Two new ursane-type nortriterpenes from Lonicera macranthoides and their iNOS-inhibitory activities

The flower buds of Lonicera macranthoides (Shan Yin-Hua), represent an important traditional Chinese medicine and food ingredient. A phytochemical investigation of the 70% EtOH extract of the flower buds of L. macranthoides resulted in the isolation of 12 triterpenoids ( 1-12 ), including two new ursane-type nortriterpenes, 2α, 24-dihydroxy-23-nor-ursolic acid ( 1 ) and 2α, 4α-dihydroxy-23-nor-ursolic acid ( 2 ). Their structures were established by multiple spectroscopic methods and comparison with literature data. All isolated compounds were evaluated for their anti-inflammatory effects in LPS-activated RAW264.7 cells. Compounds 1 and 2 exhibited inhibitory effects on iNOS at the concentration of 30 μmol·L^-1.