Detecting deep divergence in seventeen populations of tea geometrid (Ectropis obliqua Prout) in China by COI mtDNA and cross-breeding.

The tea geometrid (Ectropis obliqua Prout, Lepidoptera: Geometridae) is a dominant chewing insect endemic in most tea-growing areas in China. Recently some E. obliqua populations have been found to be resistant to the nucleopolyhedrovirus (EoNPV), a host-specific virus that has so far been found only in E. obliqua. Although the resistant populations are morphologically indistinguishable from susceptible populations, we conducted a nationwide collection and examined the genetic divergence in the COI region of the mtDNA in E. obliqua. Phylogenetic analyses of mtDNA in 17 populations revealed two divergent clades with genetic distance greater than 3.7% between clades and less than 0.7% within clades. Therefore, we suggest that E. obliqua falls into two distinct groups. Further inheritance analyses using reciprocal single-pair mating showed an abnormal F1 generation with an unbalanced sex ratio and the inability to produce fertile eggs (or any eggs) through F1 self-crossing. These data revealed a potential cryptic species complex with deep divergence and reproductive isolation within E. obliqua. Uneven distribution of the groups suggests a possible geographic effect on the divergence. Future investigations will be conducted to examine whether EoNPV selection or other factors prompted the evolution of resistance.

Characterization of a Baculovirus newly isolated from the tea slug moth, Iragoidae fasciata.

The tea slug moth Iragoidae fasciata (Lepidoptera, Eucleidae) is one of the main insect pests that attack tea bushes. A new nucleopolyhedrovirus (NPV) called Iragoidae fasciata NPV (IrfaNPV) was recently isolated from diseased larvae. An 11,626 bp fragment of the viral genomic DNA containing the polyhedrin gene and other 12 genes was cloned and sequenced. Gene comparison and phylogenetic analysis showed that IrfaNPV is a member of the Group I NPVs. However, the genomic organization of IrfaNPV is highly distinct. In addition, electron microscopy analysis showed that IrfaNPV is a single nucleocapsid NPV (SNPV). An inoculation assay showed that IrfaNPV is semi-permissive in the Trichoplusia ni cell line Tn-5Bl-4. Bioassays on lethal concentration (LC(50)) and lethal time (LT(50)) were conducted to test the susceptibility of I. fasciata larvae to the virus.

Five new cytotoxic triterpenoid saponins from the roots of Symplocos chinensis.

Five new triterpenoid saponins, named symplocososides G-K, were isolated from the roots of Symplocos chinensis. Their structures were elucidated by spectral and chemical methods as symplocososide G, 3beta-O-{[beta- D-glucopyranosyl(1-->2)][alpha-L-arabinofuranosyl(1-->4)]-beta-D-(3-O-acetyl)-glucuronopyranosyl}-21beta- O-[(2 Z)-3,7-dimethyl-2,6-octadienoyl]-22 alpha-O-(2-methylbutanoyl)-R1-barrigenol, symplocososide H, 3beta-O-{[beta-D-glucopyranosyl(1-->2)][alpha-L-arabinofuranosyl(1-->4)]- beta-D-(3-O-acetyl)-glucuronopyranosyl}-21beta-O-[(2E)3,7-dimethyl-2,6-octadienoyl]-22alpha-O-(2-methylbutanoyl)-R1-barrigenol, symplocososide I, 3beta-O-{[beta-D-glucopyranosyl(1-->2)][ alpha-L-arabinofuranosyl(1-->4)]-beta-D-(3- O-acetyl-6-O-methyl)-glucuronopyranosyl}-21beta-O-[(2 Z)3,7-dimethyl-2,6-octadienoyl]-22alpha-O-(2-methylbutanoyl)-R1-barrigenol, symplocososide J, 3 beta-O-{[ beta-D-glucopyranosyl(1-->2)][alpha-L-arabinofuranosyl(1-->4)]-beta-D-(3- O-acetyl)-glucuronopyranosyl}-21beta-O-[(2 Z)3,7-dimethyl-2,6-octadienoyl]-22alpha-O-benzoyl-R1-barrigenol, and symplocososide K, 3beta-O-{[beta-D-glucopyranosyl (1-->2)][alpha-L-arabinofuranosyl(1-->4)]- beta-D-(3-O-acetyl-6-O-methyl)-glucuronopyranosyl}-21beta-O-[(2Z)3,7-dimethyl-2,6-octadienoyl]-22alpha-O-benzoyl-R1-barrigenol. Symplocososides G-K showed significant cytotoxicity against cancer cell lines KB, HCT-8, Bel-7402, BGC-823 and A549 with IC50 values ranging from 0.82 microM to 5.09 microM, except for symplocososide I against cancer cell lines KB, BGC-823, A549 and symplocososide K against cancer cell line BGC-823 with IC50 values >10.00 microM.

[Advances in studies on chemical constituents and pharmacological activities from plants of Symplocaceae].

The chemical constituents and pharmacological activities on the genus of Symplocos were reviewed. Their constituents mainly included triterpenes and triterpenoid saponins, flavonoids, iridoids, lignans, alkaloids, polysaccharides and ellagic acids. A number of species among them have been used as folk medicine for the treatment of fever, detoxifying, acesodyne and hemostasis.