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1.
Plant Biotechnol J ; 19(1): 98-108, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32643247

RESUMO

l-Theanine is a specialized metabolite in the tea (Camellia sinensis) plant which can constitute over 50% of the total amino acids. This makes an important contribution to tea functionality and quality, but the subcellular location and mechanism of biosynthesis of l-theanine are unclear. Here, we identified five distinct genes potentially capable of synthesizing l-theanine in tea. Using a nonaqueous fractionation method, we determined the subcellular distribution of l-theanine in tea shoots and roots and used transient expression in Nicotiana or Arabidopsis to investigate in vivo functions of l-theanine synthetase and also to determine the subcellular localization of fluorescent-tagged proteins by confocal laser scanning microscopy. In tea root tissue, the cytosol was the main site of l-theanine biosynthesis, and cytosol-located CsTSI was the key l-theanine synthase. In tea shoot tissue, l-theanine biosynthesis occurred mainly in the cytosol and chloroplasts and CsGS1.1 and CsGS2 were most likely the key l-theanine synthases. In addition, l-theanine content and distribution were affected by light in leaf tissue. These results enhance our knowledge of biochemistry and molecular biology of the biosynthesis of functional tea compounds.


Assuntos
Camellia sinensis , Proteínas de Plantas , Camellia sinensis/genética , Glutamatos , Folhas de Planta/genética , Proteínas de Plantas/genética , Chá
2.
Biochem Biophys Res Commun ; 529(1): 91-96, 2020 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-32560825

RESUMO

As structural components of biological membranes, phytosterols are essential not only for a variety of cellular functions but are also precursors for brassinosteroid (BR) biosynthesis. Plant CYP51 is the oldest and most conserved obtusifoliol 14α-demethylase in eukaryotes and is an essential component of the sterol biosynthesis pathway. However, little is known about rice (Oryza sativa L.) CYP51G1. In this study, we showed that rice OsCYP51G1 shared high homology with obtusifoliol 14α-demethylase and OsCYP51G1 was strongly expressed in most of rice organs. Subcellular localization analysis indicated that OsCYP51G1 was localized to the endoplasmic reticulum. Knockdown and knockout of OsCYP51G1 resulted in delayed flowering, impaired membrane integrity, abnormal pollen, and reduced grain yield, whereas OsCYP51G1 overexpression led to increased grain yield. Knockdown of OsCYP51G1 also reduced the levels of end-products (sitosterol and stigmasterol) and increased those of upstream intermediates (24-methylene-cycloartenol and cycloeucalenol) of the OsCYP51G1-mediated sterol biosynthesis step. In contrast, overexpression of OsCYP51G1 increased the sitosterol and stigmasterol content and reduced that of cycloeucalenol. However, knockdown of OsCYP51G1 by RNAi did not elicit these BR deficiency-related phenotypes, such as dwarfism, erect leaves and small seeds, nor was the leaf lamina angle sensitive to brassinolide treatment. These results revealed that rice OsCYP15G1 encodes an obtusifoliol 14α-demethylase for the phytosterols biosynthesis and possible without affecting the biosynthesis of downstream BRs, which was different from its homolog, OsCYP51G3.


Assuntos
Oryza/metabolismo , Fitosteróis/biossíntese , Proteínas de Plantas/metabolismo , Esterol 14-Desmetilase/metabolismo , Brassinosteroides/biossíntese , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Técnicas de Inativação de Genes , Genes de Plantas , Germinação/genética , Oryza/genética , Oryza/crescimento & desenvolvimento , Proteínas de Plantas/genética , Plantas Geneticamente Modificadas , Pólen/crescimento & desenvolvimento , Pólen/metabolismo , Interferência de RNA , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Esterol 14-Desmetilase/genética
3.
J Exp Bot ; 71(1): 168-177, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31559427

RESUMO

LAZY1 family genes play important roles in both shoot and root gravitropism in plants. Here we report a Lotus japonicus mutant that displays negative gravitropic response in primary and lateral roots. Map-based cloning identified the mutant gene LAZY3 as a functional ortholog of the LAZY1 gene. Mutation of the LAZY3 gene reduced rootward polar auxin transport (PAT) in the primary root, which was also insensitive to the PAT inhibitor N-1-naphthylphthalamic acid. Moreover, immunolocalization of enhanced green fluorescent protein-tagged LAZY3 in L. japonicus exhibited polar localization of LAZY3 on the plasma membrane in root stele cells. We therefore suggest that the polar localization of LAZY3 in stele cells might be required for PAT in L. japonicus root. LAZY3 transcripts displayed asymmetric distribution at the root tip within hours of gravistimulation, while overexpression of LAZY3 under a constitutive promoter in lazy3 plants rescued the gravitropic response in roots. These data indicate that root gravitropism depends on the presence of LAZY3 but not on its asymmetric expression in root tips. Expression of other LAZY genes in a lazy3 background did not rescue the growth direction of roots, suggesting that the LAZY3 gene plays a distinct role in root gravitropism in L. japonicus.


Assuntos
Gravitropismo/genética , Lotus/genética , Proteínas de Plantas/genética , Raízes de Plantas/fisiologia , Lotus/crescimento & desenvolvimento , Lotus/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/crescimento & desenvolvimento
4.
Int J Mol Sci ; 21(1)2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31906256

RESUMO

Attachment of glycosylphosphatidylinositols (GPIs) to the C-termini of proteins is one of the most common posttranslational modifications in eukaryotic cells. GPI8/PIG-K is the catalytic subunit of the GPI transamidase complex catalyzing the transfer en bloc GPI to proteins. In this study, a T-DNA insertional mutant of rice with temperature-dependent drooping and fragile (df) shoots phenotype was isolated. The insertion site of the T-DNA fragment was 879 bp downstream of the stop codon of the OsGPI8 gene, which caused introns retention in the gene transcripts, especially at higher temperatures. A complementation test confirmed that this change in the OsGPI8 transcripts was responsible for the mutant phenotype. Compared to control plants, internodes of the df mutant showed a thinner shell with a reduced cell number in the transverse direction, and an inhomogeneous secondary wall layer in bundle sheath cells, while many sclerenchyma cells at the tops of the main veins of df leaves were shrunken and their walls were thinner. The df plants also displayed a major reduction in cellulose and lignin content in both culms and leaves. Our data indicate that GPI anchor proteins play important roles in biosynthesis and accumulation of cell wall material, cell shape, and cell division in rice.


Assuntos
Íntrons , Oryza , Fenótipo , Folhas de Planta , Brotos de Planta , Temperatura , Aciltransferases/genética , Aciltransferases/metabolismo , Parede Celular/genética , Parede Celular/metabolismo , Glicosilfosfatidilinositóis/genética , Glicosilfosfatidilinositóis/metabolismo , Mutagênese Insercional , Oryza/genética , Oryza/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Brotos de Planta/genética , Brotos de Planta/metabolismo
5.
Int J Mol Sci ; 19(8)2018 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-30126188

RESUMO

Jasmonic acid (JA) is reportedly involved in the interaction between insects and the vegetative parts of horticultural crops; less attention has, however, been paid to its involvement in the interaction between insects and the floral parts of horticultural crops. Previously, we investigated the allene oxide synthase 2 (AOS2) gene that was found to be the only JA synthesis gene upregulated in tea (Camellia sinensis) flowers exposed to insect (Thrips hawaiiensis (Morgan)) attacks. In our present study, transient expression analysis in Nicotiana benthamiana plants confirmed that CsAOS2 functioned in JA synthesis and was located in the chloroplast membrane. In contrast to tea leaves, the metabolite profiles of tea flowers were not significantly affected by 10 h JA (2.5 mM) treatment as determined using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry, and gas chromatography-mass spectrometry. Moreover, JA treatment did not significantly influence ethylene formation in tea flowers. These results suggest that JA in tea flowers may have different functions from JA in tea leaves and other flowers.


Assuntos
Camellia sinensis/metabolismo , Ciclopentanos/metabolismo , Etilenos/metabolismo , Oxirredutases Intramoleculares/metabolismo , Oxilipinas/metabolismo , Proteínas de Plantas/metabolismo , Vias Biossintéticas , Metaboloma
6.
New Phytol ; 208(3): 790-802, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26083975

RESUMO

Phytosterols are membrane components or precursors for brassinosteroid (BR) biosynthesis. As they cannot be transported long distances, their homeostasis is tightly controlled through their biosynthesis and metabolism. However, it is unknown whether microRNAs are involved in their homeostatic regulation. Rice (Oryza sativa) plants transformed with microRNA osa-miR1848 and its target, the obtusifoliol 14α-demethylase gene, OsCYP51G3, were used to investigate the role of osa-miR1848 in the regulation of phytosterol biosynthesis. osa-miR1848 directs OsCYP51G3 mRNA cleavage to regulate phytosterol and BR biosynthesis in rice. The role of OsCYP51G3 as one of the osa-miR1848 targets is supported by the opposite expression patterns of osa-miR1848 and OsCYP51G3 in transgenic rice plants, and by the identification of OsCYP51G3 mRNA cleavage sites. Increased osa-miR1848 and decreased OsCYP51G3 expression reduced phytosterol and BR concentrations, and caused typical phenotypic changes related to phytosterol and BR deficiency, including dwarf plants, erect leaves, semi-sterile pollen grains, and shorter cells. Circadian expression of osa-miR1848 regulated the diurnal abundance of OsCYP51G3 transcript in developing organs, and the response of OsCYP51G3 to salt stress. We propose that osa-miR1848 regulates OsCYP51G3 expression posttranscriptionally, and mediates phytosterol and BR biosynthesis. osa-miR1848 and OsCYP51G3 might have potential applications in rice breeding to modulate leaf angle, and the size and quality of seeds.


Assuntos
Brassinosteroides/biossíntese , MicroRNAs/metabolismo , Oryza/metabolismo , Fitosteróis/biossíntese , Esterol 14-Desmetilase/metabolismo , Ritmo Circadiano , Oryza/genética , Oryza/crescimento & desenvolvimento , Fenótipo , Desenvolvimento Vegetal , Esterol 14-Desmetilase/genética , Estresse Fisiológico
7.
Plant Cell Environ ; 38(12): 2662-73, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26012744

RESUMO

Cuticular wax forms a hydrophobic layer covering aerial plant organs and acting as a protective barrier against biotic and abiotic stresses. Compared with well-known wax biosynthetic pathway, molecular regulation of wax biosynthesis is less known. Here, we show that rice OsWS1, a member of the membrane-bound O-acyl transferase gene family, involved in wax biosynthesis and was regulated by an osa-miR1848. OsWS1-tagged green fluorescent protein localized to the endoplasmic reticulum (ER). Compared with wild-type rice, OsWS1 overexpression plants displayed a 3% increase in total wax, especially a 35% increase in very long-chain fatty acids, denser wax papillae around the stoma, more cuticular wax crystals formed on leaf and stem surfaces, pollen coats were thicker and more seedlings survived after water-deficit treatment. In contrast, OsWS1-RNAi and osa-miR1848 overexpression plants exhibited opposing changes. Gene expression analysis showed that overexpression of osa-miR1848 down-regulated OsWS1 transcripts; furthermore, expression profiles of OsWS1 and osa-miR1848 were inversely correlated in the leaf, panicle and stem, and upon water-deficit treatment. These results suggest that OsWS1 is regulated by osa-miR1848 and participates in cuticular wax formation.


Assuntos
Aciltransferases/genética , Regulação Enzimológica da Expressão Gênica , MicroRNAs/genética , Oryza/enzimologia , Ceras/metabolismo , Aciltransferases/metabolismo , Membrana Celular/enzimologia , Retículo Endoplasmático/enzimologia , Regulação da Expressão Gênica de Plantas , Genes Reporter , Oryza/citologia , Oryza/genética , Oryza/fisiologia , Epiderme Vegetal/citologia , Epiderme Vegetal/enzimologia , Epiderme Vegetal/genética , Epiderme Vegetal/fisiologia , Folhas de Planta/citologia , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Caules de Planta/citologia , Caules de Planta/enzimologia , Caules de Planta/genética , Caules de Planta/fisiologia , Plântula/citologia , Plântula/enzimologia , Plântula/genética , Plântula/fisiologia
8.
Cell Biol Int ; 38(5): 639-46, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24446394

RESUMO

Artesunate (ART), derived from a common traditional Chinese medicine, has beeen used an antimalarial for several years. In this study, the effect and mechanism of ART on anti-human cervical cancer cells was examined. The level of prostaglandin E2 (PGE2 ) and the population of CD4+CD25+Foxp3 regulatory T cells (Treg) in peripheral blood were detected by flow cytometry. In vivo antitumor activity was investigated in mice with cervical cancer by the subcutaneous injection of various concentrations of ART. The concentrations of PGE2 in the supernatants of CaSki cells were measured using an ELISA kit. Cyclooxygenase-2 (COX-2) and Foxp3 expression were determined using quantitative polymerase chain reaction (qPCR) and western blot analysis. The effect of ART on the viability of CaSki and Hela cells was evaluated with a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. It was identified that the level of PGE2 and the population of CD4+CD25+Foxp3 Treg cells in the peripheral blood were significantly higher in cervical cancer patients and mice with cervical cancer. ART was capable of inhibiting orthotopic tumor growth, which correlated with a decrease in the level of PGE2 and the percentage of Treg cells in mice with cervical cancer. Furthermore, ART decreased COX-2 expression and the production of PGE2 in CaSki and Hela cells. Notably, the supernatants of CaSki cells treated with ART lowered the expression of Foxp3 in Jurkat T cells, which was capable of being reversed by exogenous PGE2 . Our data revealed that ART may elicit an anti-tumor effect against cervical cancer by inhibition of PGE2 production in CaSki and Hela cells, which resulted in the decrease of Foxp3 expression in T cells. Therefore, ART may be an effective drug for immunotherapy of cervical cancer.


Assuntos
Artemisininas/farmacologia , Dinoprostona/antagonistas & inibidores , Fatores de Transcrição Forkhead/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica , Tolerância Imunológica/efeitos dos fármacos , Neoplasias do Colo do Útero , Animais , Artesunato , Dinoprostona/biossíntese , Feminino , Fatores de Transcrição Forkhead/biossíntese , Células HeLa , Humanos , Tolerância Imunológica/fisiologia , Células Jurkat , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias do Colo do Útero/metabolismo
9.
Plant Biotechnol J ; 11(4): 446-58, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23231455

RESUMO

The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.


Assuntos
Nitrogênio/metabolismo , Oryza/crescimento & desenvolvimento , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Oryza/genética , Proteínas de Plantas/genética
10.
J Plant Physiol ; 280: 153905, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36580705

RESUMO

Rice microRNA168a (osa-miR168a) plays important roles in mediating flowering time, grain yield and vigor, seeding growth, and immunity by targeting the RNA-induced silencing complex component Argonaute 1 (AGO1). However, the functions of miR168a exerted by targeting other genes require further clarification before it could be used in rice molecular breeding. In this study, we identified a new target gene of osa-miR168a-5p (miR168a-5p) in rice called OsOFP3 (ovate family protein 3) and investigated the roles of miR168a-5p in response to brassinosteroids (BRs), salt stress, and nitrogen allocation. Up- and downregulated miR168a-5p expression respectively decreased and increased the expression of the BR-negative regulator OsOPF3. The results of RNA ligase-mediated rapid amplification of cDNA ends (5'RLM-RACE) revealed cleavage sites in OsOPF3 and OsNPF2.4 mRNAs. The phenotype of miR168a-5p transgenic rice was BR-associated and included the lamina bending response to BR, short seeds, and low 1000-grain weight. MicroRNA 168a-5p also regulated the expression of the nitrate transporter, OsNPF2.4, which affected nitrogen allocation, and regulated OsAGO1a expression in response to salt stress. Taken together, rice miR168a-5p regulates BR-associated pathways, nitrogen transport, and stress by targeting OsOFP3, OsNPF2.4, and OsAGO1a, respectively, resulting in a series of important agronomic traits for rice breeding.


Assuntos
Oryza , Oryza/metabolismo , Tolerância ao Sal/genética , Brassinosteroides/metabolismo , Transportadores de Nitrato , Grão Comestível/metabolismo , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo
11.
Dev Comp Immunol ; 141: 104648, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36708793

RESUMO

As one of interferon-induced serine/threonine kinases, the protein kinase R (PKR) plays vital roles in antiviral defense, and functional features of PKR remain largely unknown in amphibians, which suffer from ranaviral diseases in the last few decades. In this study, a PKR gene named Xt-PKR was characterized in the Western clawed frog (Xenopus tropicalis). Xt-PKR gene was widely expressed in different organs/tissues, and was rapidly induced by poly(I:C) in spleen, kidney, and liver. Intriguingly, Xt-PKR could be up-rugulated by the treatment of type I and type III interferons, and the transcript level of Xt-PKR induced by type I interferon was much higher than that of type III interferon. Moreover, overexpression of Xt-PKR can suppress the protein synthesis and ranavirus replication in vitro, and the residue lysine required for the translation inhibition activity in mammalian PKR is conserved in Xt-PKR. The present study represents the first characterization on the functions of amphibian PKR, and reveals considerable functional conservation of PKR in early tetrapods.


Assuntos
Xenopus , eIF-2 Quinase , Animais , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo , Xenopus/metabolismo , Expressão Gênica , Especificidade de Órgãos
12.
Int J Nanomedicine ; 18: 3325-3338, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37361386

RESUMO

Purpose: Due to its competitive advantages such as small size, high stability, easy production, and good tissue penetration compared with monoclonal antibodies (mAb), nanobodies (Nbs) were considered the next generation of therapeutics. However, the absence of Fc fragments and Fc-triggered immune effectors limits their clinical applications. In order to overcome these limitations, we develop a novel approach by attaching an IgG binding domain (IgBD) to Nbs for recruiting endogenous IgG and recovering the immune effectors for tumor killing. Material and Methods: We linked a Streptococcal Protein G-derived IgBD, termed C3Fab, at the C-terminus of a CD70-specific Nb 3B6 to construct an endogenous IgG recruitment antibody (termed EIR). The recombinant Nb3B6-C3Fab was expressed in E. coli BL21 (DE3) and purified by nickel affinity chromatography. We further evaluated the binding, recruitment of IgG, and the serum half-life of Nb3B6-C3Fab. The tumor-killing effects on CD70 positive cells mediated by antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity were also detected. Results: We successfully constructed a IgBD fused Nb3B6-C3Fab with high affinity for CD70 and mouse IgG (mIgG). Nb3B6-C3Fab can specifically bind to CD70 positive tumor cells and recruit mIgG on the cell surface. Ligating of Nb3B6 with C3Fab increased its serum half-life in mice almost 39-fold from 0.96 h to 37.67 h. Moreover, we demonstrated remarkable cytotoxicity of Nb3B6-C3Fab to CD70 positive tumor cells via C3Fab by immune effector cells. Conclusion: Our study demonstrates that IgBD fusion endows Nbs with the ability for endogenous IgG recruitment and half-life promotion. Linking IgBD to Nbs is an effective strategy to recovering immune effectors for tumor killing.


Assuntos
Anticorpos Monoclonais , Neoplasias , Anticorpos de Domínio Único , Animais , Camundongos , Anticorpos Monoclonais/farmacologia , Escherichia coli , Imunoglobulina G/metabolismo , Fagocitose , Anticorpos de Domínio Único/farmacologia
13.
Gene ; 865: 147332, 2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-36871675

RESUMO

As a universal adaptor used by most TLR members, the myeloid differentiation factor 88 (MyD88) plays essential roles in TLR-mediated inflammatory response of invertebrate and vertebrate animals, and functional features of MyD88 remain largely unknown in amphibians. In this study, a MyD88 gene named Xt-MyD88 was characterized in the Western clawed frog (Xenopus tropicalis). Xt-MyD88 and MyD88 in other species of vertebrates share similar structural characteristics, genomic structures, and flanking genes, suggesting that MyD88 is structurally conserved in different phyla of vertebrates ranging from fish to mammals. Moreover, Xt-MyD88 was widely expressed in different organs/tissues, and was induced by poly(I:C) in spleen, kidney, and liver. Importantly, overexpression of Xt-MyD88 triggered a marked activation of both NF-κB promoter and interferon-stimulated response elements (ISREs), implying that it may be play important roles in inflammatory responses of amphibians. The research represents the first characterization on the immune functions of amphibian MyD88, and reveals considerable functional conservation of MyD88 in early tetrapods.


Assuntos
Fator 88 de Diferenciação Mieloide , NF-kappa B , Animais , Xenopus/genética , Xenopus/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Sequência de Aminoácidos , NF-kappa B/genética , NF-kappa B/metabolismo , Evolução Biológica , Mamíferos/metabolismo
14.
Plant Foods Hum Nutr ; 66(2): 169-74, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21523413

RESUMO

The contents of starch and catechins in the fresh leaf of 'Huang Zhi Xiang' Oolong tea trees girdled at the bottom, middle (on the big branches) and top (on the small branches) were determined. The study demonstrated that the starch contents from girdled trees were significantly higher (p<0.05) than that from non-girdled ones. Furthermore, the contents of (-)-epicatechin (EC), (-)-epigallocatechin (EGC), total catechins (TC) and simple catechins (SC) from girdled trees were significantly higher (p<0.05) than those from non-girdled ones. Especially, the contents of (-)-epigallocatechin gallate (EGCG), (-)-epicatechin gallate (ECG) and catechin gallate (CG) from girdled at the middle were also significantly higher (p<0.05) than those from the non-girdled. The starch contents were negatively correlated with the contents of (-)-gallocatechin (GC), EC, SC, TC and EGC, while positively correlated with the contents of EGCG and CG in fresh shoots.


Assuntos
Camellia sinensis/química , Catequina/análise , Folhas de Planta/química , Amido/análise , Catequina/análogos & derivados , Cromatografia Líquida de Alta Pressão , Amido/química
15.
Biopharm Drug Dispos ; 31(2-3): 138-49, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20140970

RESUMO

The purpose of this study was to formulate a drug-in-adhesive (DIA) transdermal patch containing letrozole, a third generation aromatase inhibitor for the treatment of breast cancer, using pressure-sensitive-adhesives (PSAs) and to evaluate the percutaneous penetration and pharmacokinetics of letrozole after transdermal administration, compared with that for the oral route. The formulation factors for such a patch, including the PSAs, enhancers and amount of drug loaded were investigated. Among the tested preparations, the formulation with DURO-TAK 87-4098, Azone and propylene glycol showed the highest letrozole permeation. The pharmacokinetic characteristics of an optimized DIA patch containing letrozole were determined using rats, while orally administered letrozole in solution was used as a control. The pharmacokinetic parameter, such as the mean residence time (MRT) was significantly (p<0.05) different following transdermal administration compared with oral administration. The in vivo results observed with the patches in rats were in good agreement with the plasma concentrations predicted from the in vitro penetration data. As a patient-friendly, convenient, high local drug concentration and sustained dosing therapeutic system, the transdermal patches incorporating letrozole provide a useful strategy for the prevention and treatment of breast cancer.


Assuntos
Administração Cutânea , Analgésicos Opioides/farmacocinética , Nitrilas/farmacocinética , Pele/metabolismo , Triazóis/farmacocinética , Animais , Química Farmacêutica , Composição de Medicamentos , Feminino , Humanos , Letrozol , Masculino , Camundongos , Camundongos Pelados , Ratos , Ratos Wistar , Absorção Cutânea
16.
AAPS PharmSciTech ; 11(3): 1054-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20582494

RESUMO

The aim of this work was to evaluate capability of site-specific delivery of a transdermal patch through determination of letrozole in local tissues disposition in female mice. After transdermal administration, the letrozole levels in skin, muscle, and plasma were 10.4-49.3 µg/g, 1.64-6.89 µg/g, and 0.35-1.64 µg/mL, respectively. However, after the mice received letrozole suspension, the drug concentration of plasma and muscle were 0.20-4.80 µg/mL and 0.15-2.38 µg/g. There was even no drug determined in skin through all experiments. Compared with oral administration, the transdermal patch for site-specific delivery of letrozole could produce high drug concentrations in skin and muscle and meanwhile obtain low drug level in plasma. These findings show that letrozole transdermal patch is an appropriate delivery system for application to the breast tumor region for site-specific drug delivery to obtain a high local drug concentration and low circulating drug concentrations avoiding the risk of systemic side effects.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Nitrilas/administração & dosagem , Nitrilas/farmacocinética , Adesivo Transdérmico , Triazóis/administração & dosagem , Triazóis/farmacocinética , Administração Cutânea , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacocinética , Feminino , Letrozol , Camundongos , Nitrilas/química , Distribuição Tecidual , Triazóis/química
17.
J Agric Food Chem ; 68(37): 10109-10117, 2020 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-32829629

RESUMO

Linalool is abundant in tea leaves and contributes greatly to tea aroma. The two isomers of linalool, (R)-linalool and (S)-linalool, exist in tea leaves. Our study found that (R)-linalool was the minor isomer in nine of Camellia sinensis var. sinensis cultivars. The (R)-linalool synthase of tea plant CsRLIS was identified subsequently. It is a chloroplast-located protein and specifically catalyzes the formation of (R)-linalool in vitro and in vivo. CsRLIS was observed to be a stress-responsive gene and caused the accumulation of internal (R)-linalool during oolong tea manufacture, mechanical wounding, and insect attack. Further study demonstrated that the catalytic efficiency of CsRLIS was much lower than that of (S)-linalool synthase CsSLIS, which might explain the lower (R)-linalool proportion in C. sinensis var. sinensis cultivars. The relative expression levels of CsRLIS and CsSLIS may also affect the (R)-linalool proportions among C. sinensis var. sinensis cultivars. This information will help us understand differential distributions of chiral aroma compounds in tea.


Assuntos
Monoterpenos Acíclicos/química , Camellia sinensis/enzimologia , Hidroliases/metabolismo , Proteínas de Plantas/metabolismo , Monoterpenos Acíclicos/metabolismo , Biocatálise , Camellia sinensis/química , Camellia sinensis/genética , Camellia sinensis/metabolismo , Cloroplastos/enzimologia , Cloroplastos/genética , Cloroplastos/metabolismo , Hidroliases/química , Hidroliases/genética , Odorantes/análise , Proteínas de Plantas/química , Proteínas de Plantas/genética , Estereoisomerismo , Chá/química
18.
Food Chem ; 305: 125440, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31494496

RESUMO

Tea (Camellia sinensis) contains two active glutamate decarboxylases (CsGADs), whose unclear properties were examined here. CsGAD1 was 4-fold higher than CsGAD2 in activity. Their Km values for L-glutamate were around 5 mM. CsGAD1 and CsGAD2 performed best at 55 and 40 °C, respectively, and were both stimulated by calcium/calmodulin (Ca2+/CaM). Over 40 °C, their calmodulin-binding domains degraded. CsGADs were most active at pH 5.6, and were stimulated by Ca2+/CaM at pH 5.6-6.6, but inactivated at pH 3.6. Ca2+/CaM restored the CsGAD1 activity suppressed by inhibitors. CsGADs and CsCaM were localized to the cytosol. CsGAD1 was more highly expressed in most tissues, while CsGAD2 expression was more induced under stresses. The characteristics we first elucidated here revealed that CsGAD1 is the predominant isoform in tea plant, with CsGAD2 exhibiting a supplementary role under certain conditions. The information will contribute to regulation of GABA tea quality.


Assuntos
Camellia sinensis/enzimologia , Glutamato Descarboxilase/metabolismo , Proteínas de Plantas/metabolismo , Ácido gama-Aminobutírico/metabolismo , Secas , Estabilidade Enzimática , Ácido Glutâmico/metabolismo , Concentração de Íons de Hidrogênio , Isoenzimas/metabolismo , Cinética , Temperatura
19.
J Agric Food Chem ; 68(39): 10842-10851, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32866009

RESUMO

l-Theanine has a significant role in the taste of tea (Camellia sinensis) infusions. Our previous research indicated that the lower l-theanine metabolism in ethylamine and l-glutamate is a key factor that explains the higher content of l-theanine in albino tea with yellow or white leaves, compared with that of normal tea with green leaves. However, the specific genes encoding l-theanine hydrolase in tea remains unknown. In this study, CsPDX2.1 was cloned together with the homologous Arabidopsis PDX2 gene and the recombinant protein was shown to catalyze l-theanine hydrolysis into ethylamine and l-glutamate in vitro. There were higher CsPDX2.1 transcript levels in leaf tissue and lower transcripts in the types of albino (yellow leaf) teas compared with green controls. The subcellular location of ethylamine in tea leaves was shown to be in the mitochondria and peroxisome using a nonaqueous fractionation method. This study identified the l-theanine hydrolase gene and subcellular distribution of ethylamine in tea leaves, which improves our understanding of the l-theanine metabolism and the mechanism of differential accumulation of l-theanine among tea varieties.


Assuntos
Camellia sinensis/metabolismo , Etilaminas/metabolismo , Glutamatos/metabolismo , Hidrolases/metabolismo , Folhas de Planta/enzimologia , Proteínas de Plantas/metabolismo , Sequência de Aminoácidos , Camellia sinensis/química , Camellia sinensis/enzimologia , Camellia sinensis/genética , Ácido Glutâmico/metabolismo , Hidrolases/química , Hidrolases/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Transporte Proteico , Alinhamento de Sequência
20.
Acta Chim Slov ; 67(4): 1281-1289, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33533465

RESUMO

Two vanadium(V) complexes derived from the bromo and chloro-substituted hydrazones N'-(4-bromo-2-hydroxybenzylidene)- 2-chlorobenzohydrazide (H2L1) and N'-(3-bromo-5-chloro-2-hydroxybenzylidene)-3-methylbenzohydrazide (H2L2) with the formula [VOL1(OCH3)(CH3OH)] (1) and [VOL2(OCH3)(CH3OH)] (2) were newly synthesized and characterized by IR, UV-Vis and 1H NMR spectroscopy. The structures of H2L1 and the complexes were further confirmed by single crystal X-ray diffraction. Both vanadium complexes are mononuclear, with the metal atoms coordinated by the hydrazone ligands, methanol ligands, and methanolate ligands, and the oxo groups, forming octahedral geometry. The hydrazones and the vanadium complexes were assayed for the antimicrobial activities on Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence, and the fungi Candida albicans and Aspergillus niger. The existence of the bromo and chloro groups in the hydrazone ligands may improve the antimicrobial property.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Complexos de Coordenação/farmacologia , Hidrazonas/farmacologia , Antibacterianos/síntese química , Antifúngicos/síntese química , Aspergillus niger/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Complexos de Coordenação/síntese química , Hidrazonas/síntese química , Ligantes , Testes de Sensibilidade Microbiana , Estrutura Molecular , Vanádio/química
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