Résumé
Objective: To investigate the chemical constituents from Juniperus convallium, as well as their anticomplementary and antioxidant activities. Methods: The constituents were isolated and purified by column chromatography over silica gel, Sephadex LH-20, ODS-C18, and preparative HPLC. Their structures were identified by spectra analysis. The cell hemolysis assay was used to evaluate the anticomplementary activities and the targets through classical and alternative pathways. Also the anti-oxidant activities were tested by DPPH, ABTS and FRAP methods. Results: A total of 17 compounds were obtained from the ethyl acetate extract of J. convallium and identified as amentoflavone (1), cupressuflavone (2), cupressuflavone-4″’-O-β-D-glucosides (3), naringenin-7-O- glycoside (4), apigenin (5), tiliroside (6), quercetin 3-O-β-D-glucoside (7), quercetin-3-O-rhamnoside (8), hypolaetin-7-O-β-D- glucopyranoside (9), isomassonianoside B (10), (+)-isolariciresinol 2a-O-β-D-glucoside (11), (+)-isolarisiresinol 3a-O-β-D-glucopyranoside(12), cryptomeridiol (13), 3β-hydroxysandaracopimeric acid (14), (1R,3R,4aR,4bS,7R,10aR)-7-ethenyl-1,2,3,4,4a,4b,5,6,7,9,10,10a- dodecahydro-3-hydroxy-1,4a,7-trimethyl-1-phenanthrene methanol (15), 4-hydroxy-5-methyl-coumarin (16) and β-sitosterol (17). Compounds 1-15 and 17 showed anticomplementary activities in different degrees (CH50: 0.05-3.99 mmol/L, AP50: 0.58 -19.13 mmol/L). The flavonoids, especially the biflavonoids, are the important anticomplementary constituents in J. convallium. Further analysis of structure-activity relationship showed that phenolic hydroxyl and glycosidic groups influenced their anticomplementary activity. Only the flavonoids (1-3, 5-9) and lignans (10-12) showed different degrees of antioxidant activities due to their hydroxyl groups. Conclusion: All the 17 compounds are isolated from J. convallium for the first time. The flavonoids and lignans are the important anticomplementary and antioxidant constituents in J. convallium with a certain structure-acticity relationship. This study provides a good reference for further research on the pharmacological substance and quality control of J. convallium.
Résumé
Aim To explore the anticomplementary ac-tivity and active constituents of Phyllanthus urinaria. Methods Being guided by bioactive screening,the anticomplementary constituents of P.urinaria were iso-lated and purified by solution partition and chromato-graphic techniques,and their structures were identified by 13C-NMR spectrum and the comparison of reported data. The anticomplementary activity and possible mechanism were assayed.Results The EtOAc fraction of the methanol extract of P.urinaria was shown to be the active fraction,and two compounds were purified from the fraction and were identified as corilagin and ellagic acid.The EtOAc and the two compounds signifi-cantly inhibited the hemolysis of the complement classi-cal pathway,with IC50values of 53.77 mg·L-1, 176.54 mg·L-1and 102.23 mg·L-1,respectively. While they just showed slight effect on inhibiting the hemolysis of the complement alternative pathway. All of them affected the formation of C3 convertase of the classical pathway. Conclusions The polyphenols are main anticomplentary constituents of P. urinaria,and its mechanism is related to inhibiting formation of C3 convertase of the classical pathway.