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1.
Biomed Res Int ; 2020: 5324560, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33029513

RESUMO

The ongoing global pandemic caused by the human coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has infected millions of people and claimed hundreds of thousands of lives. The absence of approved therapeutics to combat this disease threatens the health of all persons on earth and could cause catastrophic damage to society. New drugs are therefore urgently required to bring relief to people everywhere. In addition to repurposing existing drugs, natural products provide an interesting alternative due to their widespread use in all cultures of the world. In this study, alkaloids from Cryptolepis sanguinolenta have been investigated for their ability to inhibit two of the main proteins in SARS-CoV-2, the main protease and the RNA-dependent RNA polymerase, using in silico methods. Molecular docking was used to assess binding potential of the alkaloids to the viral proteins whereas molecular dynamics was used to evaluate stability of the binding event. The results of the study indicate that all 13 alkaloids bind strongly to the main protease and RNA-dependent RNA polymerase with binding energies ranging from -6.7 to -10.6 kcal/mol. In particular, cryptomisrine, cryptospirolepine, cryptoquindoline, and biscryptolepine exhibited very strong inhibitory potential towards both proteins. Results from the molecular dynamics study revealed that a stable protein-ligand complex is formed upon binding. Alkaloids from Cryptolepis sanguinolenta therefore represent a promising class of compounds that could serve as lead compounds in the search for a cure for the corona virus disease.


Assuntos
Alcaloides/farmacologia , Betacoronavirus/efeitos dos fármacos , Infecções por Coronavirus/tratamento farmacológico , Cryptolepis/química , Pneumonia Viral/tratamento farmacológico , Proteínas Virais/antagonistas & inibidores , Alcaloides/química , Antivirais/química , Antivirais/farmacologia , Betacoronavirus/enzimologia , Simulação por Computador , Infecções por Coronavirus/virologia , Cisteína Endopeptidases , Avaliação Pré-Clínica de Medicamentos , Humanos , Alcaloides Indólicos/química , Alcaloides Indólicos/farmacologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/virologia , Relação Quantitativa Estrutura-Atividade , Quinolinas/química , Quinolinas/farmacologia , RNA Replicase/antagonistas & inibidores , Proteínas não Estruturais Virais/antagonistas & inibidores
2.
J Chromatogr A ; 1626: 461359, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797838

RESUMO

The enantiomeric determination of chiral drugs in the environment is of emerging concern since their enantiomers often exhibit stereoselectivity in environmental occurrence, fate and toxicity. In this study a method based on solid-phase extraction followed by chiral liquid chromatography and high-resolution mass spectrometry has been developed for the enantiomeric determination of a group of cathinones in river water and effluent wastewater. The enantioseparation was carried out using a Chiralpak CBH column in reversed-phase mode, and optimised by evaluating the effects of flow rate, buffer concentration and organic modifier. Under optimal conditions, good enantioseparations (Rs ≥1.2) were achieved for all the analytes. Two mixed-mode cation-exchange sorbents (Oasis WCX and Oasis MCX) in solid-phase extraction were evaluated in river water. Oasis MCX sorbent showed better performance with apparent recoveries ranging from 57 to 91% and matrix effect ranging from -10 to 15%. It is worth noting that a shifting of retention times and loss of enantioresolutions in environmental water samples was observed for all the analytes when the Oasis WCX sorbent was used. The method was validated with river water and effluent wastewater samples and its overall performance was satisfactory. The method quantification limits for all the analyte enantiomers ranged from 1.0 to 2.9 ng/L in river water, and from 2.3 to 6.0 ng/L in effluent wastewater. The repeatability and reproducibility values, expressed as% relative standard deviation (n = 5) were less than 15%. The method was then applied to the analysis of river water and effluent wastewater. The racemic methylone and methedrone (EF=0.49 and 0.46, respectively) were detected at low ng/L in some of the river water samples.


Assuntos
Alcaloides/análise , Cromatografia Líquida/métodos , Espectrometria de Massas/métodos , Alcaloides/química , Alcaloides/isolamento & purificação , Reprodutibilidade dos Testes , Rios/química , Extração em Fase Sólida/métodos , Estereoisomerismo , Águas Residuárias/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
3.
J Chromatogr A ; 1626: 461361, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797840

RESUMO

The alkaloid enantiomers are well-known to have different physiological and pharmacological effects, and to play an important role in enantioselectivity metabolism with enzymes catalysis in tobacco plants. Here, we developed an improved method for simultaneous and high-precision determination of the individual enantiomers of nornicotine, anatabine and anabasine in four tobacco matrices, based on an achiral gas chromatography-nitrogen phosphorus detector (GCNPD) with commonly available Rtx-200 column using (1S)-(-)-camphanic chloride derivatization. The method development consists of the optimization of extraction and derivatization, screening of achiral column, analysis of the fragmentation mechanisms and evaluation of matrix effect (ME). Under the optimized experimental conditions, the current method exhibited excellent detection capability for the alkaloid enantiomers, with coefficients of determination (R2) > 0.9989 and normality test of residuals P > 0.05 in linear regression parameters. The ME can be neglected for the camphanic derivatives. The limit of detection (LOD) and limit of quantitation (LOQ) ranged from 0.087 to 0.24 µg g - 1 and 0.29 to 0.81 µg g - 1, respectively. The recoveries and within-laboratory relative standard deviations (RSDR) were 94.3%~104.2% and 0.51%~3.89%, respectively. The developed method was successfully applied to determine the enantiomeric profiling of cultivars and curing processes. Tobacco cultivars had a significant impact on the nornicotine, anatabine, anabasine concentration and enantiomeric fraction (EF) of (R)-nornicotine, whereas the only significant change induced by the curing processes was an increase in the EF of (R)-anabasine.


Assuntos
Alcaloides/análise , Anabasina/análise , Cromatografia Gasosa/métodos , Nicotina/análogos & derivados , Piridinas/análise , Tabaco/química , Alcaloides/química , Anabasina/química , Hidrocarbonetos Aromáticos com Pontes/química , Cloretos/química , Lactonas/química , Nicotina/análise , Nicotina/química , Piridinas/química , Estereoisomerismo
4.
Nat Commun ; 11(1): 3337, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620756

RESUMO

The tetrahydroisoquinoline (THIQ) moiety is a privileged substructure of many bioactive natural products and semi-synthetic analogs. Plants manufacture more than 3,000 THIQ alkaloids, including the opioids morphine and codeine. While microbial species have been engineered to synthesize a few compounds from the benzylisoquinoline alkaloid (BIA) family of THIQs, low product titers impede industrial viability and limit access to the full chemical space. Here we report a yeast THIQ platform by increasing production of the central BIA intermediate (S)-reticuline to 4.6 g L-1, a 57,000-fold improvement over our first-generation strain. We show that gains in BIA output coincide with the formation of several substituted THIQs derived from amino acid catabolism. We use these insights to repurpose the Ehrlich pathway and synthesize an array of THIQ structures. This work provides a blueprint for building diverse alkaloid scaffolds and enables the targeted overproduction of thousands of THIQ products, including natural and semi-synthetic opioids.


Assuntos
Alcaloides/biossíntese , Benzilisoquinolinas/metabolismo , Saccharomyces cerevisiae/metabolismo , Tetra-Hidroisoquinolinas/metabolismo , Alcaloides/química , Analgésicos Opioides/química , Analgésicos Opioides/metabolismo , Benzilisoquinolinas/química , Produtos Biológicos/química , Produtos Biológicos/metabolismo , Vias Biossintéticas/genética , Engenharia Genética , Modelos Químicos , Estrutura Molecular , Saccharomyces cerevisiae/genética , Tetra-Hidroisoquinolinas/química
5.
J Chromatogr A ; 1625: 461286, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32709336

RESUMO

In the past two decades, supercritical fluid chromatography has evolved from a niche application to a comprehensive technology and a fully-fledged alternative to conventional high-performance liquid chromatography. In this study, we have focused on chiral separation of synthetic cathinones in gradient supercritical fluid chromatography coupled to mass spectrometry using an inverse gradient of a make-up solvent. Synthetic cathinones possess an amphetamine-like effect and, therefore, are frequently being offered on the Internet as a replacement for illicit drugs. Cathinones are chiral compounds, however, they are usually marketed and used as racemic mixtures. Since the effect of individual enantiomers can significantly vary, there is a need for the development of enantioseparation methods enabling to study the biological effects of individual enantiomers. Since cathinones are basic molecules, they are easily protonated (positively charged) under weakly acidic mobile phase conditions, which is a typical feature of supercritical mobile phases with an alcohol as an organic modifier. The positively charged species represent ideal analytes for ion exchangers, such as chiral zwitterion ion exchangers Chiralpak ZWIX (+) and Chiralpak ZWIX (-), which possess a positively and negatively charged unit in the molecular structure of the selectors. The presence of the positive charge in the selector's structure, functioning as a counter-ion for the positively charged analytes, significantly reduces the required amount of a buffer, which is plausible for hyphenation of such a separation system with mass spectrometry. For mass spectrometry hyphenated to supercritical fluid chromatography, the use of a make-up solvent is required to avoid analyte precipitation when using a low concentration of an organic co-solvent (modifier) in the super-/subcritical mobile phase. Hereby, we introduce a unique approach, which is based on the gradient introduction of the make-up to the post-column effluent. Using this approach, it is possible to keep constant the overall amount of the organic solvent (modifier and make-up) introduced into the mass spectrometer when using a gradient of the organic modifier. We show that the developed gradient elution method facilitates the chiral separation of all employed analytes, while the mobile-phase gradient compensation by the inverse make-up gradient enables their detection with high signal intensities.


Assuntos
Alcaloides/química , Alcaloides/isolamento & purificação , Cromatografia com Fluido Supercrítico/métodos , Espectrometria de Massas/métodos , Reologia , Solventes/química , Alcaloides/síntese química , Cromatografia Líquida de Alta Pressão , Pressão , Estereoisomerismo , Temperatura
6.
Food Chem ; 331: 127260, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32653763

RESUMO

Monitoring of tropane alkaloids is regulated in the European Union in cereal-based foods for infants and young children, tea and herbal infusions. The European Commission's Joint Research Centre (JRC) developed an improved LC-MS/MS analytical method using a pentafluorophenyl column, validated it and conducted two proficiency tests targeting these food categories. A subset of the data gathered from laboratories that used the JRC method was additionally exploited to derive interlaboratory performance characteristics. The method showed fit-for-purpose figures of merit. The LOQs for atropine and scopolamine were around 0.4 and 1.2 µg/kg in cereal products, and in tea and herbal infusions, respectively. Uncertainties varied from 15 to 25%. The reproducibility varied from 11 to 38% for scopolamine and from 17 to 44% for atropine at levels ranging from 0.18 to 18.8 and 1.2-54.0 µg/kg, respectively. Recoveries ranged from 71 to 96%. These performance parameters render the method a good candidate for standardisation.


Assuntos
Alcaloides/análise , Grão Comestível/química , Chá/química , Tropanos/análise , Alcaloides/química , Atropina/análise , Cromatografia Líquida de Alta Pressão , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Escopolamina/análise , Espectrometria de Massas em Tandem/métodos , Tropanos/química
7.
Nat Commun ; 11(1): 3236, 2020 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-32591543

RESUMO

The promotion of apoptosis in tumor cells is a popular strategy for developing anti-cancer drugs. Here, we demonstrate that the plant indole alkaloid natural product nauclefine induces apoptosis of diverse cancer cells via a PDE3A-SLFN12 dependent death pathway. Nauclefine binds PDE3A but does not inhibit the PDE3A's phosphodiesterase activity, thus representing a previously unknown type of PDE3A modulator that can initiate apoptosis without affecting PDE3A's canonical function. We demonstrate that PDE3A's H840, Q975, Q1001, and F1004 residues-as well as I105 in SLFN12-are essential for nauclefine-induced PDE3A-SLFN12 interaction and cell death. Extending these molecular insights, we show in vivo that nauclefine inhibits tumor xenograft growth, doing so in a PDE3A- and SLFN12-dependent manner. Thus, beyond demonstrating potent cytotoxic effects of an alkaloid natural product, our study illustrates a potentially side-effect-reducing strategy for targeting PDE3A for anti-cancer therapeutics without affecting its phosphodiesterase activity.


Assuntos
Alcaloides/farmacologia , Apoptose/efeitos dos fármacos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Alcaloides/química , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cilostazol/farmacologia , Feminino , Humanos , Camundongos Nus , Inibidores da Fosfodiesterase 3/farmacologia , Estabilidade Proteica/efeitos dos fármacos , Tetra-Hidroisoquinolinas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Exp Parasitol ; 213: 107902, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32353376

RESUMO

Natural compounds played an important role for prevention and treatment of the disease as well as are the important compounds for the design of the new bioactive compounds. In this study, eight tropolone alkaloids were isolated from Colchicum kurdicum including colchicoside, 2-demethyl colchicine, 3-demethyl colchicine, demecolcine, colchifoline, N-deacetyl-N-formyl colchicine, colchicine and cornigerine by column and preparative thin layer chromatography. The chemical structures were identified by 1H NMR and 13C NMR spectroscopy. Moreover, the antileishmanial activity on Leishmania major, anti-inflammatory activity, iron chelating activity and toxicity studies including hemolytic activity, brine shrimp toxicity, cytotoxicity and acute toxicity and docking study of all isolated bioactive compounds were evaluated. As result, colchicoside and colchicine had potent leishmanicidal effects and N-deacetyl-N-formyl colchicine and cornigerine had the highest anti-inflammatory effects. All compounds had the significant iron chelating activity. According to toxicity studies, isolated compounds showed the low hemolytic activity and cytotoxicity, high LC50, LC90 and LD50. In the molecular docking study, colchicoside had the high dockscore. According to the study, with future studies all isolated compounds could be used for design the novel antileishmanial drugs.


Assuntos
Alcaloides/farmacologia , Colchicum/química , Leishmania major/efeitos dos fármacos , Extratos Vegetais/farmacologia , Tripanossomicidas/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Tropolona/química , Tripanossomicidas/química , Tripanossomicidas/isolamento & purificação
9.
Toxicol Lett ; 331: 42-52, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32464236

RESUMO

Synthetic cathinones abuse remains a serious public health problem. Kidney injury has been reported in intoxications associated with synthetic cathinones, but the molecular mechanisms involved have not been explored yet. In this study, the potential in vitro nephrotoxic effects of four commonly abused cathinone derivatives, namely pentedrone, 3,4-dimethylmethcatinone (3,4-DMMC), methylone and 3,4-methylenedioxypyrovalerone (MDPV), were assessed in the human kidney HK-2 cell line. All four derivatives elicited cell death in a concentration- and time-dependent manner, in the following order of potency: 3,4-DMMC >> MDPV > methylone ≈ pentedrone. 3,4-DMMC and methylone were selected to further elucidate the mechanisms behind synthetic cathinones-induced cell death. Both drugs elicited apoptotic cell death and prompted the formation of acidic vesicular organelles and autophagosomes in HK-2 cells. Moreover, the autophagy inhibitor 3-methyladenine significantly potentiated cell death, indicating that autophagy may serve as a cell survival mechanism that protects renal cells against synthetic cathinones toxicity. Both drugs triggered a rise in reactive oxygen and nitrogen species formation, which was completely prevented by antioxidant treatment with N­acetyl­L­cysteine or ascorbic acid. Importantly, these antioxidant agents significantly aggravated renal cell death induced by cathinone derivatives, most likely due to their autophagy-blocking properties. Taken together, our results support an intricate control of cell survival/death modulated by oxidative stress, apoptosis and autophagy in synthetic cathinones-induced renal injury.


Assuntos
Alcaloides/toxicidade , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Drogas Ilícitas/toxicidade , Rim/efeitos dos fármacos , Alcaloides/química , Benzodioxóis/química , Benzodioxóis/toxicidade , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Rim/metabolismo , Rim/patologia , Metanfetamina/análogos & derivados , Metanfetamina/química , Metanfetamina/toxicidade , Metilaminas/química , Metilaminas/toxicidade , Pentanonas/química , Pentanonas/toxicidade , Pirrolidinas/química , Pirrolidinas/toxicidade , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Fatores de Tempo
10.
Toxicol Appl Pharmacol ; 395: 114970, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32234388

RESUMO

Synthetic cathinones, such as methylone and pentedrone, are psychoactive derivatives of cathinone, sold in the internet as "plant food" or "bath salts". However, the level at which these compounds and their enantiomers cross the intestinal barrier has not been yet determined. Thus, the present study aimed to analyze the enantioselectivity on the permeability of these drugs through the intestinal barrier by using the Caco-2 cell line, a widely used in vitro model for drug permeability studies. To achieve this goal, an UHPLC-UV method was developed and validated to quantify both synthetic cathinones. The developed UHPLC-UV method revealed high selectivity and a linearity from 1 to 500 µM with correlation coefficients always higher than 0.999. The method has an accuracy that ranged between 89 and 107%, inter-day and intra-day precisions with coefficients of variation below 10%, limits of detection and quantification of 0.31 µM and 0.93 µM for methylone and 0.17 µM and 0.52 µM for pentedrone, respectively. In Caco-2 cells, a differentiated passage of the enantiomers across monolayer was observed for both cathinones. For pentedrone, the difference was observed after the first hour, being R-(-)-pentedrone the most permeable compound. Regarding methylone, the difference was noted after one hour and 30 min, with S-(-)-methylone being the most absorbed enantiomer. In conclusion, a fully validated method was successfully applied for studying the permeability of methylone and pentedrone enantiomers in an in vitro model of human intestine, which allowed to discover, for the first time, the enantioselectivity in drug permeability of this class of drugs.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Absorção Intestinal/fisiologia , Metanfetamina/análogos & derivados , Metilaminas/química , Metilaminas/farmacocinética , Pentanonas/química , Pentanonas/farmacocinética , Alcaloides/química , Células CACO-2 , Humanos , Metanfetamina/química , Metanfetamina/farmacocinética , Permeabilidade , Psicotrópicos , Sensibilidade e Especificidade , Estereoisomerismo , Relação Estrutura-Atividade
11.
Nat Commun ; 11(1): 1867, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313070

RESUMO

Plant halogenated natural products are rare and harbor various interesting bioactivities, yet the biochemical basis for the involved halogenation chemistry is unknown. While a handful of Fe(II)- and 2-oxoglutarate-dependent halogenases (2ODHs) have been found to catalyze regioselective halogenation of unactivated C-H bonds in bacteria, they remain uncharacterized in the plant kingdom. Here, we report the discovery of dechloroacutumine halogenase (DAH) from Menispermaceae plants known to produce the tetracyclic chloroalkaloid (-)-acutumine. DAH is a 2ODH of plant origin and catalyzes the terminal chlorination step in the biosynthesis of (-)-acutumine. Phylogenetic analyses reveal that DAH evolved independently in Menispermaceae plants and in bacteria, illustrating an exemplary case of parallel evolution in specialized metabolism across domains of life. We show that at the presence of azide anion, DAH also exhibits promiscuous azidation activity against dechloroacutumine. This study opens avenues for expanding plant chemodiversity through halogenation and azidation biochemistry.


Assuntos
Alcaloides/biossíntese , Compostos Ferrosos/metabolismo , Hidrolases/metabolismo , Ácidos Cetoglutáricos/metabolismo , Menispermaceae/metabolismo , Compostos de Espiro/metabolismo , Alcaloides/química , Alcaloides/genética , Bactérias/metabolismo , Biocatálise , Genes de Plantas/genética , Halogenação , Menispermaceae/embriologia , Menispermaceae/genética , Mutagênese , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteínas Recombinantes , Metabolismo Secundário/genética , Alinhamento de Sequência , Compostos de Espiro/química , Transcriptoma
12.
Top Curr Chem (Cham) ; 378(2): 22, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-32030596

RESUMO

Heterocyclic compounds having a nitrogen atom in the ring exhibit very interesting biological activities. Indole is the core structure of many bioactive compounds owing to its high affinity to bind with most biological targets. Indole is an electron-rich compound and generally prefers electrophilic rather than nucleophilic substitution. Hence, many important indole derivatives are difficult to synthesize through the conventional reactivity of indole. This limitation can be avoided by using the umpolung, from the German word meaning polarity inversion. In umpolung, the indole molecule, especially the C2 and C3 positions, behave as an electrophile. As C2-functionalized indoles have substantial importance in synthetic and pharmaceutical chemistry, this review focuses on the C2 umpolung of indoles via the indirect approach which is less explored. Unlike direct approaches of indole umpolung, indirect methods have several advantages and therefore a number of research articles have been published in this field. But no review is available up till now. This is the first review on this topic and we believe that it will surely motivate the readers to work in this area further.


Assuntos
Carbono/química , Indóis/química , Alcaloides/síntese química , Alcaloides/química , Catálise , Ciclização , Iodo/química , Quinolinas/síntese química , Quinolinas/química , Ácidos Sulfínicos/química
13.
Chem Pharm Bull (Tokyo) ; 68(2): 103-116, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32009077

RESUMO

The merits of biogenetic considerations in the chemical syntheses of natural products have been emphasized by describing the total syntheses of Lycopodium alkaloids; lycodine, flabellidine, lycopodine, and flabelliformine, as well as monoterpenoid indole alkaloids; C-mavacurine, kopsiyunnanine K, koumine, and 11-methoxy-19R-hydroxygelselegine.


Assuntos
Alcaloides/síntese química , Produtos Biológicos/síntese química , Técnicas de Química Sintética/métodos , Lycopodium/química , Alcaloides de Triptamina e Secologanina/síntese química , Alcaloides/química , Produtos Biológicos/química , Alcaloides de Triptamina e Secologanina/química
14.
Chem Pharm Bull (Tokyo) ; 68(2): 140-149, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32009081

RESUMO

Previously, we reported that the c-Met inhibitory effect of Ephedra Herb extract (EHE) is derived from ingredients besides ephedrine alkaloids. Moreover, analgesic and anti-influenza activities of EHE and ephedrine alkaloids-free Ephedra Herb extract (EFE) have been reported recently. In this study, we examined the fractions containing c-Met kinase inhibitory activity from EHE and the fractions with analgesic and anti-influenza activities from EFE, and elucidated the structural characteristics of the active fractions. Significant c-Met kinase activity was observed in 30, 40, and 50% methanol (MeOH) eluate fractions obtained from water extract of EHE using Diaion HP-20 column chromatography. Similarly, 20 and 40% MeOH, and MeOH eluate fractions obtained from water extract of EFE were found to display analgesic and anti-influenza activities. Reversed phase-HPLC analysis of the active fractions commonly showed broad peaks characteristic of high-molecular mass condensed tannin. The active fractions were analyzed using 13C-NMR and decomposition reactions; the deduced structures of active components were high-molecular mass condensed tannins, which were mainly procyanidin B-type and partly procyanidin A-type, including pyrogallol- and catechol-type flavan 3-ols as extension and terminal units. HPLC and gel permeation chromatography (GPC) analyses estimated that the ratio of pyrogallol- and catechol-type was approximately 9 : 2, and the weight-average molecular weight based on the polystyrene standard was >45000. Furthermore, GPC-based analysis was proposed as the quality evaluation method for high-molecular mass condensed tannin in EHE and EFE.


Assuntos
Ephedra/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Alcaloides/química , Alcaloides/farmacologia , Analgésicos/química , Analgésicos/farmacologia , Animais , Antivirais/química , Antivirais/farmacologia , Biflavonoides/química , Biflavonoides/farmacologia , Catequina/química , Catequina/farmacologia , Linhagem Celular Tumoral , Cães , Efedrina/química , Efedrina/farmacologia , Humanos , Células Madin Darby de Rim Canino , Masculino , Camundongos , Proantocianidinas/química , Proantocianidinas/farmacologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-met/antagonistas & inibidores
15.
Anticancer Res ; 40(2): 689-694, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32014909

RESUMO

BACKGROUND/AIM: Piperine, a major alkaloid of the fruit of black pepper plants, selectively inhibits the growth of triple-negative breast cancer cells but its lipophilicity restricts possible clinical application. This study therefore determined the feasibility of encapsulating piperine in nanoparticles (NPs) to increase its solubility in an aqueous environment. MATERIALS AND METHODS: Piperine-loaded biodegradable methoxy poly(ethylene glycol)-poly(lactic-co-glycolic) acid copolymer-based NPs were produced by single emulsion solvent extraction and thin-film hydration. Growth and viability of triple-negative breast cancer (TNBC) cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and Annexin-V-FLUOS/propidium iodide staining, respectively. RESULTS: Thin-film hydration was superior to single emulsion solvent extraction, yielding piperine-loaded NPs with an average size of 50 nm. Piperine-loaded NPs inhibited TNBC cell growth and induced apoptosis while sparing normal fibroblasts. CONCLUSION: It is feasible to deliver a cytotoxic concentration of piperine to TNBC cells via NPs with the potential for improved bioavailability and solubility in biological fluids.


Assuntos
Alcaloides/administração & dosagem , Benzodioxóis/administração & dosagem , Nanopartículas/administração & dosagem , Piperidinas/administração & dosagem , Alcamidas Poli-Insaturadas/administração & dosagem , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Alcaloides/química , Antineoplásicos Fitogênicos/administração & dosagem , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Benzodioxóis/química , Linhagem Celular Tumoral , Emulsões/administração & dosagem , Emulsões/química , Feminino , Humanos , Nanopartículas/química , Piperidinas/química , Poliésteres/administração & dosagem , Poliésteres/química , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Alcamidas Poli-Insaturadas/química , Neoplasias de Mama Triplo Negativas/patologia
16.
J Agric Food Chem ; 68(8): 2406-2417, 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32031370

RESUMO

Black pepper (Piper nigrum L.) has been commonly utilized in food preparation and traditional medicine in several countries. Seven new amide alkaloids, pipernigramides A-G (3, 10, 38, and 41-44), a new piperic ester, pipernigrester A (48), along with 47 known compounds were isolated from the EtOH extract of P. nigrum. The inhibitory effects on nitric oxide (NO) of all compounds were then evaluated. Among the tested compounds, three of them (42-44) significantly inhibited inducible nitric oxide synthase (iNOS)-mediated NO (IC50 = 4.74 ± 0.18, 4.08 ± 0.19, and 3.71 ± 0.32 µM, respectively), and IL-1ß, IL-6, TNF-α, and PGE2 release in RAW 264.7 cells stimulated by lipopolysaccharide. Moreover, 42-44 suppressed IκB degradation and further inhibited the cytosol-nucleus translocation of the p65 subunit by targeting IKK-ß. In the carrageenan-induced paw edema test, 42-44 demonstrated anti-inflammatory effects as well. These results indicate that all three compounds from P.nigrum have the potential anti-inflammatory effects.


Assuntos
Alcaloides/farmacologia , Anti-Inflamatórios/farmacologia , Macrófagos/efeitos dos fármacos , NF-kappa B/imunologia , Piper nigrum/química , Extratos Vegetais/farmacologia , Alcaloides/química , Animais , Anti-Inflamatórios/química , Dinoprostona/imunologia , Interleucina-6/genética , Interleucina-6/imunologia , Macrófagos/imunologia , Camundongos , Estrutura Molecular , NF-kappa B/genética , Óxido Nítrico Sintase Tipo II/genética , Óxido Nítrico Sintase Tipo II/imunologia , Extratos Vegetais/química , Células RAW 264.7
17.
J Agric Food Chem ; 68(10): 3140-3148, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32053361

RESUMO

3-O-Cinnamoylepicatechin (1) was synthesized along with four flavoalkaloids, (-)-6-(5‴S)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (2), (-)-6-(5‴R)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (3), (-)-8-(5‴S)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (4), and (-)-8-(5‴R)-N-ethyl-2-pyrrolidinone-3-O-cinnamoylepicatechin (5) via esterification of epicatechin followed by phenolic Mannich reaction of 1 with theanine in the presence of heat. The new compounds 1-5 were detected in leaves of three tea cultivars, Fuding-Dabai, Huangjingui, and Zimudan with the help of ultra-performance liquid chromatography hyphenated with a photodiode array detector and electrospray ionization high-resolution mass spectrometry (UPLC-PDA-ESI-HRMS), suggesting that they are naturally occurring in tea leaves. The structures of the novel natural products were characterized by one- and two-dimensional nuclear magnetic resonance (1D and 2D NMR) and mass spectroscopy. Compounds 1-5 were then evaluated for their acetylcholinesterase (AChE) inhibitory effect (IC50 = 0.12-1.02 µM). The availability of the synthesized epicatechin derivatives 1-5 via a synthetic route enabled the first unequivocal identification of these derivatives as tea secondary metabolites and made it possible to determine their content in the tea material as well as the diverse bioactivities.


Assuntos
Alcaloides/química , Camellia sinensis/química , Inibidores da Colinesterase/química , Extratos Vegetais/química , Acetilcolinesterase/química , Cromatografia Líquida de Alta Pressão , Folhas de Planta/química , Espectrometria de Massas por Ionização por Electrospray
18.
Alkaloids Chem Biol ; 83: 1-112, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32098648

RESUMO

Lamellarins are marine alkaloids containing fused 14-phenyl-6H-[1]benzopyrano[4',3':4,5]pyrrolo[2,1-a]isoquinoline or non-fused 3,4-diarylpyrrole-2-carboxylate ring systems. To date, more than 50 lamellarins have been isolated from a variety of marine organisms, such as mollusks, tunicates, and sponges. Many of them, especially fused type I lamellarins, exhibit impressive biological activity, such as potent cytotoxicity, topoisomerase I inhibition, protein kinases inhibition, and anti-HIV-1 activity. Due to their useful biological activity and limited availability from natural sources, a number of synthetic methods have been developed. In this chapter, we present an updated and comprehensive review on lamellarin alkaloids summarizing their isolation, synthesis, and biological activity.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Fármacos Anti-HIV/farmacologia , Antineoplásicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Pirróis/isolamento & purificação , Pirróis/farmacologia , Inibidores da Topoisomerase I/farmacologia , Alcaloides/síntese química , Alcaloides/química , Animais , Fármacos Anti-HIV/síntese química , Fármacos Anti-HIV/química , Fármacos Anti-HIV/isolamento & purificação , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Humanos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/isolamento & purificação , Pirróis/síntese química , Pirróis/química , Inibidores da Topoisomerase I/síntese química , Inibidores da Topoisomerase I/química , Inibidores da Topoisomerase I/isolamento & purificação
20.
Chemistry ; 26(17): 3729-3732, 2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32022300

RESUMO

An ω-transaminase-triggered intramolecular aza-Michael reaction has been employed for the preparation of cyclic ß-enaminones in good yield and excellent enantio- and diastereoselectivity, starting from easily accessible prochiral ketoynones and commercially available enzymes. The powerful thermodynamic driving force associated with the spontaneous aza-Michael reaction effectively displaces the transaminase reaction equilibrium towards product formation, using only two equivalents of isopropylamine. To demonstrate the potential of this methodology, this biocatalytic aza-Michael step was combined with annulation chemistry, affording unique stereo-defined fused alkaloid architectures.


Assuntos
Alcaloides/química , Transaminases , Biocatálise , Estrutura Molecular , Transaminases/química
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