RESUMO
The 18O enrichment (Δ18O) of cellulose (Δ18OCel) is recognized as a unique archive of past climate and plant function. However, there is still uncertainty regarding the proportion of oxygen in cellulose (pex) that exchanges post-photosynthetically with medium water of cellulose synthesis. Particularly, recent research with C3 grasses demonstrated that the Δ18O of leaf sucrose (Δ18OSuc, the parent substrate for cellulose synthesis) can be much higher than predicted from daytime Δ18O of leaf water (Δ18OLW), which could alter conclusions on photosynthetic versus post-photosynthetic effects on Δ18OCel via pex. Here, we assessed pex in leaves of perennial ryegrass (Lolium perenne) grown at different atmospheric relative humidity (RH) and CO2 levels, by determinations of Δ18OCel in leaves, Δ18OLGDZW (the Δ18O of water in the leaf growth-and-differentiation zone) and both Δ18OSuc and Δ18OLW (adjusted for εbio, the biosynthetic fractionation between water and carbohydrates) as alternative proxies for the substrate for cellulose synthesis. Δ18OLGDZW was always close to irrigation water, and pex was similar (0.53 ± 0.02 SE) across environments when determinations were based on Δ18OSuc. Conversely, pex was erroneously and variably underestimated (range 0.02-0.44) when based on Δ18OLW. The photosynthetic signal fraction in Δ18OCel is much more constant than hitherto assumed, encouraging leaf physiological reconstructions.
Assuntos
Dióxido de Carbono , Celulose , Umidade , Isótopos de Oxigênio , Folhas de Planta , Sacarose , Folhas de Planta/metabolismo , Celulose/metabolismo , Dióxido de Carbono/metabolismo , Sacarose/metabolismo , Isótopos de Oxigênio/metabolismo , Lolium/metabolismo , Lolium/crescimento & desenvolvimento , Lolium/fisiologia , Atmosfera , Fotossíntese , Água/metabolismoRESUMO
The 13C isotope composition (δ13C) of leaf dry matter is a useful tool for physiological and ecological studies. However, how post-photosynthetic fractionation associated with respiration and carbon export influences δ13C remains uncertain. We investigated the effects of post-photosynthetic fractionation on δ13C of mature leaves of Cleistogenes squarrosa, a perennial C4 grass, in controlled experiments with different levels of vapour pressure deficit and nitrogen supply. With increasing leaf age class, the 12C/13C fractionation of leaf organic matter relative to the δ13C of atmosphere CO2 (ΔDM) increased while that of cellulose (Δcel) was almost constant. The divergence between ΔDM and Δcel increased with leaf age class, with a maximum value of 1.6, indicating the accumulation of post-photosynthetic fractionation. Applying a new mass balance model that accounts for respiration and export of photosynthates, we found an apparent 12C/13C fractionation associated with carbon export of -0.5 to -1.0. Different ΔDM among leaves, pseudostems, daughter tillers, and roots indicate that post-photosynthetic fractionation happens at the whole-plant level. Compared with ΔDM of old leaves, ΔDM of young leaves and Δcel are more reliable proxies for predicting physiological parameters due to the lower sensitivity to post-photosynthetic fractionation and the similar sensitivity in responses to environmental changes.
Assuntos
Celulose , Poaceae , Poaceae/metabolismo , Celulose/metabolismo , Isótopos de Carbono , Fotossíntese/fisiologia , Carbono , Folhas de Planta/metabolismo , Dióxido de CarbonoRESUMO
An inverse sandwich structure has been computationally predicted for uranium boride and extended to the series of actinide elements (An) from Th to Cm. The electronic structure and chemical bonding of these novel compounds have been analyzed using density functional theory and multireference wave-function based methods. We report the trends in electronic structure and bonding for An2B8, and found that (d-π)π and (d-p)δ are the most important factors in the stability of An2B8. The (f-p)δ bond provides extra stabilization for Pa2B8 and U2B8, owing to the extensive interactions of An-B8-An, resulting in a short distance for the Pa-Pa and U-U bonds.
RESUMO
Global-minimum optimizations combined with relativistic quantum chemistry calculations have been performed to characterize the ground-state stable structures of four titled compounds and to analyze the bonding properties. Th2C8 was identified as being a ThC4-Th(C2)2 structure, U2C8 has been found to favor the U-U(C8) structure, and both Th3C8 and U3C8 adopt the (AnC3)2-(AnC2) structure. Then, the wave function analyses reveal that the interactions between the Th 7s-based orbital and the σg molecular orbital of the C2 unit compensate for the excitation energy of 7s16d1 â 6d2 and lead to the stabilization of two Th(IV)s in the ThC4-Th(C2)2 structure. It also reveals that the U species exhibit magnetic exchange coupling behavior in UxC8, for instance, as seen in the direct interaction of U2C8 and the superexchange pathway of U3C8, which effectively stabilizes their low-spin states. This interpretation indicates that the geometric and electronic structures of AnxC8 species are largely influenced by the local magnetic moment and spin correlation.
RESUMO
Schisandra chinensis is a monoecious plant with unisex flowers. The fruit of S. chinensis is of high medical with economic value. The yield of S. chinensis fruit is related to the ratio of its female and male flowers. However, there is little research on its floral development and sex differentiation. To elucidate the possible mechanism for the sex differentiation of S. chinensis, we collected 18 samples of female and male flowers from three developmental stages and performed a comparative RNA-seq analysis aimed at identifying differentially expressed genes (DEGs) that may be related to sex differentiation. The results showed 936, 7179, and 6890 differentially expressed genes between female and male flowers at three developmental stages, respectively, and 466 candidate genes may play roles in sex differentiation. KEGG analysis showed genes involved in the flavonoid biosynthesis pathway and DNA replication pathway were essential for the development of female flowers. 51 MADS-box genes and 10 YABBY genes were identified in S. chinensis. The DEGs analysis indicated that MADS-box and YABBY genes were strongly related to the sex determination of S. chinensis. RT-qPCR confirmed the RNA-seq results of 20 differentially expressed genes, including three male-biased genes and 17 female-biased genes. A possible regulatory model of sex differentiation in S. chinensis was proposed according to our results. This study helps reveal the sex-differentiation mechanism of S. chinensis and lays the foundation for regulating the male-female ratio of S. chinensis in the future.
Assuntos
Schisandra , Schisandra/genética , Diferenciação Sexual , Perfilação da Expressão Gênica , Transcriptoma , Flores , Regulação da Expressão Gênica de PlantasRESUMO
In this paper, we have explored the relativistic density functional theory study on a series of deprotonated porphyrinoid (Ln) complexes of uranyl to investigate the geometrical structures and chemical bonding. The ligands bound with uranyl in the 1:1 complexes [UO2(Ln)]x (n = 4, 5, 6; x = 0, -1, -2), showing more thermodynamic stability for "in-cavity" structures of L5 and L6 than that of the "side-on" structure of L4 and an increase in stability with the increase of negative charges, L2- < L3- < L4-. Among the six ligands, the cyclo[6]pyrrole presents the best selectivity toward uranyl. Based on chemical bonding analyses, the U-NL bond in the in-cavity complexes adopts a typical dative NL â U bond with mainly ionic bonding and significant covalency, which comes from the significant orbital interaction of U 5fÏ6dδ7s hybrid AOs and NL 2p-based MOs. This work provides a systematic understanding of the coordination chemistry in uranyl pyrrole-containing macrocycle complexes and the nature of chemical bonding in such systems, which may provide inspirations for the future design of synthetic targets that could be relevant to actinide separations or in the remediation of spent nuclear fuel.
RESUMO
Sclerosing epithelioid fibrosarcoma (SEF) is a rare soft tissue tumour subtype, and those arising from the spine are even rarer. To the best of our knowledge, only 3 cases with the spine as the primary site of SEF have been previously reported. We report a 61-year-old female who presented with backache and bilateral leg numbness for 3 years, worsened over the last three months. Pathological fracture of the L1 vertebra was detected, and soft tissue density in the spinal canal and left vertebral body margin was also seen on contrast CT. She underwent tumour resection via a posterior approach, decompression, bone grafting, fusion, and internal fixation. Histology confirmed the diagnosis of SEF.
Assuntos
Fibrossarcoma , Feminino , Humanos , Pessoa de Meia-Idade , Fibrossarcoma/diagnóstico por imagem , Fibrossarcoma/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Vértebras Lombares/patologia , Biomarcadores TumoraisRESUMO
Schisandra chinensis, a traditional Chinese medicinal herb, is rich in chemical constituents, including lignans, triterpenes, polysaccharides, and volatile oils. Clinically, it is commonly used to treat cardiovascular, cerebrovascular, liver, gastrointestinal, and respiratory diseases. Modern pharmacological studies have shown that S. chinensis extract and monomers have multiple pharmacological activities in lowering liver fat, alleviating insulin resistance, and resisting oxidative stress, and have good application prospects in alleviating nonalcoholic fatty liver disease(NAFLD). Therefore, this study reviewed the research progress on chemical constituents of S. chinensis and its effect on NAFLD in recent years to provide references for the research on S. chinensis in the treatment of NAFLD.
Assuntos
Resistência à Insulina , Lignanas , Hepatopatia Gordurosa não Alcoólica , SchisandraRESUMO
BACKGROUND: The pathogenesis and related factors of central nervous system abnormality in patients with type 2 diabetes mellitus (T2DM) have always been the focus of clinical research. PURPOSE: To compare and analyze the area of white matter (WM) damage in patients with T2DM based on their level of hemoglobin A1C (HBA1c) and discuss any related factors. MATERIAL AND METHODS: Based on their levels of HBA1c, 87 patients with T2DM were divided into three groups (Group B, C, or D), of which 29 non-diabetic volunteers served as the control group (Group A). DTI data analysis was based on tract-based spatial statistics (TBSS). The obtained parameters were compared among each group and the relevant clinical factors were analyzed. RESULTS: For age, sex, mini-mental state examination (MMSE), and Montreal Cognitive Assessment (MoCA) scores, there were no statistically significant differences among groups. For fractional anisotropy (FA) and radial diffusivity (RD) of WM, there were statistically significant differences (P < 0.05, two-tailed, FWE corrected) in the local area of corpus callosum, corona radiate, superior longitudinal fasciculus, etc. Most of these were significantly correlated with body mass index (BMI), left systolic blood pressure (SBP_L), and ß2 microglobulin. CONCLUSION: Before the cognitive function was obviously impaired, abnormalities of FA and RD had been found in the corpus callosum, corona radiate, and upper fasciculus in patients with T2DM, which suggested that the damage mainly occurred in the myelin sheath of WM and may be related to systemic vascular damage.
Assuntos
Diabetes Mellitus Tipo 2 , Substância Branca , Humanos , Substância Branca/diagnóstico por imagem , Substância Branca/patologia , Imagem de Tensor de Difusão , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/patologia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , AnisotropiaRESUMO
Cadmium (Cd) is a dispensable element that can be absorbed by crops, posing a threat to human health through the food chains. Melatonin (MT), as a plant growth regulator, has been used to alleviate Cd toxicity in many plant species; however, the underlying molecular mechanisms responsible for Cd toxicity in wheat are still poorly understood. In this study, the suitable exogenous MT concentration (50 µM) was screened to mitigate Cd toxicity of wheat plants by increasing the plant height, root length, fresh or dry weight and chlorophyll content, or decreasing the malondialdehyde (MDA) content. In addition, MT application significantly increased ascorbic acid (ASA) and glutathione (GSH) content by reducing ROS production, especially in roots, further decreasing Cd content in fraction of organelles. Moreover, the expression levels of ASA-GSH synthesis genes, APX, GR, and GST were significantly increased by 171.5%, 465.2%, and 256.8% in roots, respectively, whereas GSH, DHAR, or MDHAR were significantly decreased by 48.5%, 54.3%, or 60.0% in roots under MT + Cd stress. However, the expression levels of Cd-induced metal transporter genes TaNramp1, TaNramp5, TaHMA2, TaHMA3, and TaLCT1 were significantly decreased by 53.7%, 50.1%, 86.5%, 87.2%, and 94.5% in roots under MT + Cd stress compared with alone Cd treatment, respectively. In conclusion, our results suggesting that MT alleviate Cd toxicity in wheat by enhancing ASA-GSH metabolism, suppressing Cd transporter gene expression, and regulating Cd uptake and translocation in wheat plants.
Assuntos
Ácido Ascórbico , Melatonina , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Ácido Ascórbico/metabolismo , Ácido Ascórbico/farmacologia , Cádmio/metabolismo , Cádmio/toxicidade , Glutationa/metabolismo , Humanos , Melatonina/metabolismo , Melatonina/farmacologia , Estresse Oxidativo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Triticum/metabolismoRESUMO
The present study investigated the correlation of UPLC fingerprints of raw materials of Ligustici Rhizoma et Radix samples with the anti-inflammatory effect and explored the pharmacodynamic material basis for the anti-inflammatory activity. UPLC fingerprints of 18 batches of raw materials of Ligustici Rhizoma et Radix samples were established for the determination of the content of eight components. The toe swelling rate and the content of IL-1ß, IL-6, and PGE2 in rats with toe inflammation induced by carrageenin were measured. Canonical correlation analysis was used to study the spectrum-effect relationship. Cluster analysis indicated that chemical components of Ligusticum sinense and L. jeholense were similar. Methanol extracts of L. sinense, L. jeholense, and Conioselinum vaginatum significantly reduced the toe swelling rate and the content of IL-1ß, IL-6 and PGE2 in swollen tissues. The anti-inflammatory effect of C. vaginatum was weaker than that of L. sinense and L. jeholense. The results of spectrum-effect relationship indicated that there was an obvious correlation between chemical components and pharmacodynamic indexes. In UPLC fingerprints, compounds 1, 3(chlorogenic acid), 4(cryptochlorogenic acid), 5, 6(ferulic acid), 7(isochlorogenic acid B), 9, 11, 13, 15, 16, 17, 18(coniferyl ferulate), 19, 20(N-butylphthalide), 21, 22, and 23 were significantly correlated with anti-inflammation, among which compounds 5, 11, 13, 15, 17, 21, and 23 had negative correlation. This study screened out the effective components with anti-inflammatory activity in raw materials of Ligustici Rhizoma et Radix, which was of great significance to improve the quality evaluation system of raw materials of Ligustici Rhizoma et Radix.
Assuntos
Medicamentos de Ervas Chinesas , Interleucina-6 , Animais , Anti-Inflamatórios/análise , Anti-Inflamatórios/farmacologia , Dinoprostona , Medicamentos de Ervas Chinesas/química , Ratos , Rizoma/químicaRESUMO
The active components, mainly derived from secondary metabolites of medicinal plants, are the material basis for the efficacy of medicinal plants. Lignans, the secondary metabolites in plants with high bioactivity, are widely distributed in a variety of plant species, and their antiviral, antitumor, antibacterial, and antioxidant activities have been proved in clinical practice. Generally, lignans are diverse in structures with many chiral centers, and most of them are optically active. The biosynthesis of lignans depends on the oxidative coupling reaction through site selection and stereo selection, which impedes synthesized lignans to form racemates, but makes them in a three-dimensional configuration. Dirigent protein(DIR) plays an important role in guiding location selection and stereo selection of lignans in biosynthesis. In vitro studies on lignan biosynthesis have shown that racemic end products are obtained in the absence of DIR proteins, while the products in a three-dimensional configuration can be yielded in the presence of DIR proteins, indicating that DIR proteins play an asymmetric role in the biosynthesis of plant secondary metabolites. The present study reviewed the biolo-gical significance of DIR protein, the cloning of DIR gene, gene structure, catalytic mechanism, and the research progress in Isatis indigotica, Eucommia ulmoides, Forsythia suspensa, Salvia miltiorrhiza, Panax pseudoginseng var. notoginseng, and Schisandra chinensis, which provides a reference for the follow-up research of DIR gene.
Assuntos
Forsythia , Isatis , Lignanas , Plantas Medicinais , Schisandra , Lignanas/química , Plantas Medicinais/genética , Schisandra/químicaRESUMO
BACKGROUND: The detection rate of lung nodules has increased significantly among petroleum workers in North China since the low-dose CT (LDCT) screening has been widely carried out. What's more, the number of confirmed early lung cancers is increasing continuously. Therefore, a great deal of concern for the high risk of lung cancer has been shown among petroleum workers. PURPOSE: To improve the screening efficiency and maximize the benefits of the subjects, the current situation of LDCT lung cancer screening should be understood and the imaging characteristics of early lung cancer should be analyzed for petroleum workers in North China. MATERIALS AND METHODS: Firstly, the dynamic changes of LDCT early lung cancer screening for petroleum workers in North China were analyzed in recent years. Then, the survey data of 3121 petroleum workers was compared with that of 1868 non-petroleum workers, which was analyzed. Finally, 91 patients (129 nodular lung cancer) confirmed by pathology were retrospectively analyzed, and the data of which was compared with the clinical features obtained from survey data above. The imaging characteristics and related factors of different subtypes of lung adenocarcinoma were discussed and analyzed. RESULTS: Lung nodules were found in 810 cases (25.95%) out of 3121 petroleum workers; and the surgery was chosen by 42 patients, 38 of whom were confirmed as lung cancer. Compared with the data of screened petroleum workers, there were more older people and more females as well as a higher proportion of people with family malignancy history, and a lower proportion of smoking people in 91 patients with lung cancer. As the pathological grade of tumor nodules increased, the volume and diameter of nodules gradually increased, and the mean density, maximum density and standard deviation of density also increased (p < 0.001). The volume and diameter of nodules were positively correlated with ages (p < 0.05). CONCLUSION: The occurrence of lung adenocarcinoma is closely related to the family history of malignant tumors, and the constituent ratio of young women without a history of smoking increased significantly. At the same time, the quantitative information obtained by using CT images has important value in predicting its pathological subtypes.
Assuntos
Adenocarcinoma de Pulmão/diagnóstico por imagem , Detecção Precoce de Câncer , Neoplasias Pulmonares/diagnóstico por imagem , Nódulos Pulmonares Múltiplos/diagnóstico por imagem , Doenças Profissionais/diagnóstico por imagem , Saúde Ocupacional , Indústria de Petróleo e Gás , Nódulo Pulmonar Solitário/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adenocarcinoma de Pulmão/etiologia , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/cirurgia , Adulto , Biópsia , China , Feminino , Inquéritos Epidemiológicos , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/cirurgia , Masculino , Pessoa de Meia-Idade , Nódulos Pulmonares Múltiplos/etiologia , Nódulos Pulmonares Múltiplos/patologia , Nódulos Pulmonares Múltiplos/cirurgia , Gradação de Tumores , Doenças Profissionais/etiologia , Doenças Profissionais/patologia , Doenças Profissionais/cirurgia , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Nódulo Pulmonar Solitário/etiologia , Nódulo Pulmonar Solitário/patologia , Nódulo Pulmonar Solitário/cirurgia , Carga TumoralRESUMO
Melatonin (MT) is involved in various physiological processes and stress responses in animals and plants. However, little is known about the molecular mechanisms by which MT regulates potassium deficiency (DK) tolerance in crops. In this study, an appropriate concentration (50 µmol/L) was found to enhance the tolerance of wheat plants against DK. RNA-seq analysis showed that a total of 6253 and 5873 differentially expressed genes (DEGs) were separately identified in root and leaf tissues of the DK + MT-treated wheat plants. They functionally involved biological processes of secondary metabolite, signal transduction, and transport or catabolism. Of these, an upregulated high-affinity K transporter 1 (TaHAK1) gene was next characterized. TaHAK1 overexpression markedly enhanced the K absorption, while its transient silencing exhibited the opposite effect, suggesting its important role in MT-mediated DK tolerance. Moreover, yeast one-hybrid (Y1H) was used to screen the upstream regulators of TaHAK1 gene and the transcription factor TaNAC71 was identified. The binding between TaNAC71 and TaHAK1 promoter was evidenced by using Y1H, LUC, and EMSA assays. Transient overexpression of TaNAC71 in wheat protoplasts activated the TaHAK1 expression, whereas its transient silencing inhibited the TaHAK1 expression and aggravated the sensitivity to DK. Exogenous MT application greatly upregulated the expression of TaHAK1 in both transient overexpression and silencing systems. Our findings revealed some molecular mechanisms underlying MT-mediated DK tolerance and helped broaden its practical application in agriculture.
Assuntos
Proteínas de Transporte de Cátions/metabolismo , Regulação da Expressão Gênica de Plantas/fisiologia , Melatonina/metabolismo , Proteínas de Plantas/metabolismo , Deficiência de Potássio/metabolismo , Triticum/metabolismo , Adaptação Fisiológica/fisiologia , Produtos Agrícolas/metabolismo , Reguladores de Crescimento de Plantas/metabolismoRESUMO
Cambodia is rich in medicinal plant resources. One hundred and thirty-three medicinal material samples, including the hole herb, root, stem/branch, leaf, flower, fruit, seed, and resin, were collected from the Orussey Herbal Market in Phnom Penh, Cambodia, and then authenticated by ITS and psbA-trnH. A total of 46 samples were identified based on ITS sequences, belonging to 24 families, 40 genera, and 42 species. A total of 100 samples were identified by psbA-trnH sequences to belong to 42 families, 77 genera, and 84 species. A total of 103 samples were identified by two DNA barcodes. According to the morphological characteristics of the medicinal materials, 120 samples classified into 50 species, 86 genera, and 86 families were identified, and the majority of them were from Zingiberaceae, Fabaceae, and Acanthaceae. Such samples have been commonly used in traditional Cambodian medicine, Ayurvedic medicine, Unani medicine, traditional Chinese medicine, and ethnomedicine, but different medical systems focus on different functional aspects of the same medicinal material. The results of this study have demonstrated that DNA barcoding has a significant advantage in identifying herbal products, and this study has provided basic data for understanding the traditional medicinal materials used in Cambodia.
Assuntos
Código de Barras de DNA Taxonômico , Plantas Medicinais , Camboja , DNA de Plantas/genética , Humanos , Folhas de Planta , Plantas Medicinais/genéticaRESUMO
Dirigent(DIR) proteins are involved in the biosynthesis of lignin, lignans, and gossypol in plants and respond to biotic and abiotic stresses. Based on the full-length transcriptome of Schisandra chinensis, bioinformatics methods were used to preliminarily identify the DIR gene family and analyze the physico-chemical properties, subcellular localization, conserved motifs, phylogeny, and expression patterns of the proteins. The results showed that a total of 34 DIR genes were screened and the encoded proteins were 156-387 aa. The physico-chemical properties of the proteins were different and the secondary structure was mainly random coil. Half of the DIR proteins were located in chloroplast, while the others in extracellular region, endoplasmic reticulum, cytoplasm, etc. Phylogenetic analysis of DIR proteins from S. chinensis and the other 8 species such as Arabidopsis thaliana, Oryza sativa, and Glycine max demonstrated that all DIR proteins were clustered into 5 subfamilies and that DIR proteins from S. chinensis were in 4 subfamilies. DIR-a subfamily has the unique structure of 8 ß-sheets, as verified by multiple sequence alignment. Finally, through the analysis of the transcriptome of S. chinensis fruit at different development stages, the expression pattern of DIR was clarified. Combined with the accumulation of lignans in fruits at different stages, DIR might be related to the synthesis of lignans in S. chinensis. This study lays a theoretical basis for exploring the biological functions of DIR genes and elucidating the biosynthesis pathway of lignans in S. chinensis.
Assuntos
Lignanas , Schisandra , Frutas/química , Frutas/genética , Lignanas/análise , Filogenia , Alinhamento de SequênciaRESUMO
An UPLC method was established for the direct determination of six major bioactive isosteroidal alkaloids, namely peimisine, imperialine, sipeimine-3-D-glucoside, verticinone, verticine and hupehenine from the bulbus of Fritillaria(Beimu), a commonly used antitussive traditional Chinese medicinal(TCM) herb. An Acquity UPLC~(TM) CSH C_(18) column(2.1 mm×100 mm, 1.7 µm) was used for all analysis. The investigated six compounds were all separated with gradient mobile phase consisting of 0.02% diethylamine-water-methanol at a flow rate of 0.3 mL·min~(-1). The temperature of sample manager was set at 20 â. Drift tube temperature was 45 â, and spray parameter was 40% with injection volume of 1 µL. Then, the further quality assessment of Beimu was carried out by cluster analysis(CA) and principal component analysis(PCA). The investigated all had good linearity(r≥0.998 9) over the tested ranges. The method is simple, accurate and reproducible, and can be used for determining the content of six major bioactive isosteroidal alkaloids.
Assuntos
Alcaloides/análise , Medicamentos de Ervas Chinesas/química , Fritillaria/química , Alcaloides/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Raízes de Plantas/químicaRESUMO
Ferritin is a ubiquitous iron storage protein which plays key role in regulating iron homeostasis and metabolism. In this paper, the ferritin heavy chain homologs (HCH) and light chain homologs (LCH) from Bombyx mori (BmFerHCH and BmFerLCH) were amplified through PCR and cloned into the expression vector pET-30a(+). The recombinant BmFerHCH and BmFerLCH expressed in Escherichia coli were in the form of insoluble inclusion bodies, indicating that the two proteins were not in their natural structural conformation. In order to obtain refolded ferritin in vitro, the inclusion bodies (BmFerHCH and/or BmFerLCH) were dissolved in denaturing buffer (100 mM Tris, 50 mM Glycine, 8 M urea, 5 mM DTT, pH 8.0) and then refolded in refolding buffer (100 mM Tris, 400 mM L-arginine, 0.2 mM PMSF, 0.5 mM DTT). The result showed that it was only when both BmFerHCH and BmFerLCH were present together in the denaturing buffer that refolding was successful and resulted in the formation of heteropolymers (H-L chain dimers) over homopolymers (H-H chain or L-L chain dimers). Moreover, the molecules (NaCl, Triton and glycerol) were found to enhance protein refolding. The optimum temperature, pH and ratios of BmFerHCH/BmFerLCH required for refolding were found to be 10 °C, pH 7, 1:1 or 1:2, respectively. Finally, the refolded ferritin had the ability to store iron, exhibited ferroxidase activity, and could withstand high temperatures and pH treatment, which is consistent with ferritin in other species.
Assuntos
Bombyx/metabolismo , Ferritinas/metabolismo , Animais , Clonagem Molecular , Corpos de Inclusão/metabolismo , Ferro/metabolismoRESUMO
Eight new cadinene-sesquiterpenes (1-8), one eudesmane-sesquiterpene (9), and three known compounds (10-13) were isolated from an endophytic fungus, Aspergillus flavus, which was isolated from a toxic medicinal plant, Tylophora ovata. Their structures were elucidated by interpretation of spectroscopic data, and absolute configurations determined according to the specific rotation and electron circular dichroism methods. Compounds 4-8, 11, and 12 exhibited latent hepatic protection effects at 10 µM, and compound 12 selectively inhibited the proliferation of MCF-7 breast cancer cells with an IC50 values of 2.6 µM.
Assuntos
Aspergillus flavus/química , Endófitos/química , Sesquiterpenos/isolamento & purificação , Células Hep G2 , Humanos , Fígado/efeitos dos fármacos , Células MCF-7 , Espectroscopia de Ressonância Magnética , Sesquiterpenos/química , Sesquiterpenos/farmacologiaRESUMO
Antithrombus is one of the effective methods to prevent and treat cardiovascular diseases. Based on the theory of traditional Chinese medicine,the author's previous research and relevant literature,it was found that the alkaloids in Houttuynia cordata has potential antithrombotic effect. However,the pharmacological substance basis and antithrombotic mechanism of H. cordata have not been clarified. In this study,molecular docking was used for virtual screening of antithrombotic alkaloids from H. cordata. Seventy alkaloids selected from H. cordata were screened in the docking ligand data-base with teen thrombosis targets with known crystal structures as the receptors. In addition,the small-molecule approved or to be approved drugs of targets from Drug Bank database were set as a positive reference with minimum score(S value) of each target's approved or to be approved drugs as threshold. The Dock module in Molecular Operating Environment(Version 2016) software was applied to screen the potential active compounds which their scores(S value) were lower than the minimum score of reference. At last the mechanism of antithrombotic effect was preliminarily revealed by compared the main active sites of the test alkaloids with original ligands and references. This study provided some useful information to development of antithrombus drugs.