Chemical Constituents from the Aerial Parts of Triosteum pinnatifidum

Abstract

Triosteum Linn. belongs to the family Caprifoliaceae and comprises about seven species, but there are only three species in China. One of the species is Triosteum pinnatifidum, which is traditionally used for many medical purposes, including analgesia and enhancing blood circulation. It is distributed in Hebei, Shanxi, Shaanxi, Ningxia, Gansu, Henan, Hubei, and Sichuan in China, most growing on the slope of dark coniferous forests or at the sunny side of ditches over 1800–2900 m above sea level [1]. Research on its chemical constituents has not been reported up to now. Herein we report the results of a thorough phytochemical study of the aerial parts of Triosteum pinnatifidum (Linn.). Air-dried aerial parts (2.45 kg) were extracted with methanol once a week for 3 times. The methanol extract was separated from the plant residue by filtration. The filtrate was concentrated under reduced pressure by a vacuum rotary evaporator to obtain a residue (600 g). The residue was subjected to column chromatography on silica gel eluted with petroleum ether– EtOAc (20:1, 10:1, 5:1, 1:1, 0:1) and ethyl acetate–methanol (10:1, 5:1, 2:1, 0:1) to give ten subfractions, A–J. Fraction B was chromatographed on silica gel using petroleum ether with increasing amounts of EtOAc as eluent to give compounds 1 and 3. Fraction C was rechromatographed on a silica gel column using petroleum ether–acetone gradient solvent system to obtain compounds 4 and 5. Fraction D was chromatographed on silica gel using petroleum ether with increasing amounts of EtOAc as eluent to give compounds 2 and 6. Fraction E was chromatographed on a silica gel column using a petroleum ether–acetone gradient solvent system to afford compound 7. The structures of all compounds were determined by spectroscopic methods, including EI-MS and 1H and 13C NMR. The spectroscopic data of all compounds were in good agreement with the literature data. Alantolactone (1). C15H20O2, colorless needles, mp 77–79 C. ESI-MS m/z: 233 [M + H]+, 255 [M + Na]+ 2 . p-Hydroxybenzaldehyde (2). C7H6O2, white solid, mp 114–118 C. ESI-MS m/z: 123 [M + H]+, 145 [M + Na]+ 2 . Erythrodiol-3-palmitate (3). C46H80O3, white powder, mp 128–131 C. FAB-MS m/z: 681 [M + H] +, 425 [M – C16H31O2] +. 13C NMR (100 MHz, CDCl3, , ppm): 173.7 (C-1 ), 144.2 (C-13), 122.3 (C-12), 80.5 (C-3), 69.7 (C-28), 55.3 (C-5), 47.5 (C-9), 46.4 (C-19), 42.4 (C-18), 41.7 (C-14), 39.8 (C-8), 38.3 (C-4), 37.8 (C-1), 37.0 (C-10), 36.8 (C-17), 35.0 (C-2 ), 34.1 (C-21), 33.2 (C-29), 32.5 (C-7), 32.0 (C-20), 31.0 (C-22), 30.9 (C-14 ), 29.7–29.4 (10C, C-4 –C-13 ), 29.2 (C-23), 28.0 (C-2), 26.0 (C-27), 25.5 (C-15), 25.2 (C-3 ), 23.6 (C-30), 23.5 (C-11), 22.7 (C-15 ), 22.0 (C-16), 18.2 (C-6), 16.8 (C-26), 16.7 (C-25), 15.6 (C-24), 14.3 (C-16 ) [3].