Enantiomer-selective Anti-influenza Activity of Bakuchiol

Background: Novel therapeutic approaches against influenza are required. Bakuchiol is a phenolic isoprenoid found in Babchi seeds. Results: Bakuchiol enantiomer-selectively inhibited influenza A viral infection and growth and activated the Nrf2 pathway. Conclusion: Bakuchiol showed novel enantiomer-selective anti-influenza viral activity. Significance: The study of bakuchiol will contribute to the development of novel approaches to influenza therapy

Construction of Successive Chiral Centers Adjacent to a Chiral Tetraalkylated Quaternary Center Using an Asymmetric Aldol Reaction

The aldol reaction of <b>2</b>″ with a variety of different aldehydes gave the corresponding β-lactones <b>4</b> bearing successive asymmetric centers adjacent to a chiral tetraalkylated quaternary center or the (<i>E</i>)-alkenes <b>8</b>. The use of electronically neutral or electron-deficient aldehydes led to <b>4</b> in excellent yields with high diastereoselectivities, whereas electron-rich aldehydes performed poorly and underwent decarboxylation to afford <b>8</b>

Systematic Asymmetric Synthesis of All Diastereomers of (−)-Talaumidin and Their Neurotrophic Activity

(−)-Talaumidin (<b>1</b>), a 2,5-biaryl-3,4-dimethyltetrahydrofuran lignan isolated from <i>Aristolochia arcuata</i> Masters, shows significant neurite-outgrowth promotion and neuroprotection in primary cultured rat cortical neurons and in NGF-differentiated PC12 cells. The four stereogenic centers on the tetrahydrofuran moiety in <b>1</b> result in the presence of seven diastereomers except for their enantiomers. In order to investigate the stereochemistry–activity relationships of the stereoisomers, the systematic synthesis of all stereoisomers of <b>1</b> was accomplished by employing Evans aldol, diastereoselective hydroboration, reductive deoxygenation, and Mitsunobu reactions as key steps. The ability of all of the synthesized stereoisomers to promote neurite-outgrowth in PC12 and neuronal cells was evaluated. All stereoisomers exhibited moderate to potent neurotrophic activities in NGF-differentiated PC12 cells at 30 μM and in primary cultured rat cortical neuronal cells at 0.01 μM. In particular, <b>1e</b> bearing all <i>cis</i> substituents resulted in the most potent neurite-outgrowth promotion