The Synthesis and Investigation of New Electroneutral Berberine Derivatives

The possibility of obtaining electroneutral 8-substituted berberines was demonstrated experimentally as well as by DFT/B3LYP and ab initio MP2/HF quantum-chemical calculations with the 6-311+G(d,p) basis set. In alkaline media, it is possible to substitute the C-8 position of berberine with such C-nucleophiles as methyl ketones, acetic acid esters, nitriles, geminal di- and trihaloalkanes. This process proceeds stepwise. First, berberine is attacked by a hydroxide anion to form a covalently bonded 8-hydroxyberberine, then 8-hydroxyberberine reacts with a nucleophile in the nonionized (molecular) form.