Chem. Pharm. Bull. 55(1) 15—18 (2007)

Hippophae rhamnoides L. (Elaeagnaceae) is a hardy, deciduous shrub with yellow or orange berries. H. rhamnoides contains a series of chemical compounds including flavonols, sterols, lipids, triterpenoids, etc. H. rhamnoides has been used as a traditional medicine for the treatment of cough, indigestion, and blood stasis in China. Macrophages play major roles in host defense, immunity, and inflammatory responses and once activated they induce the production of proinflammatory cytokines and oxygen and nitrogen species, which recruit activated immune and inflammatory cells to the site of a lesion, thereby amplifying and perpetuating the inflammatory state. The inorganic free radical nitric oxide (NO) has been implicated in physiologic and pathologic processes such as vasodilation, nonspecific host defense, ischemia-reperfusion injury, and chronic or acute inflammation. NO can be expressed in response to proinflammatory agents such as lipopolysaccharide (LPS) in various cell types including macrophages, endothelial cells, and smooth muscle cells. In inflammatory disease such as rheumatoid arthritis, excessive NO production may be of therapeutic benefit in various types of inflammation. In our investigation of the in vitro antiinflammatory effects of H. rhamnoides extracts, the chloroform-soluble portion of the 80% acetone extract of branch bark was observed to inhibit NO production in LPS-activated macrophages. Furthermore, the chloroform-soluble portion was purified by column chromatography on silica gel and ODS and also by preparative HPLC. Two new triterpenoids, 2-O-trans-p-coumaroyl maslinic acid (1) and 2-O-caffeoyl-maslinic acid (2), and three known triterpenoids, oleanolic acid (3), 3-O-trans-pcoumaroyl oleanolic acid (4), and 3-O-caffeoyl oleanolic acid (5), and 6-methoxy-2H-1-benzopyran (6) and bsitosterol (7) were isolated from the branch bark extract. We also report on the inhibition of NO production and radical-scavenging activities of these compounds. Compound 1 was obtained as an amorphous powder. The molecular formula of 1 was established to be C39H54O6 by negative high-resolution FAB-MS (HR-FAB-MS). The UV spectrum exhibited absorption maxima at 225 and 310 nm, suggesting the presence of aromatic rings in the molecule. The IR spectrum contained absorption bands for hydroxyls (3550—3100 cm ), a ,b-unsaturated carbonyl (1696 cm ), and aromatic (1605, 1515 cm ) functionalities. The HNMR spectrum of 1 indicated seven tertiary methyls [d 0.82, 0.88, 0.90, 0.93, 1.06, 1.09, 1.18 (each 3H, s)], two hydroxymethine protons [d 5.04 (1H, ddd, J 11.8, 10.0, 4.6 Hz and d 3.24 (1H, d, J 10.0 Hz)], a trisubstituted olefinic double bond [d 5.24 ( 1H, t, J 3.7 Hz)], and a 1,4-disubstituted Triterpenoids from Hippophae rhamnoides L. and Their Nitric Oxide Production-Inhibitory and DPPH Radical-Scavenging Activities