[A new aristolochic acid derivative from Asarum himalaicum]

To study the chemical constituents of Asarum himalaicum, fifteen compounds were isolated from a 70% ethanol extract by using a combination of various chromatographic techniques including column chromatography over silica gel, Sephadex LH-20, and semi-preparative HPLC. By spectroscopic techniques including 1H NMR, 13C NMR, and HR-ESI-MS, these compounds were identified as 4-demethoxyaristolochic acid BII (1), aristolochic acid I (2), aristolochic acid Ia (3), 7-hydroxyaristolochic acid I (4), aristolochic acid IV (5), aristolic acid II (6), debilic acid (7), aristololactam I (8), 9-hydroxyaristololactam I (9), 7-methoxyaristololactam IV (10), (2S)-narigenin-5, 7-di-O-beta-D-pyranosylglucoside (11), 4-hydroxybenzoic acid (12), 3, 4-dihydroxybenzoic acid (13), 4-hydroxycinnamic acid (14), and beta-sitosterol (15). All of these compounds (1-15) were obtained from A. himalaicum for the first time. Among them, 1 was identified as a new compound, and compounds 3-6, 9, 12-14 were isolated from Asarum genus for the first time. Since the kidney toxicity of aristolochic acids and aristololactams has been reported, the result of this investigation suggests that it should be cautioned to use A. himalaicum as a medicine.