Antiarol cinnamate and africanoside, a cinnamoyl triterpene and a hydroperoxy-cardenolide from the stem bark of Antiaris africana.
From the methanol extract of the stem bark of the African tree Antiaris africana Engler, two new bioactive metabolites were isolated, namely, the α-amyrin derivative 1β,11α-dihydroxy-3β-cinnamoyl-α-amyrin (antiarol cinnamate, 1) and a cardiac glycoside, 3β-O-(α-L-rhamnopyranosyl)-14β-hydroperoxy-5β-hydroxy-19-oxo-17β-card-20(22)-enolide (africanoside, 2a), together with the known compounds β-amyrin and its acetate, β-sitosterol and its 3-O-β-D-glucopyranoside, friedelin, ursolic and oleanolic acid, 19-norperiplogenin, strophanthidol, strophanthidinic acid, periplogenin (3a), 3-epiperiplogenin, strophanthidin (3b) and 3,3'-dimethoxy-4'-O-β-D-xylopyronosyl-ellagic acid. Their structures were established on the basis of their spectroscopic data and by chemical methods, while 3a was additionally confirmed by X-ray crystal structure analysis. The aglycone moiety possessing a hydroperoxy group was found for the first time in cardenolides. Compounds 1 and 2a showed no activity against bacteria, fungi, and microalgae; however, the crude extract exhibited a high toxicity against Artemia salina and a selective antitumor activity against human tumor cell lines. Africanoside (2a) effected a concentration-dependent inhibition of tumor cell growth with a mean IC(50) value of 5.3 nM.
Department of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany.
Bertin
B
Vouffo
Etienne
E
Dongo
Petrea
P
Facey
Andrea
A
Thorn
George
G
Sheldrick
Armin
A
Maier
Heinz Herbert
HH
Fiebig
Hartmut
H
Laatsch
D000818:Animals; D031621:Antiaris / Q000737:chemistry*; D001156:Artemia / Q000187:drug effects; D002301:Cardiac Glycosides / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002934:Cinnamates / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D054697:Cytostatic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D006801:Humans; D008826:Microbial Sensitivity Tests; D019906:Nuclear Magnetic Resonance, Biomolecular; D053978:Pentacyclic Triterpenes; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018547:Plant Stems / Q000737:chemistry; D014315:Triterpenes / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
C557340:11alpha-dihydroxy-3beta-cinnamoyl-alpha-amyrin; C557339:3beta-O-(alpha-L-rhamnopyranosyl)-14beta-hydroperoxy-5beta-hydroxy-19-oxo-17beta-card-20(22)-enolide; D002301:Cardiac Glycosides; D002934:Cinnamates; D054697:Cytostatic Agents; D053978:Pentacyclic Triterpenes; D010936:Plant Extracts; D014315:Triterpenes