Regioselective synthesis of 20-hydroxyecdysone glycosides

Minor Ecdysteroid Components of Leuzea carthamoides

“…1 H and 13 C spectra together with 1 H, 1 H-COSY and 1 H, 13 C-HMQC spectra were used for complete (or nearly complete) structure assignment of carbon and proton signals. Characteristic NMR data of compounds 2, 3, 5, 7-14 (Tables II-IV) correspond with the published data of carthamosterone 3 (2), makisterone C 3,22 (3), 3-epi-20-hydroxyecdysone 23,24 (5), integristerone A 25,26 (7), integristerone B 25 (8), isovitexirone 4 (9), 22-oxo-20-hydroxyecdysone 27 (10), taxisterone 26,28 (11), rubrosterone 26,29 (12), dihydrorubrosterone 26,30 (13) and poststerone 26,31 (14), summarised in the Ecdysone 24 . Integristerones A and B (7, 8) were found in the related Rhaponticum integrifolium 25 .…”

“…The new obtained minor ecdysteroids, presented in this paper, together with selected transformed analogues are scheduled 20 for ecdysteroid receptor mapping based on their interaction with the ligand-binding domain in the B II bioassay [14][15][16] . Our results, published earlier 15 , were included also into other models, using a homology modelling and docking approach 21 .…”

“…20-hydroxyecdysone, polypodine B, ajugasterone C, makisterone A and some of their mono-or diacetonides. Some of them were utilised mainly for chemical transformations [10][11][12] , phototransformations 13,14 and bioassays reflecting the affinity of ecdysteroids to the ligand-binding site of the insect ecdysteroid receptor [14][15][16] .…”

“…All isolated and identified ecdysteroids, as well as their chemically modified analogues [10][11][12][13] were used for bioassays [14][15][16]19 . The new obtained minor ecdysteroids, presented in this paper, together with selected transformed analogues are scheduled 20 for ecdysteroid receptor mapping based on their interaction with the ligand-binding domain in the B II bioassay [14][15][16] .…”

Selective (α)-l-Rhamnosylation and Neuroprotective Activity Exploration of Cardiotonic Steroids

“…In the context of their studies focused on regioselective glycosylation of 6-deoxyerythronolide B, we utilized boronic acid esters as the traceless protecting groups. − In situ protection of the 1,3-diol moiety of 2-deoxyerythronolide B (6-dEB) was followed by the addition of glycosyl trichloroacetimidate and TMSOTf as the promoter to accomplish selective glycosylation. The basic reaction work up was used to remove the boronic acid and produce the desired glycoside as the single regioisomer.…”