New phenylethanoid glycosides from Cistanche tubulosa (SCHRENK) HOOOK. f. I.

Abstract

Four new phenylethanoid glycosides, tubulosides A (II), B (VI), C (VII) and D (VIII), have been isolated from Cistanche tubulosa (SCHRENK) HOOK. f. (Orobanchaceae), together with four known phenylethanoid glycosides, echinacoside (I), acteoside (III), acteoside isomer (IV) and 2'-acetylacteoside (V). The structures of II, VI, VII and VIII were established on the basis of chemical evidence and spectral data. Compounds VII and VIII possess a triacetylrhamnosyl moiety as the terminal sugar.

Monoterpene Constituents from Cistanche tubulosa-Chemical Structures of Kankanosides A-E and Kankanol-

“…The methanolic extract (160 g) was subjected to normal-phase silica gel column chromatography The known compounds (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18) were identified by comparison of their physical data ([a] D , IR, 1 H-NMR, 13 C-NMR, MS) with reported values 1,7,[19][20][21][22][23][24]26,27) or those of commercial samples. 25) Kankanoside A ( Enzymatic Hydrolysis of 1, 4, and 6 with b b-Glucosidase A solution of 1 (7.7 mg) in H 2 O (1.5 ml) was treated with b-glucosidase (5.0 mg, from almond, Oriental Yeast Co., Tokyo, Japan) and the solution was stirred at 37°C for 3 d. After EtOH was added to the reaction mixture, the solvent was removed under reduced pressure and the residue was purified by HPLC [MeOH-H 2 O (55 : 45, v/v)] to furnish kankagenin a (1a, 2.3 mg, 56%).…”

Iridoid and Acyclic Monoterpene Glycosides, Kankanosides L, M, N, O, and P from Cistanche tubulosa

“…The 1 H-and 13 C-NMR spectra of 1 were superimposable on those of principal iridoid constituent 6-deoxycatalpol (6), except for the signals due to the saturated d-lactol moiety. Finally, hydrogenation of 6 gave 1, so that the stereostructure of kankanoside L was elucidated to be 3,4-dihydro-6-deoxycatalpol (1 Fig. 1, the 1 H-1 H COSY experiment on 2 indicated the presence of partial structures written in bold lines and, in the HMBC experiment, long-range correlations were observed between the following proton and carbon pairs (3-H and 1-C; 7-H and 9-C; 9-H and 1-C, 8-C; 10-H 2 and 7-C, 8-C, 9-C; 1Ј-H and 10-C).…”

Iridoid Glycosides from Globularia davisiana.

“…The NMR and MS data for asperuloside (2), 7) alpinoside (3), 8) geniposide (4), 9) globularin (5), 10) globularicisin (6), 10) 10-O-benzoylcatalpol (7), 11) lytanthosalin (8), 12) melampyroside (9), 13) agnuside (10), 14,15) as well as verbascoside, 16) isoacteoside, 17) and leucosceptoside A 18) were identical with published data. All isolates were tested for their radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH).…”