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1.
Korean J Parasitol ; 60(5): 339-344, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36320110

RESUMO

The development of drug resistance is one of the most severe concerns of malaria control because it increases the risk of malaria morbidity and death. A new candidate drug with antiplasmodial activity is urgently needed. This study evaluated the efficacy of different dosages of aqueous extract of Strychnos ligustrina combined with dihydroartemisinin and piperaquine phosphate (DHP) against murine Plasmodium berghei infection. The BALB/c mice aged 6-8 weeks were divided into 6 groups, each consisting of 10 mice. The growth inhibition of compounds against P. berghei was monitored by calculating the percentage of parasitemia. The results showed that the mice receiving aqueous extract and combination treatment showed growth inhibition of P. berghei in 74% and 94%, respectively. S. ligustrina extract, which consisted of brucine and strychnine, effectively inhibited the multiplication of P. berghei. The treated mice showed improved hematology profiles, body weight, and temperature, as compared to control mice. Co-treatment with S. ligustrina extract and DHP revealed significant antimalarial and antipyretic effects. Our results provide prospects for further discovery of antimalarial drugs that may show more successful chemotherapeutic treatment.


Assuntos
Antimaláricos , Artemisininas , Malária , Strychnos , Camundongos , Animais , Plasmodium berghei , Extratos Vegetais/farmacologia , Artemisininas/farmacologia , Camundongos Endogâmicos BALB C , Fosfatos/farmacologia , Fosfatos/uso terapêutico
2.
Phytochemistry ; 203: 113353, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36007664

RESUMO

Seven undescribed monoterpenoid indole alkaloids, two N(4)-chloromethylation artifacts, and 10 known alkaloids were isolated from the stems and twigs of Strychnos cathayensis. The corresponding structures were elucidated via spectroscopic data interpretation and electronic circular dichroism. The absolute configuration of (17S)-12-hydroxy-11-methoxydiaboline, the major anomer of 12-hydroxy-11-methoxydiaboline, was characterized by X-ray diffraction analysis for the first time. At an intraperitoneal dose of 30 mg/kg, 12-hydroxy-11-methoxy-N(4)-chloromethyldiaboline and (-)-macusine A exhibited potential analgesic effects with prolongation rates of 99% and 47% for the latency time of hind-paw licking, respectively, compared to the blank control. 12-Hydroxy-11-methoxydiaboline, 12-hydroxy-11-methoxydiaboline N(4)-oxide, retuline N-oxide, and (-)-vincosamide exhibited antiviral activity against Coxsackie virus B3 (CVB3) with IC50 values of 33.33 µM.


Assuntos
Alcaloides de Triptamina e Secologanina , Strychnos , Analgésicos , Antivirais , Alcaloides Indólicos/química , Estrutura Molecular , Óxidos , Alcaloides de Triptamina e Secologanina/química , Strychnos/química
3.
Toxicon ; 215: 57-68, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35690276

RESUMO

INTRODUCTION: Plants of the Strychnos genus, which include about 200 species, are used for multiple traditional purposes as hunting poison, for example, and have shown interesting pharmacological properties, especially curarizing and tetanizing, but also against malaria. Many monoterpene indole alkaloids have already been isolated and identified. Among them, there is strychnine, a famous alkaloid that can cause death by asphyxiation. OBJECTIVE: Investigate alkaloidic molecular diversity from Strychnos genus using molecular networking technique and study the Strychnos genus from a chemotaxonomic point of view. MATERIAL AND METHODS: Twenty-eight different species and different plant parts were ground into powder using a grinder. The methanolic extracts were carried out using a pressurized solvent extraction and the alkaloid extract was performed manually with a separating funnel. The extracts were analyzed by HPLC-ESI(+)-Q/TOF. The data were processed using MZmine 2 software and the molecular network was generated on the GNPS platform. The study of the generated molecular network allowed the detection of various alkaloids. Among these is the famous strychnine which has been detected in 7 new Strychnos species not yet described as strychnine producers. This identification was investigated using orthogonal approaches, namely TLC, NMR, HPLC-UV and UHPLC-ESI(+)-Q/TOF analyses. The LOD by HPLC-UV of strychnine was also determined. RESULTS: Further analyses allowed to confirm the presence of strychnine in S. densiflora trunk barks but also to show the presence of strychnine with high probability in the trunk barks of S. camptoneura, S. congolana, S. boonei, and S. tchibangensis, and in the leaves of S. usambarensis. About the trunk barks of S. tricalyisoides, the probability of a strychnine content remains low. CONCLUSION: This work exemplified the efficiency of molecular networking in identifying known metabolites (major and minor alkaloids) involved in the chemotaxonomic study of plants from Strychnos genus.


Assuntos
Alcaloides , Strychnos , Alcaloides/química , Alcaloides Indólicos , Folhas de Planta , Estricnina/química , Estricnina/farmacologia , Strychnos/química
4.
PLoS One ; 17(5): e0268628, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35587933

RESUMO

Strychnos madagascariensis is an underutilized South African fruit-bearing tree, with the pulp being the primary consumable component. However, the seeds hold the potential as a food source due to their high nutrient composition. The aim of this study was to determine the physical properties of S. madagascariensis fruit and seeds to aid in food processing equipment development. Fruit physical properties were determined at four progressive ripening stages, as well as the seed physical properties and mineral composition. The pulp contributed the most towards fruit composition across stages of ripeness (c 50%), followed by the rind (c 30%) and seeds (c 20%). Furthermore, significant variations in seed physical properties were observed at progressive maturity stages. The seeds showed significantly greater mineral compositions in unripe-green fruit in comparison to fruit at progressive ripening stages. The data provided may serve as a basis for the development of processing procedures and equipment and suggests that seeds of unripe-green fruit hold greater nutritional benefits.


Assuntos
Frutas , Valor Nutritivo , Sementes , Strychnos , Manipulação de Alimentos
5.
J Org Chem ; 87(8): 5199-5212, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35275636

RESUMO

The complex structures and important biological functions of Strychnos alkaloids have attracted a great deal of attention from synthetic chemists. Herein, we describe the concise asymmetric total syntheses of the Strychnos alkaloids, (-)-dehydrotubifoline, (-)-tubifoline, and (-)-tubifolidine, as well as the formal total synthesis of (-)-strychnine. Our strategy features the construction of the common tetracyclic pyrrolo[2,3-d]carbazole structure using regioselective Fischer indolization on unsymmetrical cyclic ketones and late-stage functionalization for divergent synthesis. We developed a stepwise Fischer indolization featuring selective formation of enol triflate to solve the challenging regioselectivity problem, leading to the common tetracyclic ring skeleton in these Strychnos alkaloids. The regioselectivity of Fischer indolization on unsymmetrical cyclic ketones was studied on the basis of different types of ring systems and supported by density functional theory calculations. Overall, our success in the construction of this tetracyclic ring secured the syntheses of Strychnos alkaloids and may provide a general method for the total syntheses of various alkaloids containing this skeleton.


Assuntos
Alcaloides , Strychnos , Alcaloides/química , Cetonas , Estricnina/química , Strychnos/química
7.
Drug Chem Toxicol ; 45(1): 239-249, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31645139

RESUMO

Present work carried out with the objectives to isolate active component of S. potatorum and also to evaluate its free radical scavenging activity and preventing capacity against heavy metal toxicity. Solvents of different polarity were used to prepare crude extracts of S. potatorum seeds and screened for antioxidant activity. Among the crude extracts, methanolic extract was found to exhibit higher antioxidant activity (81.22%) which was fractionated by liquid-liquid partitioning method. Among the different fractions (LF1-LF4), LF-2 showed higher antioxidant activity (98.24%) as compared to other three liquid fractions and hence LF-2 was further purified by column chromatography. Among nine column fractions (CF1-CF9), fraction CF-7 was found to have higher antioxidant activity (92.14%), which was further analyzed using LC-MS and NMR and identified as loganic acid. In vitro radical scavenging assays showed remarkable antioxidant activity of loganic acid in terms of DPPH scavenging (IC50 149 µg/ml), superoxide radical scavenging (IC50 632.43 µg/ml) and hydroxyl radical scavenging (IC50 29.78 µg/ml). Loganic acid exhibited 81% prevention of heavy metal toxicity through the mechanism of inhibiting ROS generation (2046 AU vs. 5264 AU in control) and lipid peroxidation (95.01%). Thus, the active compound (loganic acid) isolated from S. potatorum has strong free radical scavenging activity and remarkable cyto-protective effect against heavy metal mediated toxicity.


Assuntos
Metais Pesados , Strychnos , Antioxidantes/farmacologia , Sequestradores de Radicais Livres/farmacologia , Iridoides , Leucócitos Mononucleares , Metais Pesados/toxicidade , Extratos Vegetais/farmacologia
8.
J Ethnopharmacol ; 283: 114704, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34601082

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Spiny monkey orange (Strychnos spinosa Lam.) is an African endemic fruit tree that is widely consumed by humans and animals for its nutritional value. In folk medicine, different parts of S. spinosa are widely used for the management of the health and well-being of humans and livestock. AIM: We provide a critical appraisal on the ethnobotanical uses, nutritional and pytochemical as well as the biological activities of S. spinosa. METHODS: Articles were mined from online databases such as Google Scholar, PubMed, Science Direct, SciELO and SpringerLink. We captured research outputs that aligned with the scope of the review. RESULTS: Strychnos spinosa remains a commonly consumed fruit due to its high nutritional (e.g. carbohydrates, crude protein and fats) content and energy. In folk medicine, different parts of S. spinosa are prescribed as remedy for diverse medical conditions especially for treating malaria, diabetes, snakebites, skin-related conditions and sexually transmitted infections in humans as well as sleeping sickness in livestock. Together with essential oils, more than 25 compounds have been profiled using Gas chromatography-mass spectrometry (GC-MS), and approximately 45 compounds have been isolated and structurally elucidated using diverse spectroscopic techniques such as UV-visible, Infrared (IR), Nuclear Magnetic Resonance (NMR) and mass spectroscopy (MS). Strychnos spinosa exerts varying degrees of biological activities against different microorganisms (bacteria and fungi) and parasites (plasmodia, trypanosomes and ticks) responsible for many diseases in humans and livestock. Furthermore, low to moderate enzyme-inhibitory effects of S. spinosa extracts suggest its ability to mitigate pains, inflammations and diabetics as well as snakebite venom. Increasing evidence from the in vivo studies support the use of the plant as a popular remedy for managing diabetics in folk medicine. The low cytotoxic effect of the plant extracts against different cell lines could be an indication of its relative safety. CONCLUSION: Strychnos spinosa exhibits various health-promoting benefits due to its diverse nutritional and phytochemical constituents. Given that the majority of the existing evidence on these aforementioned therapeutic properties and safety are in vitro-based, the clinical significance of these results remain limited.


Assuntos
Medicina Tradicional Africana/métodos , Extratos Vegetais/farmacologia , Strychnos/química , Animais , Etnobotânica , Etnofarmacologia , Frutas , Humanos , Extratos Vegetais/efeitos adversos
9.
Alkaloids Chem Biol ; 86: 1-143, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34565505

RESUMO

Of Nature's nearly 3000 unique monoterpene indole alkaloids derived from tryptophan, those members belonging to the Aspidosperma and Strychnos families continue to impact the fields of natural products (i.e., isolation, structure determination, biosynthesis) and organic chemistry (i.e., chemical synthesis, methodology development) among others. This review covers the biological activity (Section 2), biosynthesis (Section 3), and synthesis of both classical and novel Aspidosperma (Section 4), Strychnos (Section 5), and selected bis-indole (Section 6) alkaloids. Technological advancements in genetic sequencing and bioinformatics have deepened our understanding of how Nature assembles these intriguing molecules. The proliferation of innovative synthetic strategies and tactics for the synthesis of the alkaloids covered in this review, which include contributions from over fifty research groups from around the world, are a testament to the creative power and technical skills of synthetic organic chemists. To be sure, Nature-the Supreme molecular architect and source of a dazzling array of irresistible chemical logic puzzles-continues to inspire scientists across multiple disciplines and will certainly continue to do so for the foreseeable future.


Assuntos
Alcaloides , Aspidosperma , Strychnos , Biologia , Humanos , Alcaloides Indólicos
10.
Environ Monit Assess ; 193(10): 638, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34505189

RESUMO

Synthetic dyes used in the textile and paper industries pose a major threat to the environment. In the present research work, the adsorption efficiency of the natural adsorbent Strychnos potatorum Linn (Fam: Loganiaceae) seeds were examined against the reactive orange-M2R dye from aqueous solution by varying the process conditions such as contact time, pH, adsorbent dosage, and initial dye concentration on adsorption of anionic azo dye. This study compares different types of artificial neural networks which are feedforward artificial neural network (FANN) and nonlinear autoregressive exogenous (NARX) model to predict the efficiency of a cost-effective natural adsorbent Strychnos potatorum Linn seeds on removing reactive orange-M2R dye from aqueous solution. Twelve training algorithms of neural network were compared, and the prediction on the adsorption performance of anionic azo dye from aqueous solution using Strychnos potatonum Linn seeds was evaluated by using the root mean squared error (RMSE), mean absolute error (MAE), coefficient of determination (R2), and accuracy. For FANN model, Levenberg-Marquardt (LM) backpropagation with 19 hidden neurons was selected as the optimum FANN model, with R2 of 0.994 and accuracy of 87.20%, 98.21%, and 66.60% for training, testing, and validation datasets, respectively. For NARX model, LM with 8 hidden neurons was selected as the most suitable training algorithm, with R2 value of more than 0.99 and accuracy of 88.00%, 90.91%, and 75.00% for training, testing, and validation datasets, respectively. NARX model accurately predicted the adsorption of anionic azo dye from aqueous solution using Strychnos potatonum Linn seeds with better performance than FANN model.


Assuntos
Strychnos , Adsorção , Compostos Azo , Monitoramento Ambiental , Concentração de Íons de Hidrogênio , Cinética , Redes Neurais de Computação , Sementes
11.
Pak J Pharm Sci ; 33(3): 937-945, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-33191216

RESUMO

The majority of the world population suffers from mental and behavioral disorder. It is the need of the time to find an alternate of presently available medicines in order to decrease the medical expense. Homeopathic remedies are available and prescribed by homeopaths for treatment of anxiety and depression. Unfortunately, no data are available that proves its potential to relieve mental illness. The current study is designed to assess neuro behavioral and antidepressant like effects of homeopathic remedies Staphysagria, Argentum nitricum and Ignatia amara in comparison with standard drug (escitalopram). Different neuro behavioral activities were analyzed. The animals were administered the doses of all homeopathic remedied (60 µl to the rats) and escitalopram (0.042 mg to rats) through the oral route. The activities were observed on day 30th and day 60th. Our result suggests that the swimming time in Staphysagria treated group were significantly improved (p<0.001) after day 60th and significance rise was observed (p<0.01) in Ignatia amara treated animals, whereas significant decline (p<0.05) in struggling time was observed in Argentum nitricum administered animals after the 60th day as compared to 30th day. The central square crossings were improved highly significantly (p<0.001) after the 30th day dosing, by all three remedies and peripheral squares crossing were found highly significantly increased (p<0.001) after chronic dosing in Staphysagria and Ignatia amara treated groups. It is concluded from the results that all three homeopathic remedies produce comparable effects like standard drug while among all three remedies Staphysagria possess a potent antidepressant activity. To the best of our knowledge the current study reports first time the anti-depressant potential of homeopathic remedies in rodents.


Assuntos
Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Depressão/tratamento farmacológico , Homeopatia , Locomoção/efeitos dos fármacos , Extratos Vegetais/farmacologia , Nitrato de Prata/farmacologia , Animais , Delphinium , Depressão/fisiopatologia , Modelos Animais de Doenças , Feminino , Masculino , Teste de Campo Aberto , Ratos , Strychnos , Natação , Fatores de Tempo
12.
Angew Chem Int Ed Engl ; 59(40): 17556-17564, 2020 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-32476195

RESUMO

We describe enantioselective syntheses of strychnos and chelidonium alkaloids. In the first case, indole acetic acid esters were established as excellent partner nucleophiles for enantioselective cooperative isothiourea/Pd catalyzed α-alkylation. This provides products containing indole-bearing stereocenters in high yield and with excellent levels of enantioinduction in a manner that is notably independent of the N-substituent. This led to concise syntheses of (-)-akuammicine and (-)-strychnine. In the second case, the poor performance of ortho-substituted cinnamyl electrophiles in the enantioselective cooperative isothiourea/Ir catalyzed α-alkylation was overcome by appropriate substituent choice, leading to enantioselective syntheses of (+)-chelidonine, (+)-norchelidonine, and (+)-chelamine.


Assuntos
Alcaloides/química , Chelidonium/química , Strychnos/química , Alcaloides/síntese química , Alquilação , Benzofenantridinas/síntese química , Benzofenantridinas/química , Alcaloides de Berberina/síntese química , Alcaloides de Berberina/química , Catálise , Chelidonium/metabolismo , Humanos , Indóis/síntese química , Indóis/química , Irídio/química , Paládio/química , Sirtuína 1/antagonistas & inibidores , Sirtuína 1/metabolismo , Estereoisomerismo , Estricnina/síntese química , Estricnina/química , Strychnos/metabolismo , Tioureia/química
13.
J Org Chem ; 85(9): 6098-6108, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32227835

RESUMO

Indole alkaloids are important natural compounds with interesting bio-activities that can be found in various species belonging to the Amaryllidaceae, Apocynaceae, or Strychnaceae families. Although these compounds have different connections, substituents, and functionalities, their main core can be produced via the formation of a common functionalized tetracyclic subunit, which is rapidly obtained by an oxidative de-aromatization process mediated by a hypervalent iodine reagent from an inexpensive phenol containing a lactate moiety as the chiral auxiliary. A subsequent stereoselective aza-Michael addition and an intramolecular Heck-type reaction lead to the formation of a common key intermediate. This approach provides a solid foundation for the further elaborations of several natural products. The asymmetric syntheses of (-)-strychnopivotine and the polycyclic main cores of (-)-strychnosplendine, (+)-isosplendine, and (+)-malagashanol, three other indole alkaloids, are reported.


Assuntos
Apocynaceae , Strychnos , Ciclização , Humanos , Alcaloides Indólicos , Fenol
14.
Org Biomol Chem ; 18(6): 1046-1056, 2020 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-31971201

RESUMO

The fascinating structure of Strychnos alkaloids has evoked immense synthetic interest from the chemical community since the landmark synthesis of strychnine by Woodward. After that, the pursuit of the total synthesis of Strychnos alkaloids has never stopped. In this context, the synthesis of strychnine has become a benchmark for the evaluation of new synthetic strategies. Furthermore, the characteristic structure of these alkaloids has also served as an inspiration for the development of novel synthetic methodologies, which provide new synthetic strategies for the synthesis of Strychnos alkaloids. In this article, the recent progress in the total synthesis of Strychnos alkaloids since 2011 is reviewed, including successful total syntheses and synthetic efforts toward Strychnos alkaloids. According to the key feature employed in the synthesis, the content was categorized into novel synthetic methodologies and innovative strategies based on well-documented methodologies.


Assuntos
Alcaloides/síntese química , Strychnos/química , Alcaloides/química , Conformação Molecular
15.
Rapid Commun Mass Spectrom ; 34 Suppl 3: e8683, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31783430

RESUMO

RATIONALE: Monoterpene indole alkaloids (MIAs) are a large group of biologically active compounds produced by hundreds of plant species in numerous plant families, such as Apocynaceae, Loganiaceae and Rubiaceae. Although this diversity is biosynthetically intermediated by strictosidine, there are no works focused on the fragmentation patterns under collision-induced dissociation of strictosidine-derived alkaloids. METHODS: Initially, the alkaloid fingerprint of Strychnos peckii was established using leaf spray with tandem mass spectrometry (LS-MS/MS). Then, high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC/MS/MS) analyses were carried out to focus on the patterns of neutral losses in product ion scan experiments with the leaf aqueous extract. Finally, the product ion spectra from a set of presumable strictosidine-type derivatives were analyzed and organized via molecular networking (MN), and dereplicated by manual interpretation of MS/MS spectra. RESULTS: LS-MS/MS allowed the tentative identification of strictosidine-derived alkaloids in the leaves of S. peckii, showing useful neutral losses for the dereplication of strictosidine analogues by HPLC/MS/MS experiments. The use of MN combined with manual interpretation of the fragmentation patterns highlighted characteristic fragmentation pathways, and allowed the tentative identification of strictosidine, desoxycordifoline, strictosidinic acid, 10-hydroxystrictosidine, 5-carboxystrictosidine, lyaloside, 3,4-dehydrostrictosidine and strictosidine lactam. CONCLUSIONS: The use of MN combined with the analysis of the fragmentation patterns proved to be a useful strategy for the dereplication of strictosidine-derived MIAs from S. peckii, highlighting known and unprecedented structures, as well as useful diagnostic product ions. Therefore, this workflow is an effective approach for the characterization of strictosidine-type alkaloids in future dereplication works.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Alcaloides de Triptamina e Secologanina/análise , Strychnos/química , Espectrometria de Massas em Tandem/métodos , Curare/química , Folhas de Planta/química , Alcaloides de Triptamina e Secologanina/química , Alcaloides de Triptamina e Secologanina/metabolismo , Processamento de Sinais Assistido por Computador
16.
Drug Chem Toxicol ; 43(5): 539-545, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30212238

RESUMO

Strychnos pseudoquina is a plant species whose stem bark is used as bitter tonic beverage. The phytochemical analysis, as well as quantification of phenolic constituents and antioxidant activity of ethanolic extracts from S. pseudoquina stem bark, and leaves were conducted. The extracts were tested for mutagenicity (Ames test) and DNA-damaging activity (Plasmid Cleavage test). Leaves recorded the largest amount of flavonoids. The performed high-performance liquid chromatography (HPLC) showed flavonoids such as isorhamnetin and strychnobiflavone (phytochemical markers of the investigated species) in stem barks, but not in leaves. The proanthocyanidin content and antioxidant activity were significantly higher in stem barks than in leaves. Stem bark and leaf extracts presented mutagenic activity against TA98 and TA100 strains with, and without, metabolic activation (S9). The Plasmid Cleavage test did not indicate DNA-damaging activity. Our results suggest that extracts deriving from S. pseudoquina should be used with extreme caution, mainly the stem bark extract, which is widely used in folk medicine.


Assuntos
Dano ao DNA , Fenóis/análise , Casca de Planta/química , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Strychnos/química , Antioxidantes/análise , Antioxidantes/farmacologia , Etanol/química , Flavonoides/análise , Testes de Mutagenicidade , Compostos Fitoquímicos/análise , Folhas de Planta/química , Caules de Planta/química , Proantocianidinas/análise , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética
17.
Magn Reson Chem ; 58(6): 532-539, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31663170

RESUMO

The density functional theory calculation of 1 H and 13 C NMR chemical shifts in a series of ten 10 classically known Strychnos alkaloids with a strychnine skeleton was performed at the PBE0/pcSseg-2//pcseg-2 level. It was found that calculated 1 H and 13 C NMR chemical shifts provided a markedly good correlation with experiment characterized by a mean absolute error of 0.08 ppm in the range of 7 ppm for protons and 1.67 ppm in the range of 150 ppm for carbons, so that a mean absolute percentage error was as small as ~1% in both cases.


Assuntos
Alcaloides/química , Teoria da Densidade Funcional , Strychnos/química , Isótopos de Carbono , Espectroscopia de Ressonância Magnética , Conformação Molecular , Prótons
18.
Toxins (Basel) ; 11(9)2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31480508

RESUMO

Staphylococcus aureus is a major human pathogen causing a wide range of nosocomial infections including pulmonary, urinary, and skin infections. Notably, the emergence of bacterial strains resistant to conventional antibiotics has prompted researchers to find new compounds capable of killing these pathogens. Nature is undoubtedly an invaluable source of bioactive molecules characterized by an ample chemical diversity. They can act as unique platform providing new scaffolds for further chemical modifications in order to obtain compounds with optimized biological activity. A class of natural compounds with a variety of biological activities is represented by alkaloids, important secondary metabolites produced by a large number of organisms including bacteria, fungi, plants, and animals. In this work, starting from the screening of 39 alkaloids retrieved from a unique in-house library, we identified a heterodimer -carboline alkaloid, nigritanine, with a potent anti-Staphylococcus action. Nigritanine, isolated from Strychnos nigritana, was characterized for its antimicrobial activity against a reference and three clinical isolates of S. aureus. Its potential cytotoxicity was also evaluated at short and long term against mammalian red blood cells and human keratinocytes, respectively. Nigritanine showed a remarkable antimicrobial activity (minimum inhibitory concentration of 128 µM) without being toxic in vitro to both tested cells. The analysis of the antibacterial activity related to the nigritanine scaffold furnished new insights in the structure-activity relationships (SARs) of -carboline, confirming that dimerization improves its antibacterial activity. Taking into account these interesting results, nigritanine can be considered as a promising candidate for the development of new antimicrobial molecules for the treatment of S. aureus-induced infections.


Assuntos
Alcaloides/farmacologia , Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Alcaloides/química , Animais , Antibacterianos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Ovinos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/crescimento & desenvolvimento , Relação Estrutura-Atividade , Strychnos
19.
Chemistry ; 25(38): 8916-8935, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30994212

RESUMO

Monoterpenoid indole alkaloids are the major class of tryptamine-derived alkaloids found in nature. Together with their structural complexity, this has attracted great interest from synthetic organic chemists. In this Review, the syntheses of Aspidosperma and Strychnos alkaloids through dearomatization of indoles are discussed.


Assuntos
Alcaloides/síntese química , Aspidosperma/química , Técnicas de Química Sintética/métodos , Strychnos/química , Alcaloides/química , Reação de Cicloadição/métodos , Alcaloides de Triptamina e Secologanina/síntese química , Alcaloides de Triptamina e Secologanina/química
20.
Food Res Int ; 116: 870-877, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30717017

RESUMO

This paper studied the nutritional impact of the use of juice from Strychnos cocculoides (monkey orange) in a maize-based porridge. Monkey orange juice is traditionally used to supplement maize porridge - a staple breakfast cereal especially for vulnerable groups. Monkey orange fruits contain high amounts of micronutrients and phenolic compounds and are widely distributed throughout sub-Saharan Africa. The valuable components can be efficiently extracted by traditional and pectinase maceration techniques. The bioaccessibility of minerals and main phenolic compounds in maize porridge (5 g maize meal) supplemented by monkey orange juice (100 ml) were assessed after in-vitro digestion together with the kinetics of starch degradation. Caffeic and protocatechuic acids exceeded 100%, and chlorogenic acid 81% bioaccessibility after simulated intestinal digestion. Rutin was undetected after the simulated intestinal phase due to precipitation in the pellet. In-vitro bioaccessibility of minerals ranged from 12 to 62% in monkey orange enriched porridge. A 50-70% decrease of starch hydrolysis was observed at the end of the simulated intestinal digestion of monkey orange maize porridge confirming the known potential of phenolic compounds to decrease the glycaemic index of starch-rich foods. Consequently monkey orange juice appeared a suitable ingredient to enrich staple maize porridge thanks to its micronutrients and health benefit potential. Similar relationships of other fruits and starchy foods warrant study as a means to improve the nutritional quality of the diets of malnourished populations.


Assuntos
Dieta , Digestão , Grão Comestível/metabolismo , Sucos de Frutas e Vegetais , Índice Glicêmico , Fenóis/metabolismo , Amido/metabolismo , Strychnos , Zea mays/metabolismo , Comportamento do Consumidor , Culinária , Humanos , Hidrólise , Secreções Intestinais/metabolismo , Cinética , Paladar , Viscosidade
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