Chemical Investigation Of Two Mangrove Plants Excoecaria Agallocha L. And Sonneratia Caseolaris L.

This dissertation describes the isolation, structure elucidation, and bioactivity evaluation of chemical constituents isolated from the mangrove plants Excoecaria agallocha L. and Sonneratia caseolaris L.Chemical investigation of Excoecaria agallocha L. afford 40 compounds by combination of column chromatography on silica gel, RP-18, and Sephadex LH-20, as well as preparative thin layer chromatography (PTLC), recrystallization, and semi-preparative HPLC. The structures of these compounds were elucidated by means of spectroscopic methods including IR, UV, ESI-MS, EI-MS, 1D-NMR and 2D-NMR. Thirty-two compounds were identified from Excoecaria agallocha L. that included one triterpenoid reported in nature for the first time and 15 compounds isolated from Excoecaria agallocha L. for the first time.Chemical investigation of Sonneratia caseolaris L. obtained 30 compounds. Twenty-seven constituents including one new steroid were elucidated. Besides we reported the 13C-NMR data of one triterpenoid firstly. It was also the first report about the chemical constituents of Sonneratia caseolaris L.The crude extracts of Excoecaria agallocha L. and Sonneratia caseolaris L. along with parts of isolated pure compounds were screened for anti-hepatoma cell cytotoxic activity. And compound S22 showed significant activity in vitro against SMMC-7721 human hepatoma cell whose IC50 was 2.8μg/mL. However the crude extracts of Excoecaria agallocha L. and Sonneratia caseolaris L., and part of other compounds only showed weak activity. The IC50 of positive controlled sample (mitomycin C) was 1.1μg/mL.The antibacterial activities of some isolated compounds were studied. However the screened compounds showed little antibacterial activities against the tested bacterial strains.Composition and seasonal variation of the volatile constituents from mangrove plant Excoecaria agallocha L. were investigated firstly by extracted through hydro-distillation and identified by means of capillary gas chromatography combined gas chromatography-mass spectrometry (GC-MS). GC-MS results indicated that fatty acids, diterpenoids and sesquiterpenoids were main components in volatile constituents of Excoecaria agallocha L. of different seasons and the volatile constituents displayed significant seasonal variation.