Abstract
Two new acetylated flavonol glycosides, quercetin 3-
O
-[(2,4-diacetyl-α-
l
-rhamnopyranosyl)-(1→6)]-2,4-diacetyl-β-
d
-galactopyranoside (
1
) and quercetin 3-
O
-[(2,4-diacetyl-α-
l
-rhamnopyranosyl)-(1→6)]-3,4-diacetyl-β-
d
-galactopyranoside (
2
), in addition to two known acetylated quercetin glycosides quercetin 3-
O
-[(2,3,4-triacetyl-α-
l
-rhamnopyranosyl)-(1→6)-β-
d
-galactopyranoside (
3
) and quercetin 3-
O
-[(2,3,4-triacetyl-α-
l
-rhamnopyranosyl)-(1→6)-3-acetyl-β-
d
-galactopyranoside (
4
), were isolated from the aerial part of
Centaurium spicatum
(L.) Fritsch (Gentianaceae). Structure elucidation, especially the localization of the acetyl groups, and complete
1
H and
13
C NMR assignments of these biologically active compounds were carried out using one- and two-dimensional NMR measurements, including
1
H- and
13
C-NMR, DEPT-135, H–H COSY, HMQC and HMBC, in addition to HR-FAB/MS experiments.