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1.
Plant Cell Physiol ; 2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37847120

RESUMO

B-Box-containing zinc finger transcription factors (BBX) are involved in light-mediated growth, affecting processes such as hypocotyl elongation in Arabidopsis thaliana. However, the molecular and hormonal framework that regulates plant growth through BBX proteins is incomplete. Here, we demonstrate that BBX21 inhibits the hypocotyl elongation through the brassinosteroid (BR) pathway. BBX21 reduces the sensitivity to 24-epiBL, a synthetic active BR, principally at very-low concentrations in simulated shade. The biosynthesis profile of BRs showed that two active BR -brassinolide (BL) and 28-homobrassinolide (28-homoBL)- and 8 of 11 intermediates can be repressed by BBX21 under white light (WL) or simulated shade. Furthermore, BBX21 represses the expression of CYTOCHROME P450 90B1 (DWF4/CYP90B1), BRASSINOSTEROID-6-OXIDASE 1 (BR6OX1, CYP85A1) and BR6OX2 (CYP85A2) genes involved in the BR biosynthesis in WL while specifically promoting DWF4 and PHYB ACTIVATION TAGGED SUPPRESSOR 1 (CYP2B1/BAS1) expression in WL supplemented with far-red (WL+FR), a treatment that simulates shade. In addition, BBX21 represses BR signalling genes such as PACLOBUTRAZOL RESISTANCE1 (PRE1), PRE3 and ARABIDOPSIS MYB-LIKE 2 (MYBL2), and auxin-related and expansin genes, such as INDOLE-3-ACETIC ACID INDUCIBLE 1 (IAA1), IAA4 and EXPANSIN 11 (EXP11) in short-term shade. By a genetic approach we found that BBX21 acts genetically upstream of BRASSINAZOLE-RESISTANT 1 (BZR1) for the promotion of DWF4 and BAS1 gene expression in shade. We propose that BBX21 integrates the BR homeostasis and shade-light signalling allowing the fine-tuning of hypocotyl elongation in Arabidopsis.

2.
Sci Rep ; 12(1): 7011, 2022 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-35487935

RESUMO

Members of the Viola genus play important roles in traditional Asian herbal medicine. This study investigates the ability of Viola odorata L. extracts to inhibit Na+,K+-ATPase, an essential animal enzyme responsible for membrane potential maintenance. The root extract of V. odorata strongly inhibited Na+,K+-ATPase, while leaf and seeds extracts were basically inactive. A UHPLC-QTOF-MS/MS metabolomic approach was used to identify the chemical principle of the root extract's activity, resulting in the detection of 35,292 features. Candidate active compounds were selected by correlating feature area with inhibitory activity in 14 isolated fractions. This yielded a set of 15 candidate compounds, of which 14 were preliminarily identified as procyanidins. Commercially available procyanidins (B1, B2, B3 and C1) were therefore purchased and their ability to inhibit Na+,K+-ATPase was investigated. Dimeric procyanidins B1, B2 and B3 were found to be inactive, but the trimeric procyanidin C1 strongly inhibited Na+,K+-ATPase with an IC50 of 4.5 µM. This newly discovered inhibitor was docked into crystal structures mimicking the Na3E1∼P·ADP and K2E2·Pi states to identify potential interaction sites within Na+,K+-ATPase. Possible binding mechanisms and the principle responsible for the observed root extract activity are discussed.


Assuntos
Proantocianidinas , Viola , Animais , Flavonoides , Íons/metabolismo , Extratos Vegetais/farmacologia , Proantocianidinas/metabolismo , Proantocianidinas/farmacologia , Sódio/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Espectrometria de Massas em Tandem
3.
Molecules ; 27(8)2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35458607

RESUMO

The total phenolic content, anthocyanins, phenolic acids, antioxidant capacity and α-amylase inhibitory activity of black (Aydin Siyahi), purple (Kadife Kemer) and white (Trabzon Kadife) eggplants grown in Turkey were subjected to a comparative investigation. The black cultivar exhibited the highest total phenolic (17,193 and 6552 mg gallic acid equivalent/kg fw), flavonoid (3019 and 1160 quercetin equivalent/kg fw) and anthocyanin (1686 and 6167 g delphinidin-3-O-glucoside equivalent/kg fw) contents in crude extracts of the peel and pulp. The majority of the caffeic acid was identified in the ester (2830 mg/kg fw) and ester-bound (2594 mg/kg fw) forms in the peel of 'Kadife Kemer' and in the glycoside form (611.9 mg/kg fw) in 'Aydin Siyahi', as well as in the pulp of these two eggplants. 'Kadife Kemer' (purple eggplant) contained the majority of the chlorogenic acid in free form (27.55 mg/kg fw), compared to 'Aydin Siyahi' in the ester (7.82 mg/kg fw), glycoside (294.1 mg/kg dw) and ester-bound (2.41 mg/kg fw) forms. The eggplant cultivars (peel and pulp, mg/kg fw) exhibited a relatively high delphinidin-3-O-rutinoside concentration in the peel of 'Aydin Siyahi' (avg. 1162), followed by 'Kadife Kemer' (avg. 336.6), and 'Trabzon Kadife' (avg. 215.1). The crude phenolic extracts of the eggplants exhibited the highest antioxidant capacity values (peel and pulp, µmoL Trolox equivalent/kg fw) of 2,2-diphenyl-1-picrylhydrazyl (DPPH, 8156 and 2335) and oxygen radical absorbance capacity (ORAC, 37,887 and 17,648). The overall results indicate that black and purple eggplants are the cultivars with greater potential benefits in terms of their phenolics and antioxidant values than the white eggplant.


Assuntos
Antioxidantes , Solanum melongena , Antocianinas/análise , Antioxidantes/química , Ésteres/análise , Frutas/química , Fenóis/análise , Extratos Vegetais/química
4.
Plant Cell Environ ; 45(4): 1315-1332, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35064681

RESUMO

The dynamic behaviour of seeds in soil seed banks depends on their ability to act as sophisticated environmental sensors to adjust their sensitivity thresholds for germination by dormancy mechanisms. Here we show that prolonged incubation of sugar beet fruits at low temperature (chilling at 5°C, generally known to release seed dormancy of many species) can induce secondary nondeep physiological dormancy of an apparently nondormant crop species. The physiological and biophysical mechanisms underpinning this cold-induced secondary dormancy include the chilling-induced accumulation of abscisic acid in the seeds, a reduction in the embryo growth potential and a block in weakening of the endosperm covering the embryonic root. Transcriptome analysis revealed distinct gene expression patterns in the different temperature regimes and upon secondary dormancy induction and maintenance. The chilling caused reduced expression of cell wall remodelling protein genes required for embryo cell elongation growth and endosperm weakening, as well as increased expression of seed maturation genes, such as for late embryogenesis abundant proteins. A model integrating the hormonal signalling and master regulator expression with the temperature-control of seed dormancy and maturation programmes is proposed. The revealed mechanisms of the cold-induced secondary dormancy are important for climate-smart agriculture and food security.


Assuntos
Beta vulgaris , Ácido Abscísico/metabolismo , Beta vulgaris/genética , Germinação/fisiologia , Dormência de Plantas/genética , Sementes/fisiologia
5.
Sci Rep ; 10(1): 13886, 2020 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-32807910

RESUMO

Cross-talk between exogenous salicylic acid (SA) and endogenous phytohormone pathways affects the antioxidant defense system and its response to salt stress. The study presented here investigated the effects of SA treatment before and during salt stress on the levels of endogenous plant growth regulators in three barley cultivars with different salinity tolerances: Hordeum vulgare L. cvs. Akhisar (sensitive), Erginel (moderate), and Kalayci (tolerant). The cultivars' relative leaf water contents, growth parameters, proline contents, chlorophyll a/b ratios, and lipid peroxidation levels were measured, along with the activities of enzymes involved in detoxifying reactive oxygen species (ROS) including superoxide-dismutase, peroxidase, catalase, ascorbate-peroxidase, and glutathione-reductase. In addition, levels of several endogenous phytohormones (indole-3-acetic-acid, cytokinins, abscisic acid, jasmonic acid, and ethylene) were measured. Barley is known to be more salt tolerant than related plant species. Accordingly, none of the studied cultivars exhibited changes in membrane lipid peroxidation under salt stress. However, they responded differently to salt-stress with respect to their accumulation of phytohormones and antioxidant enzyme activity. The strongest and weakest increases in ABA and proline accumulation were observed in Kalayci and Akhisar, respectively, suggesting that salt-stress was more effectively managed in Kalayci. The effects of exogenous SA treatment depended on both the timing of the treatment and the cultivar to which it was applied. In general, however, where SA helped mitigate salt stress, it appeared to do so by increasing ROS scavenging capacity and antioxidant enzyme activity. SA treatment also induced changes in phytohormone levels, presumably as a consequence of SA-phytohormone salt-stress cross-talk.


Assuntos
Antioxidantes/metabolismo , Hordeum/fisiologia , Reguladores de Crescimento de Plantas/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Ácido Salicílico/farmacologia , Estresse Salino/efeitos dos fármacos , Biomassa , Clorofila/metabolismo , Clorofila A/metabolismo , Hordeum/efeitos dos fármacos , Hordeum/crescimento & desenvolvimento , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Prolina/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Fatores de Tempo , Água
6.
Planta ; 250(5): 1717-1729, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31414204

RESUMO

MAIN CONCLUSION: Seed-processing technologies such as polishing and washing enhance crop seed quality by limited removal of the outer layers and by leaching. Combined, this removes chemical compounds that inhibit germination. Industrial processing to deliver high-quality commercial seed includes removing chemical inhibitors of germination, and is essential to produce fresh sprouts, achieve vigorous crop establishment, and high yield potential in the field. Sugar beet (Beta vulgaris subsp. vulgaris var. altissima Doell.), the main sugar source of the temperate agricultural zone, routinely undergoes several processing steps during seed production to improve germination performance and seedling growth. Germination assays and seedling phenotyping was carried out on unprocessed, and processed (polished and washed) sugar beet fruits. Pericarp-derived solutes, known to inhibit germination, were tested in germination assays and their osmolality and conductivity assessed (ions). Abscisic acid (ABA) and ABA metabolites were quantified in both the true seed and pericarp tissue using UPLC-ESI(+)-MS/MS. Physical changes in the pericarp structures were assessed using scanning electron microscopy (SEM). We found that polishing and washing of the sugar beet fruits both had a positive effect on germination performance and seedling phenotype, and when combined, this positive effect was stronger. The mechanical action of polishing removed the outer pericarp (fruit coat) tissue (parenchyma), leaving the inner tissue (sclerenchyma) unaltered, as revealed by SEM. Polishing as well as washing removed germination inhibitors from the pericarp, specifically, ABA, ABA metabolites, and ions. Understanding the biochemistry underpinning the effectiveness of these processing treatments is key to driving further innovations in commercial seed quality.


Assuntos
Ácido Abscísico/metabolismo , Beta vulgaris/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/metabolismo , Beta vulgaris/fisiologia , Bioquímica , Germinação , Sementes/crescimento & desenvolvimento , Sementes/fisiologia , Espectrometria de Massas em Tandem
7.
Eur J Med Chem ; 180: 417-429, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31325787

RESUMO

Oleandrin, the major biologically active constituent of shrub Nerium oleander preparations of which have been used in traditional Mediterranean and Asian medicine, attracts a great deal of attention due to its pronounced anticancer activity. The synthesis of oleandrigenin model, 16ß-hydroxy-3ß-methoxy-5α-card-20(22)-enolide 16-acetate, from androstenolone acetate through 17ß-(3-furyl)-intermediates has been developed. Several related 17ß-(butenolidyl)- and 17ß-(furyl)-androstane derivatives were synthesized and tested for in vitro cytotoxic and Na+/K+-ATP-ase inhibitory activities. Comparison of Na+/K+-ATP-ase inhibitory and cytotoxic activity underlines complex nature of the relationship.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Cardenolídeos/farmacologia , Inibidores Enzimáticos/farmacologia , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidores , Antineoplásicos Fitogênicos/síntese química , Antineoplásicos Fitogênicos/química , Cardenolídeos/síntese química , Cardenolídeos/química , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Conformação Molecular , Nerium/química , ATPase Trocadora de Sódio-Potássio/metabolismo , Relação Estrutura-Atividade
8.
J Nat Prod ; 82(5): 1372-1376, 2019 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-30933514

RESUMO

In this study, an extract from the bulbs of Cyrtanthus contractus showed strong anti-inflammatory activity in vitro. The extract was partially separated into 14 fractions and analyzed by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry metabolomics, and the correlation coefficients were calculated between biological activities and metabolite levels. As a result, the top-scoring metabolite narciclasine (1) is proposed as the active principle of C. contractus. This was confirmed by comparing the biological effect of crude extract with that of an authentic standard.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Amaryllidaceae/química , Anti-Inflamatórios não Esteroides/farmacologia , Metabolômica , Fenantridinas/farmacologia , Alcaloides de Amaryllidaceae/química , Anti-Inflamatórios não Esteroides/química , Adesão Celular/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Cromatografia Líquida de Alta Pressão , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Humanos , Molécula 1 de Adesão Intercelular/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Espectrometria de Massas , Fenantridinas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química
9.
Phytochem Anal ; 29(1): 23-29, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28786149

RESUMO

INTRODUCTION: Various species of the Euphorbia genus contain diterpene ingenol and ingenol mebutate (ingenol-3-angelate), a substance found in the sap of the plant Euphorbia peplus and an inducer of cell death. A gel formulation of the drug has been approved by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA) for the topical treatment of actinic keratosis. OBJECTIVE: To develop a rapid and reliable method for quantification of ingenol in various plant extracts. METHODOLOGY: Methanolic extracts of 38 species of the Euphorbia genus were analysed via ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) after methanolysis and solid-phase extraction (SPE) purification. The 18 O-labelled ingenol analogue was prepared and used as an internal standard for ingenol content determination and method validation. RESULTS: The highest ingenol concentration (547 mg/kg of dry weight) was found in the lower leafless stems of E. myrsinites. The screening confirms a substantial amount of ingenol in species studied previously and furthermore, reveals some new promising candidates. CONCLUSION: The newly established UHPLC-MS/MS method shows to be an appropriate tool for screening of the Euphorbia genus for ingenol content and allows selection of species suitable for raw material production and/or in vitro culture initiation. Copyright © 2017 John Wiley & Sons, Ltd.


Assuntos
Técnica de Diluição de Radioisótopos , Cromatografia Líquida de Alta Pressão , Diterpenos , Euphorbia , Extratos Vegetais , Espectrometria de Massas em Tandem
10.
Plant Cell Rep ; 36(10): 1561-1570, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28688084

RESUMO

KEY MESSAGE: An affinity-based chemical proteomic technique enabled direct identification of BAP-interacting proteins in wheat, including the well-known cytokinin-binder, cytokinin-binding protein 1. In this work, we show the development of a chemical proteomic technique for the identification of proteins binding to natural aromatic cytokinins (CKs). 6-benzylaminopurine (BAP) and documented CK-binder, wheat germ-allocated cytokinin-binding protein 1 (CBP-1), were suggested as an ideal proof-of concept affinity pair. Therefore, wheat grains were chosen as a model plant material. The BAP affinity beads were prepared by the immobilization of synthesized BAP-derived ligand to a commercial, pre-activated resin and used to isolate target proteins. The proteomic analysis of complex plant extracts is often complicated by the presence of highly abundant background proteins; in this case, the omnipresent alpha-amylase inhibitors (AAIs). To cope with this problem, we included SDS-PAGE, in-gel trypsin digestion and fraction pooling prior to shotgun analysis, which brought about an obvious drop in the signals belonging to the obstructing proteins. This was accompanied by a sharp increase in the number of identified BAP targets in comparison to a conventional in-solution digestion approach. To distinguish specific CK-binding proteins from those having a general affinity for nucleotide-like compounds, competitive pull-downs with natural nucleotides and free BAP were included in every affinity experiment. By this approach, we were able to identify a group of BAP-interacting proteins, which were subsequently found to be related to biological processes affected by CKs. Moreover, the selected affinity enrichment strategy was verified by the detection of the aforementioned CK-interacting protein, CBP-1. We propose that the developed method represents a promising tool for appealing research of as yet unknown CK molecular partners in plants.


Assuntos
Compostos de Benzil/metabolismo , Grão Comestível/metabolismo , Proteínas de Plantas/metabolismo , Proteômica/métodos , Purinas/metabolismo , Triticum/metabolismo , Cromatografia Líquida , Citocininas/metabolismo , Eletroforese em Gel de Poliacrilamida , Ligação Proteica , Proteoma/metabolismo , Espectrometria de Massas em Tandem
11.
Talanta ; 170: 432-440, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28501193

RESUMO

Brassinosteroids (BRs) are plant-specific steroid hormones that play essential roles in the regulation of many important physiological processes in plant life. Their extremely low concentrations (~pmoles/g FW) in plant tissue and huge differences in polarity of individual members within the BR family hamper their detection and quantification. To address this problem, an immunoaffinity sorbent with broad specificity and high capacity for different BR metabolites containing a monoclonal antibody (mAb) against a BR spacer (20S)-2α,3α-dihydroxy-7-oxa-7α-homo-5α-pregnane-6-one-20 carboxylic acid (BR4812) was used for the rapid and highly selective isolation of endogenous BRs containing a 2α,3α-diol in ring A from minute plant samples. This enrichment procedure was successfully applied as a sample preparation method prior to quantitative analysis of BRs in real plant tissues by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Use of immunoaffinity chromatography (IAC) increased the sensitivity of the UHPLC-MS/MS analysis owing to improvements in the BR signal-to-noise ratio (S/N) and matrix factor (MF). Although MF values of BRs analyzed in classical samples ranged from 8.9% to 47.4%, MF values for the IAC purified samples reached 44.5-96.6%. Thus, the developed IAC-UHPLC-MS/MS approach was shown to be a simple, robust, effective and extremely fast procedure requiring minute amounts of plant samples suitable for the quantitative profiling of many BR metabolites, helping to overcome the major problems associated with their determination in very complex plant matrices.


Assuntos
Brassica napus/química , Brassinosteroides/análise , Cromatografia de Afinidade/métodos , Reguladores de Crescimento de Plantas/análise , Espectrometria de Massas em Tandem/métodos , Anticorpos Imobilizados/química , Brassinosteroides/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Imunoadsorventes/química , Extratos Vegetais/química , Reguladores de Crescimento de Plantas/isolamento & purificação
12.
Methods Mol Biol ; 1564: 1-7, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28124241

RESUMO

Brassinosteroids (BRs) are a class of steroid plant hormones that participate with other plant hormones in the regulation of numerous developmental processes, including root and shoot growth, vascular differentiation, fertility, and seed germination. A characteristic feature of all plant hormones, including BRs, is that their concentration is extremely low in plant tissues and, therefore, the methods dealing with their determination belong to ultra-trace analysis, for which very sensitive analytical tools are needed. The analysis of natural BRs is essential when their functions and roles in plant growth and development are to be elucidated. Here, we describe a reliable protocol for high-throughput extraction and purification of BRs. The procedure consists of two solid-phase extraction steps and provides selective enrichment and efficient cleanup of these compounds from complex plant extracts. The protocol is designed for sensitive liquid chromatography-tandem mass spectrometry-based method for simultaneous detection of 22 naturally occurring BRs, including their biosynthetic precursors and most of their biologically active metabolites, without need for derivatization.


Assuntos
Arabidopsis/química , Brassica napus/química , Brassinosteroides/isolamento & purificação , Reguladores de Crescimento de Plantas/isolamento & purificação , Extração em Fase Sólida/métodos , Brassinosteroides/química , Cromatografia Gasosa , Cromatografia Líquida , Espectrometria de Massas , Extratos Vegetais/química , Reguladores de Crescimento de Plantas/química
13.
Org Biomol Chem ; 14(43): 10238-10248, 2016 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-27735956

RESUMO

A practical synthesis of 28a-homo-28a-selenolupane triterpenes and the corresponding selenosaponins containing d-mannose, l-arabinose, l-rhamnose, and d-idose moieties is described. Selenium containing triterpenes were obtained from the readily available 3-O-allyl-homobetulin mesylate by nucleophilic substitution with the selenocyanate ion which upon reduction of the -SeCN group afforded the free selenol. Glycosylation using classical Schmidt donors gave 1,2-trans selenosaponins as the main product as well as minute amounts of 1,2-cis isomers. This is one of the very few examples of the synthesis of selenoglycosides by direct glycosylation of free selenols. The studied selenol showed high resistance to air oxidation resulting in good stability during the synthesis of selenolupane derivatives. Cytotoxic activities of new homoselenolupane derivatives were also evaluated in vitro and revealed that some triterpenes exhibited an interesting profile against human cancer cell lines.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Saponinas/síntese química , Saponinas/farmacologia , Selênio/química , Triterpenos/química , Antineoplásicos/química , Linhagem Celular Tumoral , Técnicas de Química Sintética , Humanos , Saponinas/química
14.
Anal Bioanal Chem ; 408(24): 6799-812, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27531032

RESUMO

The triterpenoid plant hormones brassinosteroids (BRs) are believed to influence almost every aspect of plant growth and development. We have developed a sensitive mass spectrometry-based method for the simultaneous profiling of twenty-two naturally occurring brassinosteroids including biosynthetic precursors and the majority of biologically active metabolites. Using ultra-high performance liquid chromatographic (UHPLC) analysis, the run time was reduced up to three times (to 9 min) in comparison to standard HPLC BRs analyses, the retention time stability was improved to 0.1-0.2 % RSD and the injection accuracy was increased to 1.1-4.9 % RSD. The procedures for extraction and for two-step purification based on solid-phase extraction (SPE) were optimised in combination with subsequent UHPLC analysis coupled to electrospray ionisation tandem mass spectrometry (ESI-MS/MS) using Brassica flowers and Arabidopsis plant tissue extracts. In multiple reaction monitoring (MRM) mode, the average detection limit for BRs analysed was close to 7 pg, and the linear range covered up to 3 orders of magnitude. The low detection limits for this broad range of BR metabolites enabled as little as 50 mg of plant tissue to be used for quantitative analyses. The results of determinations exploiting internal standards showed that this approach provides a high level of practicality, reproducibility and recovery. The method we have established will enable researchers to gain a better understanding of the dynamics of the biosynthesis and metabolism of brassinosteroids and their modes of action in plant growth and development.


Assuntos
Arabidopsis/química , Brassica napus/química , Brassinosteroides/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas por Ionização por Electrospray/métodos , Limite de Detecção , Extratos Vegetais/química , Reprodutibilidade dos Testes , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos
15.
Food Chem ; 201: 339-49, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-26868586

RESUMO

Phenolics and nutrient profiles of bog bilberry (Vaccinium uliginosum L.) collected from high mountain pastures in northeast Anatolia (Turkey) were examined for the first time in this study. The major soluble sugar identified in the berry was fructose, following by glucose, and the main organic acid identified was citric acid, followed by malic acid. Eleven phenolic acids and 17 anthocyanin 3-glycosides were identified and quantified. Caffeic acid in the free and glycoside forms and syringic acid in the ester form were the major phenolic acids, and the major individual anthocyanin present in the berry was malvidin 3-glucoside (24%). The highest total phenolics and anthocyanin contents were obtained from the anthocyanin fraction in conjunction with the highest antioxidant capacity, followed by the polyphenolic and aqueous fractions, FRAP, ORAC and DPPH, in that order. Our findings can be used to compare bog bilberry with other Vaccinium berries and to help clarify the relative potential health benefits of different berries.


Assuntos
Antocianinas/química , Antioxidantes/química , Fenóis/análise , Extratos Vegetais/química , Vaccinium myrtillus/química
16.
Nat Prod Commun ; 10(1): 171-82, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25920242

RESUMO

With over 500 individual compounds, the Amaryllidaceae alkaloids represent a large and structurally diverse group of phytochemicals. Coupled to this structural diversity is the significant array of biological properties manifested by many of its members, of which their relevance in motor neuron disease and cancer chemotherapy has attracted considerable attention. To this extent, galanthamine has evolved into a successful commercial drug for Alzheimer's disease since its approval by the FDA in 2001. Concurrently, there have been several positive indicators for the emergence of an anticancer drug from the Amaryllidaceae due to the potency of several of its representatives as cell line specific antiproliferative agents. In this regard, the phenanthridones such as pancratistatin and narciclasine have offered most promise since their advancement into clinical trials, following which there has been renewed interest in the cytotoxic properties of these alkaloids. Given this background, this review seeks to highlight the various mechanisms which have been invoked to corroborate the cytotoxic effects of Amaryllidaceae alkaloids.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Humanos
17.
Nat Prod Commun ; 9(4): 461-6, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24868855

RESUMO

The family Amaryllidaceae has a long history of usage in the traditional medicinal practices of the indigenous peoples of South Africa, with three of its species known to be used for cancer treatment. Furthermore, the Amaryllidaceae is widely recognized for its unique alkaloid constituents, several of which exhibit potent and selective cytotoxic activities. In this study, several crinane alkaloids derived from local Amaryllidaceae species were examined for cytotoxic effects against the human cervical adenocarcinoma cell line, of which distichamine was the most potent (IC50 2.2 microM).


Assuntos
Adenocarcinoma/tratamento farmacológico , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/farmacologia , Citotoxinas/química , Citotoxinas/farmacologia , Neoplasias do Colo do Útero/tratamento farmacológico , Feminino , Células HeLa , Humanos , Estrutura Molecular
18.
Talanta ; 112: 85-94, 2013 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-23708542

RESUMO

A robust, reliable and high-throughput method for extraction and purification of gibberellins (GAs), a group of tetracyclic diterpenoid carboxylic acids that include endogenous growth hormones, from plant material was developed. The procedure consists of two solid-phase extraction steps (Oasis(®) MCX-HLB and Oasis(®) MAX) and gives selective enrichment and efficient clean-up of these compounds from complex plant extracts. The method was tested with plant extracts of Brassica napus and Arabidopsis thaliana, from which total recovery of internal standards of about 72% was achieved. A rapid baseline chromatographic separation of 20 non-derivatised GAs by ultra performance liquid chromatography is also presented where a reversed-phase chromatographic column Acquity CSH(®) and a mobile phase consisting of methanol and aqueous 10mM-ammonium formate is used. This method enables sensitive and precise quantitation of GAs by MS/MS in multiple-reaction monitoring mode (MRM) by a standard isotope dilution method. Optimal conditions, including final flow rate, desolvation temperature, desolvation gas flow, capillary and cone voltage for effective ionisation in the electrospray ion source were found. All studied GAs were determined as free acids giving dominant quasi-molecular ions of [M-H](-) with limits of detection ranging between 0.08 and 10 fmol and linear ranges over four orders of magnitude. Taking advantage of highly effective chromatographic separation of 20 GAs and very sensitive mass spectrometric detection, the presented bioanalytical method serves as a useful tool for plant biologists studying the physiological roles of these hormones in plant development.


Assuntos
Arabidopsis/química , Brassica napus/química , Giberelinas/análise , Extratos Vegetais/análise , Cromatografia Líquida/métodos , Flores/química , Brotos de Planta/química , Extração em Fase Sólida , Espectrometria de Massas em Tandem/métodos
19.
Nat Prod Commun ; 8(12): 1705-10, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24555277

RESUMO

In this study, the South African Amaryllid Boophone haemanthoides was examined for its phytochemical composition and cytotoxicity. In the process eight alkaloid structures, including the new compound distichaminol, were identified in bulb ethanolic extracts. Of the isolates, lycorine and distichamine exhibited strong activities against human acute lymphoblastic leukemia (CEM), breast adenocarcinoma (MCF7) and cervical adenocarcinoma (HeLa) cells with IC50S ranging from 1.8 to 9.2 microM.


Assuntos
Alcaloides de Amaryllidaceae/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Liliaceae/química , Alcaloides de Amaryllidaceae/química , Antineoplásicos Fitogênicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Células MCF-7 , Estrutura Molecular , Fenantridinas/isolamento & purificação
20.
Planta ; 236(6): 1775-90, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22886380

RESUMO

The effect of supplementing either meta-topolin (mT) or N(6)-benzyladenine (BA) requiring cultures with roscovitine (6-benzylamino-2-[1(R)-(hydroxymethyl)propyl]amino-9-isopropylpurine), a cyclin-dependent kinase (CDK) and N-glucosylation inhibitor, and INCYDE (2-chloro-6-(3-methoxyphenyl)aminopurine), an inhibitor of cytokinin (CK) degradation, on the endogenous CK profiles and physiology of banana in vitro was investigated. Growth parameters including multiplication rate and biomass were recorded after 42 days. Endogenous CK levels were quantified using UPLC-MS/MS while the photosynthetic pigment and phenolic contents were evaluated spectrophotometrically. The highest regeneration rate (93 %) was observed in BA + roscovitine while mT + INCYDE plantlets produced most shoots. Treatment with BA + roscovitine had the highest shoot length and biomass. Although not significant, there was a higher proanthocyanidin level in BA + roscovitine treatments compared to the control (BA). The levels of total phenolics and flavonoids were significantly higher in mT + roscovitine treatment than in the mT-treated regenerants. The presence of roscovitine and/or INCYDE had no significant effect on the photosynthetic pigments of the banana plantlets. Forty-seven aromatic and isoprenoid CKs categorized into nine CK-types were detected at varying concentrations. The presence of mT + roscovitine and/or INCYDE increased the levels of O-glucosides while 9-glucosides were higher in the presence of BA. Generally, the underground parts had higher CK levels than the aerial parts; however, the presence of INCYDE increased the level of CK quantified in the aerial parts. From a practical perspective, the use of roscovitine and INCYDE in micropropagation could be crucial in the alleviation of commonly observed in vitro-induced physiological abnormalities.


Assuntos
Citocininas/metabolismo , Musa/efeitos dos fármacos , Musa/fisiologia , Fotossíntese/efeitos dos fármacos , Reguladores de Crescimento de Plantas/metabolismo , Purinas/farmacologia , Adenina/análogos & derivados , Adenina/farmacologia , Compostos de Benzil , Biomassa , Quinases Ciclina-Dependentes/antagonistas & inibidores , Citocininas/análise , Citocininas/farmacologia , Cinetina/farmacologia , Musa/crescimento & desenvolvimento , Oxirredutases/antagonistas & inibidores , Fenóis/metabolismo , Componentes Aéreos da Planta/efeitos dos fármacos , Componentes Aéreos da Planta/crescimento & desenvolvimento , Componentes Aéreos da Planta/fisiologia , Reguladores de Crescimento de Plantas/análise , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/antagonistas & inibidores , Roscovitina , Transdução de Sinais , Técnicas de Cultura de Tecidos
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