Freestanding and Sandwich MXene-Based Cathode with Suppressed Lithium Polysulfides Shuttle for Flexible Lithium-Sulfur Batteries.

Flexible lithium-sulfur (Li-S) batteries with high mechanical compliance and energy density are highly desired. This manuscript reported that large-area freestanding MXene (Ti3C2Tx) film has been obtained through a scalable drop-casting method, significantly improving adhesion to the sulfur layer under the continuously bent. Titanium oxide anchored on holey Ti3C2Tx (TiO2/H-Ti3C2Tx) was also produced by the well-controlled oxidation of few-layer Ti3C2Tx, which greatly facilitates lithium ion transport as well as prevents the shuttling of lithium polysulfides. Therefore, the obtained sandwich electrode has demonstrated a high capacity of 740 mAh g-1 at 2 C and a high capacity retention of 81% at 1 C after 500 cycles. Flexible Li-S batteries based on this sandwich electrode have a capacity retention as high as 95% after bending 500 times. This work provides effective design strategies of MXene for flexible batteries and wearable electronics.

Stabilized Solid Electrolyte Interphase Induced by Ultrathin Boron Nitride Membranes for Safe Lithium Metal Batteries.

Lithium-ion batteries (LIBs) are still facing safety problems, mainly due to dendrite growth on the anode that leads to combustion and explosion. Forming a stable solid electrolyte interface (SEI) layer is an effective way to suppress this. To induce the formation of stable SEI using simple methods at a low cost, we report an ultrathin and large-scale hexagonal boron nitride (h-BN)/polyimide (PI) layer that was coated on a commercial polypropylene (PP) separator. The formation of a stabilized SEI component induced by the h-BN coating layer is proposed, as suggested by theoretical calculations and confirmed by electrochemical analysis and spectroscopy. It effectively suppresses Li dendrite growth and reduces the consumption of active lithium. The separator also has good electrolyte wettability, excellent mechanical strength and thermal conductivity, and high thermal stability. When using the h-BN modified separator in a full cell, the capacity is extremely stable after long cycling and high temperature.

Comparative transcriptomic analyses of normal and peloric mutant flowers in Cymbidium goeringii Rchb.f identifies differentially expressed genes associated with floral development.

Cymbidium geringii has high ornamental and economic importance. Its traits, including flower shape, size, and color, are highly sought by orchid breeders. Gaining insights into the molecular basis of C. geringi flower development would accelerate genetic improvement of other orchids. Methods and Results: Here, C. goeringii RNA was purified from normal and peloric mutant flowers, and cDNA libraries constructed for Illumina sequencing. We generated 329,156,782 clean reads, integrated them, and then assembled into 236,811 unigenes averaging 595 bp long. A total of 11,992 differentially expressed genes s, of which 6119 were upregulated and 5873 downregulated, were uncovered in peloric mutant flower buds relative to normal flower buds. Kyoto Encyclopedia of Genes and Genomes enrichment assessments posited that these differentially expressed genes are associated with "Photosynthesis", "Linoleic acid metabolism", as well as "Plant hormone signal transduction" cascades. The DEGs were designated to 12 remarkably enriched GO terms, and 16 cell wall associated GO terms. The expression level of 16 determined genes were verified using RT-qPCR. Conclusions: Our gene expression data may be used to study the regulatory mechanism of flower organ development in C. geringi.

Identification and expression profiling of selected MADS-box family genes in Dendrobium officinale.

Dendrobium officinale, a herb with highly medicinal and ornamental value, is widely distributed in China. MADS-box genes encode transcription factors that regulate various growth and developmental processes in plants, particular in flowering. However, the MADS-box genes in D. officinale are largely unknown. In our study, expression profiling analyses of selected MADS-box genes in D. officinale were performed. In total, 16 DnMADS-box genes with full-length ORF were identified and named according to their phylogenetic relationships with model plants. The transient expression of eight selected MADS-box genes in the epidermal cells of tobacco leaves showed that these DnMADS-box proteins localized to the nucleus. Tissue-specific expression analysis pointed out eight flower-specific expressed MADS-box genes in D. officinale. Furthermore, expression patterns of DnMADS-box genes were investigated during the floral transition process. DnMADS3, DnMADS8 and DnMADS22 were significantly up-regulated in the reproductive phase compared with the vegetative phase, suggesting putative roles of these DnMADS-box genes in flowering. Our data showed that the expressions of MADS-box genes in D. officinale were controlled by diverse exogenous phytohormones. Together, these findings will facilitate further studies of MADS-box genes in Orchids and broaden our understanding of the genetics of flowering.

Comparative transcriptomic analysis reveal the regulation mechanism underlying MeJA-induced accumulation of alkaloids in Dendrobium officinale.

Dendrobium officinale is a traditional medicinal herb with a variety of bioactive components. Alkaloid is one of the major active ingredients of Dendrobium plants, and its immune regulatory effects have been well-studied. Although a number of genes involved in the biosynthetic pathway of alkaloids have been elucidated, the regulation mechanism underlying the methyl-jasmonate (MeJA)-induced accumulation of alkaloids in D. officinale is largely unknown. In our study, a total of 4,857 DEGs, including 2,943 up- and 1,932 down-regulated genes, were identified between the control and MeJA-treated groups. Kyoto Encyclopedia of Genes and Genomes annotation showed that a number of DEGs were associated with the putative alkaloid biosynthetic pathway in D. officinale. The main group of Dendrobium alkaloids are sesquiterpene alkaloids, which are the downstream products of mevalonate (MVA) and methylerythritol 4-phosphate (MEP) pathway. Several MVA and MEP pathway genes were significantly up-regulated by the MeJA treatment, suggesting an active precursor supply for the alkaloid biosynthesis under MeJA treatment. A number of MeJA-induced P450 family genes, aminotransferase genes and methyltransferase genes were identified, providing several important candidates to further elucidate the sesquiterpene alkaloid biosynthetic pathway of D. officinale. Furthermore, a large number of MeJA-induced transcript factor encoding genes were identified, suggesting a complex genetic network affecting the sesquiterpene alkaloid metabolism in D. officinale. Our data aids to reveal the regulation mechanism underlying the MeJA-induced accumulation of sesquiterpene alkaloids in D. officinale.

B and E MADS-box genes determine the perianth formation in Cymbidium goeringii Rchb.f.

Cymbidium goeringii Rchb.f. is an important ornamental plant with a striking well-differentiated lip. Its complex floral architecture presents an exciting opportunity to examine perianth development. In flowering plants, class A, B and E floral homeotic genes play key roles in the specification of perianth identity. In this study, we used a cDNA library of wild-type C. goeringii flower buds for transcriptome sequencing. Eighteen candidate class A, B and E genes (including AP1/FUL-, AP2-, DEF-, GLO-, SEP- and AGL6-like genes) were identified. Quantitative real time polymerase chain reaction (qRT-PCR) results showed that CgDEF1, CgSEP2 and CgAGL6-1 were strongly detected only in the sepals and petals and were significantly downregulated in the lips. CgDEF3, CgDEF4 and CgAGL6-3 were highly expressed in the lips and lip-like petals but were only minimally detected in the sepals. Yeast two-hybrid analysis indicated that CgDEF1 and CgGLO formed a heterodimer. CgAGL6-1/CgSEP2 and CgDEF1 formed higher-order protein complexes with the assistance of the CgGLO protein, and both CgAGL6-1 and CgSEP2 formed a heterodimer. CgDEF3/CgDEF4 could interact independently with CgGLO and CgAGL6-3, respectively, while CgDEF3 and CgDEF4 also formed heterodimers with the assistance of the CgGLO. Based on a comprehensive analysis relating these gene expression patterns to protein interaction profiles, the mechanism of sepal/petal/lip determination was studied in C. goeringii. Furthermore, a hypothesis explaining the sepal/petal/lip determination of C. goeringii is proposed. The lip-quartet (CgDEF3/CgDEF4/CgAGL6-3/CgGLO) promoted lip formation, whereas the sepal/petal-quartet (CgDEF1/CgAGL6-1/CgSEP2/CgGLO) promoted sepal/petal formation. These results enrich the current knowledge regarding the mechanism and pathways of perianth formation in orchids.

7-(Pyrazol-4-yl)-3H-imidazo[4,5-b]pyridine-based derivatives for kinase inhibition: Co-crystallisation studies with Aurora-A reveal distinct differences in the orientation of the pyrazole N1-substituent.

Introduction of a 1-benzyl-1H-pyrazol-4-yl moiety at C7 of the imidazo[4,5-b]pyridine scaffold provided 7a which inhibited a range of kinases including Aurora-A. Modification of the benzyl group in 7a, and subsequent co-crystallisation of the resulting analogues with Aurora-A indicated distinct differences in binding mode dependent upon the pyrazole N-substituent. Compounds 7a and 14d interact with the P-loop whereas 14a and 14b engage with Thr217 in the post-hinge region. These crystallographic insights provide options for the design of compounds interacting with the DFG motif or with Thr217.

Dietary effect of Dendrobium officinale leaves on chicken meat quality, fatty acid composition, and volatile compounds profile.

Dendrobium officinale leaves (DOL) contain many active ingredients with various pharmacological effects, but are still ineffectively utilized. To investigate the feasibility of developing DOL as a feed additive, it is necessary to determine whether dietary supplementing DOL had any effect on meat quality and flavor. Our results showed that supplementation with DOL decreased the shear force while increased the pH and fat content in breast meat. Meat from DOL-fed chickens had higher levels of n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs, but lower n-6/n-3 ratios. Moreover, volatile compounds profile indicated that contents of aldehydes, including hexanal, pentanal, and heptanal, etc.), which were identified as the key volatile compounds in chicken meat, exhibited noteworthy rise in DOL intake groups. Octanal, 1-octen-3-ol, and 2-pentylfuran also contributed greatly to the meat overall aroma. These data provide a foundation for the comprehensive utilization of DOL as a feed additive with antibiotic substitution potential.

Dietary supplementation with Dendrobium officinale leaves improves growth, antioxidant status, immune function, and gut health in broilers.

Background: The Dendrobium officinale leaves (DOL) is an underutilized by-product with a large biomass, which have been shown to exhibit immunomodulatory and antioxidant functions. The purpose of this research was to investigate the effects of DOL on broiler growth performance, antioxidant status, immune function, and gut health. Methods: One hundred and ninety-two 1-day-old chicks were selected and divided into 4 groups at random, 6 replicates for each group and 8 in each. Chicks were given a basal diet supplemented with different amounts of DOL: 0% (control group, NC), 1% (LD), 5% (MD), or 10% (HD). During the feeding trial (70 days), broiler body weight, feed intake, and residual feeding were recorded. On d 70, 12 broilers from each group were sampled for serum antioxidant and immune indexes measurement, intestinal morphological analysis, as well as 16S rRNA sequencing of cecal contents and short-chain fatty acid (SCFA) determination. Results: In comparison to the NC group, the LD group had greater final body weight and average daily gain, and a lower feed conversion ratio (p < 0.05, d 1 to 70). However, in MD group, no significant change of growth performance occurred (p > 0.05). Furthermore, DOL supplementation significantly improved the levels of serum total antioxidant capacity, glutathione peroxidase, superoxide dismutase, and catalase, but reduced the level of malondialdehyde (p < 0.05). Higher serum immunoglobulin A (IgA) content and lower cytokine interleukin-2 (IL-2) and IL-6 contents were observed in DOL-fed broilers than in control chickens (p <0.05). Compared to the NC group, duodenal villus height (VH) and villus height-to-crypt depth (VH:CD) ratio were considerably higher in three DOL supplementation groups (p < 0.05). Further, 16S rRNA sequencing analysis revealed that DOL increased the diversity and the relative abundance of cecal bacteria, particularly helpful microbes like Faecalibacterium, Lactobacillus, and Oscillospira, which improved the production of SCFA in cecal content. According to Spearman correlation analysis, the increased butyric acid and acetic acid concentrations were positively related to serum antioxidant enzyme activities (T-AOC and GSH-Px) and immunoglobulin M (IgM) level (p < 0.05). Conclusion: Overall, the current study demonstrated that supplementing the dies with DOL in appropriate doses could enhance growth performance, antioxidant capacity, and immune response, as well as gut health by promoting intestinal integrity and modulating the cecal microbiota in broilers. Our research may serve as a preliminary foundation for the future development and application of DOL as feed additive in broiler chicken diets.

Flexible Zinc-Air Batteries with Ampere-Hour Capacities and Wide-Temperature Adaptabilities.

Flexible Zn-air batteries (FZABs) have significant potentials as efficient energy storage devices for wearable electronics because of their safeties and high energy-to-cost ratios. However, their application is limited by their short cycle lives, low discharge capacities per cycle, and high charge/discharge polarizations. Accordingly, herein, a poly(sodium acrylate)-polyvinyl alcohol (PANa-PVA)-ionic liquid (IL) hydrogel (PANa-PVA-IL) is prepared using a hygroscopic IL, 1-ethyl-3-methylimidazolium chloride, as an additive for twin-chain PANa-PVA. PANa-PVA-IL exhibits a high conductivity of 306.9 mS cm-1 and a water uptake of 2515 wt% at room temperature. Moreover, a low-cost bifunctional catalyst, namely, Co9 S8 nanoparticles anchored on N- and S-co-doped activated carbon black pearls 2000 (Co9 S8 -NSABP), is synthesized, which demonstrates a low O2 reversibility potential gap of 0.629 V. FZABs based on PANa-PVA-IL and Co9 S8 -NSABP demonstrate high discharge capacities of 1.67 mAh cm-2 per cycle and long cycle lives of 330 h. Large-scale flexible rechargeable Zn-air pouch cells exhibit total capacities of 1.03 Ah and energy densities of 246 Wh kgcell -1 . This study provides new information about hydrogels with high ionic conductivities and water uptakes and should facilitate the application of FZABs in wearable electronics.

Collaborative and privacy-preserving retired battery sorting for profitable direct recycling via federated machine learning.

Unsorted retired batteries with varied cathode materials hinder the adoption of direct recycling due to their cathode-specific nature. The surge in retired batteries necessitates precise sorting for effective direct recycling, but challenges arise from varying operational histories, diverse manufacturers, and data privacy concerns of recycling collaborators (data owners). Here we show, from a unique dataset of 130 lithium-ion batteries spanning 5 cathode materials and 7 manufacturers, a federated machine learning approach can classify these retired batteries without relying on past operational data, safeguarding the data privacy of recycling collaborators. By utilizing the features extracted from the end-of-life charge-discharge cycle, our model exhibits 1% and 3% cathode sorting errors under homogeneous and heterogeneous battery recycling settings respectively, attributed to our innovative Wasserstein-distance voting strategy. Economically, the proposed method underscores the value of precise battery sorting for a prosperous and sustainable recycling industry. This study heralds a new paradigm of using privacy-sensitive data from diverse sources, facilitating collaborative and privacy-respecting decision-making for distributed systems.

Probing the effects of lipid substitution on polycation mediated DNA aggregation: a molecular dynamics simulations study.

Understanding the molecular mechanism of DNA aggregation and condensation is of importance to DNA packaging in cells, and applications of gene delivery therapy. Modifying polycations such as polyethylenimine with lipid substitution was found to improve the performance of polycationic gene carriers. However, the role of the lipid substitution in DNA binding and aggregation is not clear and remains to be probed at the molecular level. In this work, we elucidated the role of lipid substitution through a series of all-atom molecular dynamics simulations on DNA aggregation mediated by lipid modified polyethylenimine (lmPEI). We found that the lipids associate significantly with one another, which links the lmPEIs and serves as a mechanism of aggregating the DNAs and stabilizing the formed polyplex. In addition, some lipid tails on the lmPEIs stay at the periphery of the lmPEI/DNA polyplex and may provide a mechanism for hydrophobic interactions. The enhanced stability and hydrophobicity might contribute to better cellular uptake of the polyplexes.

Species-Specific Gene Expansion of the Cellulose synthase Gene Superfamily in the Orchidaceae Family and Functional Divergence of Mannan Synthesis-Related Genes in Dendrobium officinale.

Plant Cellulose synthase genes constitute a supergene family that includes the Cellulose synthase (CesA) family and nine Cellulose synthase-like (Csl) families, the members of which are widely involved in the biosynthesis of cellulose and hemicellulose. However, little is known about the Cellulose synthase superfamily in the family Orchidaceae, one of the largest families of angiosperms. In the present study, we identified and systematically analyzed the CesA/Csl family members in three fully sequenced Orchidaceae species, i.e., Dendrobium officinale, Phalaenopsis equestris, and Apostasia shenzhenica. A total of 125 Cellulose synthase superfamily genes were identified in the three orchid species and classified into one CesA family and six Csl families: CslA, CslC, CslD, CslE, CslG, and CslH according to phylogenetic analysis involving nine representative plant species. We found species-specific expansion of certain gene families, such as the CslAs in D. officinale (19 members). The CesA/Csl families exhibited sequence divergence and conservation in terms of gene structure, phylogeny, and deduced protein sequence, indicating multiple origins via different evolutionary processes. The distribution of the DofCesA/DofCsl genes was investigated, and 14 tandemly duplicated genes were detected, implying that the expansion of DofCesA/DofCsl genes may have originated via gene duplication. Furthermore, the expression profiles of the DofCesA/DofCsl genes were investigated using transcriptome sequencing and quantitative Real-time PCR (qRT-PCR) analysis, which revealed functional divergence in different tissues and during different developmental stages of D. officinale. Three DofCesAs were highly expressed in the flower, whereas DofCslD and DofCslC family genes exhibited low expression levels in all tissues and at all developmental stages. The 19 DofCslAs were differentially expressed in the D. officinale stems at different developmental stages, among which six DofCslAs were expressed at low levels or not at all. Notably, two DofCslAs (DofCslA14 and DofCslA15) showed significantly high expression in the stems of D. officinale, indicating a vital role in mannan synthesis. These results indicate the functional redundancy and specialization of DofCslAs with respect to polysaccharide accumulation. In conclusion, our results provide insights into the evolution, structure, and expression patterns of CesA/Csl genes and provide a foundation for further gene functional analysis in Orchidaceae and other plant species.

Characterization of repetitive sequences in Dendrobium officinale and comparative chromosomal structures in Dendrobium species using FISH.

Tandem repeats are one of the most conserved features in the eukaryote genomes. Dendrobium is the third largest genus in family Orchidaceae compromising over 1,200 species. However, the organization of repetitive sequences in Dendrobium species remains unclear. In this study, we performed the identification and characterization of the tandem repeats in D. officinale genome using graph-based clustering and Fluorescence in situ hybridization (FISH). Six major clusters including five satellite DNAs (DofSat1-5) and one 5S rDNA repeat (Dof5S) were identified as tandem repeats. The tandem organization of DofSat5 was verified by PCR amplification and southern blotting. The chromosomal locations of the repetitive DNAs in D. officinale were investigated by FISH using the tandem repeats and oligos probes. The results showed that each of the DofSat5, 5S and 45S rDNA had one pair of strong signals on D. officinale chromosomes. The distribution of repetitive DNAs along chromosomes was also investigated based on genomic in situ hybridization (GISH) among four Dendrobium species. The results suggested complex chromosomal fusion/segmentation and rearrangements during the evolution of Dendrobium species. In conclusion, the present study provides new landmarks for unequival differentiation of the Dendrobium chromosomes and facilitate the understanding the chromosome evolution in Dendrobium speceis.

Molecular dynamics simulations of DNA/PEI complexes: effect of PEI branching and protonation state.

Complexes formed by DNA and polyethylenimine (PEI) are of great research interest because of their application in gene therapy. In this work, we carried out all-atom molecular dynamics simulations to study eight types of DNA/PEI complexes, each of which was formed by one DNA duplex d(CGCGAATTCGCG)(2) and one PEI. We used eight different PEIs with four different degrees of branching and two protonation ratios of amine groups (23% and 46%) in the simulations to investigate how the branching degree and protonation state can affect the binding. We found that 46% protonated PEIs form more stable complexes with DNA, and the binding is achieved mainly through direct interaction between the protonated amine groups on PEI and the electronegative oxygens on the DNA backbone, with some degree of interaction with electronegative groove nitrogens/oxygens. For the 23% protonated PEIs, indirect interaction mediated by one or more water molecules plays an important role in binding. Compared with the protonation state, the degree of branching has a smaller effect on binding, which essentially diminishes at the protonation ratio of 46%. These simulations shed light on the detailed mechanism(s) of PEI binding to DNA, and may facilitate the design of PEI-based gene delivery carriers.

Molecular dynamics simulations of PEI mediated DNA aggregation.

Understanding the molecular mechanism of polycation induced DNA aggregation and condensation is important for optimal design of gene delivery carriers. In this work, we performed a series of all-atom molecular dynamics (MD) simulations to investigate polyethylenimine (PEI) mediated DNA aggregation. We found that PEIs condense DNA through two mechanisms: polyion bridging and electrostatic screening of the DNA charges. At PEI/DNA charge ratio >1, PEIs can completely neutralize DNAs at a short distance (∼12 Šfrom the C1' atoms), and this distance is found to be insensitive to the exact value of the charge ratio. When excess PEIs are added to a formed DNA-PEI aggregate, they are found to bind to the aggregate and increase its cationic charge. The added PEIs can also replace the PEIs previously bound to the aggregate. The excess PEIs, however, do not change the spacing of the DNAs in the aggregates. Our simulation results shed light on the mechanisms of PEI, and more generally polycation, mediated DNA aggregation and condensation.

Floral organ-specific proteome profiling of the floral ornamental orchid (Cymbidium goeringii) reveals candidate proteins related to floral organ development.

BACKGROUND: Cymbidium goeringii, belonging to the Orchidaceae family, is an important ornamental plant with striking petals and lips. Extremely diversified floral patterns and morphologies make C. goeringii good research material to examine floral development of orchids. However, no floral organ-specific protein has been identified yet. To screen floral development associated proteins, four proteomes from petal (PE), lip (LI), gynostemium (GY), and sepal (SE) were analyzed using Tandem Mass Tag-based proteomic analysis. RESULTS: A total of 6626 unique peptides encoding 2331 proteins were identified in our study. Proteins in several primary metabolic pathways, including amino acid metabolism, energy metabolism, and lipid metabolism, were identified as differentially expressed proteins. Interestingly, most of the energy metabolism-related proteins highly expressed in SE, indicating that SE is an important photosynthetic organ of C. goeringii flower. Furthermore, a number of phytohormone-related proteins and transcription factors (TFs) were identified in C. goeringii flowers. Expression analysis showed that 1-aminocyclopropane-1-carboxylate oxidase highly expressed in GY, IAA-amino acid hydrolase ILR1-like 4 and gibberellin receptor 1 C greatly expressed in LI, and auxin-binding protein ABP20 significantly expressed in SE, suggesting a significant role of hormones in the regulation of flower morphogenesis and development. For TFs, GY-highly expressed bHLH13, PE-highly expressed WRKY33, and GY-highly expressed VIP1, were identified. CONCLUSIONS: Mining of floral organ differential expressed enzymes and TFs helps us to excavate candidate proteins related to floral organ development and to accelerate the breeding of Cymbidium plants.

Phylogenetic relationships of sucrose transporters (SUTs) in plants and genome-wide characterization of SUT genes in Orchidaceae reveal roles in floral organ development.

Sucrose is the primary form of photosynthetically produced carbohydrates transported long distance in many plant species and substantially affects plant growth, development and physiology. Sucrose transporters (SUTs or SUCs) are a group of membrane proteins that play vital roles in mediating sucrose allocation within cells and at the whole-plant level. In this study, we investigated the relationships among SUTs in 24 representative plant species and performed an analysis of SUT genes in three sequenced Orchidaceae species: Dendrobium officinale, Phalaenopsis equestris, and Apostasia shenzhenica. All the SUTs from the 24 plant species were classified into three groups and five subgroups, subgroups A, B1, B2.1, B2.2, and C, based on their evolutionary relationships. A total of 22 SUT genes were identified among Orchidaceae species, among which D. officinale had 8 genes (DoSUT01-08), P. equestris had eight genes (PeqSUT01-08) and A. shenzhenica had 6 genes (AsSUT01-06). For the 22 OrchidaceaeSUTs, subgroups A, B2.2 and C contained three genes, whereas the SUT genes were found to have significantly expanded in the monocot-specific subgroup B2.1, which contained 12 genes. To understand sucrose partitioning and the functions of sucrose transporters in Orchidaceae species, we analyzed the water-soluble sugar content and performed RNA sequencing of different tissues of D. officinale, including leaves, stems, flowers and roots. The results showed that although the total content of water-soluble polysaccharides was highest in the stems of D. officinale, the sucrose content was highest in the flowers. Moreover, gene expression analysis showed that most of the DoSUTs were expressed in the flowers, among which DoSUT01,DoSUT07 and DoSUT06 had significantly increased expression levels. These results indicated that stems are used as the main storage sinks for photosynthetically produced sugar in D. officinale and that DoSUTs mainly function in the cellular machinery and development of floral organs. Our findings provide valuable information on sucrose partitioning and the evolution and functions of SUT genes in Orchidaceae and other species.

Structure-based design of imidazo[1,2-a]pyrazine derivatives as selective inhibitors of Aurora-A kinase in cells.

Co-crystallisation of the imidazo[1,2-a]pyrazine derivative 15 (3-chloro-N-(4-morpholinophenyl)-6-(pyridin-3-yl)imidazo[1,2-a]pyrazin-8-amine) with Aurora-A provided an insight into the interactions of this class of compound with Aurora kinases. This led to the design and synthesis of potent Aurora-A inhibitors demonstrating up to 70-fold selectivity in cell-based Aurora kinase pharmacodynamic biomarker assays.

Comparative metabolomic analyses of Dendrobium officinale Kimura et Migo responding to UV-B radiation reveal variations in the metabolisms associated with its bioactive ingredients.

BACKGROUND: Dendrobium officinale Kimura et Migo, a member of the genus Dendrobium, is a traditional Chinese medicine with high commercial value. The positive roles of UV-B radiation on active ingredient metabolism in various medicinal plants have been studied. However, the metabolic responses of D. officinale stems to UV-B treatment is largely unknown. METHODS: An untargeted metabolomics method was used to investigate the metabolic variations in D. officinale stems between the control and UV-B treatments. RESULTS: In total, 3,655 annotated metabolites, including 640 up- and 783 down-regulated metabolites, were identified and grouped into various primary metabolic categories. Then, a number of metabolites involved in the polysaccharide, alkaloid and flavonoid biosynthesis pathways were identified. For polysaccharide biosynthesis, several intermediate products, such as pyruvate, secologanate, tryptophan and secologanin, were significantly up-regulated by the UV-B treatment. For polysaccharide biosynthesis, many key fundamental building blocks, from the glycolysis, starch and sucrose metabolism, and fructose and mannose metabolism pathways, were induced by the UV-B treatment. For flavonoid metabolism, accumulations of several intermediate products of chalcone synthase, chalcone isomerase and flavanone 3-hydroxylase were affected by the UV-B treatment, indicating an involvement of UV-B in flavonoid biosynthesis. The UV-B induced accumulation of polysaccharides, alkaloids and flavonoids was confirmed by HPLC analysis. Our study will help to understand the effects of UV-B on the accumulation of active ingredients in D. officinale.