Chemical Constituents From Hovenia Acerba Lindl

The plants of the genus Hovenia are widely distributed in East Asia, and there are five species in China. The fruits and seeds of some Hovenia species have been used as traditional Chinese medicines for the treatment of crapulence and liver diseases. Pharmacological studies have indicated that the extracts of Hovenia plants possess hepatoprotective, sweetness-reducing, antimicrobial, neuroprotective, and histamine release inhibiting activities. In searching for bioactive constituents, we had systematically investigated the chemical constituents of H. acerba.The chemical constituents of H. acerba were studied by multiple chromatogr-gaphical techniques, such as silica gel, sephadex LH-20, HPLC, ODS and TLC chromatographies.25 compounds were isolated and 23 of them were identified by means of spectroscopic methods and physical data as hovenin A (HT-1), hovenin B (HT-2), hovenin C (HT-3), hovenin D (HT-4), kaemperol (HT-5), quecetin (HT-6), myricitin (HT-7), laricetin (HT-8), (2R,3R)-dihydrokaemperol (HT-9), (2R, 3R)-3,3',5',5,7-pentahydroflavanone (HT-10), (2R,3R)-dihydromyricitin (HT-11), hovenitin I (HT-12), (+)-eriodictyol (HT-13),(-)-gallocatechin (HT-14), myricetin 3-O-β-D-glucopyranoside(HT-15), vitexin 2"O-β-D-glucopyranoside (HT-16), isovitexin 2"O-β-D-glucopyranoside (HT-17), isospinosin (HT-18), phloretin 3',5'-di-C-β-D-glucopyranoside (HT-19), acerboside A(HT-20), acerboside B (HT-21), (-)-tryptophan (HT-22) and gallic acid (HT-23), respectively. Compounds HT-1～HT-4 were two pairs of new diastereoisomeric flavonolignans, compounds HT-20～HT-21 were two new triterpenoid saponins, compounds HT-13～HT-19 and HT-22～HT-23 were isolated from this plant for the first time.The anti-inflammatory activity of compounds HT-1～HT-4 on the production of NO and IL-6 in response to LPS-stimulated Raw264.7 cells were evaluated.All compounds were significantly inhibited NO and IL-6 generation in LPS-stimulated cells in a dose-dependent manner.