Corrigendum to “Oleanane-type triterpenoids from Panax stipuleanatus and their anticancer activities” [Bioorg. Med. Chem. Lett. 20(23) (2010) 7110–7115]

Oleanane‐Type Triterpene Glycosides from Camellia phanii and Their α‐Glucosidase Inhibitory Activity

“…Using chromatographic methods such as silica gel, RP‐18, and HPLC, three new and five known compounds were isolated. The known compounds were elucidated to be chikusetsusaponin IVa ( 4 ), spinasaponin A 28‐ O ‐glucoside ( 5 ), [5] (−)‐epicatechin ( 6 ), (−)‐epicatechin 3‐ O ‐gallate ( 7 ), and (−)‐epigallocatechin 3‐ O ‐gallate ( 8 ), [4b] which were in good agreement in the literature.…”

A Stereoselective Glycosylation Approach to the Construction of 1,2‐trans‐β‐d‐Glycosidic Linkages and Convergent Synthesis of Saponins

“…Subjection of 19 and 20 to the removal of the benzoyl groups under Zemplén conditions and the 4',6'-Obenzylidene (for 20) and the 28-O-benzyl ester by hydrogenolysis furnished saponins 1 (59 % in 2 steps) and 2 (54 % in 2 steps). Saponins 3 and 4 are typical oleanolic acid saponins bearing an additional ester β-d-glucopyranosyl residue at C28, which were isolated from Eclipata prostrata [14] and Panax stipuleanatus, [15] respectively. Glycosylation of oleanolic acid peracetylglucosyl ester 12 b with disaccharide imidates 11 d and 11 h led to 3-O-β-glycosides 24 and 25 in excellent yields (92 and 96 %, respectively) and exclusive β selectivity.…”

“…[11] Depicted in Figure 2 are a few common (1!2)-linked di-and trisaccharides (G1-G6) and representative triterpene saponins (1-10) which contain such glycans. [12][13][14][15][16][17][18][19][20][21] Herein, we report a highly stereoselective glycosylation method to the construction of the 1,2-trans-β-d-or α-lglycosidic linkages without resorting to NPG and the application of this method to the convergent synthesis of relevant glycoconjugates as exemplified by the efficient synthesis of triterpene saponins 1-10.…”