The mitotic spindle is a microtubule-based machine that segregates a replicated set of chromosomes during cell division. Many cancer drugs alter or disrupt the microtubules that form the mitotic spindle. Microtubule-dependent molecular motors that function during mitosis are logical alternative mitotic targets for drug development. Eg5 (Kinesin-5) and Kif15 (Kinesin-12), in particular, are an attractive pair of motor proteins, as they work in concert to drive centrosome separation and promote spindle bipolarity. Furthermore, we hypothesize that the clinical failure of Eg5 inhibitors may be (in part) due to compensation by Kif15. In order to test this idea, we screened a small library of kinase inhibitors and identified GW108X, an oxindole that inhibits Kif15 in vitro. We show that GW108X has a distinct mechanism of action compared with a commercially available Kif15 inhibitor, Kif15-IN-1 and may serve as a lead with which to further develop Kif15 inhibitors as clinically relevant agents.

The total synthesis of hemiketal E (HKE) has been accomplished using a gold(I)-mediated cycloisomerization followed by oxidation of the enol ether product to introduce a unique keto-hemiketal, the core structure of HKE. Synthetic hemiketal E reproduced biosynthetically derived HKE in the inhibition of human platelet aggregation.

The lipid peroxidation product malondialdehyde and the DNA peroxidation product base-propenal react with dG to generate the exocyclic adduct, M 1 dG. This mutagenic lesion has been found in human genomic and mitochondrial DNA. M 1 dG in genomic DNA is enzymatically oxidized to 6-oxo-M 1 dG, a lesion of currently unknown mutagenic potential. Here, we report the synthesis of an oligonucleotide containing 6-oxo-M 1 dG and the results of extension experiments aimed at determining the effect of the 6-oxo-M 1 dG lesion on the activity of human polymerase iota (hPol ι). For this purpose, a liquid chromatography−tandem mass spectrometry (LC−MS/MS) assay was developed to obtain reliable quantitative data on the utilization of poorly incorporated nucleotides. Results demonstrate that hPol ι primarily incorporates deoxycytidine triphosphate (dCTP) and thymidine triphosphate (dTTP) across from 6-oxo-M 1 dG with approximately equal efficiency, whereas deoxyadenosine triphosphate (dATP) and deoxyguanosine triphosphate (dGTP) are poor substrates. Following the incorporation of a single nucleotide opposite the lesion, 6-oxo-M 1 dG blocks further replication by the enzyme.

A convergent total synthesis of the siderophore coelichelin is described. The synthetic route also provided access to acetyl coelichelin and other congeners of the parent siderophore. The synthetic products were evaluated for their ability to bind ferric iron and promote growth of a siderophore-deficient strain of the Gram-negative bacterium Pseudomonas aeruginosa under iron restriction conditions. The results of these studies indicate coelichelin and several derivatives serve as ferric iron delivery vehicles for P. aeruginosa.