazole derivatives inhibiting CK2 with Ki values between 40 and 400 nM are presented. The ligands bind to the CK2 active site in a different way with respect to the parent compound TBB. They enter more deeply into the cavity, establishing halogen bonds with the backbone of Glu114 and Val116 in the hinge region. A detailed analysis of the interactions highlights a major role of the hydrophobic effect in establishing the rank of potency within this class of inhibitors and shows that polar interactions are responsible for the different orientation of the molecules in the active site.     

Metallation reactions. XXXIV. Synthesis of 2‐(1‐hydroxy‐1‐arylethyl)‐1,3‐benzoxathiol‐3‐oxide derivatives

The reaction of benzoxathiole‐3‐oxide with lithiumdiisopropylamide in tetrahydrofuran gave an anion, which was reacted with various aryl‐methyl‐ketones to give 2‐(1‐hydroxy‐1‐arylethyl)‐1,3‐benzoxathiol‐3‐oxide derivatives. The reaction was carried out in different temperature conditions: at ‐88 °C the trans addition stereoisomers to the sulfoxide oxygen atom were the main products.     

Optimization of an urban particulate matter multi-element analysis method by inductively coupled plasma--atomic emission spectrometry (ICP-AES)

In the present work a method for simultaneous metals determination, in urban air particulate matter by ICP-AES has been set up. A large number of elements (18) has been analyzed, including major (Al, Fe, K, and Mg), minor (Na, Pb and Zn) and trace (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Sb, Sr and V) elements. The procedure consists of microwave sample acidic total digestion by HNO3/HF mixture and subsequent analysis by ICP-AES, using different assemblies depending on sample treatment procedure: a quartz Meinhard nebulizer/cyclonic chamber, if HF excess was eliminated, or a cross-flow nebulizer/plastic Scott chamber, suitable for application with HF. A cyclonic chamber for hydride generation was used for As, Sb and Hg determination. The procedure was tested with Standard Reference Materials 1648 NIST Urban Particulate Matter and Certified Reference Material No8 NIES "Vehicle Exhaust Particulates". Two sampling supports, quartz fibre and polycarbonate filters, have been examined in order to find the most suitable i.e. the one characterized by less interference. Some real samples of urban air particulate matter, TSP, PM10 and PM2.5 fractions, collected during an intercomparison campaign promoted by Regione Lombardia, have been analyzed with the procedure developed.     

Essential oils of Daucus carota subsp. carota of Tunisia obtained by supercritical carbon dioxide extraction

The essential oils and supercritical CO2 extracts of wild Daucus carota L. subsp. carota from two different sites in Tunisia were investigated. The main components of the essential oil of the flowering and mature umbels with seeds from Sejnane were eudesm-7(11)-en-4-ol (8.2 - 8.5%), carotol (3.5 - 5.2%), sabinene (12.0 -14.5%), a-selinene (7.4 - 8.6) and 11-alpha-(H)-himachal-4-en-1-beta-ol (12.7 - 17.4%), whereas the oils from Tunis were predominantly composed of elemicin (31.5 - 35.3%) and carotol (48.0 - 55.7%). The antimicrobial activity of the essential oils were assayed by using the broth dilution method on Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and clinical strains of Candida albicans and C. tropicalis 1011 RM. The MIC values obtained were all > 2.5% (v/v).     

Polyol Process Synthesis of Monodispersed FePt Nanoparticles

Monodispersed FePt nanoparticles are synthesized by reduction of iron(II) acetylacetonate and platinum(II) acetylacetonate with 1,2-hexadecanediol as the reducing reagent in the polyol process. As-prepared FePt nanoparticles are chemically disordered with fcc phase. Transmission electron microscopy (TEM) images show a self-assembled particle array with an average particle size of 3 nm and a standard deviation about 10%. The transformation from chemically disordered fcc to chemically ordered L10 phase is achieved by annealing at 650 degrees C for 30 min in Ar atmosphere where the oxygen level is less than 1 ppm. Magnetic hysteresis measurements show a coercivity of 9.0 kOe at 293K, and 16.7 kOe at 5 K for the annealed FePt nanoparticles.     

One-pot synthesis of chiral multifunctionalized aziridines

A direct synthetic procedure to obtain chiral aziridines is reported, involving a diastereoselective aza-MIRC (Michael Initiated Ring Closure) reaction. Multifunctionalized aziridines are obtained in high overall yields (82-92%) and with a diastereomeric ratio up to 99:1. Further synthetic elaboration can lead to the formation of interesting biochemical molecules, such as amino glycosides. The diastereomeric induction seems to be strongly controlled both by the choice of chiral moiety and by the electron withdrawing groups (EWG) present on the starting alkenes.     

Translocation of radioactivity from substrate to macromycetes in the Crucea (Romania) uranium mining area

The present study follows the extent of translocation radioactivity from the substrates of the Crucea uranium mining area to the macromycetes spontaneously occurred during June–October 2008. To this end, radioactivity measurements (gross α + β and ¹³⁷Cs) on both macromycetes and their substrates were made. The resultants obtained were confirmed by FT-IR spectroscopy, evidencing the presence of characteristic bands around of 910 cm⁻¹, corresponding to the asymmetric stretching vibration of the uranyl unit and to the interaction between the UO₂ ²⁺ ions and the group belonging to various cellular components.     

New 9,10‐Secosteroids from Biotransformations of Bile Acids with Rhodococcus ruber

The biotransformations of cholic, deoxycholic, and hyocholic acids with Rhodococcus ruber are reported. In all biotransformations, the C₁₇‐side chain is partially degraded, and the new 9,10‐secosteroids 4a (54%) and 4b (55%) are obtained from cholic and deoxycholic acids, respectively. The loss of H₂O from C(11)? C(12) of secosteroids 4a and 4b affords the compounds 5a (5%) and 5b (20%), respectively. On the other hand, in the biotransformation of hyocholic acid with R. ruber the 9,10‐secosteroid 4c is not detected, but, rearranging to an intramolecular hemiacetal form, it evolves to the final furan derivative 6c (35%) by easy elimination of two molecules of H₂O. The new secosteroids were characterized by IR, NMR, and 2D‐NMR spectroscopy, and mass spectroscopy.     

Combining Spontaneous Polymerization and Click Reactions for the Synthesis of Polymer Brushes: A “Grafting Onto” Approach

Two novel benzofulvene monomers bearing propargyl or allyl groups have been synthesized by means of readily accessible reactions, and were found to polymerize spontaneously by solvent removal, in the apparent absence of catalysts or initiators, to give the corresponding polybenzofulvene derivatives bearing clickable propargyl or allyl moieties. The clickable propargyl and allyl groups were exploited in appropriate click reactions to develop a powerful and versatile “grafting onto” synthetic methodology for obtaining tailored polymer brushes.