Reference substances (purity ≥98%) including monotropein, deacetylasperulosidic acid, asperulosidic acid, asperuloside, and rubiadin were purchased from Sichuan Weikeqi Biological Technology Co., Ltd. (Sichuan, China) while rubiadin-1-methyl ether (purity ≥90%) was supplied by Shanghai Yuanye Biotechnology Co., Ltd. (Shanghai, China). Saccharide references with purity ≥98%, namely, Lrhamnose, D-xylose, D-arabinose, D-fructose, D-mannose, D-glucose, Dgalactose, and sucrose, were obtained from Sigma while inulin-type fructooligosaccharide (FOS) references with 3?5 degrees of polymerization (DP), including 1-kestose (DP3), nystose (DP4), and 1Ffructofuranosylnystose (DP5), were obtained from Sichuan Weikeqi Biological Technology Co., Ltd., for quantitative analysis of saccharides.
|