Showing papers on "Indole alkaloid published in 1997"
TL;DR: Methanol extracts of root barks of Alstonia macrophylla, A. glaucescens, and A. scholaris have been assessed for cytotoxic activity against two human lung cancer cell lines, MOR-P (adenocarcinoma) and COR-L23 (large cell carcinoma), using the SRB assay.
Abstract: Methanol extracts of root barks of Alstonia macrophylla, A. glaucescens, and A. scholaris, collected from Thailand, have been assessed for cytotoxic activity against two human lung cancer cell lines, MOR-P (adenocarcinoma) and COR-L23 (large cell carcinoma), using the SRB assay. Significant cytotoxic activity was exhibited by the extract of A. macrophylla on both cell lines. Activity-directed fractionation led to the isolation of a novel indole alkaloid, O-methylmacralstonine, from the most active fraction of A. macrophylla along with four known alkaloids, talcarpine, villalstonine, pleiocarpamine, and macralstonine. Structure elucidation of the novel alkaloid was based on spectroscopic methods, especially 2D-NMR. The bisindole villalstonine was found to possess pronounced activity on both cell lines with an IC50 value less than 5 muM, but was about 10(3) times less potent than vinblastine sulphate. The monomeric alkaloid, talcarpine, was found to be inactive. Pleiocarpamine, O-methylmacralstonine and macralstonine were all considerably less active than villalstonine.
91 citations
TL;DR: An indole alkaloid, hirsutine (1), was found to exhibit potent inhibitory effect against influenza A virus in vitro, and the essential structural feature for revealing the activity was elucidated by study of the structure-activity relationship using natural and synthetic derivatives of 1 as mentioned in this paper.
39 citations
TL;DR: A new cytotoxic indole alkaloid containing an isonitrile group, brasilidine A (1), has been isolated from the actinomycete Nocardia brasiliensis IFM 0089 and the structure elucidated on the basis of its spectroscopic data.
Abstract: A new cytotoxic indole alkaloid containing an isonitrile group, brasilidine A (1), has been isolated from the actinomycete Nocardia brasiliensis IFM 0089 and the structure elucidated on the basis of its spectroscopic data
35 citations
TL;DR: A binding study of 1, 4b, and 5 on various receptors and ionic channels showed that none of the compounds had a strong affinity for the receptors tested.
Abstract: The natural indole alkaloid (-)-tabersonine (1) easily provided (-)-decahydrotabersonine (4a), isolated as dihydrochloride (4b), by catalytic hydrogenation. Saponification of 4a led to the beta-amino acid 5. A binding study of 1, 4b, and 5 on various receptors and ionic channels showed that none of the compounds had a strong affinity for the receptors tested.
3 citations