Propolis or bee glue is a resinous mixture that honey bees produce by mixing saliva and beeswax with exudate gathered from tree buds or sap flows. The ingredients of bee propolis are quite complicated and have been separated more than 300 kinds so far.
  
The flavone compound shows yellow in the color and has a wide variety of physiological activities. It has already attracted highly attention among the medical staff and food industry.

The terpenoid is a hydrocarbon compound that possesses strong odor and physiological activities. The valuable Chinese drugs, such as ganoderma, ginseng and Astragalus mongholicus all possess the terpenoid with special physiological activities. The unique odor and spicy numbness of bee propolis are closely related to the terpenoid.