The antiandrogenic and gestagenic steroid cyproterone acetate (CPA) has been widely used in human therapy. There is currently a debate about the safety of CPA, since it proved to be genotoxic in rat liver and human hepatocytes [I. Neumann et al., Carcinogenesis (Lond.), 13: 373-378, 1992, J. Topinka et al., Carcinogenesis (Lond.), 14: 423-427, 1993, L. R. Schwarz et al., Biological Reactive Int...

A type of novel hypercross-linked fiber adsorbent was obtained by sulfonation and cross-linking reaction of polypropylene fiber grafted styrene-divinylbenzene. The aim of the fiber sulfonation and cross-linking method was to prepare rigid three dimensional networks in the entire fiber and change the ion exchange capacity of fiber. The hypercross-linked fiber adsorbent possesses a principall...

A type of novel hypercross-linked fiber adsorbent was obtained by sulfonation and cross-linking reaction of polypropylene fiber grafted styrene-divinylbenzene. The aim of the fiber sulfonation and cross-linking method was to prepare rigid three dimensional networks in the entire fiber and change the ion exchange capacity of fiber. The hypercross-linked fiber adsorbent possesses a principall...

Direct sulfonation of methane with SO3 to methanesulfonic acid (MSA) is accomplished in sulfuric acid with almost 100% selectivity in the presence of a catalyst, namely, Ce and Rh salts and molecular oxygen as the catalyst regenerator. In the absence of O2, the catalyst remains effective but the selectivity to MSA decreases to 53% and byproducts, principally CH3OSO3H, are formed. The effects of...

Electrophilic aromatic sulfonation of benzene with sulfur trioxide is studied with ab initio molecular dynamics simulations in gas phase, and in explicit noncomplexing (CCl3F) and complexing (CH3NO2) solvent models. We investigate different possible reaction pathways, the number of SO3 molecules participating in the reaction, and the influence of the solvent. Our simulations confirm the existen...

Microporous carbon catalysts with large surface areas (800-1100 m(2) g(-1)) and high densities of SO3H groups (ca. 1.1 mmol g(-1)) were synthesized by sulfonation of zeolite-templated microporous carbon. The resulting SO3H-bearing microporous carbon catalysts exhibited higher catalytic performance for the hydrolysis of cellobiose and the Beckmann rearrangement than conventional solid acid catal...