Coumarin-based fluorogenic probes for no-wash protein labeling.

A fluorescent protein-labeling strategy was developed in which a protein of interest (POI) is genetically tagged with a short peptide sequence presenting two Cys residues that can selectively react with synthetic fluorogenic reagents. These fluorogens comprise a fluorophore and two maleimide groups that quench fluorescence until they both undergo thiol addition during the labeling reaction. Novel fluorogens were prepared and kinetically characterized to demonstrate the importance of a methoxy substituent on the maleimide in suppressing reactivity with glutathione, an intracellular thiol, while maintaining reactivity with the dithiol tag. This system allows the rapid and specific labeling of intracellular POIs.

A natural product inspired tetrahydropyran collection yields mitosis modulators that synergistically target CSE1L and tubulin.

A Prins cyclization between a polymer-bound aldehyde and a homoallylic alcohol served as the key step in the synthesis of tetrahydropyran derivatives. A phenotypic screen led to the identification of compounds that inhibit mitosis (as seen by the accumulation of round cells with condensed DNA and membrane blebs). These compounds were termed tubulexins as they target the CSE1L protein and the vinca alkaloid binding site of tubulin.

Charting, navigating, and populating natural product chemical space for drug discovery.

Natural products are a heterogeneous group of compounds with diverse, yet particular molecular properties compared to synthetic compounds and drugs. All relevant analyses show that natural products indeed occupy parts of chemical space not explored by available screening collections while at the same time largely adhering to the rule-of-five. This renders them a valuable, unique, and necessary component of screening libraries used in drug discovery. With ChemGPS-NP on the Web and Scaffold Hunter two tools are available to the scientific community to guide exploration of biologically relevant NP chemical space in a focused and targeted fashion with a view to guide novel synthesis approaches. Several of the examples given illustrate the possibility of bridging the gap between computational methods and compound library synthesis and the possibility of integrating cheminformatics and chemical space analyses with synthetic chemistry and biochemistry to successfully explore chemical space for the identification of novel small molecule modulators of protein function.The examples also illustrate the synergistic potential of the chemical space concept and modern chemical synthesis for biomedical research and drug discovery. Chemical space analysis can map under explored biologically relevant parts of chemical space and identify the structure types occupying these parts. Modern synthetic methodology can then be applied to efficiently fill this "virtual space" with real compounds.From a cheminformatics perspective, there is a clear demand for open-source and easy to use tools that can be readily applied by educated nonspecialist chemists and biologists in their daily research. This will include further development of Scaffold Hunter, ChemGPS-NP, and related approaches on the Web. Such a "cheminformatics toolbox" would enable chemists and biologists to mine their own data in an intuitive and highly interactive process and without the need for specialized computer science and cheminformatics expertise. We anticipate that it may be a viable, if not necessary, step for research initiatives based on large high-throughput screening campaigns,in particular in the pharmaceutical industry, to make the most out of the recent advances in computational tools in order to leverage and take full advantage of the large data sets generated and available in house. There are "holes" in these data sets that can and should be identified and explored by chemistry and biology.

Practical and efficient multigram preparation of a camphor-derived diol for the enantioselective Lewis acid catalyzed allylboration of aldehydes.

[reaction: see text] Chiral diols are important molecules with widespread use as chiral auxiliaries and ligands in enantioselective synthesis. Therefore, efficient and practical syntheses of highly dissymmetrical nonracemic diols are still a meaningful pursuit. Two new routes to access camphor-derived chiral diol 1 have been developed. One route employs camphorquinone (3) as the starting material, affording in only two steps the desired diol in 55% overall yield. The second route, from camphor (2), leads to the desired diol in an efficient four-step synthesis, with an overall yield of 55%.

Design and synthesis of a potent macrocyclic 1,6-naphthyridine anti-human cytomegalovirus (HCMV) inhibitors.

A novel class of macrocyclic 1,6-napthyridines designed to adopt the presumed bioactive conformation of anti-HCMV acyclic 1,6-napthyridines are described. Both 14- and 15-membered macrocycles were shown to be highly potent against HCMV HSV-1 and HSV-2.

Scandium-catalyzed allylboration of aldehydes as a practical method for highly diastereo- and enantioselective construction of homoallylic alcohols.

A general approach for the allylation of aldehydes using stable, air-tolerant camphor-based chiral allylboronates under Sc(OTf)3 catalysis is described. This practical methodology provides both syn and anti propionate units and other homoallylic alcohols with very high levels of diastereo- and enantioselectivity for several substrates, including functionalized aliphatic aldehydes useful toward the elaboration of complex natural products.