Degradation study of stevioside using RP-HPLC and ESI-MS/MS

Abstract

Stevioside is very potential to be an antidiabetic pro-drug. In processing, the active ingredient may be degraded. This research conducted a study of the degradation of stevioside on several stress factors such as acid and base hydrolysis; exposure to UV rays, thermal heating and oxidation using RP-HPLC. The degradation products were identified using ESI-MS/MS. Hydrolysis of acid-base solution and exposure to UV254 nm rays caused the breakdown of glycoside bonds in the analyte. Stevioside was unstable in dry heating at 105oC for 48 hours due to degradation of 91%. Stevioside was oxidized under H2O2 oxidation for 48 hours. Based on the ESI-MS/MS analysis, the identified stevioside degradation products were [M-H] ̶ with m/z = 803 as stevioside; [M-H] ̶ with the value of m/z = 641 as steviolbioside; [M-H] ̶ with m/z = 479 as steviolmonoside; [M-H] ̶ with m/z = 317 as steviol. Termination of glucose was characterized by fragmentation [M-162] ̶.Our study provides a basic view on the stability and degradation characteristics of stevioside, and demonstrates the formation of degradation products.