A new dihydroxanthenone from a plant-associated strain of the fungus Chaetomium globosum demonstrates anticancer activity.
Bioassay-guided fractionation of a cytotoxic EtOAc extract of the fungal strain, Chaetomium globosum, inhabiting the rhizosphere of the Christmas cactus, Opuntia leptocaulis, of the Sonoran desert afforded a new dihydroxanthenone, globosuxanthone A (1), a new tetrahydroxanthenone, globosuxanthone B (2), two new xanthones, globosuxanthone C (3) and D (4), 2-hydroxyvertixanthone (5), and two known anthraquinones (6 and 7). The structures of the new compounds 1-4 were elucidated by NMR and MS techniques, and the relative stereochemistry of 1 was determined by X-ray crystallographic analysis. Of the compounds encountered, 1 was found to exhibit strong cytotoxicity against a panel of seven human solid tumor cell lines, disrupt the cell cycle leading to the accumulation of cells in either G2/M or S phase, and induce classic signs of apoptosis.
Wijeratne
E M Kithsiri
EM
Southwest Center for Natural Products Research and Commercialization, Office of Arid Lands Studies, College of Agriculture and Life Sciences, The University of Arizona, 250 E. Valencia Road, Tucson, AZ 85706-6800, USA.
Turbyville
Thomas J
TJ
Fritz
Anne
A
Whitesell
Luke
L
Gunatilaka
A A Leslie
AA
D000880:Anthraquinones; D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D002597:Chaetomium / Q000737:chemistry*; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D015394:Molecular Structure; D013237:Stereoisomerism; D014966:Xanthenes / Q000302:isolation & purification / Q000494:pharmacology*
D000880:Anthraquinones; D000970:Antineoplastic Agents; D014966:Xanthenes