[Chemical constituents of Illicium burmanicum].

Chemical constituents of ethyl acetate extract of Illicium burmanicum were isolated and purified by various chromatographic methods,including Silica gel, Sephadex LH-20, C18 reverse-phased silica gel, Preparative TLC and Preparative HPLC. Their structures were identified by spectral analysis including NMR and MS data. Fourteen compounds were separated from I. burmanicum and their structures were identified as 7S,8R-erythro-4,7,9,9'-tetrahydroxy-3,3'-dimethoxy-8-O-4'-neolignan (1), 7R,8R-threo-4,7, 9,9'-tetrahydroxy-3,3 '-dimethoxy-8-O-4'-neolignan(2) ,polystachyol(3), (-) -massoniresinol(4), angustanoic acid F (5), trans-sobrerol(6), (3S,6R) -6,7-dihydroxy-6,7-dihydrolinalool (7), (3S, 6S) -6,7-dihydroxy-6,7-dihydrolinalool (8), 2,6-dimethoxy-4-allyl-phenol (9), 3,5-dihydroxy4-hydroxy benzaldehyde (10), 3-hydroxy4-methoxybenzaldehyde (11), methyl vanillate (12), shikimic acid ethylester (13) and beta-sitosrerol (14). Except compound 14, the rest thirteen compounds were separated from this plant for the first time.

Global landscape of structural proteins of infectious spleen and kidney necrosis virus.

Infectious spleen and kidney necrosis virus (ISKNV), the type species of the genus Megalocytivirus in the family Iridoviridae, causes severe damage to mandarin fish cultures in China. Little is known about the proteins of ISKNV virions. In this study, a total of 38 ISKNV virion-associated proteins were identified by four different workflows with systematic and comprehensive proteomic approaches. Among the 38 identified proteins, 21 proteins were identified by the gel-based workflows (one-dimensional [1-D] and two-dimensional [2-D] gel electrophoresis). Fifteen proteins were identified by 1-D gel electrophoresis, and 16 proteins were identified by 2-D gel electrophoresis, with 10 proteins identified by both methods. Another 17 proteins were identified only by liquid chromatography (LC)-based workflows (LC-matrix-assisted laser desorption ionization [MALDI] and linear trap quadrupole [LTQ]-Orbitrap). Among these 17 LC-identified proteins, 5 proteins were identified uniquely by the LC-MALDI workflow, whereas another 6 proteins were identified only by the LTQ-Orbitrap workflow. These results underscore the importance of incorporation of multiple approaches in identification of viral proteins. Based on viral genomic sequence, genes encoding these 38 viral proteins were cloned and expressed in vitro. Antibodies were produced against these 38 proteins to confirm the ISKNV structural proteins by Western blotting. Of the newly identified proteins, ORF 056L and ORF 118L were identified and confirmed as two novel viral envelope proteins by Western blotting and immunoelectron microscopy (IEM). The ISKNV proteome reported here is currently the only characterized megalocytivirus proteome. The systematic and comprehensive identification of ISKNV structural proteins and their localizations in this study will facilitate future studies of the ISKNV assembly process and infection mechanism.

Antigenic identification of virion structural proteins from infectious spleen and kidney necrosis virus.

Infectious spleen and kidney necrosis virus (ISKNV), belonging to the genus Megalocytivirus in the family Iridoviridae, is one of the major agents causing mortality and economic losses to the freshwater fish culture industry in Asian countries. Currently, little information regarding the antigenic properties of Megalocytivirus (especially ISKNV) is available. Our previous study using four different workflows with systematic and comprehensive proteomic approaches led to the identification of 38 ISKNV virion-associated proteins (J. Virol. 2869-2877, 2011). Thus, in this report, the antigenicity of 31 structural proteins from ISKNV virion was investigated. A one-dimensional gel electrophoresis immunoblot profile coupled with MALDI-TOF-TOF MS/MS was applied to identify six immunogenic viral proteins, namely, ORFs major capsid protein (006L), 054L, 055L, 101L, 117L, and 125L. Then, the antigenicity of 31 structural proteins was characterized by Western blot by using pooled sera from mandarin fish that survived ISKNV infection. Of the 31 viral proteins, 22 were recognized by the fish ISKNV antiserum. Furthermore, this antiserum neutralizes MFF-1 cells ISKNV infection. To our knowledge, this study is the first report on the immunogenicity of viral proteins and characterization of the proteome of megalocytivirus infective agents. Our findings are expected to promote the development of effective vaccine candidates.

Proteomic analysis of zebrafish (Danio rerio) infected with infectious spleen and kidney necrosis virus.

Iridovirus infections remain a severe problem in aquaculture industries worldwide. Infectious spleen and kidney necrosis virus (ISKNV), the type species of the genus Megalocytovirus in the family Iridoviridae, has caused significant economic losses among freshwater fish in different Asian countries. To investigate the molecular mechanism of iridoviral pathogenesis, we analyzed the differential proteome from the spleen of ISKNV-infected zebrafish through two-dimensional gel electrophoresis (2-DE). Mass spectrometry revealed 35 altered cellular protein spots, including 15 upregulated proteins and 20 downregulated proteins at five days post-infection. The altered host proteins were classified into 13 categories based on their biological processes: cytoskeletal protein, stress response, lipoprotein metabolism, ubiquitin-proteasome pathway, carbohydrate metabolism, signal transduction, proteolysis, ion binding, transport, metabolic process, catabolic process, biosynthesis, and oxidation reduction. Moreover, 14 corresponding genes of the differentially expressed proteins were validated by RT-PCR. Western blot analysis further demonstrated the changes in α-tubulin, ß-actin, HSC70, and major capsid protein (MCP) during infection. ß-Actin was selected for further study via co-immunoprecipitation analyses, which confirmed that the cellular ß-actin interacts with the MCP protein of ISKNV in the infected zebrafish. These findings provide insight into the interactions between iridoviruses (especially ISKNV) and host, as well as the mechanism and pathogenesis of ISKNV infections.