No abstract

Macrolones are a novel class of potent antimicrobial agents that consist of a macrolide scaffold to which a quinolone unit is tethered by various linkers to the 4′′-O-position of the cladinose sugar. In this paper is described a modified 13-step route to a lead compound in the series. Critical reaction steps in the medicinal chemistry route were modified for an initial scale-up process, and as a result, a synthetic procedure suitable for preparation of multihundred gram quantities of the final product, with 98% purity, has been developed. The new procedure does not require any purification by column chromatography for any of the reaction steps. The overall yield was increased from 5−8% in the medicinal chemistry route to 27% in the improved procedure.

Selective oxidation of diethylene glycol by a ruthenium(VIII) species, obtained in situ from ruthenium(III) chloridesodium periodate in the presence of a catalytic quantity of water, affords a monoaldehyde in the form of the internal acetal 2-hydroxy-1,4-dioxane. This compound was used in reductive alkylations of selected primary and secondary amines, demonstrating its utility in the preparation of target structures with the 2-(2-hydroxyethoxy)ethylamino unit.

No abstract

The process of identifying the protein targets and off-targets of a biologically active compound is of great importance in modern drug discovery. Various chemical proteomics approaches have been established for this purpose. To compare the different approaches, and to understand which method would provide the best results, we have chosen the EGFR inhibitor lapatinib as an example molecule. Lapatinib derivatives were designed using linkers with motifs, including amino (amidation), alkyne (click chemistry) and the diazirine group (photo-affinity). These modified lapatinib analogues were validated for their ability to inhibit EGFR activity in vitro and were shown to pull down purified recombinant EGFR protein. In all of the approaches evaluated here, we identified EGFR as the main protein target from the lysate of immortalised cell line expressing EGFR, thus validating its potential use to identify unknown protein targets. Taken together, the results reported here give insight into the cellular activities of lapatinib.