title: Neo-clerodane diterpenoids from Scutellaria barbata with activity against Epstein-Barr virus lytic replication.
abstract: Bioassay-guided fractionation was conducted on an EtOAc-soluble extract of the whole plants of Scutellaria barbata, monitored by inhibition of Epstein-Barr virus (EBV) lytic replication. Twenty-six neo-clerodane diterpenoids were isolated, of which 13 are new (1-13, scutolides A-L) and 13 previously known (14-26). The structures of 1-13 were elucidated by analysis of their NMR and MS spectroscopic data. Furthermore, the configurations of the new compounds 1 and 11 were confirmed by single-crystal X-ray diffraction. All of the isolated compounds were evaluated for inhibitory effects against EBV lytic replication. Eleven compounds (3, 4, 6, 11, 12, 15, 16, 17, 20, 22, and 24) exhibited moderate to potent inhibition, with EC50 values from 3.2 to 23.6 μM and selective index (SI) values from 2.1 to 109.2. More specifically, the new compound 4 showed the most potent activity, with EC50 and SI values of 3.2 μM and 46.1, respectively, while compound 24 (EC50 = 16.4 μM) exhibited the highest SI of 109.2. This study is the first to report that neo-clerodane diterpenoids demonstrate significant inhibition against EBV lytic replication.
authors: †Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.
authors: Taizong
authors: T
authors: Wu
authors: ‡The Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China.
authors: Qian
authors: Q
authors: Wang
authors: †Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.
authors: Cheng
authors: C
authors: Jiang
authors: §Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States.
authors: Susan L
authors: SL
authors: Morris-Natschke
authors: †Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.
authors: Hui
authors: H
authors: Cui
authors: ‡The Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China.
authors: Yan
authors: Y
authors: Wang
authors: ‡The Institute of Human Virology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong 510080, People's Republic of China.|⊥Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
authors: Yuan
authors: Y
authors: Yan
authors: †Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.
authors: Jun
authors: J
authors: Xu
authors: §Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States.|∥Chinese Medicine Research and Development Center, China Medical University and Hospital, Taichung, Taiwan.
authors: Kuo-Hsiung
authors: KH
authors: Lee
authors: †Research Center for Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, People's Republic of China.|§Natural Products Research Laboratories, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599, United States.
authors: Qiong
authors: Q
authors: Gu
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D045785:Diterpenes, Clerodane / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D004854:Herpesvirus 4, Human / Q000187:drug effects*; D015394:Molecular Structure; D031363:Scutellaria / Q000737:chemistry*
chemical_list: D000998:Antiviral Agents; D045785:Diterpenes, Clerodane