title: Mulberrofuran G and isomulberrofuran G from Morus alba L.: anti-hepatitis B virus activity and mass spectrometric fragmentation.
abstract: Mulberrofuran G (1) and isomulberrofuran G (2), a pair of isomeric Diels-Alder-type adducts, were isolated from the root bark of  Morus alba  L. Isomulberrofuran G (2) as a new IIB-type Diels-Alder-type adduct, was elucidated by extensive (1)H, (13)C, and two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectroscopic analyses. A fragmentation study on compounds 1 and 2 was performed by high-resolution electrospray ionization (ESI) multistage tandem mass spectrometry linked with ion-trap (IT) and time-of-flight (TOF) mass analyzers (ESI-MS(n)/IT-TOF) in negative mode, which resulted in obviously different fragmentations. In the MS(2) experiments, the characteristic ions at m/z 451 and 439 could be revealed as their respective diagnostic ions. Mulberrofuran G (1) showed moderate activity, inhibiting hepatitis B virus (HBV) DNA replication with the IC(50) value of 3.99 μM, according to the anti-HBV assay on the HepG 2.2.15 cell line in vitro.
authors: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan 650201, People's Republic of China.
authors: Chang-An
authors: CA
authors: Geng
authors: Yun-Bao
authors: YB
authors: Ma
authors: Xue-Mei
authors: XM
authors: Zhang
authors: Shu-Ying
authors: SY
authors: Yao
authors: Duo-Qing
authors: DQ
authors: Xue
authors: Rong-Ping
authors: RP
authors: Zhang
authors: Ji-Jun
authors: JJ
authors: Chen
mesh_terms: D000998:Antiviral Agents / Q000494:pharmacology*; D001572:Benzofurans / Q000494:pharmacology*; D004279:DNA, Viral / Q000235:genetics; D006515:Hepatitis B virus / Q000187:drug effects* / Q000502:physiology; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D031625:Morus / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology; D021241:Spectrometry, Mass, Electrospray Ionization; D053719:Tandem Mass Spectrometry; D013729:Terpenes / Q000494:pharmacology*; D014779:Virus Replication
chemical_list: D000998:Antiviral Agents; D001572:Benzofurans; D004279:DNA, Viral; D010936:Plant Extracts; D013729:Terpenes; C047825:mulberrofuran G