Sesquiterpene lactone and its unique proaporphine hybrids from Magnolia grandiflora L. and their anti-inflammatory activity

Two undescribed sesquiterpene lactone-proaporphine hybrid skeletons, two undescribed sesquiterpenes, and four known compounds were isolated from the aerial part of Magnolia grandiflora L. The structures of isolated compounds were unambiguously determined based on the interpretation of a combination of NMR spectroscopy, HRESIMS, DP4+ probability calculation of carbon data, X-ray crystallographic analyses, and ECD calculation. The isolated compounds were investigated for their anti-inflammatory activity against nitric oxide production and the protein expression of COX-2 in LPS-stimulated RAW 264.7 cells.