Notes Notes Bull. Korean Chem. Soc. 2013, Vol. 34, No. 2 633 http://dx.doi.org/10.5012/bkcs.2013.34.2.633 Chemical Constituents of the Rhizome of Eleutherine bulbosa and Their Inhibitory Effect on the Pro-Inflammatory Cytokines Production in Lipopolysaccharide -Stimulated Bone Marrow-derived Dendritic Cells Le Minh Ha, Do Thi Thanh Huyen, Phan Van Kiem, † Chau Van Minh, † Nguyen Thi Hong Van, Nguyen Xuan Nhiem, †,‡ Bui Huu Tai, †,‡ Pham Quoc Long, † Bui Kim Anh, ¶ Seung Hyun Kim, # Hye-Jin Hong, † Sohyun Kim, § Young-Sang Koh, † and Young Ho Kim ‡,* Institute of Natural Products Chemistry, Vietnam Academy of Science and Technology (VAST), Hanoi, Vietnam † Institute of Marine Biochemistry, VAST, Hanoi, Vietnam ‡ College of Pharmacy, Chungnam National University, Daejeon 305-764, Korea. * E-mail: yhk@cnu.ac.kr § School of Medicine, Brain Korea 21 Program, and Institute of Medical Science, Jeju National University, Jeju 690-756, Korea # College of Pharmacy, Yonsei University, Incheon 406-840, Korea ¶ Institute of Chemistry, VAST, Hanoi, Vietnam Received September 12, 2012, Accepted November 6, 2012 Key Words : Eleutherine bulbosa, Iridaceae, Dihydroeleutherinol-8-O-β-D-glucopyranoside, IL-12 p40, IL-6 Inflammatory responses, initiated by the invasion of patho- gens or by tissue injury caused by free radicals, are a series of vascular and cellular reactions. Some important chemical mediators of inflammation are interleukin (IL)-1, -6, -12, and tumor necrosis factor-α, prostaglandins, etc… IL-6 has pro- and anti-inflammatory properties. IL-6 is involved not only in the activation of the immune system but also in regenerative process as well as in the regulation of meta- bolism. 1 The IL-12 family of cytokines is key players in the regulation of T cell responses. IL-12 has both early pro- inflammatory and late anti-inflammatory effects. 2 In addi- tion to these, TNF-α is a well-characterized pro-inflammatory cytokine released primarily from monocytes and macro- phages upon invasion of the host by a wide variety of patho- gens. It plays a crucial role in host defense and in the inflammatory response. Although it has numerous beneficial roles in immune regulation, it has also been implicated in the pathogenesis of both acute and chronic inflammatory disease. 3 Since ancient times, traditional medicines and phyto- pharmaceuticals have been used for the treatment of inflam- matory and other disorders. Natural products offer great hope in the identification of bioactive compounds and their development into drugs for the treatments of inflammatory diseases. One of the well-known drugs, aspirin was dis- covered based on the known analgesic and antipyretic pro- perties of the bark of willow-tree since 400 BC. 4 Recently, we have focused on a number of medicinal plants with anti- inflammatory activities and found some of them to possess the anti-inflammatory active compounds such as Acanthopanax koreanum 5 and Hedychium coronarium. 6 Eleutherine bulbosa (Miller) Urb. is an herbal medicinal plant from Iridaceae family. This plant is used in oriental medicine for the treatment of diseases such as heart failure, cancer, intestinal disorders, skin disease, and infertility. 7 Previous phytochemical investigation of E. bulbosa has resulted in the identification of some aromatic compounds and their glycosides such as eleutherinone, eleutherine, iso- eleutherine, eleutherol, 8 (R)-4-hydroxyeleutherin, eleuthone, isoeleuthoside C, eleutherinol 8-O-β-D-glucoside. 9 In the course of screening of medicinal plants for anti- inflammatory activities, we found the methanol extract of the rhizome of E. bulbosa potently inhibit the lipopoly- saccharide (LPS)-stimulated productions of IL-12 p40 and IL-6 cytokines in bone marrow-derived dendritic cells (DCs) with IC 50 values of 0.1 ± 0.05 and 16.2 ± 0.3 μg/mL, respec- tively (Table 2). SB203580, an inhibitor of cytokine suppre- ssive binding protein/p38 kinase, was used as a positive control. SB203580 inhibited IL-12 p40 and IL-6 production with IC 50 values of 2.5 ± 0.1 and 1.7 ± 0.2 μg/mL, respec- tively. The methanol extract of the E. bulbosa rhizome was then fractionated with chloroform, ethyl acetate, and water. From these fractions and using combined chromatographic separations, one new and fourteen known compounds were isolated. Compound 1 was obtained as a pale yellow powder. Its basic ion peak at m/z 419 [M–H] – was observed on negative- ion ESI-MS, and HR-ESI-MS analysis revealed the mole- cular formula to be C 21 H 24 O 9 , with a cluster ion peak at m/z 419.1338 [M–H] – (calcd for C 21 H 23 O 9 , 419.1342). The 1 H- NMR spectrum of 1 (in CD 3 OD) showed the following signals: a tertiary methyl group at δ H 2.45, a secondary methyl group at δ H 1.46 (d, J = 6.1 Hz), three singlet aromatic protons at δ H 6.45, 6.67, and 6.85, and an anomeric proton at δ H 4.93 (Table 1). The 13 C-NMR and DEPT data of 1 reveal-