Chemistry of Natural Compounds, Vol. 49, No. 2, May, 2013 [Russian original No. 2, March–April, 2013]
FLAVONOID AND CYCLOARTANE GLYCOSIDES FROM
SEEDS OF Koelreuteria paniculata
1
1*
1
M. G. Sutiashvili, M. D. Alaniya, V. D. Mshvildadze,
UDC 547.972;547,918-547-926
1
2
2
A. V. Skhirtladze, A. Pichette, and S. Lavoie
In continuation of research on the chemical components of Koelreuteria paniculata Laxm. (Sapindaceae L.), two
compounds 1 and 2 were obtained in addition to the previously isolated compound saponin B [1]. Herein we present proof of
the structures based on UV, IR, PMR, 13C NMR, HSQC, and HMBC spectroscopic data and mass spectrometry.
Compound 1, yellowish powder, positive Shinoda reaction [2] and negative Bryant [3]. IR spectrum (KBr,
–
1
ꢀmax, cm ): 3600 (OH), 1694 and 1650 (C=O). UV spectrum (ꢁ , nm): 360, 255, 314sh. Mass spectrum m/z: 1209.3
max
–
–
–
[
+
+
M – H] ; 1063 [M – 146 – H] (cleavage of p-coumaric acid); 1047 [M – 162 – H] (cleavage of D-glucose); 917 [M – (146
146) – H] ; 777 [M – (286 + 146) – H] ; 739 [M – (162 ꢂ 2) – 146] ; 593 [M – (146 ꢂ 2) + (162 ꢂ 2) – H] ; 285 [M – (146 ꢂ 3)
(162 ꢂ 3) – H] ; 147 (p-coumaric acid). C H O .
–
–
–
–
-
–
5
4 66 31
Acid hydrolysis of 1 produced the genin (20%) with mp 280–282°C that was identified as kaempferol [4]. Paper
chromatography (PC) and LC of the carbohydrate part of the hydrolysate identified L-rhamnose, D-glucose, and p-coumaric
acid in a 2:3:1 ratio.
According to UV, PMR, and 13C NMR spectra (Table 1), the carbohydrate units in 1 were located on the
kaempferol C-3 and C-7 positions. The SSCC of the anomeric protons were consistent with the pyranose form of the
4
carbohydrates. Monosaccharides of the D-series had the C -conformation and the ꢃ-configuration; of the L-series, the
1
1
C4-conformation and the ꢄ-configuration.
The HMBC spectrum showed correlation peaks between resonances of anomeric L-rhamnose protons with C-7 and
C-3 of the genin. Thus, the L-rhamnose was terminal; the two D-glucoses, end; and the p-coumaric acid, located within the
chain of the tetraose and bonded to D-glucose C-6 which was bonded to L-rhamnose C-3ꢅ.
A comparison of the results with the literature [5] identified 1 as kaempferol-7-O-ꢄ-L-rhamnopyranosyl, 3-O-ꢄ-L-
[
(2ꢅꢆ1ꢅꢇ)-O-ꢃ-D-glucopyranosyl), (3ꢅꢆ1ꢅꢅ)-O-ꢃ-D-(6ꢅꢅꢆ9ꢅꢅꢅ)-p-coumaroylglucopyranosyl, (4ꢅꢆ1ꢅꢅꢇ)-ꢃ-D-
glucopyranosyl]rhamnopyranoside.
Compound 2. MW 664 g/mol, C H O , mp 225–227°C (CHCl :MeOH, 1:1). IR spectrum (KBr, ꢀ , cm ):
–
1
3
7
60 10
3
max
–
–
3
(
363 (OH), 3050 (CH of cyclopropane ring), 1755, 1245 (ester). Mass spectrum m/z: 687 [M + Na] ; 627 [M + Na – 60]
2
–
cleavage of acetyl); 495 [M + Na – 60 – 132] (cleavage of D-xylose).
Acid hydrolysis of 2 produced a genin with mp 196–197°C (MeOH). A solution of the genin in Me CO in the
2
presence of H SO did not form a monoacetonide, indicating the absence of an ꢄ-diol group in the side chain [6]. The
2
4
compound was identified as cyclogalegigenin [7]. PC of the carbohydrate part of the hydrolysate detected D-xylose.
Compound 2 with KOH solution (0.5%) at room temperature gave a glycoside with mp 253–255°C that was identified
as cyclogaleginoside B [7]. This indicated that an acetyl was present in the studied glycoside.
1
3
Judging from the C NMR spectrum and HMBC spectral analysis, the carbohydrate part of glycoside 2 was located
on C-3 of the genin (Table 2). The SSCC of the anomeric proton of the monosaccharide was consistent with the ꢃ-configuration
1
3
and the pyranose form of D-xylose. The chemical shift of C-2 of D-xylose in the C NMR spectrum also indicated that the
acetyl was bonded to the same position.
An analysis of the results characterized 2 as 3-O-ꢃ-D-(2ꢇ-O-acetyl)-xylopyranosyl-20S,24R-epoxycycloartan-
3
ꢃ,6ꢄ,16ꢃ,25-tetraol (cyclogaleginoside A) [7].
Glycosides 1 and 2 were isolated from K. paniculata for the first time.
1
) I. G. Kutateladze Institute of Pharmaceutical Chemistry, Tbilisi, fax: (99532) 25 00 26, e-mail:
merialania@yahoo.com; 2) Department des Sciences Fundamentales, Universite du Quebec a Chicoutimi, Quebec, Canada
G7H 2B1, Translated from Khimiya Prirodnykh Soedinenii, No. 2, March–April, 2013, pp. 333–334. Original article submitted
February 16, 2012.
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009-3130/13/4902-0395 ©2013 Springer Science+Business Media New York
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