Chemical identification and quality assessment of radix Angelicae sinensis (Danggui roots)

Radix Angelicae Sinensis (Danggui, Angelica sinensis (Oliv.) Diels, DG) is one of the most important and widely used Chinese medicinal herbs. In order to develop the chemical methods for identification of DG and assessment of its quality, more than fifty related herbs including DG, Japanese Danggui ( A. acutiloba Kitagawa and A. acutiloba Kitagawa var. sugiyamae Hikino, JDG), Chuanxiong ( Ligusticum chuanxiong Hort., CX) and Japanese Chuanxiong (Cnidium officinale Makino, JCX) were collected and studied according to the following aspects:; HPLC-fingerprint of DG was firstly developed on the analysis of 53 herbal samples by HPLC-DAD and HPLC-MS-MS techniques. The similarities of chromatograms between intra- and inter-species samples were compared on the correlation coefficients of the entire chromatographic patterns and the principal component analysis. The relative retention times and peak area of the characteristic peaks were calculated for quantitative expression on the chemical properties of these chromatograms. The results indicate that among different species samples, it was possible to distinguish by either their chromatogram features or identities of specific chemical markers. Therefore, the simulative mean chromatograms were generated and used as representative standard fingerprints for genuine identification of these herbs.; New quantitative analysis methods for assay of Z- and E-ligustilide, free ferulic acid and total ferulic acid were then developed by HPLC-DAD-MS techniques. For the development of the HPLC method to detect ligustilide, an appropriate UV absorption wavelength at 350 nm was chosen as measurement wavelength. Z- and E-ligustilide were baseline separated and their interference peaks were minimized in the chromatograms. For assay of ferulic acid in DG samples, the stabilities of ferulic acid and coniferyl ferulate were examined, with two new terms of 'free ferulic acid' and 'total ferulic acid' were introduced. Furthermore, a new quantitative analysis technique for assay of free and total feruic acid were developed. The levels of Z- and E-ligustilide, free and total ferulic acid were quantified and compared in different forms of DG, JDG, CX and JCX samples.; Finally, with the aim to develop a rapid analytical method for facile identification of DG samples, FTIR spectroscopy combined with the secondary derivative technique and 2D-IR were employed to analyze of DG samples. This included samples from different processing methods, different parts, raw material, extracts and extracted residue. It was suggested that FTIR spectroscopy could be used to rapidly screen for the quality of DG samples.