title: A new carbamate with cytotoxic activity from the aerial parts of Siegesbeckia pubecens.
abstract: OBJECTIVE
  To study the chemical constituents of Siegesbeckia pubescens.
  
  
  METHODS
  The chemical constituents were isolated by extraction, crystallization and various chromatographic methods, and the chemical structures were elucidated on the basis of spectral analysis. In addition, the cytotoxic activity of compound 1 was evaluated using human lung cancer cell A 549.
  
  
  RESULTS
  Four compounds were obtained, and their structures were identified as (E)-3-(3-oxobut-1-enyl)phenyl dimethylcarbamate (1), ent-2-oxo-15, 16, 19-trihydroxypimar-8(14)-ene (2), 16-acetylkirenol (3), 3, 7-dimethylquercetin (4).
  
  
  CONCLUSIONS
  Compound 1 is a new carbamate, and the IC(50) in MTT method of compound 1 was 58 μg·mL(-1).
authors.affiliation: Department of Natural Medicinal Chemistry, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.forename: Rong
authors.initials: R
authors.lastname: Chen
authors.forename: Yu
authors.initials: Y
authors.lastname: Nie
authors.forename: Lin
authors.initials: L
authors.lastname: Feng
authors.forename: Hai-Dao
authors.initials: HD
authors.lastname: Li
authors.forename: Jing-Yu
authors.initials: JY
authors.lastname: Liang
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D019659:Asteraceae / Q000737:chemistry*; D002219:Carbamates / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D006801:Humans; D020128:Inhibitory Concentration 50; D008175:Lung Neoplasms / Q000188:drug therapy*; D015394:Molecular Structure; D008517:Phytotherapy; D035261:Plant Components, Aerial / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology / Q000627:therapeutic use*; D011794:Quercetin / Q000031:analogs & derivatives / Q000302:isolation & purification
chemical_list: C582400:(E)-3-(3-oxobut-1-enyl)phenyl dimethylcarbamate; D000972:Antineoplastic Agents, Phytogenic; D002219:Carbamates; D010936:Plant Extracts; D011794:Quercetin