Studies on thermal stabilities of typhaneoside and isorhamnetin-3-O-neohesperidoside

Objective: To study the effects of time and temperature on the stabilities of typhaneoside and isorhamnetin-3-O-neohesperidoside.Method:Typhaneoside and isorhamnetin-3-O-neohesperidoside were heated in different time under different temperatures respectively.The samples were analyzed by high performance liquid chromatorgraphy(HPLC).Result: Typhaneoside and isorhamnetin-3-O-neohesperidoside changed into a series of compounds in the heating process.Isorhamnetin was the common intermediates.Heated for 3 h under 140 ℃ or heated for 1 h under 160 ℃,typhaneoside and isorhamnetin-3-O-neohesperidoside did not undergo structural changes;Decomposition products were detected after 10 min of heating under 180 ℃,typhaneoside,isorhamnetin-3-O-neohesperidoside and their decomposition products were detected after 3 h of heating under 180 ℃,typhaneoside,isorhamnetin-3-O-Neo-hesperidoside and their decomposition products were non-detectable after 1 h of heating under 200 ℃ or 220 ℃. Conclusion:When Pollen Typhae were carbonized with an oven,the temperature and the heating time should be controlled from 160 ℃ to180 ℃(170 ℃),from 1h to 3 h(2 h) respectively.