Synthesis and anti-influenza activities of novel baicalein analogs

Chem Pharm Bull (Tokyo). 2014;62(5):415-21. doi: 10.1248/cpb.c13-00897. Epub 2014 Feb 25.

Abstract

A series of novel flavones derivatives were synthesized based on modification of the active ingredients of a traditional Chinese medicine Scutellaria baicalensis GEORGI and screened for anti-influenza activity. The synthetic baicalein (flavone) analogs, especially with the B-rings substituted with bromine atoms, were much more potent than oseltamivir or ribavirin against H1N1 Tamiflu-resistant (H1N1 TR) virus and usually with more favorable selectivity. The most promising were 5b, 5c, 6b and 6c, all displaying an 50% effective concentration (EC50) at around 4.0-4.5 µM, and a selective index (SI=50% cytotoxic concentration (CC50)/EC50)>70. For seasonal H3N2-infected influenza virus, both 5a and 5b with SI >17.3 indicated superior to ribavirin. The flavonoids having both not-naturally-occurring bromo-substituted B-rings and appropriate hydroxyls positioning on the A-rings might be critical in determining the activity and selectivity against H1N1-Tamiflu-resistant infected influenza viruses.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiviral Agents / chemical synthesis
  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology*
  • Dose-Response Relationship, Drug
  • Flavanones / chemical synthesis
  • Flavanones / chemistry*
  • Flavanones / pharmacology*
  • Influenza A Virus, H1N1 Subtype / drug effects*
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Scutellaria baicalensis / chemistry*
  • Structure-Activity Relationship

Substances

  • Antiviral Agents
  • Flavanones
  • baicalein