D. Sloman, Branko Mitasev, S. S. Scully
Mar 7, 2011
Citations
0
Influential Citations
44
Citations
Journal
Angewandte Chemie
Abstract
The kibdelones A-C (1-3) and their isomeric metabolites (cf. isokibdelone C 4) are hexacyclic tetrahydroxanthone natural products recently isolated by Capon and coworkers from the rare Australian actinomycete Kibdelosporangium sp. (Figure 1).[1] An interesting property is the facile equilibration of kibdelones B 2, and C 3 to a mixture of 1-3via keto/enol tautomerizations followed by quinone/hydroquinone redox reactions.[1] Related natural products include simaomicin α 5 which has been shown to sensitize cancer cells to cytotoxic agents including bleomycin at nanomolar concentrations and to exhibit potent antimalarial and anticoccidial activities. [2] Evaluation of the kibdelones in the NCI 60-cell panel of human cancer cell lines revealed that they are active at low nanomolar concentrations against a number of human tumor cell lines. For example, kibdelone A has a GI50 of 1.2 nm against a SR (leukemia) tumor cell line and <1 nm (GI50) against SN12C (renal) cell carcinoma.[1] In addition, the kibdelones were shown to display novel COMPARE analysis profiles for cancer cell growth inhibition.