Yves Rolland

Synthesis of Functionalized Bicyclo[3.1.0]hexanes from Aucubin: An Access to Fused Aminocyclopentitols

Treatment of iodolactone 8a, having a cyclopentano[c]pyran skeleton and deriving from aucubin (1) (Scheme 1), with sodium trimethylsilanolate permitted a straightforward rearrangement to bicyclo[3.1.0]hexenes 10a and 10b (Schemes 3 and 4). Introduction of an N-atom via a modified Curtius reaction provided an easy entry to fused aminocyclopentitols (Schemes 4 and 5). Target 4 is a conformationally restricted cyclopropane-fused analogue of the glycosidase inhibitors mannostatins A (2) and B (3).

Synthesis and anti-proliferative activity of 2-hydroxy-1,2-dihydroacronycine glycosides

AbstractPurpose. Combination of the acronycine pharmacophore with various sugar units appeared of interest, since numerous anticancer agents possess a sugar moiety, which strongly influence both their bioavailability and their selective toxicity towards tumor cells. Methods. A series of 2-hydroxy-1,2-dihydroacronycine glycosides were synthetized, by condensation of the racemic aglycone with appropriate glycoside donors. Their effect on the inhibition of L1210 cell proliferation were evaluated. Results. Compounds 6a, 6b, 11a, 11b, and 12a, 12b, including a halogenated sugar moiety displayed activities of the same order of magnitude as acronycine itself. Compounds 7a, 7b, and 8a, 8b, bearing a 2,3,6-trideoxy-3-azido-L-lyxo- and L-arabino-hexopyranose unit respectively, were significantly more potent than acronycine in inhibiting cell proliferation. Conclusions. The activity of 2-hydroxy-1,2-dihydroacronycine glycosides seems to be related to the lipophilicity of the sugar unit.

Alcaloïdes des feuilles de Voacanga thouarsii

Resume Des feuilles de Voacanga thouarsii Roerm. et Schult. ont ete isoles 3 alcaloides indoliques (ibogaine, voacangine, voacristine) et 12 alcatoides ‘bis-indoliques’ dont trois deja connus (yobtusine, vobtusinelactone et subsessiline) et neuf nouveaux (bases A a I).