Activity-guided fractionation of the seeds of Ziziphus jujuba using a cyclooxygenase-2 inhibitory assay

Bioactivity-guided fractionation of petroleum ether- and EtOAc-soluble extracts of the seeds of Ziziphusjujuba using a cyclooxygenase-2 assay as a monitor indicated that the triglyceride, 1,3-di-O-[9(Z)-octadecenoyl]-2-O-[9(Z),12(Z)-octadecadienoyl]glycerol (3), and a fatty acid mixture of linoleic, oleic and stearic acids, were the major active components. A new pentacyclic lupane-type triterpene derivative, 3-O-[9(Z)-octadecenoyl]betulinic acid (1), and betulinic acid (2) were also isolated and identified. All isolates as well as pure linoleic, oleic and stearic acids were evaluated for their inhibitory effects against both cyclooxygenases-1 (COX-1) and -2 (COX-2).