Study On The Bioactive Components From Peels Of Clausena Lansium

Clausena lansium (Lour.) Skeels is a species of the genus Clausena. In order to discover the bioactive constituents with medicinal value in peels of C. lansium in Hainan, its chemical constituents were extracted, isolated and elucidated. In addition, bioassay of the extracts and monomer compounds including hypoglycemic, anti-tumor and anti-bacterial activities were performed.Thirty-one compounds were isolated from the ethanol extract of the peels of C. lansium by column chromatography, and their structures were identified by physicochemical and spectroscopic methods including IR, UV, MS, ID and2D-NMR etc. They are claulansine K (1), clauslactone V (2), clauslactone W (3), claulansoside A (4), nerol oxide-8-carboxlic acid (5), lansine (6),3-formylcarbazole (7),3-formyl-6-methoxy carbazole (8), methyl6-methoxycarbazole-3-carboxylate (9), claulansine J (10), methyl8-hydroxycarbazole-3-carboxylate (11), carbazole-3-carboxylic acid (12), O-demethylmurrayamine (13), methyl carbazole-3-carboxylate (14), mukonal (15), anisolactone (16),2",3"-dihydroxyanisolactone (17), wampetin (18),(E,E)-8-(7-hydroxy-3,7-dimethylocta-2,5-dienyloxy)psoralen (19),8-hydroxy furanocoumarins (20), umbelliferone (21), clausenalansimin B (22), ξ-clausenamide (23), clausenamide (24), quercetin (25), isorhamnetin (26), dihydromyric (27),(6R,7E,9S)-9-hydroxy-4,7-megastigmadien-3-one (28),p-hydroxycinnamate (29),β-sitosterol (30) and β-daucosterol (31). Compounds1-5were new compounds, and compound11was a new natural product. The hypoglycemic activities of compounds1-29were evaluated in vitro by the inhibition of a-glucosidase method, and compoundsl-3,6,16-24exhibit a-glucosidase inhibitory activity in vitro. The cytotoxicities of compounds1-29were assayed in vitro using the MTT method. Compound6showed inhibitory activities towards human hepatoma (BEL-7402), human gastric carcinoma (SGC-7901) and chronic myelogenous leukemia (K562) cell lines. Compound18showed inhibitory activities towards human hepatoma (BEL-7402) cell lines. The antimicrobial activities against Staphylococcus aureus of compounds1-29were measured using paper disc diffusion method, among which compounds1,5,7,8,10,17,20,21, and29exhibited antimicrobial activities.In this thesis, thirty-one compounds were isolated and identified through the study on chemical constituents and their biological activities in peels of C. lansium. Five new compounds and a new natural product were identified, and compound6exhibited biological activities well. The coumarins showed universal hypoglycemic activity better than carbazole alkaloids, amide alkaloids and flavonoids, which indicated that coumarins were the main constituents of hypoglycemic activity in peels of C. lansium. The results of this study may be supplements of the scientific basis on developing this medicinal and edible fruit.