Studies On The Anti-Major Pathogenic Fungal Chemical Constituents From Five Marine Sponges And Three Plants

To find novel bioactive compounds and leading compounds from natural products is the main goal of natural products chemstry. To search for anti-major pathogenic fungal natural compounds, by means of bioassay guided isolation, phytochemical investigations of five marine sponges Hyrtios sp.,Igernella mirabilis,Leucetta chagosensis, Agelas sp., Polycarpa aurata,and three plants Verbesina virginica, Gaura longiflor, Tricalysia okelensis afforded twenty-nine compounds by silica gel, reversed-phase (ODS) column chromatography. The Structures of the isolated compounds were were elucidated by means of spectroscopic techniques including 1D and 2D-NMR (¹H-NMR, ¹³C-NMR, ¹H-¹H COSY, HMQC, HMBC and NOESY) as well as UV, IR , HR-ESI-MS in combination with chemical methods. Among isolated compounds, fourteen new compounds were reported and six antifungal compounds were also obtained. The results are concluded as follows:By means of bioassay guided isolation, three compounds (2-1～2-3)were isolated form marine sponges Hyrtios sp.. Among them, compound 2-1 was new compound, compound 2-2 and 2-3 showed antifungal activity.By means of bioassay guided isolation, four antifungal compounds (3-1～3-4)were isolated form marine sponges Igernella mirabilis,Leucetta chagosensis, Agelas sp., Polycarpa aurata. Compound 3-3, Agelasine-D inhibited strongly the growth of C. neoformans ATCC 90113 their IC50 / MIC were 0.76/1.25 ug / mL .Phytochemical investigation of the leaves and flowers of native American plant Verbesina virginica afforded nine compounds(4-1～4-9), including eight new compounds (4-2～4-9)and two antimicrobial compounds(4-1～4-2). Compounds (4-4～4-9) were named as Verbesinosides A-F. These six new 15,27-cyclooleanane-type triterpenoid saponins carried different aromatic acyl moieties on the aglycon, This is the first report of triterpenoid saponins possessing the unique 15,27-cyclooleanane skeleton.Phytochemical investigation of the native American plant Gaura longiflora led to the isolation of three new(5-1～5-3) and eight known (5-4～5-11) flavonol glycosides. It is noted that SciFinder? has incorrectly assigned compound 5-2 (CA registry # 78510-18-6). Phytochemical investigation of the plant Tricalysia okelensis led to the isolation of two new ent-kaurane glycoside(s6-1～6-2). This is first report of ent-kaurane glycosides attaching sugar moiety at C-3 position from this genus.As a conclusion, the anti-major pathogenic fungal chemical constituents of five marine sponges and three plants were studied in this thesis. The present results established the basis for discovery of antifungal lead compounds and provided theoretical foundation for further utilization of the natural resources studied.