Complete 1 H and 13 C NMR assignments for two new monodesmoside saponins from Pentaclethra macroloba (Willd.) Kuntze

• Published in: Magnetic resonance in chemistry Vol. 42; no. 8; pp. 695 - 699
• Main Authors: Viana, Francisco Arnaldo, Pouliquen, Yvone Brígido M., Andrade‐Neto, Manoel, Santiago, Gilvandete Maria P., Pessoa, Otília Deusdênia L., Rodrigues‐Filho, Edson, Braz‐Filho, Raimundo
• Format: Journal Article
• Language: English
• Published: 01-08-2004
• ISSN: 0749-1581; 1097-458X
• DOI: 10.1002/mrc.1421

A detailed NMR study and full assignments of the
1
H and
13
C spectral data for two novel triterpenoid saponins isolated from the stem bark of
Pentaclethra macroloba
(Willd.) Kuntze are described. Their structures were established using a combination of 1D and 2D NMR techniques including
1
H,
1
H‐COSY, TOCSY, NOESY, gs‐HMQC and gs‐HMBC, and also electrospray ionization mass spectrometry and chemical methods. The structures were established as 3β‐
O
‐{[
O
‐β‐
D
‐glucopyranosyl‐(1→2)‐
O
‐β‐
D
‐glucopyranosyl‐(1→4)‐
O
‐β‐
D
‐glucopyranosyl‐(1→3)‐
O
‐α‐
L
‐rhamnopyranosyl‐(1→2)]‐[
O
‐β‐
D
‐glucopyranosyl‐(1→3)‐
O
‐β‐
D
‐glucopyranosyl‐(1→4)]}‐α‐
L
‐arabinopyranosylhederagenin (
1
) and 3β‐
O
‐{[
O
‐β‐
D
‐glucopyranosyl‐(1→2)‐
O
‐β‐
D
‐glucopyranosyl‐(1→4)‐
O
‐β‐
D
‐glucopyranosyl‐(1→3)‐
O
‐α‐
L
‐rhamnopyranosyl‐(1→2)]‐[
O
‐β‐
D
‐glucopyranosyl‐(1→3)‐
O
‐β‐
D
‐glucopyranosyl‐(1→4)]}‐α‐
L
‐arabinopyranosyloleanolic acid (
2
). Copyright © 2004 John Wiley & Sons, Ltd.