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In a survey of chemical components from useful plants grown in western North America, we have identified a number of various types of phenolic compounds (nine phenylpropanoids, six neolignans, and seven flavonoids) in their glycoside form from the aerial parts of Juniperus communis var. depressa (Cupressaceae) and those results were reported in our previous papers.1,2) Upon continued chemical investigation of the same plant material, a new monoterpene glucoside (1) and three new natural megastigmane glycosides (2-4) were isolated together with a known megastigmane, corchoionoside C (5).3) In the present paper, we describe the isolation, structure elucidation, and biological activity of these constituents.The n-BuOH-soluble part obtained from the MeOH extract was separated by a combination of silica gel, octadecyl silica gel (ODS), and Sephadex LH-20 column chromatographies, followed by HPLC separation to afford each of the four new natural terpenic compounds (1-4) and the known megastigmane.Compound 1, a white powder, [a] D Ϫ36.3°, gave the [MϪH] Ϫ ion peak at m/z 345 in the FAB-MS (negative mode). The high-resolution (HR) spectrum in the same mode revealed the molecular formula to be C 16 H 26 O 8 . The 1 H-and 13 C-NMR spectral data (Table 1) suggested 1 to be a b-D-glucopyranoside. 4,5) On the aglycone, proton signals due to two tert methyls (d 1.35, 1.39, both s) and an olefinic proton (d 7.27, br dd, Jϭ3.0, 3.0 Hz) and 10 carbon signals including two tert methyls (d C 23.3, 24.8) and a carboxyl group (d C 169.9) were observed. The two-dimensional (2D) study using 1 H-1 H shift-correlation spectroscopy (COSY) indicated that a menthane-type monoterpene is assigned to the aglycone. The position of the carboxyl group was determined to be at C-1 based on the presence of a cross peak between H-2 and the carboxylic carbon (C-7) in heteronuclear multiple-bond correlation spectroscopy (HMBC), suggesting that the planar Biology, Southern Oregon University; 1250 Siskiyou, Ashland, OR 97520-5071, U.S.A.: d Gifu Pharmaceutical University; 5-6-1 Mitahora-higashi, Gifu 502-8585, Japan: e Gifu Prefectural Institute of Health and Environmental Sciences; 1-1 Naka Fudogaoka, Kakamigahara, Gifu 504-0838, Japan: and f Osaka Prefectural Institute of Public Health; 1-3-69 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan. Received February 7, 2005; accepted March 15, 2005 A new monoterpene glucoside (1) and three new natural megastigmane glycosides (2-4) were isolated along with a known megastigmane glucoside (5) from twigs with leaves of Juniperus communis var. depressa (Cupressaceae) collected in Oregon, U.S.A., and their structures were determined on the basis of spectral and chemical evidence. In addition, the antibacterial activities of the isolated components against Helicobacter pylori were also investigated.

A new flavone xyloside, 1, and two new flavan-3-ol glucosides, 3 and 4, were isolated together with three known flavones, 2, 11, and 12, five known flavans, 5-9, and a known dihydrochalcone, 10, from the stems and leaves of Juniperus communis var. depressa (Cupressaceae) collected in Oregon, U.S.A., and their structures were determined on the basis of spectral evidence. A novel flavone nucleus such as that in 1 is seldom found in nature today, and new methylcatechin glucosides 3 and 4 are also rare in nature. In addition, we investigated the inhibitory activity of individual components, i.e., 8-11, and others, that were abundantly isolated from the same plant material for the Maillard reaction.

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