Chemical profiles and screening of potential α-glucosidase inhibitors from Sichuan pepper using ultra-filtration combined with UHPLC-Q-TOF

Sichuan pepper, commonly used as a food seasoning, possesses unique anti-diabetic properties. This study uses ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF) to elucidate the chemical profile of Sichuan pepper. Further, an ultra-filtration was coupled with UHPLC-Q-TOF to screen the alpha-glucosidase inhibitors (AGIs) for the first time. Results confirmed significant variation in the content of hydroxyl-alpha-sanshool (HAS) (44.27-115.28 mg/g DW) and hydroxyl-beta-sanshool (HBS) (0.36-1.22 mg/g DW). A total of 23 compounds were identified by UHPLC-Q-TOF. Among these, eleven sanshoamides predominantly constituted AGIs. It is worth noting that both HAS and HBS demonstrated the significantly higher inhibition of alpha-glucosidase activity (IC50 = 9.5 and 18.6 mu g/mL), approximately 13 similar to 25 times higher than that of acarbose (IC50 = 241 mu g/mL). This study provided vital phytochemical information on Sichuan peppers, which could be applied to the management of type-2 diabetes mellitus.