Studies On The Chemical Constituents Of Two Tibetan Medicinal Herbs, Lancea Tibetica And Quercus Semicarpifolia

Because of special growth environments of their original plants, traditional Tibetan medicines showed attractive specialties in prevention and treatment of human disease like tumor and cardiac disease. Two traditional Tibetan medicinal herbs, Lartcea tibetica (Scrophuhrhceae) and Quercus semicarpifolia (Fagaceae) were wildly used in Tibet. The former is used for treatment of leukaemia, heart disease, influenza, pneumonia, asthma, and the latter for fever, diarrhea and enteritis. To search for the bioactive components, their chemical constituents were studied.The ethanol extract of Lancea tibetica was successively was successively partitioned between water and cyclohexane and ethyl acetate to yield crude extracts. From the bioactive part, eighteen compounds 1~18 were isolated by repeated column chromatography on silica gel, Sephadex LH-20 and RP-18, followed by reverse-phase high performance liquid chromatography and recrystallization. By means of spectroscopic method (UV, IR, MS, 1D-NMR, 2D-NMR) and their physicochemical properties, the structures of compounds 1~16 were elucidated as R-(+)-3-(3, 4, 5-trimethyxyphenyl)-1, 2-propanediol (1), R-(+)3-(5-methoxy-3, 4-Methylenedioxy-phenyl)-1, 2-propanediol (2), (+)-3-(3, 4-methylenedioxy phenyl)-1, 2-propanediol (3), 1-(3-methoxy-4-hydroxyphenyl)-1, 2-propanediol (4), (+)-erythro- (7S, 8R)-△8'-4, 7-dihydroxy-3, 3', 5'-trimethoxy-8-O-4'-neolignan (5), (+)-erythro-(7S, 8R)-△8'-7-hydroxy-3, 4, 5, 3', 5'-pentamethoxy-8-O-4'-neolignan (6), (+)-erythro-(7S, 8R)-△8'-7-aceto-3, 4, 3', 5'-tetramethoxy-8-O-4'-neolignan (7), (-)-threo-(7S, 8S)-△7'-3, 4-dihydroxy-3'-methoxy-7-O-4', 8-5'-neolignan (8), (-)-threo-(7S, 8R, 7'S, 8'5)-3, 3'-dimethoxy-4, 5'-dihydroxy-7-O-7', 8-8'-neolignan (9), 1-(1, 3dihydroxyphenyl)-9- (4-hydroxyphenyl)nonan-1-one (10), 1-(1, 3dihydroxyphenyl)-9-(3, 4-dihydroxy phenyl) nonan-1-one (11), 3, 4-dihydroxybenzaldehyde (12), Tibeticone A (13), Tibeticone B (14), Tibeticone C (15), Ergosterol (16). Tibeticone B (14) and Tibeticone C (15)were the novel compounds with special molecular skeleton, and 7, 9, 13 were the new compounds. 4 and 9 showed anti-oxidation activity in the DPPH-Microplate assay.The ethanol extract of Quercus semicarpifoli was successively partitioned between water and petroleum ether and EtOAc to yield crude extracts. From the bioactive part, seven compounds 19~25 were isolated by column chromatography on Sephadex LH-20, silica gel and RP18, followed by reverse-phase high performance liquid chromatography and recrystallization. By comparison their spectra data and other physical properties with those publishing data, compounds 19~25 were identified as β-sitosterol (18), β-daucosterol (19), α-Daucosterol (20), oleanolic acid (21), arjunolic acid (22), arjungenin (23), sericic acid (24), respectively. Arjunolic acid 22 and sericic acid 24 showed moderate anti-tumor activities against tsFT210 cell.