Location: Natural Products Utilization ResearchTitle: Biologically active secondary metabolites from Asphodelus microcarpus Author
Submitted to: Natural Product Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/17/2013
Publication Date: 8/8/2013
Citation: Ghoneim, M.M., Ma, G., El-Hela, A.A., Mohammad, A., Kottob, S., El-Ghaly, S., Cutler, S.J., Ross, S.A. 2013. Biologically active secondary metabolites from Asphodelus microcarpus. Natural Product Communications. 8(8):1117-1119. Interpretive Summary: The bulbs and roots of Asphodelus microcarpus are used to treat ectodermal parasites, jaundice, and psoriasis, by Bedouins as an antimicrobial agent so we tried to isolate and identify these active metabolites. This work resulted in the isolation of one new metabolite as well as nine known compounds. Three of these compounds showed good to potent activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 6.6, 9.4µg/mL and 1.4 µg/mL respectively. The result of this work could improve our goal to treat infective diseases from natural sources.
Technical Abstract: Bioassay guided fractionation of the ethanolic extract of Asphodelus microcarpus Salzm.et Vivi (Asphodelaceae) resulted in the isolation of one new metabolite, 1,6-dimethoxy-3-methyl-2-naphthoic acid (1) as well as nine known compounds: asphodelin (2), chrysophanol (3), 8-methoxychrysophanol (4), emodin (5), 2-acetyl-1,8-dimethoxy-3-methylnaphthalene (6), 10-(chrysophanol-7'-yl)-10-hydroxychrysophanol-9-anthrone (7), aloesaponol-III-8-methyl ether (8), ramosin (9) and aestivin (10). The compounds were identified by 1D and 2D NMR and HRESIMS. Compounds 3, 6 and 10 were isolated for the first time from this species. Compounds 3 and 4 showed moderate to weak antileishmanial activity with IC50 values of 14.3 and 35.1 µg/mL, respectively. Compound 4 exhibited moderate antifungal activity against Cryptococcus neoformans with an IC50 value of 15.0 µg/mL, while compounds 5, 7 and 10 showed good to potent activity against methicillin resistant Staphylococcus aureus (MRSA) with IC50 values of 6.6, 9.4 µg/mL and 1.4 µg/mL respectively. Compounds 5, 8 and 9 displayed good activity against S. aureus with IC50 values of 3.2, 7.3 and 8.5 µg/mL, respectively. Compounds 7 and 9 exhibited a potent cytotoxic activity against leukemia LH60 and K562 cell lines. Compound 10 showed potent antimalarial activities against both chloroquine-sensitive and chloroquine-resistant strains of Plasmodium falciparum with IC50 values in the range of 0.8-0.7 µg/mL without showing any cytotoxicity to mammalian cells. Interpretive Summary: