[Synthesis of baicalin-copper and baicalin-aluminium complex and its bioactivity]

To study synthesis of baicalin-copper and baicalin-aluminium complex and its antimicrobial, anti-tumor activity and anti-tumor effect against macrophages.

Baicalin was reacted with metallic salt under a weak base condition to produce baicalin-copper and baicalin-aluminium complex. Baicalin and its synthesized complex were detected for antimicrobial activity against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans by twofold broth dilution technique. Their anti-tumor activity against A549 and IC50 of HepG2 cells and anti-tumor effect against macrophages were detected by the MTT. And their phagocytic effect on macrophages was determined by the neutral red assay.

The yields of baicalin-copper and baicalin-aluminium complex were 73.93% and 91.08%, respectively. The minimum inhibitory concentration (MIC) value against Staphylococcus aureus, Hay bacillus, Escherichia coli, Salmonella and Candida albicans was 0.0004, 0.0009, 0.0004, 0.0009, 0.000 4 mol x L(-1) for baicalin-copper complex and 0.0011, 0.0011, 0.0011, 0.0011, 0.0005 mol x L(-1) for baicalin-aluminium complex. The IC50 values against A549 and HepG2 cells were 89.6, 22.6 micromol x L(-1) for baicalin-copper complex, and 138.8, 97.2 micromol x L(-1) for baicalin-aluminium complex. The inhibitory ratio of macrophage on A549 cell was 43.52%, 80.89%, 52.66%, respectively, after the macrophages were stimulated by baicalin, baicalin-copper and baicalin-aluminium complex at a concentration of 160 micromol x L(-1).

The acute toxicity test in mice showed that the complex was nontoxic to mice. Baicalin-copper complex showed the highest antimicrobial, anti-tumor activity, and the strongest effect on the anti-tumor activity of macrophage, while baicalin showed the lowest activities compared with baicalin-copper and baicalin-aluminium complex.