Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 97
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PLoS One ; 16(9): e0258028, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34591908

RESUMO

Lycoris species have various chromosome numbers and karyotypes, but all have a constant total number of chromosome major arms. In addition to three fundamental types, including metacentric (M-), telocentric (T-), and acrocentric (A-) chromosomes, chromosomes in various morphology and size were also observed in natural populations. Both fusion and fission translocation have been considered as main mechanisms leading to the diverse karyotypes among Lycoris species, which suggests the centromere organization playing a role in such arrangements. We detected several chromosomal structure changes in Lycoris including centric fusion, inversion, gene amplification, and segment deletion by using fluorescence in situ hybridization (FISH) probing with rDNAs. An antibody against centromere specific histone H3 (CENH3) of L. aurea (2n = 14, 8M+6T) was raised and used to obtain CENH3-associated DNA sequences of L. aurea by chromatin immunoprecipitation (ChIP) cloning method. Immunostaining with anti-CENH3 antibody could label the centromeres of M-, T-, and A-type chromosomes. Immunostaining also revealed two centromeres on one T-type chromosome and a centromere on individual mini-chromosome. Among 10,000 ChIP clones, 500 clones which showed abundant in L. aurea genome by dot-blotting analysis were FISH mapped on chromosomes to examine their cytological distribution. Five of these 500 clones could generate intense FISH signals at centromeric region on M-type but not T-type chromosomes. FISH signals of these five clones rarely appeared on A-type chromosomes. The five ChIP clones showed similarity in DNA sequences and could generate similar but not identical distribution patterns of FISH signals on individual chromosomes. Furthermore, the distinct distribution patterns of FISH signals on each chromosome generated by these five ChIP clones allow to identify individual chromosome, which is considered difficult by conventional staining approaches. Our results suggest a different organization of centromeres of the three chromosome types in Lycoris species.


Assuntos
Centrômero , Cromossomos de Plantas , DNA Ribossômico , Histonas/genética , Lycoris/genética , Imunoprecipitação da Cromatina , Amplificação de Genes , Deleção de Genes , Histonas/metabolismo , Hibridização in Situ Fluorescente , Cariótipo , Lycoris/metabolismo
2.
Biomolecules ; 11(2)2021 02 09.
Artigo em Inglês | MEDLINE | ID: mdl-33572277

RESUMO

This study aimed to elucidate the variations in primary and secondary metabolites during Lycorisradiata flower development using high performance liquid chromatography (HPLC) and gas chromatography time-of-flight mass spectrometry (GC-TOFMS). The result showed that seven carotenoids, seven phenolic acids, three anthocyanins, and galantamine were identified in the L. radiata flowers. Most secondary metabolite levels gradually decreased according to the flower developmental stages. A total of 51 metabolites, including amines, sugars, sugar intermediates, sugar alcohols, amino acids, organic acids, phenolic acids, and tricarboxylic acid (TCA) cycle intermediates, were identified and quantified using GC-TOFMS. Among the hydrophilic compounds, most amino acids increased during flower development; in contrast, TCA cycle intermediates and sugars decreased. In particular, glutamine, asparagine, glutamic acid, and aspartic acid, which represent the main inter- and intracellular nitrogen carriers, were positively correlated with the other amino acids and were negatively correlated with the TCA cycle intermediates. Furthermore, quantitation data of the 51 hydrophilic compounds were subjected to partial least-squares discriminant analyses (PLS-DA) to assess significant differences in the metabolites of L. radiata flowers from stages 1 to 4. Therefore, this study will serve as the foundation for a biochemical approach to understand both primary and secondary metabolism in L. radiata flower development.


Assuntos
Flores/crescimento & desenvolvimento , Lycoris/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão/métodos , Flores/metabolismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Lycoris/metabolismo , Metabolômica/métodos
3.
Aging Cell ; 20(2): e13307, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33455051

RESUMO

Lycorine, a natural compound isolated from the traditional Chinese medicinal herb Lycoris radiata, exhibits multiple pharmacological effects, such as anti-inflammatory, antiviral, and anticancer effects. Accumulating evidence also indicates that lycorine might hold the potential to treat age-associated Alzheimer's disease. However, whether lycorine is involved in delaying the onset of cellular senescence and its underlying mechanisms has not been determined. Here, we demonstrate that the salt of lycorine, lycorine hydrochloride, significantly suppressed stress-induced premature cellular senescence (SIPS) by ~2-fold, as determined by senescence-associated beta-galactosidase (SA-ß-gal) staining and the expression of p16 and p21. In addition, pretreating cells with lycorine hydrochloride significantly inhibited the expression of CXCL1 and IL1α, two factors of the senescence-associated secreted phenotype (SASP) in SIPS cells. Further experiments revealed that lycorine hydrochloride promoted both the homologous recombination (HR) and nonhomologous end joining (NHEJ) pathways of DNA double-strand break (DSB) repair. Mechanistic studies suggested that lycorine hydrochloride treatment promoted the transcription of SIRT1 and SIRT6, critical longevity genes positively regulating both HR and NHEJ repair pathways, thereby stimulating DSB repair and stabilizing genomes. Inhibiting SIRT1 enzymatic activity abrogated the protective effect of lycorine hydrochloride on delaying the onset of SIPS, repairing DSBs, and restoring genome integrity. In summary, our work indicates that lycorine hydrochloride might hold therapeutic potential for treating age-associated diseases or promoting healthy aging by stabilizing genomes.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Fenantridinas/farmacologia , Células Cultivadas , Senescência Celular/efeitos dos fármacos , Senescência Celular/genética , Humanos , Lycoris/química , Medicina Tradicional Chinesa , Estresse Oxidativo/efeitos dos fármacos
4.
BMC Plant Biol ; 20(1): 522, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-33198627

RESUMO

BACKGROUND: The Lycoris genus includes many ornamentally and medicinally important species. Polyploidization and hybridization are considered modes of speciation in this genus, implying great genetic diversity. However, the lack of effective molecular markers has limited the genetic analysis of this genus. RESULTS: In this study, mining of EST-SSR markers was performed using transcriptome sequences of L. aurea, and 839 primer pairs for non-redundant EST-SSRs were successfully designed. A subset of 60 pairs was randomly selected for validation, of which 44 pairs could amplify products of the expected size. Cross-species transferability of the 60 primer pairs among Lycoris species were assessed in L. radiata Hreb, L. sprengeri Comes ex Baker, L. chinensis Traub and L. anhuiensis, of which between 38 to 77% of the primers were able to amplify products in these Lycoris species. Furthermore, 20 and 10 amplification products were selected for sequencing verification in L. aurea and L. radiata respectively. All products were validated as expected SSRs. In addition, 15 SSRs, including 10 sequence-verified and 5 unverified SSRs were selected and used to evaluate the genetic diversity of seven L. radiata lines. Among these, there were three sterile lines, three fertile lines and one line represented by the offspring of one fertile line. Unweighted pair group method with arithmetic mean analysis (UPGMA) demonstrated that the outgroup, L. aurea was separated from L. radiata lines and that the seven L. radiata lines were clustered into two groups, consistent with their fertility. Interestingly, even a dendrogram with 34 individuals representing the seven L. radiata lines was almost consistent with fertility. CONCLUSIONS: This study supplies a pool of potential 839 non-redundant SSR markers for genetic analysis of Lycoris genus, that present high amplification rate, transferability and efficiency, which will facilitate genetic analysis and breeding program in Lycoris.


Assuntos
Etiquetas de Sequências Expressas , Marcadores Genéticos , Hibridização Genética , Lycoris/classificação , Lycoris/genética , Repetições de Microssatélites , Polimorfismo Genético , DNA de Plantas , Filogenia
5.
Molecules ; 25(20)2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33086636

RESUMO

Lycoris Herbert, family Amaryllidaceae, is a small genus of about 20 species that are native to the warm temperate woodlands of eastern Asia, as in China, Korea, Japan, Taiwan, and the Himalayas. For many years, species of Lycoris have been subjected to extensive phytochemical and pharmacological investigations, resulting in either the isolation or identification of more than 110 Amaryllidaceae alkaloids belonging to different structural types. Amaryllidaceae alkaloids are frequently studied for their interesting biological properties, including antiviral, antibacterial, antitumor, antifungal, antimalarial, analgesic, cytotoxic, and cholinesterase inhibition activities. The present review aims to summarize comprehensively the research that has been reported on the phytochemistry and pharmacology of the genus Lycoris.


Assuntos
Alcaloides de Amaryllidaceae/uso terapêutico , Amaryllidaceae/química , Antimaláricos/uso terapêutico , Lycoris/química , Alcaloides de Amaryllidaceae/química , Antimaláricos/química , China , Humanos , Compostos Fitoquímicos/uso terapêutico , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Raízes de Plantas/química
6.
Int J Mol Sci ; 21(16)2020 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-32785156

RESUMO

The genus Lycoris (about 20 species) includes important medicinal and ornamental plants. Due to the similar morphological features and insufficient genomic resources, germplasm identification and molecular phylogeny analysis are very limited. Here, we sequenced the complete chloroplast genomes of L. chinensis, L. anhuiensis, and L. aurea; they have very similar morphological traits that make it difficult to identify. The full length of their cp genomes was nearly 158k bp with the same guanine-cytosine content of 37.8%. A total of 137 genes were annotated, including 87 protein-coding genes, 42 tRNAs, and eight rRNAs. A comparative analysis revealed the conservation in sequence size, GC content, and gene content. Some variations were observed in repeat structures, gene expansion on the IR-SC (Inverted Repeat-Single-Copy) boundary regions. Together with the cpSSR (chloroplast simple sequence repeats), these genetic variations are useful to develop molecular markers for germplasm identification. Phylogenetic analysis showed that seven Lycoris species were clustered into a monophyletic group, and closed to Narcissus in Amaryllidaceae. L. chinensis, L. anhuiensis, and L. longituba were clustered together, suggesting that they were very likely to be derived from one species, and had the same ancestor with L. squamigera. Our results provided information on the study of genetic diversity, origins or relatedness of native species, and the identification of cultivars.


Assuntos
Cloroplastos/genética , Genes de Plantas , Genoma de Cloroplastos , Lycoris/classificação , Lycoris/genética , Filogenia , Composição de Bases , Uso do Códon , Genes de RNAr , Tamanho do Genoma , Repetições de Microssatélites , Polimorfismo Genético , RNA Ribossômico/genética , RNA de Transferência/genética , Análise de Sequência de DNA
7.
Microbiol Res ; 239: 126501, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32585579

RESUMO

Lycoris radiata is the major source of Amaryllidaceae alkaloids, having various medicinal activities. However, the low content of these alkaloids in planta limits their pharmaceutical development and utilization. In this study, the ability of bacterial endophytes to enhance the accumulation of five important Amaryllidaceae alkaloids was investigated. A total of 188 bacterial endophytes were isolated from L. radiata and their composition and diversity were analyzed. Fourteen ones were demonstrated to significantly increase the concentration of the alkaloids of interest in different organs, up to 11.1-fold over the control level, with no adverse influence on the plant growth. An additional 3 bacterial endophytes were found to significantly increase the dry weight of L. radiata with no adverse influence on the concentration of the alkaloids in planta, so the total yield of alkaloids in planta was increased up to 2.4-fold over the control level. Considering the plant growth-promoting abilities of these bacterial endophytes, it is speculated that the indole-3-acetic acid and siderophore secreted by them, combined with their nitrogen fixation ability, may contribute to the enhanced plant growth and the increased alkaloid accumulation in L. radiata. To our knowledge, this work is firstly defining the diversity of culturable bacterial endophytes in L. radiata and determining which species promoted the accumulation of Amaryllidaceae alkaloids. It provides several valuable bacterial inoculants that can be further applied to improve alkaloid production in L. radiata and broadens our understanding of the interactions between a medicinal plant and the bacterial endophytes.


Assuntos
Alcaloides de Amaryllidaceae/metabolismo , Bactérias/metabolismo , Endófitos/metabolismo , Lycoris/microbiologia , Raízes de Plantas/microbiologia , Lycoris/metabolismo , Estrutura Molecular
8.
BMC Plant Biol ; 20(1): 180, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-32334530

RESUMO

BACKGROUND: Lycoris species have great ornamental and medicinal values; however, their low regeneration efficiency seriously restricts their commercial production. Understanding the mechanism of bulblet propagation in this genus, which has remained underexplored to date, could provide a theoretical basis for improving the reproductive efficiency. Therefore, we studied the bulblet initiation and developmental processes in Lycoris radiata. RESULTS: We found that bulblets are formed on the junctions of the innermost layers of scales and the basal plate, and initially present as an axillary bud and gradually develop into a bulblet. We also determined the changes in carbohydrate and endogenous hormone contents during bulblet initiation and development, as well as the expression patterns of genes involved in carbohydrate metabolism and hormone biosynthesis and signaling through transcriptome analysis. Soluble sugars derived from starch degradation in the outer scales are transported to and promote bulblet initiation and development through starch synthesis in the inner scales. This process is mediated by several genes involved in carbohydrate metabolism, especially genes encoding ADP glucose pyrophosphorylase, a crucial starch synthesis enzyme. As for hormones, endogenous IAA, GA, and ABA content showed an increase and decrease during bulblet initiation and development, respectively, which were consistent with the expression patterns of genes involved in IAA, GA, and ABA synthesis and signal transduction. In addition, a decrease in ZR content may be down- and up-regulated by CK biosynthesis and degradation related genes, respectively, with increasing auxin content. Furthermore, expression levels of genes related to BR, JA, and SA biosynthesis were increased, while that of ethylene biosynthesis genes was decreased, which was also consistent with the expression patterns of their signal transduction genes. CONCLUSIONS: The present study provides insights into the effect of carbohydrate metabolism and endogenous hormone regulation on control of L. radiata bulblet initiation and development. Based on the results, we propose several suggestions to improve L. radiata propagation efficiency in production, which will provide directions for future research.


Assuntos
Metabolismo dos Carboidratos , Lycoris/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento , Lycoris/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Reprodução
9.
PLoS One ; 15(3): e0230177, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32182273

RESUMO

Jasmonates (JAs) are key phytohormones involved in regulation of plant growth and development, stress responses, and secondary metabolism. It has been reported that treatments with JAs could increase the contents of Amaryllidaceae alkaloids in Amaryllidaceae plants. Jasmonate ZIM (zinc-finger inflorescence meristem) domain (JAZ) proteins are key components in JA signal processes. However, JAZ proteins have not been characterized in genus Lycoris. In this study, we identified and cloned seven differentially expressed JAZ genes (namely LaJAZ1-LaJAZ7) from Lycoris aurea. Bioinformatic analyses revealed that these seven LaJAZ proteins contain the ZIM domain and JA-associated (Jas, also named CCT_2) motif. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis revealed that these LaJAZ genes display different expression patterns in L. aurea tissues, and most of them are inducible when treated with methyl jasmonate (MeJA) treatment. Subcellular localization assay demonstrated that LaJAZ proteins are localized in the cell nucleus or cytoplasm. In addition, LaJAZ proteins could interact with each other to form homodimer and/or heterodimer. The findings in this study may facilitate further functional research of the LaJAZ genes, especially the potential regulatory mechanism of plant secondary metabolites including Amaryllidaceae alkaloids in L. aurea.


Assuntos
Regulação da Expressão Gênica de Plantas/genética , Lycoris/genética , Proteínas de Plantas/genética , Dedos de Zinco/genética , Acetatos/farmacologia , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/genética , Biologia Computacional/métodos , Ciclopentanos/farmacologia , Citoplasma/efeitos dos fármacos , Citoplasma/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Lycoris/efeitos dos fármacos , Oxilipinas/farmacologia , Reguladores de Crescimento de Plantas/farmacologia , Domínios Proteicos/genética
10.
Food Chem ; 316: 126263, 2020 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-32045812

RESUMO

In this study, starch was isolated from 13 genotypes of 12 Lycoris species, and the morphology, granule size distribution and physicochemical properties, including apparent amylose content (AAC), Rapid Visco Analyzer (RVA) pasting properties, textural properties, thermal and retrogradation properties were characterized. The majority of starch granules of the 13 Lycoris genotypes were oval in shape, and granule size followed a normal distribution with a mean diameter of 20-30 µm. Contrary to previously published findings, the XRD results revealed that lycoris starches had either C-type or CA-type crystallinity. All lycoris starches showed high AAC varying from 25.6% to 32.7%, and low gelatinization temperature (GT) ranging from 58.8 to 69.7℃. Inter-relationships among 18 starch quality traits were analyzed based on correlation analysis. The present study provides information on lycoris starch characteristics which should serve as a useful guide for later studies on lycoris starch utilization in food and non-food industries.


Assuntos
Lycoris/química , Amido/química , Amilose/química , Fenômenos Químicos , Genótipo , Lycoris/genética , Amido/isolamento & purificação , Temperatura
11.
Environ Microbiol ; 22(4): 1421-1434, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32090436

RESUMO

Lycoris radiata is a main source of Amaryllidaceae alkaloids; however, the low content of these alkaloids in planta remains a limit to their pharmaceutical development and utilization. The accumulation of secondary metabolites can be enhanced in plants inoculated with fungal endophytes. In this study, we analysed the diversity of culturable fungal endophytes in different organs of L. radiata. Then, by analysing the correlation between the detectable rate of each fungal species and the content of each tested alkaloid, we proposed several fungal candidates implicated in the increase of alkaloid accumulation. This was verified by inoculating these candidates to L. radiata plants. Based on the results of two independent experiments conducted in May 2018 and October 2019, the individual inoculation of nine fungal endophytes significantly increased the total content of the tested alkaloids in the entire L. radiata plants. This is the first study in L. radiata to show that fungal endophytes are able to improve the accumulation of various alkaloids. Therefore, our results provide insights into a better understanding of interactions between plants and fungal endophytes and suggest an effective strategy for enhancing the alkaloid content in the cultivation of L. radiata.


Assuntos
Alcaloides de Amaryllidaceae/metabolismo , Endófitos/metabolismo , Fungos/metabolismo , Lycoris/metabolismo , Lycoris/microbiologia
12.
J Chromatogr A ; 1609: 460506, 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31526637

RESUMO

A high-performance liquid chromatography-mass spectrometry technique hyphenated on-line with an immobilized enzyme reactor (IMER) was developed by the use of 3 known acetylcholinesterase (AChE) inhibitors (galanthamine, huperzine A and tacrine). This bioanalytical device allows qualitative comparison of the inhibitory strengths of AChE inhibitors. The AChE inhibitory strengths were evaluated and compared by the corresponding acetylcholine peak areas (mass signal) obtained after a chromatographic separation and the elution through the IMER. Only one injection of the analytes is needed to get this comparative analysis. This bioanalytical device was then applied to the extract of a natural plant, Lycoris radiata, which is known to contain AChE inhibitors such as galanthamine and lycoramine. Aside from the demonstration of the inhibitory activity of the two known AChE inhibitors, the AChE inhibitory activity of another compound (dihydro-latifaliumin C) was revealed. This is the first report describing the AChE inhibitory activity of this compound.


Assuntos
Inibidores da Colinesterase/análise , Cromatografia Líquida de Alta Pressão/métodos , Enzimas Imobilizadas/análise , Espectrometria de Massas/métodos , Sistemas On-Line , Acetilcolina/análise , Acetilcolinesterase/química , Reatores Biológicos , Galantamina/análise , Limite de Detecção , Lycoris/química , Extratos Vegetais/química , Reprodutibilidade dos Testes
13.
Int J Biol Macromol ; 141: 680-692, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494163

RESUMO

Amaryllidaceae alkaloids are unique benzylphenethylamine derivatives that comprise of more than 600 members with a huge chemical diversity. Most of them showed interesting bioactivities, for instance, galanthamine (GAL) is clinically used for Alzheimer's disease treatment. All Amaryllidaceae alkaloids had been thought to be derived from 4'-O-methylnorbelladine originated from norbelladine catalyzed by norbelladine 4'-O-methyltransferase (N4OMT). Herein we mined the transcriptome datasets of Lycoris radiata, a GAL-producing plant. LrOMT was cloned, overexpressed in Escherichia coli, and purified to homogeneity. Bioinformatics analysis and enzymatic activity assays revealed that LrOMT is an S-adenosylmethionine-dependent Class I OMT. LrOMT exhibited both para- and meta-O-methylation activities toward norbelladine to give 4'- and 3'-O-methylnorbelladine. Twenty-four analogues, including the proposed biosynthetic intermediates, were introduced to investigate the substrate scope of LrOMT and it showed that the aromatic substrates should have two vicinal hydroxyl groups. The LrOMT-catalyzed O-methylation preference is dependent on the properties of the binding group of the substrates. The transcription levels of LrOMT were positively associated with the accumulation of the Amaryllidaceae alkaloids and the biosynthetic intermediates in L. radiata. The present work revealed that LrOMT catalyzes multiple O-methylation reactions and its characterization will be helpful to uncover novel biosynthetic genes for Amaryllidaceae alkaloids biosynthesis.


Assuntos
Alcaloides de Amaryllidaceae/metabolismo , Biocatálise , Lycoris/enzimologia , Metiltransferases/metabolismo , Sequência de Aminoácidos , Clonagem Molecular , Biologia Computacional , Lycoris/genética , Lycoris/metabolismo , Metilação , Metiltransferases/química , Metiltransferases/genética , Modelos Moleculares , Conformação Proteica
14.
J Agric Food Chem ; 67(35): 9796-9804, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31393712

RESUMO

Overactivated microglia and persistent neuroinflammation hold an important role in the pathophysiology of neurodegenerative diseases. The extract of Lycoris chejuensis (CJ) and its active compound, 7-deoxy-trans-dihydronarciclasine (named E144), attenuated expressions of pro-inflammatory factors, including nitric oxide, prostaglandin E2, inducible nitric oxide synthase, cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), and interleukin 6, secreted by lipopolysaccharide-activated BV-2 microglial cells, as measured by an enzyme-linked immunosorbent assay or western blotting. In contrast, CJ extract and E144 promoted the secretion of the anti-inflammatory cytokine, interleukin 10. Moreover, we found that E144 attenuated the expression of TNF-α and COX-2 in the cerebral cortex of lipopolysaccharide-treated mice and/or T2576 transgenic mice as well as reduced the reactive immune cells visualized by ionized calcium-binding adaptor molecule 1. Our results suggest the possibility of E144 to serve as a potential anti-neuroinflammatory agent by preventing excess production of pro-inflammatory factors.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/imunologia , Isoquinolinas/administração & dosagem , Lycoris/química , Extratos Vegetais/administração & dosagem , Doença de Alzheimer/genética , Animais , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/imunologia , Modelos Animais de Doenças , Humanos , Interleucina-6/genética , Interleucina-6/imunologia , Isoquinolinas/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Microglia/efeitos dos fármacos , Microglia/metabolismo , NF-kappa B/genética , NF-kappa B/imunologia , Extratos Vegetais/química , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
15.
Bioelectrochemistry ; 129: 199-205, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31200249

RESUMO

The identification of plant species not only is a hobby but also has important application value in plant resources science. Traditional plant identification often relies on the experience of botanists. The infrageneric identification of plants is easily mistaken due to similarities in organ features. In this work, we propose an electrochemical method to obtain fingerprints of plant petal tissue. Fourteen species of Lycoris were used as a model for validating this methodology. Pattern and color recognition were established for visualization of electrochemical fingerprints recorded after various solvent extractions. In addition, the infrageneric relationships of these Lycoris species were deduced from the electrochemical fingerprints since the type and content of electroactive compounds in plants are controlled by genes. The results indicate that the electrochemical fingerprints of Lycoris petals are correlated with the infrageneric relationships of native Lycoris species.


Assuntos
Técnicas Eletroquímicas/métodos , Flores/classificação , Lycoris/classificação , Adsorção , Flores/química , Grafite/química , Lycoris/química , Extratos Vegetais/química , Extratos Vegetais/classificação , Solventes , Especificidade da Espécie
16.
Appl Environ Microbiol ; 85(9)2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30824447

RESUMO

Fungal infections not only cause extensive agricultural damage but also result in serious diseases in the immunodeficient populations of human beings. Moreover, the increasing emergence of drug resistance has led to a decrease in the efficacy of current antifungals. Thus, screening of new antifungal agents is imperative in the fight against antifungal drug resistance. In this study, we show that an endophytic bacterium, Burkholderia gladioli HDXY-02, isolated from the medicinal plant Lycoris aurea, showed broad-spectrum antifungal activity against plant and human fungal pathogens. An antifungal ability assay indicated that the bioactive component was produced from strain HDXY-02 having an extracellular secreted component with a molecular weight lower than 1,000 Da. In addition, we found that this new antifungal could be produced effectively by liquid fermentation of HDXY-02. Furthermore, the purified component contributing to the antifungal activity was identified to be toxoflavin, a yellow compound possessing a pyrimido[5,4-e][1,2,4]triazine ring. In vitro bioactivity studies demonstrated that purified toxoflavin from B. gladioli HDXY-02 cultures had a significant antifungal activity against the human fungal pathogen Aspergillus fumigatus, resulting in abolished germination of conidia. More importantly, the growth inhibition by toxoflavin was observed in both wild-type and drug-resistant mutants (cyp51A and non-cyp51A) of A. fumigatus Finally, an optimized protocol for the large-scale production of toxoflavin (1,533 mg/liter) has been developed. Taken together, our findings provide a promising biosynthetic resource for producing a new antifungal reagent, toxoflavin, from isolates of the endophytic bacterium B. gladioli IMPORTANCE Human fungal infections are a growing problem associated with increased morbidity and mortality. Moreover, a growing number of antifungal-resistant fungal isolates have been reported over the past decade. Thus, the need for novel antifungal agents is imperative. In this study, we show that an endophytic bacterium, Burkholderia gladioli, isolated from the medicinal plant Lycoris aurea, is able to abundantly secrete a compound, toxoflavin, which has a strong fungicidal activity not only against plant fungal pathogens but also against human fungal pathogens Aspergillus fumigatus and Candida albicans, Cryptococcus neoformans, and the model filamentous fungus Aspergillus nidulans More importantly, toxoflavin also displays an efficacious inhibitory effect against azole antifungal-resistant mutants of A. fumigatus Consequently, our findings provide a promising approach to abundantly produce toxoflavin, which has novel broad-spectrum antifungal activity, especially against those currently problematic drug-resistant isolates.


Assuntos
Antifúngicos/farmacologia , Burkholderia gladioli/química , Fungicidas Industriais/farmacologia , Pirimidinonas/farmacologia , Triazinas/farmacologia , Lycoris/microbiologia
17.
Food Chem ; 275: 8-14, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724263

RESUMO

The effects of microwave treatment (MT), heat-moisture treatment (HMT) and autoclaving treatment (GT) on the structural and physicochemical characteristics of lycoris starch (LS) were investigated. The HMT-LS and GT-LS particles were larger and rougher with block-like characteristics compared to the LS particles. The XRD results revealed that HMT and GT converted native starch (A-type) into B-type starch. The density of the starch crystallization zone after HMT and GT was higher than that of LS, while MT had the weakest effect. The solubility and swelling power of MT-LS, HMT-LS and GT-LS were significantly (p < 0.05) lower at 65 and 95 °C, but opposite trends were observed at 55 °C. The RVA viscograms for MT-LS, HMT-LS, and GT-LS showed a lower breakdown and setback value compared to that of LS, reflecting stronger starch aggregations and lower retrogradation tendencies. Additionally, both G' and G″ of the treated starch were lower, which indicated weaker gel structures.


Assuntos
Lycoris/química , Amido/química , Cristalização , Temperatura Alta , Reologia , Solubilidade , Viscosidade , Difração de Raios X
18.
Food Chem Toxicol ; 125: 605-613, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30738987

RESUMO

Lycoris radiata (L'Her.) Herb. (L. radiata) was traditionally used as a folk medicine in China for treatment of Alzheimer's disease. However, the specific component responsible for its considerable toxicity remained unclear thus restricting its clinical trials. Narciclasine (NCS) was isolated from L. radiata and treatment of NCS for 72 h exhibited significant antiproliferative effects against L02, Hep G2, HT-29 and RAW264.7 cells. However, what needs to be emphasized is that at safe working concentrations of 0.001-0.016 µM, administration of NCS for 24 h inhibited the mRNA expression of inducible nitric oxide synthase (iNOS), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-ɑ), interleukin-1beta (IL-1ß) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-induced macrophages thereby suppressing production of nitric oxide (NO), IL-6, TNF-ɑ and IL-1ß. NCS supplementation also inhibited nuclear factor-kappa B (NF-κB) activation by suppressing NF-κB P65 phosphorylation and nuclear translocation, IκBɑ degradation and phosphorylation, and IκKɑ/ß phosphorylation. The phosphorylation of c-Jun N-terminal kinase (JNK) and P38, and expression of COX-2 was also attenuated by NCS. These results suggested that NCS might exert anti-inflammatory effects through inhibiting NF-κB and mitogen-activated protein kinase (MAPK) pathways even at very low doses.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Anti-Inflamatórios/farmacologia , Lycoris/química , Macrófagos/efeitos dos fármacos , Fenantridinas/farmacologia , Alcaloides de Amaryllidaceae/isolamento & purificação , Alcaloides de Amaryllidaceae/toxicidade , Animais , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/toxicidade , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antineoplásicos/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ciclo-Oxigenase 2/metabolismo , Citocinas/genética , Citocinas/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Inflamação/induzido quimicamente , Lipopolissacarídeos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , NF-kappa B/metabolismo , Fenantridinas/isolamento & purificação , Fenantridinas/toxicidade , Componentes Aéreos da Planta/química , Células RAW 264.7 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
19.
Phytochem Anal ; 30(3): 268-277, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30548356

RESUMO

INTRODUCTION: Lycorine, one of the most common alkaloids in Lycoris spp., is believed to possess pharmacological activity. OBJECTIVE: To discover and identify lycorine-type alkaloids in the crude extracts of bulbs from six Lycoris spp. by ultra-high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) detection. METHODOLOGY: A qualitative analytical method with a data mining strategy was utilised. Based on the fragmentation patterns of standards investigated in positive tandem mass spectrometry (MS/MS) mode, the fragmentation rules of lycorine-type alkaloids were summarised. These types of alkaloids were additionally classified as different subtypes based on structural features and MS/MS fragmentation patterns, and the diagnostic ions for characterisation of different subtypes of alkaloids were designated. RESULTS: Thirty-seven lycorine type alkaloids, including 16 previously undescribed compounds, were efficiently screened out and tentatively identified from the crude extracts of six Lycoris spp. Lycoris sprengri may be a preferable species for studying or extracting lycorine-type alkaloids because of elevated relative concentrations and highest diversity of alkaloids. CONCLUSION: The UHPLC-QTOF-MS and MS/MS data-mining strategy proved useful for the detection and tentative identification of lycorine-type alkaloids in bulbs of Lycoris spp. and could be extended to other Amaryllidaceae genera. The consequent profiling of the lycorine-type alkaloids will be useful in the quality control of raw materials of Lycoris species and the exploration of superior species.


Assuntos
Alcaloides de Amaryllidaceae/química , Cromatografia Líquida de Alta Pressão/métodos , Lycoris/química , Fenantridinas/química , Espectrometria de Massas em Tandem/métodos , Mineração de Dados , Lycoris/classificação , Estrutura Molecular , Extratos Vegetais/química , Raízes de Plantas/química , Especificidade da Espécie , Estereoisomerismo
20.
Molecules ; 23(12)2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30513965

RESUMO

p-Coumaric acid is a commercially available phenolcarboxylic acid with a great number of important applications in the nutraceutical, pharmaceutical, material and chemical industries. p-Coumaric acid has been biosynthesized in some engineered microbes, but the potential of the plant CYP450-involved biosynthetic route has not investigated in Escherichia coli. In the present study, a novel trans-cinnamic acid 4-hydroxylase (C4H) encoding the LauC4H gene was isolated from Lycoris aurea (L' Hér.) Herb via rapid amplification of cDNA ends. Then, N-terminal 28 amino acids of LauC4H were characterized, for the subcellular localization, at the endoplasmic reticulum membrane in protoplasts of Arabidopsis thaliana. In E. coli, LauC4H without the N-terminal membrane anchor region was functionally expressed when fused with the redox partner of A. thaliana cytochrome P450 enzyme (CYP450), and was verified to catalyze the trans-cinnamic acid to p-coumaric acid transformation by whole-cell bioconversion, HPLC detection and LC-MS analysis as well. Further, with phenylalanine ammonia-lyase 1 of A. thaliana, p-coumaric acid was de novo biosynthesized from glucose as the sole carbon source via the phenylalanine route in the recombinant E. coli cells. By regulating the level of intracellular NADPH, the production of p-coumaric acid was dramatically improved by 9.18-fold, and achieved with a titer of 156.09 µM in shake flasks. The recombinant cells harboring functional LauC4H afforded a promising chassis for biological production of p-coumaric acid, even other derivatives, via a plant CYP450-involved pathway.


Assuntos
Escherichia coli/metabolismo , Lycoris/enzimologia , Propionatos/metabolismo , Transcinamato 4-Mono-Oxigenase/genética , Transcinamato 4-Mono-Oxigenase/metabolismo , Arabidopsis/genética , Clonagem Molecular , Escherichia coli/genética , Glucose/metabolismo , Lycoris/genética , NADP/metabolismo , Plantas Geneticamente Modificadas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...