BackgroundFerns, originated about 360 million years ago, are the sister group of seed plants. Despite the remarkable progress in our understanding of fern phylogeny, with conflicting molecular evidence and different morphological interpretations, relationships among major fern lineages remain controversial.ResultsWith the aim to obtain a robust fern phylogeny, we carried out a large-scale phylogenomic analysis using high-quality transcriptome sequencing data, which covered 69 fern species from 38 families and 11 orders. Both coalescent-based and concatenation-based methods were applied to both nucleotide and amino acid sequences in species tree estimation. The resulting topologies are largely congruent with each other, except for the placement of Angiopteris fokiensis, Cheiropleuria bicuspis, Diplaziopsis brunoniana, Matteuccia struthiopteris, Elaphoglossum mcclurei, and Tectaria subpedata.ConclusionsOur result confirmed that Equisetales is sister to the rest of ferns, and Dennstaedtiaceae is sister to eupolypods. Moreover, our result strongly supported some relationships different from the current view of fern phylogeny, including that Marattiaceae may be sister to the monophyletic clade of Psilotaceae and Ophioglossaceae; that Gleicheniaceae and Hymenophyllaceae form a monophyletic clade sister to Dipteridaceae; and that Aspleniaceae is sister to the rest of the groups in eupolypods II. These results were interpreted with morphological traits, especially sporangia characters, and a new evolutionary route of sporangial annulus in ferns was suggested. This backbone phylogeny in ferns sets a foundation for further studies in biology and evolution in ferns, and therefore in plants.

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To investigate how cold shock may affect chilling injury in mango fruit (Mangifera indica L. cv. 'Wacheng'), the fruit were treated for 3, 4 or 5 h at 0 • C, or treated for 8, 10 or 12 h at 4 • C, respectively, then transferred to 20 • C for 20 h prior to being stored at 2 • C, 85-95% RH. The chilling injury index of mango treated at 0 • C for 4 h was 59.7% lower than that of the control fruit directly stored at 2 • C, 85-95% RH. Some attributes were assayed in the fruit treated at 0 • C for 4 h. Ion leakage of the cold-shock fruit at 0 • C for 4 h was 16% or 10% lower than that of the control on day 9 or day 12 of storage, respectively. Malondialdehyde content of the cold-shocked fruit was 70% or 50% lower than that of the control on day 6 or day 12 of storage at 2 • C, respectively. Activities of catalase, ascorbate peroxidase, and contents of glutathione and phenolic compounds in the fruit during storage were all markedly enhanced by the cold-shock treatment, whereas activities of superoxide dismutase, glutathione reductase and content of ascorbic acid in the mango were slightly influenced by the cold-shock treatment. These results suggest that cold-shock treatment may hold promise as an alternative approach to reduce chilling injury in mango fruit during cold storage.

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Three new diterpenes, xishacorenes A-C, featuring an undescribed bicyclo[3.3.1]nonane nucleus bearing 1-vinyl and 13-[(E)-4-methylpenta-1,3-dien-1-yl] alkyl chains, and a related monocyclic known compound, were isolated from the Xisha soft coral Sinularia polydactyla. The structures of xishacorenes A-C, including their absolute configurations, were elucidated by extensive spectroscopic analysis and TDDFT ECD calculations. The new compounds exhibit an interesting dose-dependent promotion effect on the ConA-induced T lymphocyte proliferation. A plausible biosynthetic pathway of xishacorenes A-C is proposed.

The sulfinatodehalogenation reaction represents one of the most important methodologies to incorporate fluorine into organic molecules. Using inexpensive sulfur-containing reactants such as Na(2)S(2)O(4) under mild conditions, per- and polyfluoroalkyl halides (R(F)X, X = Br, I, CCl(3)) can be transformed smoothly into the corresponding sulfinate salts. This method is also used for the perfluoroalkylation of alkenes, dienes, alkynes and aromatics. Notably, after 1998, the sulfinatodehalogenation of perfluoroalkyl chlorides (R(F)Cl) has been realized by using dimethylsulfoxide (DMSO) as a solvent instead of CH(3)CN/H(2)O in the Na(2)S(2)O(4)/NaHCO(3) initiation system. Perfluoroalkyl chlorides, ethyl chlorofluoroacetates and chlorodifluoroacetates, and even nonfluorinated compounds, such as ethyl chloro- or dichloroacetates and chloroform, were either converted into the corresponding sulfinate salts or alkylated alkenes, alkynes and aromatics (including porphyrins). The sulfinatodehalogenation reaction has remarkable advantages. With the increasing demands to utilize the unique properties of fluorine and fluorinated functional groups in medicinal, agricultural and material sciences, we believe that there will continue to be useful developments in sulfinatodehalogenation chemistry and it will be applied more widely in the future.

Seven new prieurianin-type limonoids, aphapolynins C-I (1-7), and a new aphanamolide-type limonoid, aphanamolide B (8), along with seventeen known compounds, were isolated from the fruits of Aphanamixis polystachya. The structures of these compounds were established on the basis of spectroscopic studies. The absolute configurations were determined by combination of electronic circular dichroism (ECD) calculation, CD exciton chirality method, and single crystal X-ray diffraction. All these isolates were evaluated for their cytotoxicities against three human cancer cell lines, for their inhibitory effects on lipopolysaccharide (LPS) induced RAW264.7 murine macrophages, and for their fungicidal, herbicidal, and insecticidal activities. Compounds 1, 14, 16, and 17 exhibited significant fungicidal activities; 1 and 25 in particular showed good insecticidal activities. The α,β-unsaturated lactone and 14,15-epoxy ring moieties were essential for the insecticidal activity.

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