Extracting phenolic compounds from bee propolis
Propolis is a glue made by honey bees from a mixture of saliva, beeswax, and tree resin or plant sap, which the bees use to fix up the hive. Humans have found an alternative use for it: as a treatment for a wide range of medical conditions, including minor infections and dry skin.
Even though humans have used propolis as a medical treatment for thousands of years, scientists are still working to identify the active ingredients responsible for its medicinal properties. What makes this process so difficult is that not only is propolis a highly complex substance, comprising many different compounds, but its composition can differ substantially between different hives and seasons. This is because bees produce it using resin or sap from whatever trees or plants are growing near their hive.
One specific class of organic molecules that scientists are focusing on is phenols, as they are known to have medicinal properties and are abundant in propolis. Because of the complexity of propolis, scientists first need to extract the phenolic compounds from any samples before they can identify them with a technique such as liquid chromatography-mass spectrometry (LC-MS). Existing methods for doing this are slow and not particularly environmentally friendly, because they tend to involve extracting the phenolic compounds with large volumes of organic solvents...