Propolis recently been isolated from red propolis, and prenylated acids such as 4-hydroxy-3,5-diprenyl cinnamic acid have been documented. An analysis of propolis from Henan, China found sinapinic acid, isoferulic acid, caffeic acid, and chrysin, with the first three compounds demonstrating antibacterial properties. Also, Brazilian red propolis, largely derived from "Dalbergia ecastaphyllum" plant resin, has high relative percentages of the isoflavonoids 3-hydroxy-8,9-dimethoxypterocarpan and medicarpin. Other flavonoids commonly present include galangin and pinocembrin. Caffeic acid phenethyl ester (CAPE) is also a component of some varieties of propolis from New Zealand. Occasionally, worker bees will even gather various caulking compounds of human manufacture, when
Hoof glue it retains some flexibility, thus making it ideal for applications where some give in the joint or covering is required. Hoof glue Hoof glue is an adhesive made by boiling down the hooves of ungulates. It is a partially hydrolyzed keratin. It is a type of animal glue. Hoof glue was widely used throughout human history. The oldest known bow was 10,000 years old and made using hoof glue. Hoof glues have been used for things like stiffening bow strings, adhering fabric to wood, stiffening fabric, creating thin lacquers to protect valuable objects , as well as sealing glass into