Data Views Exclude Ubiquitous Chemicals Activities: 350 Chemicals w/Activities: 21 CSV Excel PDF All Chemicals: 37 Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column # Activity Chemical Part All Flower Leaf Root Bark Low PPM High PPM StdDev *Reference 77 77 ZINC Root Bark 10.0 15.0 -0.82 * *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.