1. DNA-damaging steroidal alkaloids from Eclipta alba from the suriname rainforest1.
- Author
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Abdel-Kader MS, Bahler BD, Malone S, Werkhoven MC, van Troon F, David, Wisse JH, Bursuker I, Neddermann KM, Mamber SW, and Kingston DG
- Subjects
- Alkaloids isolation & purification, Candida albicans drug effects, Cell Line, India, Magnetic Resonance Spectroscopy, Phytosterols isolation & purification, Saccharomyces cerevisiae drug effects, Suriname, Alkaloids pharmacology, Asteraceae chemistry, DNA drug effects, DNA Damage, Phytosterols pharmacology, Plants, Medicinal chemistry
- Abstract
Bioassay-guided fractionation of the MeOH extract of Eclipta alba using three yeast strains (1138, 1140, and 1353) resulted in the isolation of eight bioactive steroidal alkaloids (1-8), six of which are reported for the first time from nature. The major alkaloid was identified as (20S)(25S)-22,26-imino-cholesta-5,22(N)-dien-3beta-ol (verazine, 3), while the new alkaloids were identified as 20-epi-3-dehydroxy-3-oxo-5,6-dihydro-4,5-dehydroverazine (1), ecliptalbine [(20R)-20-pyridyl-cholesta-5-ene-3beta,23-diol] (4), (20R)-4beta-hydroxyverazine (5), 4beta-hydroxyverazine (6), (20R)-25beta-hydroxyverazine (7), and 25beta-hydroxyverazine (8). Ecliptalbine (4), in which the 22,26-imino ring of verazine was replaced by a 3-hydroxypyridine moiety, had comparable bioactivity to verazine in these assays, while a second alkaloid (8) showed good activity against Candida albicans. All the alkaloids showed weak cytotoxicity against the M-109 cell line.
- Published
- 1998
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