title: Antiviral activity of daphnoretin isolated from Wikstroemia indica.
abstract: The ethanol extract of Wikstroemia indica was fractionated with organic solvents of different polarities, and various fractions were screened for their antiviral activity against respiratory syncytial virus (RSV) using a cytopathic effect (CPE) reduction assay. The ethyl acetate fraction was most active against RSV with 50% inhibition concentration (IC(50)) value < 3.9 microg/mL and a selectivity index (SI) > 64.1. Further isolation and purification of the fraction led to a purified compound, daphnoretin. Daphnoretin was tested for its anti-RSV activity using a plaque reduction assay and found active against RSV, with an IC(50 )value of 5.87 microg/mL and SI value of 28.17. The mode of antiviral action study revealed that daphnoretin could slightly inhibit the early events of the viral infection but its effect was mainly on the later phase of the replication cycle.
authors.affiliation: Department of Biology, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China.
authors.forename: Wing-Shan
authors.initials: WS
authors.lastname: Ho
authors.forename: Jun-Yi
authors.initials: JY
authors.lastname: Xue
authors.forename: Samuel S M
authors.initials: SS
authors.lastname: Sun
authors.forename: Vincent E C
authors.initials: VE
authors.lastname: Ooi
authors.forename: Yao-Lan
authors.initials: YL
authors.lastname: Li
mesh_terms: D000998:Antiviral Agents / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D003374:Coumarins / Q000302:isolation & purification / Q000494:pharmacology*; D004365:Drugs, Chinese Herbal / Q000494:pharmacology; D006801:Humans; D020128:Inhibitory Concentration 50; D010936:Plant Extracts / Q000494:pharmacology*; D012136:Respiratory Syncytial Viruses / Q000187:drug effects*; D010948:Viral Plaque Assay; D032365:Wikstroemia / Q000737:chemistry*
chemical_list: D000998:Antiviral Agents; D003374:Coumarins; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; C035316:daphnoretin