The isolation and structure elucidation of acyclic diterpene glycosides designated as capsianosides II, IX-X, XIII, and XV-XVI from the fruits of paprika Capsicum annuum L. var. grossum 2) and C-F, 3) and IЈ-III and IV from the fruits of pimiento Capsicum annuum L. var. grossum 1) have been reported. Now our study is focused on the water-soluble constituents of the aerial parts of paprika and pimiento. In this study, we have isolated three new acyclic diterpene glycosides named capsianosides

more »

... I (1), V methyl ester (2) and XIV (3) along with capsianosides I 1) and II. 2) The distribution of these new compounds is summarized in Table 1 . Capsianoside XVII (1) : An amorphous powder, [a] D Ϫ53.6°(MeOH), was found to have a molecular formula C 44 H 74 O 21 Na at m/z 961.4678 by HR-FAB-MS. The 13 C-NMR spectrum of 1 showed signals due to eight double bond carbons at d 115.8, 144.5, 126.0, 135.9, 152.6, 110.5, 131.1, and 132.9; one methylene carbon at d 67.9, one methine carbon at d 75.3 and one quarternary carbon at d 81.5 with an oxygen function; three methyl carbons at d 16.3, 21.9, and 23.3; and six methylene carbons d 42.7, 23.6, 36.9, 35.0, 32.5, and 27.3. Further, the 1 H-NMR spectrum disclosed the presence of terminal vinyl protons at d 5.20 (1H, br d, Jϭ11.0 Hz, H-1b), 5.23 (1H, br d, Jϭ17.7 Hz, H-1a), and 5.93 (1H, dd, Jϭ11.0, 17.7 Hz, H-2), two olefinic protons at d 5.15 (1H, m, H-6) and 5.45 (1H, t, H-14); one secondary hydroxyl group at d 3.99 (1H, m, H-10); seven methylene groups at d 1.61ϫ2 (each 2H, m, H 2 -4, 9), 1.95-2.30 (8H , m, 8, 12, 13), 4.16 (1H, d, Jϭ11.6 Hz, and 4.34 (1H, d, Jϭ11.6 Hz, H-17a); one olefinic methylene group at d 4.89 Paprika and pimiento are used as vegetables and spices. We have obtained three new acyclic diterpene glycosides, called capsianosides XVII (1), V methyl ester (2) and XIV (3) together with capsianosides I 1) and II 2) from the aerial parts of paprika and pimiento. The structures of these compounds have been established by 1 H-and 13 C-NMR spectra and two-dimensional NMR methods.