Hexavalent chromium removal from water: adsorption properties of in natura and magnetic nanomodified sugarcane bagasse.

Biosorption has become a viable and ecological process in which biological materials are employed as adsorbents for the removal of potentially toxic metals, such as hexavalent chromium, from aqueous matrices. This work proposed the use of in natura (SB) and nanomodified sugarcane bagasse (SB-NP) with ferromagnetic nanoparticles (FeO) to adsorb Cr(VI) from water. These materials were analyzed by X-ray Spectroscopy (XRD), Scanning Electron Microscopy (SEM), and Fourier Transform Infrared Spectroscopy (FTIR) to investigate their morphology and interaction with Cr(VI).

Nanomodified sugarcane bagasse biosorbent: synthesis, characterization, and application for Cu(II) removal from aqueous medium.

Biosorption is a technique widely used in the remediation of contaminated effluents, and its main advantages are its easy applicability, high efficiency rate, versatility, and its economic viability. Associated with nanotechnology, this work proposes the use of nanocomposites of sugarcane bagasse (SB) and ferromagnetic nanoparticles (FeO) in the removal of metallic ions present in contaminated water. SB is a promising adsorbent material since it is an abundant agricultural residue, easily accessed.

Agricultural solid waste for sorption of metal ions: part I-characterization and use of lettuce roots and sugarcane bagasse for Cu(II), Fe(II), Zn(II), and Mn(II) sorption from aqueous medium.

Sugarcane bagasse and hydroponic lettuce roots were used as biosorbents for Cu(II), Fe(II), Zn(II), and Mn(II) removal from monoelemental solutions in aqueous medium, at pH 5.5, using batch procedures. These biomasses were studied in natura (lettuce roots, NLR, and sugarcane bagasse, NSB) and modified with HNO (lettuce roots, MLR, and sugarcane bagasse, MSB).

20S proteasome as novel biological target for organochalcogenanes.

A series of hypervalent selenium- and tellurium-containing compounds (organoselenuranes and organotelluranes) was evaluated aiming novel inhibitors of a threonine protease, namely the 20S proteasome (20S PT). In vitro assays demonstrated high inhibitory potency and specificity of these compounds toward the β2 catalytic site of the 20S PT. Organotelluranes were identified as more potent inhibitors than organoselenuranes since their IC50 ranged from 3.

Omega-transaminases as efficient biocatalysts to obtain novel chiral selenium-amine ligands for Pd-catalysis.

Omega-transaminases have been evaluated as biocatalysts in the reductive amination of organoselenium acetophenones to the corresponding amines, and in the kinetic resolution of racemic organoselenium amines. Kinetic resolution proved to be more efficient than the asymmetric reductive amination. By using these methodologies we were able to obtain both amine enantiomers in high enantiomeric excess (up to 99%).

Aziridine sulfides and disulfides as catalysts for the enantioselective addition of diethylzinc to aldehydes.

Chiral aziridine sulfides and disulfides were synthesized from readily available and inexpensive R-cysteine by a Mitsunobu reaction; their application in the addition of diethylzinc to aldehydes provides secondary alcohols with up to 99% ee and S-configuration.