Seven undescribed guaiane-type sesquiterpenoids named biscogniauxiaols A-G (-) were isolated from the endophytic fungus on Their structures were determined by extensive spectroscopic analyses, electronic circular dichroism (EC) and specific rotation (SR) calculations. Compound represented a new family of guaiane-type sesquiterpenoids featuring an unprecedented [5/6/6/7] tetracyclic system. A plausible biosynthetic pathway for compounds - was proposed.
View Article and Find Full Text PDFInduced water hyacinth with purple roots (PRWH) exerts a significant inhibitory effect on the growth of blue-green algae. Interestingly, its chemical constituents differ from those of wild-type water hyacinth and have not yet been reported. This study aimed to explore the chemical constituents of PRWH and its bioactive components serving as allelopathic agents against blue-green algae.
View Article and Find Full Text PDFTwo new pyrazinoquinazoline alkaloids, epi-fiscalin D (1) and epi-fiscalin E (2), as well as three known analogues, norquinadoline A (3), quinadoline A (4), and fiscalin C (5), were isolated from ethyl acetate extract of the fermentation broth of Stentrophomonas maltophilia QB-77. The structures of new compounds were elucidated on the basis of extensive spectroscopic data analysis including UV, HRESIMS, and 1D and 2D NMR experiments. All the isolated compounds were tested for their in vitro cytotoxicity against five human cancer cell lines (SMMC-7721, MCF-7, HL-60, SW480, and A-549) and antibacterial activities against Bacillus subtilis, Escherichia coli, and Staphylococcus aureus.
View Article and Find Full Text PDFChemical investigation on the aqueous fraction of the stems of Epigynum cochinchinensis led to the isolation of a new pregnane glycoside named as epigycoside A (1) along with three known analogues (2-4). The structure of compound 1 was elucidated by means of spectroscopic techniques, including HRESIMS, and 1D and 2D NMR experiments. The immunosuppressive activity of 1 was evaluated by an in vitro model of concanavalin A-induced mice splenocytes proliferation.
View Article and Find Full Text PDFSeven new clerodane diterpenoids, dysoxydensins A-G (1-7), together with six known clerodanes, were isolated from Dysoxylum densiflorum. The structures of all the compounds were elucidated by extensive spectroscopic analysis. These compounds were evaluated for their cytotoxic activities against five human cancer cell lines, and compounds 2, 3, and 5 showed moderate cytotoxic activities.
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