Effects of sesquiterpenes and triterpenes from the rhizome of Alisma orientale on nitric oxide production in lipopolysaccharide-activated macrophages: absolute stereostructures of alismaketones-B 23-acetate and-C 23-acetate - Matsuda, H; Kageura, T; Toguchida, I; Murakami, T; Kishi, A; Yoshikawa, M (Bioorg Med Chem Lett, 1999)