Extra weak chemiluminescence of drugs. VI. Extra weak chemiluminescence accompanied by extraction processes of herbal drugs

Abstract

Extra weak chemiluminescence (CL) from 30 kinds of crude drugs observed during extraction was measured. Among these drugs, Atractylodis Lanceae Rhizoma, Zingiberis Rhizoma, Ginseng Radix, Magnoliae Cortex, Astragali Radix, Rehmanniae Radix, Cnidii Rhizoma, Glycyrrhizae Radix, Bupleuri Radix and Fritillariae Bulbus showed high CL intensities. Furthermore, the emission spectra of these drugs resembled each other and had emission bands identical with those from active oxygen. CL generated from Glycyrrhizae Radix was easily quenched by replacing air or oxygen gas by nitrogen gas. It was also quenched effectively in the presence of antioxidants such as ascorbic acid or thioglycerol. The water extract of Glycyrrhizae Radix was fractionated by column chromatography. The fractions containing triterpenoids, flavones, cumarins, amino acids and amino acid derivatives generated intense CL. However, the authentic solution of glycyrrhetic acid, liquiritin or amino acids did not show CL. It was assumed that CL produced on extraction of Glycyrrhizae Radix originated from active oxygen generated by oxidation of amino acid derivatives. This chemiluminescence technique may be useful as a monitor of the quality of Kampo Herbal Drugs.