Elsevier

Phytochemistry

Volume 65, Issue 2, January 2004, Pages 207-213
Phytochemistry

Neolignan and flavonoid glycosides in Juniperus communis var. depressa

https://doi.org/10.1016/j.phytochem.2003.10.025Get rights and content

Abstract

Two neolignan glycosides (junipercomnosides A and B) were isolated from aerial parts of Juniperus communis var. depressa along with two known neolignan glycosides and seven flavonoid glycosides. The structures of the isolated compounds were determined by spectral analysis, in particular by 2D-NMR analysis. The significance of distribution of flavonoids in the chemotaxonomy of genus Juniperus was also discussed.

Two neolignan glycosides were isolated from Juniperus communis var. depressa along with known neolignan and flavonoid glycosides.

  1. Download : Download full-size image

Introduction

Genus Juniperus belongs to Family Cupressaceae, which comprises about 70 species distributed in the Northern Hemisphere. Among them, Juniperus communis is a familiar species with the characteristic flavor of distilled liquor “gin” (Bailey et al., 1976). Biflavones (De Pascual et al., 1980, Ilyas and Ilyas, 1990) and diterpenes (Kagawa et al., 1993, San Feliciano et al., 1991) have previously been isolated from J. communis. Recently, we reported the characterization of two novel phenol glucosides together with known biflavones and diterpene in leaves of J. occidentalis. In continuation of this study, we now report the isolation and structure determination of the constituents of J. communis var. depressa.

Chromatographical separation and purification with silica gel, ODS and HPLC of the n-BuOH soluble part (see Section 3) resulted in isolation of eleven phenolic compounds; four neolignan glycosides (1–4) and seven flavonoid glycosides (5–11) including two new neolignan glycosides, named junipercomnosides A (Fig. 1, Fig. 2) and B (Fig. 2, Fig. 3). In the present paper, we wish to describe the structure determination of the isolated compounds. In addition, the chemotaxonomical significance of flavonoids such as isoscutellarein and hypolaetin glycosides is discussed.

Section snippets

Results and discussion

Compound Fig. 1, Fig. 2 (junipercomnoside A), a colorless amorphous powder, showed the [M–H] ion peak at m/z 477.1759 in the negative ion HRFAB-MS, indicating the molecular formula C24H30O10. The 1D 1H NMR and 2D 1H–1H COSY spectra (Fig. 1) showed the presence of a 1,2,4-trisubstituted benzene ring (ring A) [δ 7.06 (1H, d, J=1.8 Hz, H-2′), 7.05 (1H, d, J=8.4 Hz, H-5′) and 6.94 (1H, dd, J=8.4, 1.8 Hz, H-6′), a 1,2,3,5-tetrasubstituted benzene ring (ring B) [δ 6.59 (1H, br s, H-4) and 6.57 (1H,

General

1H and 13C NMR spectra were measured on a GE-Omega 600 (1H at 600 MHz and 13C at 150 MHz) or JEOL JNM-GX 400 (1H at 400 MHz and 13C at 100 MHz) spectrometers. Chemical shifts were given in δ values (ppm) relative to trimethylsilane (TMS) as an internal reference. FAB and HR-FAB-MS spectra in a negative mode (matrix; triethanolamine except for compound 4; compound 4 matrix: glycerine), along with EI-MS spectra, were obtained with a JEOL JMS-700T spectrometer. UV spectra were recorded on a

Acknowledgements

We are grateful to Dr. Robert P. Adams, Director of Pacific Center for Molecular Biodiversity, Bishop Museum, USA, for identification of the plant. This study was supported in part by a Grant-in-Aid for Scientific Research (No. 09041194) from the Ministry of Education, Science, and Culture, Japan.

References (16)

There are more references available in the full text version of this article.

Cited by (95)

View all citing articles on Scopus
View full text