Data Views Exclude Ubiquitous Chemicals Activities: 314 Chemicals w/Activities: 21 CSV Excel PDF All Chemicals: 38 Previous12 Show all rows. Paginate rows. Click on column headings to sort table by that column # Activity Chemical Part All Flower Leaf Plant Root Shoot Low PPM High PPM StdDev *Reference 176 176 QUERCETIN Leaf -- -- * *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.