Abstract
Bioassay-guided fractionation of the root and stem extracts of Mendoncia cowanii led to the isolation of two new and two known naphthoquinones. The structures of the new compounds, avicequinones D and E (1 and 2 ), were determined using 1D and 2D NMR spectroscopy and by chemical conversion of compound 1 to 2 . The new compounds were active in the A2780 human ovarian cancer cell line with IC50 values of 7.4 - 50 μM, respectively, and 1 , 3 , and 4 were subsequently found to be weakly active in an assay for inhibition of the kinase Akt.
References
1 Biodiversity, conservation and drug discovery in Madagascar. Part 19, this manuscript. For part 18. Cao S, Radwan MM, Norris A, Miller JS, Ratovoson F, Mamisoa A et al Cytotoxic and other compounds from Didymochlaena truncatula from the Madagascar rain forest . J Nat Prod 2006 69: 284-6
2 Missouri Botanical Garden. Available at http://mobot.mobot.org/cgi-bin/search_vast?ssdp = 01 885 737. Accessed in 2005.
3
Ito C, Katsuno S, Kondo Y, Tan H T-W, Furukawa H.
Chemical constituents of Avicennia alba . Isolation and structural elucidation of new naphthaquinones and their analogs.
Chem Pharm Bull.
2000;
48
339-43
4
Mock J, Murphy S T, Ritchie E, Taylor W C.
Chemical studies of the Proteateae VI. Two naphthaquinones from Stenocarpus salignus
.
Aust J Chem.
1973;
26
1121-30
5 Thomson R H. Naturally occurring quinones. 2nd edition New York; Academic Press 1971: p 49-57
6
Zhou H, Li X -M, Meinkoth J, Pittman R N.
Akt regulates cell survival and apoptosis at a postmitochondrial level.
J Cell Biol.
2000;
151
483-94
7
Datta S R, Brunet A, Greenberg M E.
Cellular survival: a play in three Akts.
Genes Dev.
1999;
13
2905-27
8
Cardone M H, Roy N, Stennicke H R, Salvesen G S, Franke T F, Stanbridge E. et al .
Regulation of cell death protease caspase-9 by phosphorylation.
Science.
1998;
282
1318-21
9
Tran H, Brunet A, Grenier J M, Datta S R, Fornace Jr. A J, DiStefano P S. et al .
DNA repair pathway stimulated by the forkhead transcription factor FOXO3a through the Gadd45 protein.
Science.
2002;
296
530-4
10
Brunet A, Bonni A, Zigmond M J, Lin M Z, Juo P, Hu L S. et al .
Akt promotes cell survival by phosphorylating and inhibiting a forkhead transcription factor.
Cell.
1999;
96
857-68
11
Williams R B, Norris A, Slebodnick C, Merola J, Miller J S, Andriantsiferana R. et al .
Cytotoxic sesquiterpene lactones from Vernonia pachyclada from the Madagascar rainforest.
J Nat Prod.
2005;
68
1371-4
12 Ferreira V F, Pinto A V, Pinto M CFR, Silva M M. Selective reduction in pyranonaphthoquinone systems. J Chem Res Synop 1987: 26
13
Louie K G, Behrens B C, Kinsella T J, Hamilton T C, Grotzinger K R, McKoy W M. et al .
Radiation survival parameters of antineoplastic drug-sensitive and -resistant human ovarian cancer cell lines and their modification by buthionine sulfoximine.
Cancer Res.
1985;
45
2110-5
Prof. Dr. David G. I. Kingston
Department of Chemistry
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