Abstract: Natural pigments were extracted from 12 plants including Rhizoma Crumumae Longae,orange peel,and peanut skin.Their antimicrobial activity was tested.3 pigments among them were purified,and the inhibitory activity between the raw and the refined was compared.The results of inhibitory tests showed as follows:the MIC of curcomine against most bacteria was 0.025 g/ml;to bacteria and mold the MIC of Blyyonatum Sibiricam Redoute was 0.03 g/ml;the MIC of tea pigments against Staphylococcus aureus and Escherichia coli was 0.025 g/ml,and against Bacillus Subtilis was 0.05 g/ml and the MIC of Boraginacere against Penicillium sp. was 0.05 g/ml.The refined Curcomine had less inhibitory effect than the raw.Pure yellow and red tea pigments had better inhibitory effects than the original extracts,but after pruification Boraginacere pigment had no inhibitory activity at all.

Key words: Pigment , Inhibitory activity against bacteria