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New saponins from Sechium mexicanum
Author(s) -
HernándezCarlos Beatriz,
CarmonaPineda Miriam,
VillanuevaCañongo Claudia,
LópezOlguín Jesús F.,
AragónGarcía Agustín,
JosephNathan Pedro
Publication year - 2009
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.2487
Subject(s) - chemistry , stereochemistry
The chemical study of Sechium mexicanum roots led to the isolation of the two new saponins {3‐ O ‐β‐ D ‐glucopyranosyl (1 → 3)‐β‐ D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐ O ‐α‐ L ‐rhamnopyranosyl‐(1 → 3)‐β‐ D ‐xylopyranosyl‐(1 → 4)‐α‐ L ‐rhamnopyranosyl‐(1 → 2)‐α‐ L ‐arabinopyranoside} (1) and {3‐ O ‐β‐ D ‐glucopyranosyl (1 → 3)‐β‐ D ‐glucopyranosyl‐2β,3β,16α,23‐tetrahydroxyolean‐12‐en‐28‐oic acid 28‐ O ‐α‐ L ‐rhamnopyranosyl‐(1 → 3)‐β‐ D ‐xylopyranosyl‐(1 → 4)‐[β‐ D ‐apiosyl‐(1 → 3)]‐α‐ L ‐rhamnopyranosyl‐(1 → 2)‐α‐ L ‐arabinopyranoside} (2), together with the known compounds {3‐ O ‐β‐ D ‐glucopyranosyl‐(1 → 3)‐β‐ D ‐glucopyranosyl‐2β,3β,6β,16α,23‐pentahydroxyolean‐12‐en‐28‐oic acid 28‐ O ‐α‐ L ‐rhamnopyranosyl‐(1 → 3)‐β‐ D ‐xylopyranosyl‐(1 → 4)‐α‐ L ‐rhamnopyranosyl‐(1 → 2)‐α‐ L ‐arabinopyranoside} (3), tacacosides A 1 (4) and B 3 (5). The structures of saponins 1 and 2 were elucidated using a combination of 1 H and 13 C 1D‐NMR, COSY, TOCSY, gHMBC and gHSQC 2D‐NMR, and FABMS of the natural compounds and their peracetylated derivates, as well as by chemical degradation. Compounds 1–3 are the first examples of saponins containing polygalacic and 16‐hydroxyprotobasic acids found in the genus Sechium , while 4 and 5, which had been characterized partially by NMR, are now characterized in detail. Copyright © 2009 John Wiley & Sons, Ltd.