Identification of four ene reductases and their preliminary exploration in the asymmetric synthesis of (R)-dihydrocarvone and (R)-profen derivatives

Structural and functional characterization of a new thermophilic-like OYE from Aspergillus flavus

Old yellow enzymes (OYEs) have been proven as powerful biocatalysts for the asymmetric reduction of activated alkenes. Fungi appear to be valuable sources of OYEs, but most of the fungal OYEs are unexplored. To expand the OYEs toolbox, a new thermophilic-like OYE (AfOYE1) was identified from Aspergillus flavus strain NRRL3357. The thermal stability analysis showed that the T1/2 of AfOYE1 was 60 °C, and it had the optimal temperature at 45 °C. Moreover, AfOYE1 exhibited high reduction activity in a wide pH range (pH 5.5-8.0). AfOYE1 could accept cyclic enones, acrylamide, nitroalkenes, and α, β-unsaturated aldehydes as substrates and had excellent enantioselectivity toward prochiral alkenes (> 99% ee). Interestingly, an unexpected (S)-stereoselectivity bioreduction toward 2-methylcyclohexenone was observed. The further crystal structure of AfOYE1 revealed that the "cap" region from Ala132 to Thr182, the loop of Ser316 to Gly325, α short helix of Arg371 to Gln375, and the C-terminal "finger" structure endow the catalytic cavity of AfOYE1 quite deep and narrow, and flavin mononucleotide (FMN) heavily buried at the bottom of the active site tunnel. Furthermore, the catalytic mechanism of AfOYE1 was also investigated, and the results confirmed that the residues His211, His214, and Tyr216 compose its catalytic triad. This newly identified thermophilic-like OYE would thus be valuable for asymmetric alkene hydrogenation in industrial processes. KEY POINTS: A new thermophilic-like OYE AfOYE1 was identified from Aspergillus flavus, and the T1/2 of AfOYE1 was 60 °C AfOYE1 catalyzed the reduction of 2-methylcyclohexenone with (S)-stereoselectivity The crystal structure of AfOYE1 was revealedv.

Bio-oriented synthesis of ibuprofen derivatives for enhancement efficacy in post-operative and chronic inflammatory pain models

The discovery of post-operative, chronic inflammatory pain and any gastroulcerogenic potential using well-established animal models in vivo with new structures, high efficiency, broad-spectrum, and low toxicity has been the focus of medicinal chemists. In the present article, we are reporting the design and synthesis of various derivatives of ibuprofen by modifying the carboxyl group of ibuprofen using three steps reactions; esterification under microwave-irradiation in 10 minutes, hydrazide formation, and finally schiff's base reaction. Microwave-assisted esterification reaction can be employed to quickly explore and increase molecular diversity in synthetic chemistry. All of the newly synthesized compounds (NS1-NS4) were characterized by ¹H-, ¹³C-NMR, and HR-ESI-MS spectroscopy and evaluated for post-operative, chronic inflammatory pain and any gastroulcerogenic potential using well-established animal models in vivo. The synthesized compounds at the tested doses of 100 and 150 mg kg^-1 significantly attenuated the incisional-injury induced post-operative pain like condition and, also inhibited the phologistic agent induced inflammatory responses in both the acute and chronic testing paradigms. The gastric histological and biochemical parameters exhibited that the synthesized compounds were devoid of any ulcerogenic potential in comparison to aspirin and ibuprofen. These findings concluded that the synthesized ibuprofen derivatives exhibited profound analgesic, anti-inflammatory properties with reduced ulcerogenic potential and might be considered as effective therapeutic agents to treat pathological conditions associated with pain and inflammation.