Synthesis of 28a-homoselenolupanes and 28a-homoselenolupane saponins

0467449 - ÚEB 2017 RIV GB eng J - Journal Article
Sidoryk, K. - Rárová, L. - Oklešťková, Jana - Pakulski, Z. - Strnad, Miroslav - Cmoch, P. - Luboradzki, R.
Synthesis of 28a-homoselenolupanes and 28a-homoselenolupane saponins.
Organic & Biomolecular Chemistry. Roč. 14, č. 43 (2016), s. 10238-10248. ISSN 1477-0520. E-ISSN 1477-0539
R&D Projects: GA MŠMT(CZ) LO1204; GA ČR GA14-19590S
Institutional support: RVO:61389030
Keywords : organoselenium compounds * everninomicin 13,384-1 * coupling-constants * stereocontrolled synthesis * glycosidase inhibitors * cytotoxic agents * in-vitro * selenium * derivatives * thioglycosides
Subject RIV: CE - Biochemistry
Impact factor: 3.564, year: 2016

A practical synthesis of 28a-homo-28a-selenolupane triterpenes and the corresponding selenosaponins containing D-mannose, L-arabinose, L-rhamnose, and D-idose moieties is described. Selenium containing triterpenes were obtained from the readily available 3-O-allyl-homobetulin mesylate by nucleophilic substitution with the selenocyanate ion which upon reduction of theSeCN group afforded the free selenol. Glycosylation using classical Schmidt donors gave 1,2-trans selenosaponins as the main product as well as minute amounts of 1,2-cis isomers. This is one of the very few examples of the synthesis of selenoglycosides by direct glycosylation of free selenols. The studied selenol showed high resistance to air oxidation resulting in good stability during the synthesis of selenolupane derivatives. Cytotoxic activities of new homoselenolupane derivatives were also evaluated in vitro and revealed that some triterpenes exhibited an interesting profile against human cancer cell lines.
Permanent Link: http://hdl.handle.net/11104/0265619