Data Views Exclude Ubiquitous Chemicals Activities: 12 Chemicals w/Activities: 1 CSV Excel PDF All Chemicals: 1 Click on column headings to sort table by that column # Activity Chemical Part All Bark Low PPM High PPM StdDev *Reference 13 13 BETULIN Bark -- -- Jim Duke's personal files. *Unless otherwise noted all references are to Duke, James A. 1992. Handbook of phytochemical constituents of GRAS herbs and other economic plants. Boca Raton, FL. CRC Press.