Biochemical characterization and molecular docking of a novel alkaline-stable keratinase from Amycolatopsis sp. BJA-103.

Amycolatopsis sp. BJA-103 was isolated for its exceptional feather-degradation capability, leading to the purification, cloning, and heterologous expression of the keratinase enzyme, KER0199. Sequence analysis places KER0199 within the S8 protease family, revealing <60 % sequence similarity to known proteases.

Enantioselective palladium-catalyzed C(sp)-C(sp) σ bond activation of cyclopropenones by merging desymmetrization and (3 + 2) spiroannulation with cyclic 1,3-diketones.

Catalytic asymmetric variants for functional group transformations based on carbon-carbon bond activation still remain elusive. Herein we present an unprecedented palladium-catalyzed (3 + 2) spiro-annulation merging C(sp)-C(sp) σ bond activation and click desymmetrization to form synthetically versatile and value-added oxaspiro products. The operationally straightforward and enantioselective palladium-catalyzed atom-economic annulation process exploits a TADDOL-derived bulky P-ligand bearing a large cavity to control enantioselective spiro-annulation that converts cyclopropenones and cyclic 1,3-diketones into chiral oxaspiro cyclopentenone-lactone scaffolds with good diastereo- and enantio-selectivity.

Universal adaptive control for a class of nonlinear time-varying delay systems with unknown output function.

This paper considers the stabilization problem for a class of nonlinear time-varying delay systems with unknown homogeneous growth rates and unknown output function. By introducing the dynamic gain into the system, an adaptive observer is designed. Then, combined with the Lyapunov-Krasovskii functional, an adaptive controller is proposed to guarantee the global stabilization of the closed-loop system.