Synthesis and Biological Activity Evaluation of 2-Cyanopyrrole Derivatives as Potential Tyrosinase Inhibitors.

In order to find potential inhibitors of tyrosinase, two series of pyrrole derivatives A (1-17) and B (1-8) were synthesized and screened for their inhibitory activities on tyrosinase. Most of the 2-cyanopyrrole derivatives exhibited effective inhibitory activities. In particular, A12 exhibited the strongest inhibitory activities, with the IC50 values of 0.97 µM, which is ∼30 times stronger than the reference inhibitor kojic acid (IC50: 28.72 µM). The inhibitory mechanism analysis results revealed that A12 was a reversible and mixed-type inhibitor. Molecular docking experiments clarified the interaction between A12 with tyrosinase. Furthermore, A12 (100 µM) presented effective inhibitory effect on tyrosinase in B16 melanoma cells with inhibition of 33.48%, which was equivalent to that of Kojic acid (39.81%). Accordingly, compound A12 may serve as the lead structure for the further design of potent tyrosinase inhibitors. Molecular docking studies confirmed the interaction between the compound and tyrosinase.

Total Synthesis of (±)-Furanether A.

The first total synthesis of (±)-furanether A, which exhibits good antifeedant activity, has been concisely achieved in 13 linear steps. Notably, the key rigid tetracyclic skeleton containing a 1-methyl-8-oxabicyclo[3.2.1]octane moiety with two vicinal quaternary carbon centers was rapidly constructed in one step through a unique tandem C-H oxidation/oxa-[3,3] Cope rearrangement/aldol cyclization sequence.

Direct synthesis of 2-substituted benzonitriles via alkylcyanation of arynes with N,N-disubstituted aminomalononitriles.

An efficient alkylcyanation of in situ generated arynes by N,N-disubstituted aminomalononitriles is described, enabling the direct synthesis of 2-substituted benzonitriles.