title: Antiviral flavans from the leaves of Pithecellobium clypearia.
abstract: Two new antiviral flavan derivatives were isolated from a methanol extract of leaves of Pithecellobium clypearia as guided by antiviral assays. The structures were characterized, by spectroscopic analyses, as 7-O-galloyltricetifavan (1) and 7,4'-di-O-galloyltricetifavan (2). Cytopathic effect (CPE) reduction assay showed that both compounds 1 and 2 possess antiviral activity against respiratory syncytial virus (RSV), with 50% inhibition concentration (IC(50)) values of 5 and 10 microg/mL, respectively; influenza A (H1N1) virus, with IC(50) values of 15.7 and 30 microg/mL; Coxsackie B3 (Cox B3) virus, with IC(50) values of 12.5 and 25 microg/mL, respectively; and Herpes simplex virus type 1 (HSV-1) with IC(50) values of 30 and 20 microg/mL, respectively. Cytotoxicity evaluation using the MTT assay showed that both compounds 1 and 2 were also moderately toxic to several cultured cell lines.
authors.affiliation: Department of Chemistry, Jinan University, Guangzhou, Guangdong, People's Republic of China.
authors.forename: Yaolan
authors.initials: Y
authors.lastname: Li
authors.forename: Kam-Tong
authors.initials: KT
authors.lastname: Leung
authors.forename: Fenghe
authors.initials: F
authors.lastname: Yao
authors.forename: Linda S M
authors.initials: LS
authors.lastname: Ooi
authors.forename: Vincent E C
authors.initials: VE
authors.lastname: Ooi
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D002522:Chlorocebus aethiops; D029822:Enterovirus B, Human / Q000187:drug effects; D007887:Fabaceae / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018259:Herpesvirus 1, Human / Q000187:drug effects; D018258:Herpesvirus 2, Human / Q000187:drug effects; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry*; D012136:Respiratory Syncytial Viruses / Q000187:drug effects; D014709:Vero Cells
chemical_list: D000998:Antiviral Agents; D005419:Flavonoids