UPLC-Q-TOF-MS and UPLC-QQQ-MS were used for the qualitative and quantitative analysis of oligosaccharides in Fufang Ejiao Syrup

Fufang Ejiao Syrup (FES) is a syrup made from Colla Corii Asini (CCA) and four botanicals (Codonopsis Radix (CR), Ginseng Radix et Rhizoma Rubra (GRRR), Rehmanniae Radix Praeparata (RRP) and Crataegi Fructus (CF)) as a result of modern processing and refining technology. FES has a lengthy history and is frequently used in clinical practice. Modern pharmacological studies have confirmed that oligosaccharides in any of the main medicinal herbs of FES, such as CR, GRRR, and RRP, have significant immune-enhancing effects. Therefore, the oligosaccharide component in FES could be its important pharmacologic substance, however, no studies on the content, structural analysis and source attribution of oligosaccharides in FES have been reported. The objective of this study is to systematically analyze the oligosaccharide in FES, compare the differences of the major oligosaccharides in different batches of FES produced by one manufacturer, and construct the content determination method for determining the content of the major oligosaccharides in FES, to provide technical support for FES quality assessment. This analysis revealed that a total of 13 oligosaccharides were identified from the FES, including 3 disaccharides, 4 trisaccharides, 3 tetrasaccharides, and 3 pentasaccharides. The constructed UPLC-QQQ-MS fingerprint of FES oligosaccharide is simple, stable, and reproducible, making it a useful tool for assessing FES's quality. There was a significant difference between the oligosaccharide fingerprints of 16 batches of FES,the results of fingerprint analysis combined with the statistical analysis suggested that the differences in stachyose, sucrose and raffinose contents in FES may be the reason for the great variations in oligosaccharide fingerprints of different batches of FES. For the 5 oligosaccharides in FES, the UPLC-QQQ-MS technique showed significant linearity in the linear range, along with good stability, repeatability, and recovery. Mannotriose was found to be higher in FES, followed by sucrose and stachyose, while kestose and raffinose were relatively lower. The results of this study reveal that oligosaccharides are important components of FES, and the method of fingerprinting and content determination constructed has strong practical value and is expected to be used for FES quality control.