Screening and identification of α‐glucosidase inhibitors from Shenqi Jiangtang Granule by ultrafiltration liquid chromatography and mass spectrometry

Shenqi Jiangtang Granule, a well‐known traditional Chinese herbal preparation, has been widely used for the treatment of type II diabetes mellitus. In this work, an ultrafiltration liquid chromatography with quadrupole time‐of‐flight mass spectrometry method was proposed for the rapid identification of bioactive ingredients from Shenqi Jiangtang Granule using α‐glucosidase as an example. First, the chemical profile of this preparation was clarified, including 37 saponins, 17 flavonoids, 37 lignans, and seven other compounds. After incubation with α‐glucosidase in vitro, the methanol extract with an IC 50 value of 0.19 mg/mL exhibited significant inhibitory activity. Then, 18 specific binding peaks were screened, and 15 peaks were identified. Among these, ten compounds were reported to have potential α‐glucosidase inhibitory activity for the first time. Subsequently, the inhibitory activities of these active compounds were evaluated by ultraviolet spectrophotometry with p ‐nitrophenyl α ‐d‐ glucopyranoside as a substrate. As a result, gomisin J and gomisin D exhibited stronger α‐glucosidase inhibitory activities than other active compounds with IC 50 values of 77.69 and 133.85 μM, respectively. The results demonstrated that the integrated ultrafiltration liquid chromatography with mass spectrometry method was an effective and powerful tool for the discovery of active ingredients in Shenqi Jiangtang Granule.