Achyranthosides C and D, novel glucuronide saponins from achyranthes fauriei root.

Abstract

Two novel saponins, achyranthosides C and D, were isolated from Achyranthes faurei root, and their structures were characterized based on the chemical and spectroscopic evidence.

Achyranthoside H methyl ester, a novel oleanolic acid saponin derivative from Achyranthes fauriei roots, induces apoptosis in human breast cancer MCF-7 and MDA-MB-453 cells via a caspase activation pathway

“…As shown in Fig methods. As reported previously [3,16], AC, a natural compound found in the methanol-soluble fraction of A. fauriei roots, is a parent molecule of AH-Me (Fig. 2).…”

Two new glucuronide saponins, Achyranthosides G and H, from Achyranthes fauriei root

“…Achyranthoside G methyl ester (1a) was obtained as a white powder, [a] 13 C NMR spectrum of 1a showed 51 carbon signals, and was similar to those of achyranthoside D methyl ester (4a) [9], except for the appearance of an esteric methyl carbon signal at d 52.1 in 1a instead of b-Dglucopyranosyl carbon signals in 4a (Table 1). Achyranthoside D methyl ester (4a) was saponified with 2 N aqueous sodium hydroxide and methylated with diazomethane etherate to a product, which was identified as 1a by direct comparison.…”

“…The column was washed with H 2 O and then eluted with MeOH to give MeOH eluent (42.1 g). The MeOH eluent was treated repeatedly with excess diazomethane etherate in MeOH, and the reaction mixture was separated by repeated column chromatography (CC) on SiO 2 and ODS to afford the following 16 compounds: 1a (188 mg), 2a (25 mg), achyranthoside A methyl ester (191 mg), achyranthoside B methyl ester (93 mg) [8], achyranthoside C methyl ester (3a, 425 mg), achyranthoside D methyl ester (4a, 339 mg) [9], achyranthoside E methyl ester (576 mg), achyranthoside F methyl ester (39 mg) [10], chikusetsusaponin IVa methyl ester (689 mg), chikusetsusaponin V methyl ester (147 mg), 28-deglucosyl chikusetsusaponin V methyl ester (472 mg), pseudoginsenoside RT 1 methyl ester (105 mg) [7], oleanolic acid 3-O-b-D-glucuronopyranoside 28,6'-dimethyl ester (332 mg) [14], oleanolic acid 28-O-b-Dglucopyranoside (97 mg) [15], b-ecdysterone (5.69 g) and polypodine B (480 mg) [16] (Fig. 1).…”

“…In continuation of our phytochemical investigation on A. fauriei root, two new analogous saponins named achyranthosides G (1) and H (2) were isolated as methyl esters from the crude saponin fraction after methylation with diazomethane etherate, together with 12 known oleanolic acid glycosides (methyl esters of achyranthosides A -F chikusetsusaponins IVa, V, 28-deglucosyl chikusetsusaponin V, pseudoginsenoside RT 1 , and oleanolic acid 3-O-b-D-glucuronopyranoside) as well as oleanolic acid 28-O-b-D-glucopyranoside and two phytoecdysones, b-ecdysterone and polypodine B. The present paper describes the isolation of all the compounds from A. fauriei root and the structure determination of the new glycosides, 1 and 2, because the other achyranthosides were only reported as short communications [8][9][10].…”

“…We reported previously the isolation and characterization of six novel triterpene glycosides, achyranthosides A -F, together with four known saponins, chikusetsusaponins IVa, V, 28-deglucosyl chikusetsusaponin V and pseudoginsenoside RT 1 from dried A. fauriei root [7][8][9][10]. Later, Mitaine-Offer et al reported analogous saponins, named bidentatosides I and II [11,12], and then Li et al also reported 14 analogous saponins as methyl and butyl esters [13].…”