New Thymoquinol Glycosides and Neuroprotective Dibenzocyclooctane Lignans from the Rattan Stems of Schisandra chinensis.

Three new lignans (1 - 3), together with four new thymoquinol glycosides (4 - 7), were isolated from 70%-EtOH extract of the rattan stems of Schisandra chinensis. The structures of 1 - 7 were elucidated by detailed spectroscopic analyses, and these new compounds were identified as pinobatol-9-O-ß-d-glucopyranoside (1), 1,2,13,14-tetramethoxydibenzocyclooctadiene 3,12-O-ß-d-diglucopyranoside (2), 3,7-dihydroxy-1,2,13,14-tetramethoxydibenzocyclooctadiene 12-O-ß-d-glucopyranoside (3), thymoquinol 2-O-ß-d-apiofuranosyl-(1→6)-ß-d-glucopyranoside (4), thymoquinol 2-O-α-d-arabinofuranosyl-(1→6)-ß-d-glucopyranoside (5), thymoquinol 5-O-ß-d-apiofuranosyl-(1→6)-ß-d-glucopyranoside (6), and thymoquinol 5-O-α-d-arabinofuranosyl-(1→6)-ß-d-glucopyranoside (7). The neuroprotective activity of 1 - 7 was evaluated on PC12 cells with neurotoxicity induced by amyloid-beta 1 - 42 (Aß1 - 42 ). Compounds 2 and 3 showed protecting activity against Aß-induced toxicity in PC12 cells.

The LRR receptor-like kinase ALR1 is a plant aluminum ion sensor.

Plant survival requires an ability to adapt to differing concentrations of nutrient and toxic soil ions, yet ion sensors and associated signaling pathways are mostly unknown. Aluminum (Al) ions are highly phytotoxic, and cause severe crop yield loss and forest decline on acidic soils which represent ∼30% of land areas worldwide. Here we found an Arabidopsis mutant hypersensitive to Al. The gene encoding a leucine-rich-repeat receptor-like kinase, was named Al Resistance1 (ALR1). Al ions binding to ALR1 cytoplasmic domain recruits BAK1 co-receptor kinase and promotes ALR1-dependent phosphorylation of the NADPH oxidase RbohD, thereby enhancing reactive oxygen species (ROS) generation. ROS in turn oxidatively modify the RAE1 F-box protein to inhibit RAE1-dependent proteolysis of the central regulator STOP1, thus activating organic acid anion secretion to detoxify Al. These findings establish ALR1 as an Al ion receptor that confers resistance through an integrated Al-triggered signaling pathway, providing novel insights into ion-sensing mechanisms in living organisms, and enabling future molecular breeding of acid-soil-tolerant crops and trees, with huge potential for enhancing both global food security and forest restoration.

[Chemical constituents from Hydrangea macrophylla].

OBJECTIVE: To investigate chemical constituents from Chinese herbal medicine Hydrangea macrophylla. METHOD: The compounds were separated and purified by column chromatography over silica gel, ODS, and preparative HPLC. Their structures were identified by spectral methods including 1H, 13C-NMR and MS. RESULT: Eleven compounds were isolated and identified as zeorin, hopane-6, 22-diol (1), botulin (2), betulinic acid (3), 2-ethyl-3-methyl-maleimide-N-beta-D-glucopyranoside (4), uridine (5), thymidine (6), adenosine (7), nicotinamide (8), methyl pyroglutamate (9), hydrangenol (10) and hydrangenol-4'-O-beta-D-glucopyranoside (11), respectively. CONCLUSION: Compounds 14 and 7-9 were obtained from the genus Hydrangea for the first time.

MetaTISA: Metagenomic Translation Initiation Site Annotator for improving gene start prediction.

SUMMARY: We proposed a tool named MetaTISA with an aim to improve TIS prediction of current gene-finders for metagenomes. The method employs a two-step strategy to predict translation initiation sites (TISs) by first clustering metagenomic fragments into phylogenetic groups and then predicting TISs independently for each group in an unsupervised manner. As evaluated on experimentally verified TISs, MetaTISA greatly improves the accuracies of TIS prediction of current gene-finders. AVAILABILITY: The C++ source code is freely available under the GNU GPL license via http://mech.ctb.pku.edu.cn/MetaTISA/.

New lignan from the rattan stems of Schisandra chinensis.

A new lignan named schilignan F (1), together with twelve known ones (2-13), were isolated from the rattan stems of Schisandra chinensis. Their chemical structures were elucidated by spectroscopic methods including one and two-dimensional NMR spectra referring to the literatures as well as high-resolution mass spectrometric analysis. All compounds were evaluated for their cytotoxicities against human Hela cancer cell lines in vitro. The results showed that compounds 2, 6 and 8 exhibited weak cytotoxic activity with IC50 values of 30.6, 86.3 and 41.0 µM, and cisplatin showed cytotoxic activity with IC50 value of 27.3 µM.

Aromatic monoterpenoid glycosides from rattan stems of Schisandra chinensis and their neuroprotective activities.

Six new monoterpenoid glycosides, including thymoquinol 5-O-α-L-arabinopyranosyl-(1 → 6)-ß-D-glucopyranoside (1), cuminic acid 7-O-α-D-arabinofuranosyl-(1 → 6)-ß-d-glucopyranosyl ester (2), p-cymene 7-O-α-D-arabinofuranosyl-(1 → 6)-ß-D-glucopyranoside (3), p-methylhyd- ratropic acid 9-O-α-D-arabinofuranosyl-(1 → 6)-ß-d-glucopyranosyl ester (4), (R)-p-cymene 9-O-α- D-arabinofuranosyl-(1 → 6)-ß-D-glucopyranoside (5), and (R)-p-cymene 9-O-ß-D-apiofuranosyl-(1 → 6)-ß-D-glucopyranoside (6), together with three known compounds, such as (R)-p-cymene 9-O-ß-D-glucopyranoside (7), thymoquinol 5-O-ß-D-glucopyranoside (8), and thymoquinol 2-O-ß-D-glucopyranoside (9) were isolated from the 70%-EtOH extract of Schisandra chinensis rattan stems. The structures of the new compounds were elucidated by detailed spectroscopic analyses. Meanwhile, the neuroprotective activities of compounds 1-9 were evaluated on the two co-culture models of microglia and neurons cells and astrocytoma and neurons cells.

Phylogeography of two East Asian species in Croomia (Stemonaceae) inferred from chloroplast DNA and ISSR fingerprinting variation.

The genus Croomia (Stemonaceae) comprises three herbaceous perennial species that are distributed in temperate-deciduous forests in Southeastern North America (C.pauciflora) and East Asia (C. japonica, C. heterosepala). The two Asian species have abutting ranges in South Japan, but C. japonica also occurs disjunctively on the adjacent Asiatic mainland in East China. In our phylogenetic analysis of Croomia, based on chloroplast (cp) DNA sequence variation of the trnL-F region, and rooted with Stemona spp., the two Asian species are identified as sister that likely diverged in the Mid-to-Late Pleistocene (0.84-0.13 mya), whereas the divergence of C. pauciflora dates back to the Late Plio-/Pleistocene (<2.6 mya). Phylogeographical analysis of the two East Asian species detected seven cpDNA (trnL-F) haplotypes across 16 populations surveyed, and all of those were fixed for a particular cpDNA haplotype (H(E)=0.0, G(ST)=1). A survey of inter-simple sequence repeats (ISSRs) markers also detected remarkably low levels of within-population diversity (C. japonica: H(E)=0.085; C. heterosepala: H(E)=0.125), and high levels of inter-population differentiation (C. japonica: Phi(ST)=0.736; C. heterosepala: Phi(ST)=0.550), at least partly due to pronounced regional genetic substructure within both species. Non-overlapping distributions of cpDNA haplotypes and strong genetic (cpDNA/ISSR) differentiation among populations and/or regions accord with findings of a nested clade analysis, which inferred allopatric fragmentation as the major process influencing the spatial haplotype distribution of the two species. Based on mismatch distribution analysis and neutrality tests, we do not find evidence of population expansion in both species. Overall, we conclude that components of temperate-deciduous forest types in South Japan and East China are particularly sensitive to range fragmentation, isolation, and enhanced (incipient) species formation through climate-induced expansions of other forest types over glacial and interglacial periods of the (Late) Quaternary.