Objective:To develop a catalytic system for the asymmetric Morita-Baylis-Hillman ( MBH) reaction of conjugated ni-troalkene with activated aldehyde, and screen out the chiral catalysts with high activity and enantioselectivity. Methods: Totally 21 chiral organocatalysts were applied in the asymmetric MBH reaction ofβ-nitrostyrene with ethyl glyoxylate, and the ee value was deter-mined by chiral HPLC. The effects of temperature, solvent and substrate ratio on the catalytic reaction were investigated. Results: In the presence of cinchona alkaloid catalyst (DHQ)2AQN, β-nitrostyrene reacted with ethyl glyoxylate in toluene at 0℃ affording the MBH adduct in 60% yield with good enantioselectivity (up to 56.9% ee). Conclusion: The bis-cinchona alkaloids with aromatic bridging group are the efficient catalysts for the asymmetric MBH reaction ofβ-nitrostyrene with ethyl glyoxylate, and moderate isolated yield and enantioselectivity are obtained.

Reverse prediction and molecular docking techniques were employed to evaluate the feasibility of reniformin A(RA) as an anti-tumor leading compound. Based on the reverse prediction, network pharmacology was used to construct a "disease-compound-target-pathway" network. Thirty-nine tumor-related targets of RA were predicted, which participated in the regulation of multiple cellular activities such as apoptosis, cell cycle, and tumor metastasis, and regulated estrogen signal transduction and inflammatory response. Discovery Studio 2020 was adopted for molecular docking and toxicity prediction(TOPKAT). As revealed by the results, the binding affinity of RA with the tumor-related targets ABL1, ESR1, SRC and BCL-XL was stronger than that of oridonin(OD), while its mutagenicity, rodent carcinogenesis, and oral LD_(50) in rats were all inferior to that of OD. Furthermore, in vitro experiments were performed to confirm the anti-tumor activity of RA, and the mechanism was preliminarily discussed. The results demonstrated that RA was superior to OD in cytotoxicity, inhibition of cell colony formation, and induction of apoptosis. RA, possessing potent anti-tumor activity, is expected to be a new anti-tumor leading compound.
Animals ; Drugs, Chinese Herbal/pharmacology* ; Lead ; Molecular Docking Simulation ; Neoplasms/genetics* ; Rats ; Signal Transduction