Correlation Between Effective Components Content and Color Values of Indigo Naturalis Basde on Chromatometry / 中国实验方剂学杂志

ABSTRACT

Objective: To study the correlation between the color of Indigo Naturalis (powder and it's extracting solution) and effective components (indigo and indirubin) content. Method: The contents of indigo and indirubin in 27 batches of Indigo Naturalis were determined by HPLC,and the chromaticity values L*,a* and b* of powder and extracting solution were determined by color colorimeter. SPSS 20.0 software was used to analyze the correlation and multiple linear regression between the content of active components and the chromaticity values of Indigo Naturalis. Result: By visual observing the appearance of the powder,we find that,as the powder color deepened,the brightness values (L*) of the powder and extract were decreased,while the red-green value (a*) were increased. The correlation analysis showed that the contents of indigo were negatively correlated with the brightness value (L*) of the powder(Pa*)(PL*) of powder and extract (Pa*) (PConclusion: The darker the powder color of Indigo Naturalis,the higher the content of indigo and indirubin. The L* and a* values of indigo powder were more correlated with indigo and indirubin content than with the extracting solution. The color of powder was significantly correlated with the content of indigo and indirubin,which provided reference for rapid identification of Indigo Naturalis. The method of measuring the color of Indigo Naturalis by color colorimeter is stable,scientific and reliable.