Ji Li

Academic misconduct poses a severe threat to scientific integrity and medical ethics. While gender disparities in misconduct are widely documented, the und

Ent-abietane diterpenoids constitute a class of terpenes with a C₂₀ carbon skeleton that underlie a wide range of biological activities. Ent-abietane diterpenoids, enantiomeric to the abietane counterparts, represent a family of diterpenoid natural products characterized by their distinct 6/6/6 tricyclic carbocyclic skeletons with exceptional structural complexity. An increasing number of these ent-abietane diterpenoids have recently been identified, constituting a well-defined group of naturally occurring compounds. This review provides a comprehensive summary of the natural sources, chemical structures, biological profiles and total synthesis of these ent-abietane diterpenoids from 2016 to early 2025.

A simple, rapid and sensitive chiral capillary zone electrophoresis coupled with acetonitrile-field-amplified sample stacking method was developed that allows the simultaneous enantioselective separation of the mirtazapine, N-demethylmirtazapine, 8-hydroxymirtazapine and mirtazapine-N-oxide. The separation was achieved on an uncoated 40.2 cm × 75 μM fused silica capillary with an applied voltage of 16 kV. The electrophoretic analyses were carried out in 6.25 mM borate–25 mM phosphate solution at pH 2.8 containing 5.5 mg/mL carboxymethyl-β-cyclodextrin. The detection wavelength was 200 nm. Under these optimized conditions, satisfactory chiral separations of four pair enantiomers were achieved in less than 7 min in vitro. After one step clean-up liquid-liquid extraction using 96-well format, sample was introduced capillary zone electrophoresis with acetonitrile-field-amplified sample stacking to enhance the sensitivity of enantiomers. The method was validated with respect to specificity, linearity, lower limit of quantitation, accuracy, precision, extraction recovery and stability. The lower limit of quantification was 0.5 ng/mL with linear response over the 0.5–50 ng/mL concentration range for each mirtazapine, N-demethylmirtazapine and 8-hydroxymirtazapine enantiomer. The developed and validated method has been successfully applied to the enantioselective pharmacokinetic studies in 12 healthy volunteers after oral administration of rac- mirtazapine.