title: Bioactive Sesquiterpenes and Lignans from the Fruits of Xanthium sibiricum.
abstract: Seven new sesquiterpenes (1, 3-8), a new sesquiterpene natural product (2), and two new lignans (9 and 10), together with 15 known compounds, were isolated from the fruits of Xanthium sibiricum. The structures of the new compounds were established by NMR spectroscopic analysis, ECD calculations, and Mo2(OAc)4-induced circular dichroism, with the structures of 1 and 4 confirmed by single-crystal X-ray diffraction. Compound 1 is the first example of a 3/5/6/5 tetracyclic eudesmane sesquiterpene lactone formed at C-6 and C-7. In turn, compound 4 is the first example of a natural xanthane tetranorsesquiterpene, while compounds 5-8 are the first xanthane trinorsesquiterpenes found to date. Compounds 8, 11-15, 17, and 24 exhibited indirect anti-inflammatory activity by suppressing the lipopolysaccharide-induced proinflammatory factors in BV2 microglial cells, with IC50 values between 1.6 and 8.5 μM. Furthermore, compounds 13 and 17 exhibited anti-inflammatory activity against ear edema in mice produced by croton oil, with inhibition rates of 46.9% and 37.7%, respectively. Compounds 8, 11, 12, 23, and 24 exhibited potent activity against influenza A virus (A/FM/1/47, H1N1) with IC50 values between 3.7 and 8.4 μM.
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Shi
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Yun-Bao
authors.initials: YB
authors.lastname: Liu
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Shuang-Gang
authors.initials: SG
authors.lastname: Ma
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Li
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Qu
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Shao-Peng
authors.initials: SP
authors.lastname: Yuan
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Hou
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Yu-Huan
authors.initials: YH
authors.lastname: Li
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Jian-Dong
authors.initials: JD
authors.lastname: Jiang
authors.affiliation: †State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Institute of Materia Medica, and ‡Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100050, People's Republic of China.
authors.forename: Shi-Shan
authors.initials: SS
authors.lastname: Yu
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004285:Dogs; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005638:Fruit / Q000737:chemistry; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects; D020128:Inhibitory Concentration 50; D017705:Lignans / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects; D061985:Madin Darby Canine Kidney Cells / Q000187:drug effects; D051379:Mice; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D014709:Vero Cells / Q000187:drug effects; D031210:Xanthium / Q000737:chemistry*
chemical_list: D000893:Anti-Inflammatory Agents; D004365:Drugs, Chinese Herbal; D017705:Lignans; D012717:Sesquiterpenes