Three series of isomeric pyrrolo-and furo-fused 7deazapurine ribonucleosides were synthesized and screened for cytostatic and antiviral activity. The synthesis was based on heterocyclizations of hetaryl-azidopyrimidines to form the tricyclic heterocyclic bases, followed by glycosylation and final derivatizations through cross-coupling reactions or nucleophilic substitutions. The pyrrolo[2′,3′:4,5]pyrrolo[2,3-d]pyrimidine and furo[2′,3′:4,5]pyrrolo-[2,3-d]pyrimidine ribonucleosides were found to be potent cytostatics, whereas the isomeric pyrrolo[3′,2′,4,5]pyrrolo[2,3-d]pyrimidine nucleosides were inactive. The most active were the methyl, methoxy, and methylsulfanyl derivatives exerting submicromolar cytostatic effects and good selectivity toward cancer cells. We have shown that the nucleosides are activated by intracellular phosphorylation and the nucleotides get incorporated to both RNA and DNA, where they cause DNA damage. They represent a new type of promising candidates for preclinical development toward antitumor agents.

A general and modular synthesis of substituted benzene and pyridine 2′‐C‐methyl‐C‐ribonucleosides was developed. Benzyl‐protected haloaryl‐C‐nucleoside intermediates were prepared by the addition of bromo(het)aryllithium reagents to a protected lactone, followed by acetylation and reduction. These halogenated intermediates were further transformed by Pd‐catalysed cross‐couplings, aminations, or hydroxylations. The final deprotection was rather troublesome, and different procedures involving catalytic hydrogenation on Pd/C, or treatment with BCl3, were optimized for each derivative. The final C‐nucleosides were also all converted into the corresponding NTPs. None of the C‐nucleosides showed any activity in the HCV replicon assay, and none of the NTPs showed any significant inhibition of the HCV polymerase.

A novel concept of nonhydrolytic enzyme sensing based on aggregation-induced emission is described. As a proof of principle, fluorogenic probes for methionine sulfoxide reductases have been developed. Changes in the polarity and electronic nature upon reduction of sulfoxide to sulfide are translated to the aggregation potential of the probe. The new probes enable sensitive and highly spatially resolved imaging of the enzymatic activity.

In the Acknowledgments, the last line of column 1 should be "the Czech Science Foundation (16-00178S to A.T. and M. Hocek)" instead of "the Czech Science Foundation (16-001785 to A.T. and M. Hocek)".