DNA-Damaging Steroidal Alkaloids from Eclipta alba from the Suriname Rainforest

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.

Evaluation of hydro-alcoholic extract of Eclipta alba for its anticancer potential: An in vitro study

“…Abdel-Kader et al (1998) have reported some of the DNA damaging steroidal alkaloids from Eclipta alba. These results further establish the DNA damaging properties of this plant extract in cancerous cells.…”

Synthesis and Antifungal Activity of Natural Product-Based 6-Alkyl-2,3,4,5-tetrahydropyridines

“…12 The analog 25 β -hydroxyverazine isolated from S. surinamense also showed potent antifungal activities and low cytotoxicities. 13 Assuming the antifungal activities of these steroidal alkaloids were associated with their heterocyclic ring, simple 6-alkyl-2,3,4,5-tetrahydropyridine derivatives with the alkyl length up to nine carbons as well as 6-phenyl-2,3,4,5-tetrahydropyridine and 6-(4-chlorophenyl)-2,3,4,5-tetrahydropyridine were synthesized for structure–activity relationship (SAR) studies. However, these compounds failed to exhibit antifungal activity.…”

Potential of Steroidal Alkaloids in Cancer: Perspective Insight Into Structure–Activity Relationships

“…Abdel-Kader et al. compared 25 β -hydroxyverazine (107) with verazine (105), concluding that the introduction of the hydroxy group at C-25 reduced the cytotoxic activity against the M-109 cell line ( 35 ).…”