Abstract
Fractionation of EtOAc and aqueous MeOH extracts of Ajuga remota underground part has led to the isolation of four new iridoid glycosides identified as 2′,3′-diacetylharpagide (1), 6′-O-rhamnosylharpagide (2), 6′-O-galloyl-7,8-dehydroharpagide (3) and 6-O-xylosylharpagoside-B (4). Together with these were known compounds 8-O-acetylharpagide(5), harpagide (6), cyasterone (7), 20-hydroecdysone (8), sengosterone (9), 3-O- β-glucopyranosylstigmasta-5, 25-diene (10), stigmasterol (11) and ergosterol-5, 8-endoperoxide (12). Their structures were determined using spectroscopic methods as well as comparison with data from known compounds. In the in vitro larvicidal tests using 2 nd instar Aedes aegypti larvae, the EtOAc extract was found to be toxic with LC 50 of 5.30 ± 1.3 μg/mL, while the MeOH extract exhibited weak toxicity with an LC 50 value of 65.94 ± 0.4 μg/mL. Among the pure isolates tested, compound 12 associated with EtOAc extract was the active principal with LC 50 value of 4.40± 0.2.
Original language | English |
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Pages (from-to) | 147-157 |
Number of pages | 11 |
Journal | Records of Natural Products |
Volume | 5 |
Issue number | 3 |
State | Published - 2011 |
Keywords
- Ajuga remota
- Iridoid glycosides
- Larvicidal activity
- Phytoecdysteroids
- Sterol glycoside