title: 2-Benzyl-benzofurans from the tubers ofOphiopogon japonicus.
abstract: BACKGROUND
  The overproduction of nitric oxide (NO) is known to involve in various inflammatory processes. A methanol extract of the tubers ofOphiopogon japonicuswas found to strongly inhibit NO production. The present paper deals with the isolation, structural identification and NO inhibitory effect of five compounds isolated from the MeOH extract ofO. japonicustubers.
  
  
  RESULTS
  Three new compounds were elucidated to be (2R)-(4-methoxybenzyl)-5,7-dimethyl-6-hydroxyl-2,3-dihydrobenzofuran (1), 2-(2-hydroxyl-4-methoxy-benzyl)-5-methyl-6-methoxyl-2,3-dihydrobenzofuran (2), and 2-(4-hydroxy-benzyl)-5,6-dihydroxybenzofuran (3). In addition, two known compounds were isolated from a natural source for the first time including 2-(4-methoxy-benzyl)-6,7-dimethoxyl-2,3-dihydrobenzofuran (4), and 2-(4-methoxy-benzyl)-6,7-methylenedioxy-2,3-dihydrobenzofuran (5). The absolute configuration of compound1was determined by experimental and calculated circular dichroism spectra. The effects of the isolated compounds on LPS-induced NO production in RAW264.7 cells were evaluated. Compound1and2showed the inhibitory activity with IC50values of 11.4 and 29.1 μM, respectively.
  
  
  CONCLUSIONS
  The class of 2-benzyl-2,3-dihydrobenzofuran is uncommon in nature. In this work, three such compounds were isolated fromO.japonicus. Two of them showed promising anti-inflammatory activity by inhibition of NO production.
authors.affiliation: Advanced Center for Bio-organic Chemistry, Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nguyen Hai
authors.initials: NH
authors.lastname: Dang
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.|Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nguyen Dinh
authors.initials: ND
authors.lastname: Chung
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Ha Manh
authors.initials: HM
authors.lastname: Tuan
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.|Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Thanh
authors.affiliation: National Institute of Medicinal Materials, 1B Quang Trung, Hoan Kiem, Hanoi, Vietnam.
authors.forename: Nguyen Tuan
authors.initials: NT
authors.lastname: Hiep
authors.affiliation: Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, 02841 Republic of Korea.
authors.forename: Dongho
authors.initials: D
authors.lastname: Lee
authors.affiliation: Institute of Marine Biochemistry, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.|Graduate University of Science and Technology, Vietnam Academy of Science and Technology (VAST), 18-Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam.
authors.forename: Nguyen Tien
authors.identifier: 0000-0003-3645-5157
authors.initials: NT
authors.lastname: Dat
keywords: 2-Benzyl-2,3-dihydroxybenzofuran; 2-Benzyl-benzofuran; Dihydrobenzofuran; Inhibition of NO production; Ophiopogon japonicas