ABSTRACT
As a precious traditional Chinese medicine(TCM), snake bile has been widely used in numerous Chinese medicine prescriptions. Bile acid(BA) derivatives have been demonstrated as the primary chemical family in snake bile. In-depth chemical characterization of BAs is of great importance towards the establishment of quality standards and clarification of the effective material basis for snake bile. This study firstly employed ~1H-NMR to preliminarily analyze the chemical profiles of snake bile, an automated fraction collector was subsequently implemented to obtain the fractions-of-interest. The fraction was then concentrated and re-analyzed by LC-MS. Based on ~1H-NMR, BAs were found to be the main components of snake bile, and six BAs including CDCA, CA, TCDCA, TCA, TDCA and GCA were tentatively identified from the representative spectrum with the assistance of literature and reference compounds. Whereas the content of TCA in snake bile was too great, resulting in a great obstacle for the detection of trace components, the automated fraction collector was subsequently implemented to obtain the fractions-of-interest for LC-MS analysis. According to matching MS/MS information and retention time with reference compounds as well as database retrieval, a total of 57 BAs were detected and annotated. Because of the combination of ~1H-NMR and LC-MS platforms, the findings are beneficial for the in-depth characterization of BAs in snake bile, which provides references for the establishment of quality control and evaluation methods of snake bile.
Subject(s)
Animals , Bile , Bile Acids and Salts , Chromatography, Liquid , Snakes , Tandem Mass SpectrometryABSTRACT
Echinacoside (ECH) is one of the active ingredients in Cistanche Herba and the principal effective component of Memoregain© as well. Moreover, a new agent namely Naoqing Zhiming tablet, derived from ECH has been licensed for clinical trials. However, the knowledge regarding the stability of is limited, till now, initiating a significant barrier for its further development along with the clinical trials. Herein, we aim to in depth characterize the transformation pattern of ECH in methanol. When ECH was stored in methanol, two primary products (P1 and P2) could be observed in HPLC chromatogram. A home-made automated fraction collector was configured via employing two 2-phase/6-port electronic valves to prepare P1 and P2. Following ¹H-NMR and LC-MS/MS assays, P1 and P2 were unambiguously identified as acteoside and cistanoside A, respectively. Moreover, the existences of cis-ECH, cis-acteoside, and cis-cistanoside A were claimed after careful analysis of the ¹H-NMR spectra of ECH, P1 and P2. Above all, the primary transformation pathways of ECH in methanol included methylation as well as hydrolysis, and mild transformation could also be initiated by cis/trans- configuration transferring for the caffeoyl group. The findings obtained in current study are envisioned to provide useful insight for the further development of ECH and the impurity detection of Naoqing Zhiming tablet. Moreover, the automated fraction collector configured in current study is able to serve as a versatile tool for the collection of signals-of-interest within phytochemical evaluations and impurity isolation.