title: Antiviral constituents against respiratory viruses from Mikania micrantha.
abstract: Phytochemical investigation of the dried aerial parts of Mikania micrantha led to the isolation of a new sesquiterpene, 3beta-acetoxy-1,10-epoxy-4-germacrene-12,8;15,6-diolide (1), along with six known constituents: 1,10-epoxy-4-germacrene-12,8;15,6-diolide (2), dihydromikanolide (3), potassium mikanin 3-sulfate (4), mikanin (5), alpinetin (6), and ergosta-7,22-dien-3beta-ol (7). Their structures were elucidated by spectroscopic methods, and the molecular structures and stereochemistry of sesquiterpene lactones 1-3 were revealed by single-crystal X-ray analysis. Compound 2 showed moderate activity against respiratory syncytial virus (IC(50) = 37.4 uM) and parainfluenza type 3 virus (IC(50) = 37.4 uM) with a therapeutic index (TI) of 16.0 for both compounds. Compound 4, the main component of M. micrantha, exhibited inhibitory activity against parainfluenza type 3 virus with IC(50) (19.7 uM) and TI (24.0) values comparable to those of ribavirin, serving as a positive control.
authors.affiliation: Department of Biology and Biochemistry and Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, People's Republic of China. paulbut@cuhk.edu.hk
authors.forename: Paul Pui-Hay
authors.initials: PP
authors.lastname: But
authors.forename: Zhen-Dan
authors.initials: ZD
authors.lastname: He
authors.forename: Shuang-Cheng
authors.initials: SC
authors.lastname: Ma
authors.forename: Yiu-Man
authors.initials: YM
authors.lastname: Chan
authors.forename: Pang-Chui
authors.initials: PC
authors.lastname: Shaw
authors.forename: Wen-Cai
authors.initials: WC
authors.lastname: Ye
authors.forename: Ren-Wang
authors.initials: RW
authors.lastname: Jiang
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D006723:Hong Kong; D020128:Inhibitory Concentration 50; D035742:Mikania / Q000737:chemistry*; D008968:Molecular Conformation; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D010224:Parainfluenza Virus 3, Human / Q000187:drug effects; D012136:Respiratory Syncytial Viruses / Q000187:drug effects; D012254:Ribavirin / Q000494:pharmacology; D012717:Sesquiterpenes / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D045788:Sesquiterpenes, Germacrane
chemical_list: C550874:3beta-acetoxy-1,10-epoxy-4-germacrene-12,8;15,6-diolide; D000998:Antiviral Agents; D012717:Sesquiterpenes; D045788:Sesquiterpenes, Germacrane; D012254:Ribavirin