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1.
PLoS One ; 15(9): e0239364, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991579

RESUMO

Natural products obtained from species of the genus Abuta (Menispermaceae) are known as ethnobotanicals that are attracting increasing attention due to a wide range of their pharmacological properties. In this study, the alkaloids stepharine and 5-N-methylmaytenine were first isolated from branches of Abuta panurensis Eichler, an endemic species from the Amazonian rainforest. Structure of the compounds was elucidated by a combination of 1D and 2D NMR spectroscopic and MS and HRMS spectrometric techniques. Interaction of the above-mentioned alkaloids with acetylcholinesterase enzyme and interleukins IL-6 and IL-8 was investigated in silico by molecular docking. The molecules under investigation were able to bind effectively with the active sites of the AChE enzyme, IL-6, and IL-8 showing affinity towards the proteins. Along with the theoretical study, acetylcholinesterase enzyme inhibition, cytotoxic, and immunomodulatory activity of the compounds were assessed by in vitro assays. The data obtained in silico corroborate the results of AChE enzyme inhibition, the IC50 values of 61.24µM for stepharine and 19.55µM for 5-N-methylmaytenine were found. The compounds showed cytotoxic activity against two tumor cell lines (K562 and U937) with IC50 values ranging from 11.77 µM to 28.48 µM. The in vitro assays revealed that both alkaloids were non-toxic to Vero and human PBMC cells. As for the immunomodulatory activity, both compounds inhibited the production of IL-6 at similar levels. Stepharine inhibited considerably the production of IL-8 in comparison to 5-N-methylmaytenine, which showed a dose dependent action (inhibitory at the IC50 dose, and stimulatory at the twofold IC50 one). Such a behavior may possibly be explained by different binding modes of the alkaloids to the interleukin structural fragments. Occurrence of the polyamine alkaloid 5-N-methylmaytenine was reported for the first time for the Menispermaceae family, as well as the presence of stepharine in A. panurensis.


Assuntos
Acetilcolinesterase/metabolismo , Alcaloides/farmacologia , Antineoplásicos/farmacologia , Inibidores da Colinesterase/farmacologia , Simulação por Computador , Fatores Imunológicos/farmacologia , Menispermaceae/química , Alcaloides/metabolismo , Antineoplásicos/metabolismo , Linhagem Celular Tumoral , Inibidores da Colinesterase/metabolismo , Humanos , Fatores Imunológicos/metabolismo , Interleucina-6/química , Interleucina-6/metabolismo , Interleucina-8/química , Interleucina-8/metabolismo , Simulação de Acoplamento Molecular , Conformação Proteica
2.
Food Chem ; 332: 127412, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32623128

RESUMO

In this study, metabolomics and proteomics were employed to investigate the change mechanism of nonvolatile compounds during white tea processing. A total of 99 nonvolatile compounds were identified, among which the contents of 13 free amino acids, caffeine, theaflavins, 7 nucleosides and nucleotides, and 5 flavone glycosides increased significantly, while the contents of theanine, catechins, theasinesins, 3 proanthocyanidins, and phenolic acids decreased significantly during the withering period. The results of proteomics indicated that the degradation of proteins accounted for the increase in free amino acid levels; the weakened biosynthesis, in addition to oxidation, also contributed to the decrease in flavonoid levels; the degradation of ribonucleic acids contributed to the increase in nucleoside and nucleotide levels during the withering period. In addition, the drying process was found to slightly promote the formation of white tea taste. Our study provides a novel characterization of white tea taste formation during processing.


Assuntos
Camellia sinensis/química , Metabolômica/métodos , Chá/química , Alcaloides/análise , Alcaloides/metabolismo , Camellia sinensis/metabolismo , Catecóis/análise , Catecóis/metabolismo , Flavonoides/análise , Flavonoides/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Análise de Componente Principal , Proteômica , Chá/metabolismo
3.
Plant Mol Biol ; 103(6): 705-718, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32577984

RESUMO

Fritillariae Bulbus are the most commonly used antitussive and edible herbs in China. Based on UPLC-QTOF-MS and UPLC-QQQ-MS, the validated MRM-based non-targeted quantitative method was applied to determinate the contents of 48 Fritillaria alkaloids (FAs) in three Fritillaria species (F. thunbergii Miq., F. unibracteata and F. ussuriensis). The RNA-Seq results showed that gene transcript levels have different expression patterns in three Fritillaria species. Based on transcriptome data, the full-length cDNA sequences of squalene epoxidase gene were cloned and characterized. Natural evolution of squalene epoxidase genes resulted in four mutations (C236R, M489L, G510A and K517R) in three Fritillaria species. Molecular docking analysis showed that the 236 residue is located inside the pocket and the binding center while other three residues are located on the surface of the protein. Functional verification indicated the mutations of SQE (C236R) could effectively increase the activity of SQE and obtain higher yield of 2,3-oxidosqualene in recombinant yeast. And the mutations of SQE (M489L and G510A), which increased the hydrophobicity of the protein surface, could also enhance the activity of SQE. This study provides major insights into the metabolites differentiation of FAs biosynthesis, and a firm foundation for the quality control and metabolic engineering of Fritillariae bulbus.


Assuntos
Fritillaria/enzimologia , Esqualeno Mono-Oxigenase/metabolismo , Alcaloides/metabolismo , Cromatografia Líquida de Alta Pressão , DNA Complementar/genética , Simulação de Acoplamento Molecular , Mutação/genética , Filogenia , Alinhamento de Sequência , Esqualeno Mono-Oxigenase/genética
4.
Plant Mol Biol ; 103(4-5): 581-596, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32409993

RESUMO

KEY MESSAGE: N-glycans play a protective or monitoring role according to the folding state of associated protein or the distance from structural defects. Asparagine-linked (Asn/N-) glycosylation is one of the most prevalent and complex protein modifications and the associated N-glycans play crucial roles on protein folding and secretion. The studies have shown that many glycoproteins hold multiple N-glycans, yet little is known about the redundancy of N-glycans on a protein. In this study, we used BRI1 to decipher the roles of N-glycans on protein secretion and function. We found that all 14 potential N-glycosylation sites on BRI1 were occupied with oligosaccharides. The elimination of single N-glycan had no obvious effect on BRI1 secretion or function except N154-glycan, which resulted in the retention of BRI1 in the endoplasmic reticulum (ER), similar to the loss of multiple highly conserved N-glycans. To misfolded bri1, the absence of N-glycans next to local structural defects enhanced the ER retention and the artificial addition of N-glycan could help the misfolded bri1-GFPs exiting from the ER, indicating that the N-glycans might serve as steric hindrance to protect the structure defects from ER recognition. We also found that the retention of misfolded bri1-9 by lectins and chaperones in the ER relied on the presence of multiple N-glycans distal to the local defects. Our findings revealed that the N-glycans might play a protective or monitoring role according to the folding state of associated protein or the distance from structural defects.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Retículo Endoplasmático/metabolismo , Polissacarídeos/metabolismo , Proteínas Quinases/metabolismo , Transdução de Sinais/fisiologia , Alcaloides/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Glicoproteínas/metabolismo , Glicosídeo Hidrolases/metabolismo , Glicosilação , Modelos Moleculares , Oligossacarídeos/metabolismo , Plantas Geneticamente Modificadas , Conformação Proteica , Domínios Proteicos , Processamento de Proteína Pós-Traducional , Plântula , Sementes/citologia , Sementes/metabolismo , Transdução de Sinais/genética
5.
Psychopharmacology (Berl) ; 237(8): 2327-2343, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32399631

RESUMO

RATIONALE: The c-Jun N-terminal kinase (JNK) pathway and neurotrophic factor dysregulation play a critical role in the pathogenesis of neurobehavioral disorders (anxiety and depression). Targeting the JNK pathway and BDNF/VEGF signaling may signify a new avenue for the treatment of neurobehavioral disorders. OBJECTIVES: The present study investigated the effect of matrine (Mat) against anxiety- and depressive-like emotional status in an acute mouse model of burn injury and explores its underlying mechanism. METHODS: In the mouse model of thermal injury, anxiety- and depression-related behaviors were evaluated using the elevated plus-maze test, the light-dark box test, the open-field test, the forced swimming test, and the tail suspension test. The JNK/caspase-3 and BDNF/VEGF proteins were determined by immunohistochemistry. Additionally, proinflammatory cytokine, antioxidant, nitric oxide, and corticosterone levels were also measured. RESULTS: The results showed that treatment with Mat significantly improves anxiety- and depressive-like behaviors. It remarkably reduced the levels of proinflammatory cytokines, malondialdehyde, and nitric oxide in the hippocampus and prefrontal cortex of a mouse brain. It considerably improved burn-induced alteration in the antioxidant status, corticosterone, and BDNF/VEGF. It also inhibited burn-induced apoptotic signaling by downregulating the expression of JNK/caspase-3. Similarly, it prevented DNA damage and histopathological changes in the dentate gyrus of the hippocampus. Furthermore, molecular docking results showed that Mat possess better binding affinity for JNK/caspase-3 and BDNF/VEGF proteins. CONCLUSIONS: These findings provide convincing evidence that Mat improves anxiety- and depressive-like emotional status through modulation of JNK-mediated inflammatory, oxidative stress, apoptotic, and BDNF/VEGF signaling in an acute mouse model of burn injury.


Assuntos
Alcaloides/metabolismo , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Queimaduras/metabolismo , Caspase 3/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Quinolizinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Alcaloides/farmacologia , Alcaloides/uso terapêutico , Animais , Ansiolíticos/metabolismo , Ansiolíticos/farmacologia , Ansiolíticos/uso terapêutico , Ansiedade/tratamento farmacológico , Ansiedade/metabolismo , Fator Neurotrófico Derivado do Encéfalo/antagonistas & inibidores , Queimaduras/tratamento farmacológico , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Simulação de Acoplamento Molecular/métodos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Quinolizinas/farmacologia , Quinolizinas/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores
6.
Life Sci ; 253: 117671, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32335165

RESUMO

AIMS: We still do not have effective treatment for hippocampal demyelination and memory deficit, the two common comorbidities in multiple sclerosis (MS). This study aimed to assess the therapeutic effect of Piperine (the main alkaloid of black pepper) in an experimental model of demyelination. MAIN METHODS: Demyelination was induced in male Wistar rats by bilateral injection of lysolecithin (LPC) into the CA1 region of the hippocampus. Piperine (5, 10, 20 mg/kg) was daily injected intraperitoneally three days post LPC injection for ten days. The spatial memory was examined by the Morris water maze task. Demyelination and astrocyte activation were assessed by an immunohistological study. The gene expression analysis of TNF-α, IL1-ß, NF-κB, IL-10, Foxp3, iNOS, Nrf2, HO1, MBP, and BDNF was done using qPCR. The total antioxidant capacity of hippocampal tissue was measured using FRAP assay. KEY FINDINGS: Our results showed that piperine improved the memory performance and myelin repair in the hippocampal demyelination model. Piperine inhibited iNOS expression concomitant with enhanced expression levels of Nrf2, HO1 and the total antioxidant capacity in the hippocampal tissue. Piperine treatment significantly reduced the gene expression level of TNF-α, IL1-ß, NF-κB, and glial activation in the injured area; however, the mRNA level of IL-10, Foxp3, BDNF and MBP were significantly increased. SIGNIFICANCE: We found piperine to be an effective treatment for spatial memory impairment and myelin repair in the hippocampal demyelination model. However, further experimental evidence is needed to investigate the precise mechanisms underlying piperine as a promising therapeutic target in MS patients.


Assuntos
Alcaloides/farmacologia , Benzodioxóis/farmacologia , Doenças Desmielinizantes/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Lisofosfatidilcolinas/metabolismo , Transtornos da Memória/tratamento farmacológico , Bainha de Mielina/efeitos dos fármacos , Piperidinas/farmacologia , Alcamidas Poli-Insaturadas/farmacologia , Alcaloides/metabolismo , Animais , Antioxidantes/metabolismo , Antioxidantes/farmacologia , Benzodioxóis/metabolismo , Citocinas/genética , Citocinas/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Modelos Animais , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Piperidinas/metabolismo , Alcamidas Poli-Insaturadas/metabolismo , Ratos , Ratos Wistar , Memória Espacial/efeitos dos fármacos
7.
J Chem Ecol ; 46(4): 442-454, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32314119

RESUMO

Elevational gradients affect the production of plant secondary metabolites through changes in both biotic and abiotic conditions. Previous studies have suggested both elevational increases and decreases in host-plant chemical defences. We analysed the correlation of alkaloids and polyphenols with elevation in a community of nine Ficus species along a continuously forested elevational gradient in Papua New Guinea. We sampled 204 insect species feeding on the leaves of these hosts and correlated their community structure to the focal compounds. Additionally, we explored species richness of folivorous mammals along the gradient. When we accounted for Ficus species identity, we found a general elevational increase in flavonoids and alkaloids. Elevational trends in non-flavonol polyphenols were less pronounced or showed non-linear correlations with elevation. Polyphenols responded more strongly to changes in temperature and humidity than alkaloids. The abundance of insect herbivores decreased with elevation, while the species richness of folivorous mammals showed an elevational increase. Insect community structure was affected mainly by alkaloid concentration and diversity. Although our results show an elevational increase in several groups of metabolites, the drivers behind these trends likely differ. Flavonoids may provide figs with protection against abiotic stressors. In contrast, alkaloids affect insect herbivores and may provide protection against mammalian herbivores and pathogens. Concurrent analysis of multiple compound groups alongside ecological data is an important approach for understanding the selective landscape that shapes plant defences.


Assuntos
Alcaloides/metabolismo , Altitude , Ficus/química , Flavonoides/metabolismo , Cadeia Alimentar , Herbivoria , Feromônios/análise , Animais , Biota , Insetos/fisiologia , Mamíferos/fisiologia , Papua Nova Guiné , Folhas de Planta/química
8.
J Chem Ecol ; 46(4): 410-421, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32125583

RESUMO

The symbiotic Epichloë festucae var. lolii endophyte produces alkaloids which can provide its host grass, perennial ryegrass (Lolium perenne L), with a selective advantage in both natural and agricultural managed ecosystems. This study focuses on understanding the alkaloid concentrations that occur in endophyte-infected perennial ryegrass during the early establishment phase. In a glasshouse experiment fungal alkaloid concentrations (peramine, lolitrem B, ergovaline, and epoxy-janthitrems) were measured in perennial ryegrass seedlings infected with E. festucae var. lolii proprietary strains AR1, AR37, NEA2, and NZ common toxic for 69 days after sowing. The endophyte becomes metabolically active, starting alkaloid production, as early as 6 days after sowing. Alkaloid concentrations peaked in 8- to 10- day-old seedlings due to a seedling growth slowdown. This study provides data showing that the loss of insect protection in endophyte-infected seedlings is linked to a reduction in chemical defence after seed-stored, maternally synthesised alkaloids are diluted by seedling dry matter accumulation.


Assuntos
Alcaloides/metabolismo , Endófitos/metabolismo , Epichloe/metabolismo , Lolium/crescimento & desenvolvimento , Lolium/microbiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Simbiose
9.
Int J Mol Sci ; 21(3)2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-32013237

RESUMO

Dendrobium is widely used in traditional Chinese medicine, which contains many kinds of active ingredients. In recent years, many Dendrobium transcriptomes have been sequenced. Hence, weighted gene co-expression network analysis (WGCNA) was used with the gene expression profiles of active ingredients to identify the modules and genes that may associate with particular species and tissues. Three kinds of Dendrobium species and three tissues were sampled for RNA-seq to generate a high-quality, full-length transcriptome database. Based on significant changes in gene expression, we constructed co-expression networks and revealed 19 gene modules. Among them, four modules with properties correlating to active ingredients regulation and biosynthesis, and several hub genes were selected for further functional investigation. This is the first time the WGCNA method has been used to analyze Dendrobium transcriptome data. Further excavation of the gene module information will help us to further study the role and significance of key genes, key signaling pathways, and regulatory mechanisms between genes on the occurrence and development of medicinal components of Dendrobium.


Assuntos
Dendrobium/genética , Proteínas de Plantas/genética , Transcriptoma , Alcaloides/análise , Alcaloides/metabolismo , Análise por Conglomerados , Dendrobium/química , Dendrobium/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Genômica , Medicina Tradicional Chinesa , Proteínas de Plantas/metabolismo , Polissacarídeos/análise , Polissacarídeos/metabolismo
10.
Artigo em Inglês | MEDLINE | ID: mdl-32050157

RESUMO

Dendrobium nobile is an important medicinal food beneficial for human health, well known for polysaccharides and dendrobine. For fast, accurate, and comprehensive comparison of its quality, high performance liquid chromatography (HPLC) fingerprinting method was constructed. Firstly, spring frost stressed D. nobile herb was observed for assessment. Decreased leaf thickness, chlorophyll, and drying rate, and increased free-proline indicated heavy damages on growth. But, the content of polysaccharides increased significantly in during-frost (DF), and dropped significantly in after-frost (AF). The content of dendrobine accumulated significantly in AF. Then, low similarity among HPLC fingerprints of before-frost (BF), DF, and AF, and 75.82% of significantly variant peaks indicated the changing of much more components. Especially, some less-polar components increased significantly in DF, but not in AF. Moreover, the highest suppression rates (SRs) to A549 lung cancer cells were up to 33.08% in DF, but only 15.63% and 12.12% in BF and AF. After association analysis, eleven less-polar components were found to be significantly and positively correlated to SRs under relatively high concentration. The result shows that frost stress not only causes damages to plant growth, but also promotes the accumulation of some health-beneficial bioactive metabolites. HPLC based fingerprinting method shows good applicability on quality evaluation and bioactivity correlation analysis of complexed agricultural products.


Assuntos
Alcaloides/metabolismo , Antineoplásicos/metabolismo , Dendrobium/química , Extratos Vegetais/metabolismo , Folhas de Planta/química , Polissacarídeos/metabolismo , Células A549 , Alcaloides/análise , Antineoplásicos/análise , Apoptose/efeitos dos fármacos , Cromatografia Gasosa , Cromatografia Líquida de Alta Pressão , Humanos , Extratos Vegetais/análise , Polissacarídeos/análise , Reprodutibilidade dos Testes , Metabolismo Secundário
11.
Acta Crystallogr F Struct Biol Commun ; 76(Pt 2): 74-80, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32039888

RESUMO

Cytisine, a natural product with high affinity for clinically relevant nicotinic acetylcholine receptors (nAChRs), is used as a smoking-cessation agent. The compound displays an excellent clinical profile and hence there is an interest in derivatives that may be further improved or find use in the treatment of other conditions. Here, the binding of a cytisine derivative modified by the addition of a 3-(hydroxypropyl) moiety (ligand 4) to Aplysia californica acetylcholine-binding protein (AcAChBP), a surrogate for nAChR orthosteric binding sites, was investigated. Isothermal titration calorimetry revealed that the favorable binding of cytisine and its derivative to AcAChBP is driven by the enthalpic contribution, which dominates an unfavorable entropic component. Although ligand 4 had a less unfavorable entropic contribution compared with cytisine, the affinity for AcAChBP was significantly diminished owing to the magnitude of the reduction in the enthalpic component. The high-resolution crystal structure of the AcAChBP-4 complex indicated close similarities in the protein-ligand interactions involving the parts of 4 common to cytisine. The point of difference, the 3-(hydroxypropyl) substituent, appears to influence the conformation of the Met133 side chain and helps to form an ordered solvent structure at the edge of the orthosteric binding site.


Assuntos
Alcaloides/metabolismo , Aplysia/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Conformação Proteica , Receptores Nicotínicos/metabolismo , Termodinâmica , Alcaloides/química , Animais , Azocinas/química , Azocinas/metabolismo , Sítios de Ligação , Cristalografia por Raios X , Humanos , Ligantes , Modelos Moleculares , Ligação Proteica , Quinolizinas/química , Quinolizinas/metabolismo
12.
Food Chem ; 317: 126406, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32097823

RESUMO

In this study, 50 tomato landraces grown in Turkey were investigated in terms of their secondary metabolite profiles. Each accession was planted in 2016 and 2017 in 3 replicates in an open field. In this study, color, pH and brix of the fruit samples were measured and an unbiased LCMS-based metabolomics approach was applied. Based on Principal Components Analysis (PCA) and Hierarchical Cluster Analysis (HCA) of the relative abundance levels of >250 metabolites, it could be concluded that fruit size was the most influential to the biochemical composition, rather than the geographical origin of accessions. Results indicated substantial biodiversity in various metabolites generally regarded as key to fruit quality aspects, including sugars; phenolic compounds like phenylpropanoids and flavonoids; alkaloids and glycosides of flavour-related volatile compounds. The phytochemical data provides insight into which Turkish accessions might be most promising as starting materials for the tomato processing and breeding industries.


Assuntos
Frutas/metabolismo , Lycopersicon esculentum/metabolismo , Alcaloides/análise , Alcaloides/metabolismo , Cromatografia Líquida , Análise por Conglomerados , Flavonoides/análise , Flavonoides/metabolismo , Frutas/química , Glicosídeos/análise , Glicosídeos/metabolismo , Concentração de Íons de Hidrogênio , Lycopersicon esculentum/química , Espectrometria de Massas , Metabolômica/métodos , Metabolômica/estatística & dados numéricos , Fenóis/análise , Fenóis/metabolismo , Análise de Componente Principal , Metabolismo Secundário , Turquia
14.
J Med Chem ; 63(6): 3131-3141, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32105468

RESUMO

Structure-based stabilization of protein-protein interactions (PPIs) is a promising strategy for drug discovery. However, this approach has mainly focused on the stabilization of native PPIs, and non-native PPIs have received little consideration. Here, we identified a non-native interaction interface on the three-dimensional dimeric structure of the N-terminal domain of the MERS-CoV nucleocapsid protein (MERS-CoV N-NTD). The interface formed a conserved hydrophobic cavity suitable for targeted drug screening. By considering the hydrophobic complementarity during the virtual screening step, we identified 5-benzyloxygramine as a new N protein PPI orthosteric stabilizer that exhibits both antiviral and N-NTD protein-stabilizing activities. X-ray crystallography and small-angle X-ray scattering showed that 5-benzyloxygramine stabilizes the N-NTD dimers through simultaneous hydrophobic interactions with both partners, resulting in abnormal N protein oligomerization that was further confirmed in the cell. This unique approach based on the identification and stabilization of non-native PPIs of N protein could be applied toward drug discovery against CoV diseases.


Assuntos
Alcaloides/farmacologia , Antivirais/farmacologia , Indóis/farmacologia , Proteínas do Nucleocapsídeo/metabolismo , Multimerização Proteica/efeitos dos fármacos , Alcaloides/química , Alcaloides/metabolismo , Sequência de Aminoácidos , Animais , Antivirais/química , Antivirais/metabolismo , Chlorocebus aethiops , Cristalografia por Raios X , Desenho de Fármacos , Interações Hidrofóbicas e Hidrofílicas , Indóis/química , Indóis/metabolismo , Coronavírus da Síndrome Respiratória do Oriente Médio/química , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Simulação de Acoplamento Molecular , Proteínas do Nucleocapsídeo/química , Ligação Proteica , Domínios Proteicos , Alinhamento de Sequência , Células Vero
15.
Molecules ; 25(4)2020 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-32070000

RESUMO

Invertebrates are an important source of structurally-diverse and biologically-active halogenated metabolites. The sea hare Aplysia dactylomela Rang has long been known to possess halogenated metabolites of dietary origin that are used as a self-defense mechanism. The compounds from Aplysia dactylomela Rang are comprised mainly of terpenoids and small percentages of C-15 acetogenins, indoles, macrolides, sterols and alkaloids with potent cytotoxic, anti-microbial and anti-inflammatory properties. For decades the metabolites discovered have been investigated for their medical and pharmaceutical applications, so much so that the ecological role of the metabolites has been overlooked. The interaction between Aplysia dactylomela Rang and its diet that is comprised of seaweed can provide information into the distribution and diversity of the seaweed, the application of bioaccumulated secondary metabolites as part of its defense mechanism and the potential roles of these metabolites for adaptation in the marine environment. This paper compiles the diversity of halogenated secondary metabolites documented from Aplysia dactylomela Rang.


Assuntos
Aplysia/metabolismo , Acetogeninas/metabolismo , Alcaloides/metabolismo , Animais , Halogenação , Indóis/metabolismo , Macrolídeos/metabolismo , Alga Marinha , Esteróis/metabolismo
16.
Lett Appl Microbiol ; 70(4): 318-325, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31951031

RESUMO

Fermentation is a traditional processing method that can impact the abundance of relevant components in Chinese herbal medicines. Huafeng Dan Yaomu was processed by fermentation. In this study, we investigated changes in toxic alkaloids using high-performance liquid chromatography and analysed the changes in microbial communities during fermentation of Huafeng Dan Yaomu by Illumina MiSeq platform. The results indicated that highly toxic alkaloid compounds including aconitine, mesaconitine and hypaconitine were decreased, whereas benzoylmesaconine and benzoylhypaconitine were increased during fermentation. The dominant bacterial genera in the raw material (day 0) were Bacillus (58·38%), Enterobacter (16·05%), Enterococcus (4·10%) and others (11·48%). After 7 days of fermentation, Pediococcus predominated, increasing from 98·26 to 99·97%. The dominant fungal genera in the raw material (day 0) were Incertae_Sedis_incertae_sedis (45·36%), Eurotiales_unclassified (20·63%), Millerozyma (15·58%) and Saccharomycopsis (10·64%). After 7 days of fermentation, Saccharomycopsis was increased to 90·84%. After 14 days of fermentation, Pichia became the main fungal genera in the fermentation process. There were 16 bacterial genera and seven fungal genera that displayed significant correlation with toxic alkaloids. The dynamics of the microbiota and chemical compounds during fermentation of Huafeng Dan Yaomu were revealed, providing a foundation for further investigation of the effects of microbes on chemical compounds and insights into the manufacturing of Huafeng Dan Yaomu. SIGNIFICANCE AND IMPACT OF THE STUDY: Huafeng Dan Yaomu is a unique fermentation-based micro-organism product. This study reveals that the change in toxic alkaloids during fermentation was related to micro-organisms. The results of this study can be used to improve the Chinese herb medicine fermentation process, such as the selection of beneficial strains and their composition for modern fermentation. The results of this study may also provide new ideas for the processing of Traditional Chinese Medicine.


Assuntos
Alcaloides/metabolismo , Bactérias/metabolismo , Medicamentos de Ervas Chinesas/metabolismo , Fungos/metabolismo , Plantas Medicinais/microbiologia , Alcaloides/análise , Alcaloides/toxicidade , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Medicamentos de Ervas Chinesas/análise , Fermentação , Fungos/classificação , Fungos/genética , Fungos/isolamento & purificação , Microbiota
17.
IET Nanobiotechnol ; 14(1): 78-85, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31935682

RESUMO

The study aims to document the effect of starch-stabilised copper-based nanoparticles (CuNPs) on the biosynthesis of pharmaceutically valuable secondary metabolites, especially saponins, of the reputed nootropic herb Bacopa monnieri (L.) Pennell. CuNPs were synthesised chemically by the reduction of cupric sulphate pentahydrate with ascorbic acid using starch as the capping agent. They were characterised by UV-visible spectrophotometry, Fourier-transform infra-red spectroscopy, X-ray diffraction, high-resolution transmission electron microscopy and zeta potential. The nanoparticles consisted of cuprous oxide and metallic copper, were approximately spherical, polydispersed with diameter <20 nm. Hydroponically grown B. monnieri plants were treated in vivo with the CuNPs between the concentrations of 0-100 mg l-1. Spectrophotometric estimation of the total contents of saponins, alkaloids, phenolics, flavonoids and DPPH radical scavenging capacity from the methanolic extracts of the whole plants showed a hormetic increase in the content of secondary metabolites in a concentration-dependent manner from 5 mg l-1 until it declined at toxic metabolic concentration. This was accompanied by an increase in ROS markers hydrogen peroxide and malondialdehyde as well as a hormetic effect on activities of phenylalanine ammonia lyase and antioxidant enzymes catalase, ascorbate peroxidase and superoxide dismutase. CuNPs at sub-toxic concentrations were found to enhance secondary metabolism and antioxidant capacity in Bacopa monnieri through ROS-mediated defence response.


Assuntos
Bacopa , Cobre/farmacologia , Nanopartículas Metálicas/química , Alcaloides/metabolismo , Antioxidantes/análise , Antioxidantes/metabolismo , Bacopa/efeitos dos fármacos , Bacopa/enzimologia , Bacopa/metabolismo , Cobre/química , Hidroponia , Nanopartículas Metálicas/toxicidade , Tamanho da Partícula , Fenóis/metabolismo , Saponinas/metabolismo , Amido
18.
J Agric Food Chem ; 68(5): 1169-1185, 2020 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-31922733

RESUMO

Epichloë endophytes in forage grasses have attracted widespread attention and interest of chemistry researchers as a result of the various unique chemical structures and interesting biological activities of their secondary metabolites. This review describes the diversity of unique chemical structures of taxa from Epichloë endophytes and grass infected with Epichloë endophytes and demonstrates their reported biological activities. Until now, nearly 160 secondary metabolites (alkaloids, peptides, indole derivatives, pyrimidines, sesquiterpenoids, flavonoids, phenol and phenolic acid derivatives, aliphatic metabolites, sterols, amines and amides, and others) have been reported from Epichloë endophytes and grass infected with Epichloë endophytes. Among these, non-alkaloids account for half of the population of total metabolites, indicating that they also play an important role in Epichloë endophytes and grass infected with Epichloë endophytes. Also, a diverse array of secondary metabolites isolated from Epichloë endophytes and symbionts is a rich source for developing new pesticides and drugs. Bioassays disclose that, in addition to toxic alkaloids, the other metabolites isolated from Epichloë endophytes and symbionts have notable biological activities, such as antifungal, anti-insect, and phytotoxic activities. Accordingly, the biological functions of non-alkaloids should not be neglected in the future investigation of Epichloë endophytes and symbionts.


Assuntos
Alcaloides/metabolismo , Endófitos/química , Epichloe/química , Poaceae/microbiologia , Simbiose , Alcaloides/química , Alcaloides/toxicidade , Animais , Endófitos/fisiologia , Epichloe/metabolismo , Insetos/efeitos dos fármacos , Gado/metabolismo , Poaceae/fisiologia
19.
J Biol Chem ; 295(6): 1598-1612, 2020 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-31914404

RESUMO

Benzylisoquinoline alkaloids (BIAs) are a major class of plant metabolites with many pharmacological benefits. Sacred lotus (Nelumbo nucifera) is an ancient aquatic plant of medicinal value because of antiviral and immunomodulatory activities linked to its constituent BIAs. Although more than 30 BIAs belonging to the 1-benzylisoquinoline, aporphine, and bisbenzylisoquinoline structural subclasses and displaying a predominant R-enantiomeric conformation have been isolated from N. nucifera, its BIA biosynthetic genes and enzymes remain unknown. Herein, we report the isolation and biochemical characterization of two O-methyltransferases (OMTs) involved in BIA biosynthesis in sacred lotus. Five homologous genes, designated NnOMT1-5 and encoding polypeptides sharing >40% amino acid sequence identity, were expressed in Escherichia coli Functional characterization of the purified recombinant proteins revealed that NnOMT1 is a regiospecific 1-benzylisoquinoline 6-O-methyltransferase (6OMT) accepting both R- and S-substrates, whereas NnOMT5 is mainly a 7-O-methyltransferase (7OMT), with relatively minor 6OMT activity and a strong stereospecific preference for S-enantiomers. Available aporphines were not accepted as substrates by either enzyme, suggesting that O-methylation precedes BIA formation from 1-benzylisoquinoline intermediates. Km values for NnOMT1 and NnOMT5 were 20 and 13 µm for (R,S)-norcoclaurine and (S)-N-methylcoclaurine, respectively, similar to those for OMTs from other BIA-producing plants. Organ-based correlations of alkaloid content, OMT activity in crude extracts, and OMT gene expression supported physiological roles for NnOMT1 and NnOMT5 in BIA metabolism, occurring primarily in young leaves and embryos of sacred lotus. In summary, our work identifies two OMTs involved in BIA metabolism in the medicinal plant N. nucifera.


Assuntos
Benzilisoquinolinas/metabolismo , Metiltransferases/metabolismo , Nelumbo/enzimologia , Proteínas de Plantas/metabolismo , Alcaloides/metabolismo , Sequência de Aminoácidos , Vias Biossintéticas , Metiltransferases/química , Metiltransferases/genética , Metiltransferases/isolamento & purificação , Nelumbo/química , Nelumbo/genética , Nelumbo/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/isolamento & purificação , Alinhamento de Sequência
20.
Nat Commun ; 11(1): 492, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980615

RESUMO

White lupin (Lupinus albus L.) is an annual crop cultivated for its protein-rich seeds. It is adapted to poor soils due to the production of cluster roots, which are made of dozens of determinate lateral roots that drastically improve soil exploration and nutrient acquisition (mostly phosphate). Using long-read sequencing technologies, we provide a high-quality genome sequence of a cultivated accession of white lupin (2n = 50, 451 Mb), as well as de novo assemblies of a landrace and a wild relative. We describe a modern accession displaying increased soil exploration capacity through early establishment of lateral and cluster roots. We also show how seed quality may have been impacted by domestication in term of protein profiles and alkaloid content. The availability of a high-quality genome assembly together with companion genomic and transcriptomic resources will enable the development of modern breeding strategies to increase and stabilize white lupin yield.


Assuntos
Genoma de Planta , Lupinus/genética , Sementes/fisiologia , Análise de Sequência de DNA , Solo , Alcaloides/química , Alcaloides/metabolismo , Centrômero/genética , Ecótipo , Evolução Molecular , Dosagem de Genes , Duplicação Gênica , Variação Genética , Variação Estrutural do Genoma , Lupinus/crescimento & desenvolvimento , Modelos Genéticos , Anotação de Sequência Molecular , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento , Polimorfismo de Nucleotídeo Único/genética , Sequências Repetitivas de Ácido Nucleico/genética , Sintenia/genética , Transcriptoma/genética
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