Prune juice.
First thing this anon does is search for food plants (Gods pharmacy) that contain what is need.
Quercetin: Capers, Elderberry, Lovage
Boron:
https://www.webmd.com/diet/foods-high-in-boron#1
Healthy Foods That Are High in Boron Beneficial
for bone health and more
https://www.verywellhealth.com/best-boron-rich-foods-5092054