Oleanolic acid or oleanic acid is a naturally occurring pentacyclic triterpenoid related to betulinic acid. It is widely distributed in food and plants where it exists as a free acid or as an aglycone of triterpenoid saponins.
Oleanolic acid can be found in olive oil, Phytolacca americana (American pokeweed), and Syzygium spp, garlic, etc. It was first studied and isolated from several plants, including Olea europaea (leaves, fruit), Rosa woodsii (leaves), Prosopis glandulosa (leaves and twigs), Phoradendron juniperinum (whole plant), Syzygium claviflorum (leaves), Hyptis capitata (whole plant), Mirabilis jalapa[4] and Ternstroemia gymnanthera (aerial part). Other Syzygium species including java apple (Syzygium samarangense) and rose apples contain it.
