In vivo functional analysis of the cotton bollworm Helicoverpa armigera 24-dehydrocholesterol reductase (HaDHCR24) in phytosterol metabolism.

Insects have to obtain sterols from food due to the inability to synthesize this essential nutrient de novo. For lepidopteran insects, they can convert a variety of phytosterols into cholesterol to meet their growth needs. The final step of the cholesterol biosynthesis is the metabolism of desmosterol catalyzed by 24-dehydrocholesterol reductase (DHCR24).

Comparative study of the interaction mechanism of astilbin, isoastilbin, and neoastilbin with CYP3A4.

The interactions of human CYP3A4 with three selected isomer flavonoids, such as astilbin, isoastilbin and neoastilbin, were clarified using spectral analysis, molecular docking, and molecular dynamics simulation. During binding with the three flavonoids, the intrinsic fluorescence of CYP3A4 was statically quenched in static mode with nonradiative energy conversion. The fluorescence and ultraviolet/visible (UV/vis) data revealed that the three flavonoids had a moderate and stronger binding affinity with CYP3A4 due to the order of the K and K values ranging from 10 to 10  L·mol .

Formal [4+1] Annulation of Azoalkenes with CF-Imidoyl Sulfoxonium Ylides and Dual Double Bond Isomerization Cascade: Synthesis of Trifluoromethyl-Containing Pyrazole Derivatives.

A straightforward strategy for the metal-free construction of trifluoromethyl-containing pyrazole derivatives has been achieved from readily available α-halo hydrazones and CF-imidoyl sulfoxonium ylides. The cascade transformation proceeds through the formal [4+1] cycloaddition followed by an unexpected dual double bond isomerization. The protocol features mild conditions, easy operation, excellent substrate compatibility, and good regioselectivity.

Silver-Mediated [3 + 2] Cycloaddition of Azomethine Ylides with Trifluoroacetimidoyl Chlorides for the Synthesis of 5-(Trifluoromethyl)imidazoles.

A silver-mediated [3 + 2] cycloaddition of azomethine ylides with trifluoroacetimidoyl chlorides for the rapid assembly of 5-(trifluoromethyl)imidazoles has been developed. Notable features of the reaction include readily accessible reagents, a broad substrate scope, and high efficiency. The protocol can be successfully applied to construct the analogue of the specific allosteric modulator of GABA receptors.