Synthesizing a Berberine Derivative and Evaluating Antimicrobial Activity To Reinforce with Students the Potential Significance of Small Chemical Structure Changes for Biological Systems

The convenient synthesis of dihydroberberine by the reduction of berberine is described as an experiment for an upper-division undergraduate organic chemistry laboratory course. Students obtained up to 74% yield of the desired pure product without the use of chromatographic techniques. The antimicrobial activities of both compounds against Staphylococcus aureus and Candida albicans were then assessed and compared in an upper-division undergraduate microbiology laboratory course. The students verified that berberine shows higher antimicrobial activity than its derivative dihydroberberine, demonstrating that small changes in a chemical structure can result in great biological differences.