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
Speed glue few extra grams may cause the player to not perform as well. The more the glue builds up on the rubber, the more glue must be applied on the next application to achieve the same effect. After 5-10 layers of glue, some players peel the old glue off to reduce the weight of the sponge, and to reduce the amount of glue needed to obtain the optimum effect. Another disadvantage is that the increased tension on the sponge from the glue will cause the rubber to wear out faster than usual. In order to prolong the life of the rubber,