Antiphotooxidative activities of elm (Ulmus davidiana Planch) root bark extracts on methylene blue-sensitized photooxidation of lipids and isolation and identification of active compounds

Methanol extracts of elm ( Ulmus davidiana Planch) root bark were fractionated and purified to obtain active antiphotooxidative compounds against methylene blue sensitized photooxidation of oil. Crude extracts of elm root bark exhibited a strong protective activity, comparable to α-tocopherol, against methylene blue sensitized photooxidation of oil. Butanol and ethylacetate fractions of crude extracts showed strong antiphotooxidative activities. Four isolated pure compounds were obtained and positively identified as catechin-7- O - d -xylopyranoside (CXP), catechin-7- O - d -apiofuranosid (CAF), catechin (C), and mansonone E. CXP, CAF, and C were identified as active compounds showing strong protective activities against methylene blue sensitized photooxidation. However, mansonone E at a 300 ppm concentration induced a 20% increase in hydroperoxide formation. These 3 compounds are major active compounds for the antiphotooxidative activities of elm root bark extracts against methylene blue sensitized photooxidation of oils.