Anti-Inflammatory Terpenoids from the Rhizomes of Shell Ginger.

Shell ginger ( Alpinia zerumbet ) is a perennial ornamental plant of ginger native to East Asia, which can be used as a flavoring agent in food or beverage, as well as a traditional Chinese medicine. In this study, a total of 37 terpenoids, including 7 new compounds, zerumin D1 to zerumin D7 ( 2 , 3 , 28 - 30 , 36 , and 37 ), and 5 new naturally occurring compounds, zerumin D10 to zerumin D14 ( 9 , 12 , 15 , 20 , and 24 ), were isolated and identified from the rhizomes of shell ginger. Compound 3 was an unprecedented variant labdane diterpenoid featuring a unique 6/7/6/3 tetracyclic cyclic ether system in its side chain. The anti-inflammatory activities of the isolated terpenoids were assessed in RAW 264.7 macrophages stimulated by lipopolysaccharide (LPS). Compound 4 significantly inhibited the production of nitric oxide with an IC 50 value of 5.4 μM. Further investigation revealed that compounds 2 and 3 may inhibit the nuclear translocation of NF-κB, thus suppressing the expression of IL-6, IL-1β, iNOS, and COX-2 to exert the anti-inflammatory effects.