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Regioselective enzymatic acylation of vicinal diols of steroids
Silva, M. Manuel Cruz; Riva, Sergio; Melo, M. Luísa Sá eMonoacylated derivatives of a complete set of 2,3- and 3,4-vicinal diols of steroids were prepared by regioselective lipase-catalysed transesterification reactions. The enzymes displayed different selectivities towards the vicinal diols depending on the configuration of the hydroxyl groups. ; http://www.sciencedirect.com/science/article/B6THR-4FGX84H-2/1/c23744db4c590d02acf7c82018be5720
Biocatalyzed Generation of Molecular Diversity: Selective Modification of the S...
Monti, Daniela; Candido, Andrea; Cruz Silva, M. Manuel; Kren, Vladimir; Riva, Sergio; Danieli, BrunoAn array of different derivatives of the complex ursane-type triterpene glycoside asiaticoside (1), a saponin component isolated from the perennial herb Centella asiatica, was generated by exploiting the stereo-, regio- and site-selectivity of four groups of enzymes (glycosidases, glycosyltransferases, lipases and laccases). A library of extracellular alpha-L-rhamnosidases (31 different items) was obtained by s...
Highly selective lipase-mediated discrimination of diastereomeric 5,6-epoxyster...
Silva, M. Manuel Cruz; Riva, Sergio; Melo, M. Luísa Sá eStereoisomerically pure 3[beta]-hydroxy-5,6-epoxysteroids were obtained by combining selective chemical methods for [alpha]- and [beta]-epoxidation of [Delta]5-unsaturated steroids with enzymatic stereoselective esterification of the 3[beta]-hydroxyl group. 5[beta],6[beta]-Epoxy-3[beta]-hydroxysteroids were efficiently acylated by Novozym 435 and lipase AK, whereas 5[alpha],6[alpha]-epoxy-3[beta]-hydroxysteroid...
The biocatalyzed stereoselective preparation of polycyclic cyanohydrins
Silva, M. Manuel Cruz; Melo, M. Luísa Sá e; Parolin, Marco; Tessaro, Davide; Riva, Sergio; Danieli, BrunoThe enzyme-mediated preparation of enantiomerically or diastereomerically enriched polycyclic cyanohydrins has been investigated. Oxynitrilase-catalyzed cyanurations gave excellent results with the bicyclic aldehydes tested. On the other hand, enantio- or diastereoselective acylation, catalyzed by lipase PS or subtilisin, proved to be a more versatile methodology, giving good results even with sterically hinder...
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