title: Geranylated flavonoids displaying SARS-CoV papain-like protease inhibition from the fruits of Paulownia tomentosa.
abstract: SARS-CoV papain-like protease (PLpro) is an important antiviral target due to its key roles in SARS virus replication. The MeOH extracts of the fruits of the Paulownia tree yielded many small molecules capable of targeting PLpro. Five of these compounds were new geranylated flavonoids, tomentin A, tomentin B, tomentin C, tomentin D, tomentin E (1-5). Structure analysis of new compounds (1-5) by NMR showed that they all contain a 3,4-dihydro-2H-pyran moiety. This chemotype is very rare and is derived from cyclization of a geranyl group with a phenol functionality. Most compounds (1-12) inhibited PLpro in a dose dependent manner with IC50's raging between 5.0 and 14.4 μM. All new compounds having the dihydro-2H-pyran group showed better inhibition than their parent compounds (1 vs 11, 2 vs 9, 4 vs 12, 5 vs 6). In kinetic studies, 1-12 emerged to be reversible, mixed inhibitors.
authors.affiliation: Division of Applied Life Science (BK21 program), IALS, Gyeongsang National University, Jinju 660-701, Republic of Korea.
authors.forename: Jung Keun
authors.initials: JK
authors.lastname: Cho
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Curtis-Long
authors.forename: Kon Ho
authors.initials: KH
authors.lastname: Lee
authors.forename: Dae Wook
authors.initials: DW
authors.lastname: Kim
authors.forename: Hyung Won
authors.initials: HW
authors.lastname: Ryu
authors.forename: Heung Joo
authors.initials: HJ
authors.lastname: Yuk
authors.forename: Ki Hun
authors.initials: KH
authors.lastname: Park
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry* / Q000302:isolation & purification; D000086782:Coronavirus 3C Proteases; D003546:Cysteine Endopeptidases / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D005638:Fruit / Q000737:chemistry; D007700:Kinetics; D019684:Magnoliopsida / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D045473:Severe acute respiratory syndrome-related coronavirus / Q000201:enzymology*; D014764:Viral Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry
chemical_list: D000998:Antiviral Agents; D005419:Flavonoids; D010936:Plant Extracts; D011994:Recombinant Proteins; D014764:Viral Proteins; D003546:Cysteine Endopeptidases; D000086782:Coronavirus 3C Proteases