RESUMO
The alkaloids are one of the most represented family of natural occurring biological active compounds. Amaryllidaceae are also very well known for their beautiful flower and are thus used as ornamental plants in historic and public gardens. The Amaryllidacea alkaloids constitute an important group that is subdivided into different subfamilies with different carbon skeletons. They are well known from ancient times for their long application in folk medicine, and in particular, Narcissus poeticus L. was known to Hippocrates of Cos (ca. B.C. 460-370), who treated uterine tumors with a formulate prepared from narcissus oil. To date, more than 600 alkaloids of 15 chemical groups exhibiting various biological activities have been isolated from the Amaryllidaceae plants. This plant genus is diffused in regions of Southern Africa, Andean South America and the Mediterranean basin. Thus, this review describes the chemical and biological activity of the alkaloids collected in these regions in the last two decades as weel those of isocarbostyls isolated from Amaryllidaceae in the same regions and same period.
Assuntos
Alcaloides , Alcaloides de Amaryllidaceae , Amaryllidaceae , Narcissus , Extratos Vegetais/química , África do Sul , Narcissus/química , Alcaloides de Amaryllidaceae/químicaRESUMO
RATIONALE: Narcissus cv. Hawera has been found to biosynthesize some Sceletium-type alkaloids with antidepressant and anxiolytic activities. This ornamental plant has been poorly studied as a source of bioactive alkaloids including some contraversive reports on in vitro and intact plants. In this study, a detailed GC-MS characterization of its alkaloid fractions is presented. METHODS: GC-MS was used for the identification of compounds in the alkaloid fractions. Both underivatized and silylated samples were analyzed simultaneously. Elevated plus maze and tail suspension tests were used to assay the anxiolytic and antidepressant activities. Ellman's and MTT-dye reduction assays were used to evaluate the acetylcholinesterase (AChE) inhibitory and cytotoxicity activities, respectively. RESULTS: Of the 29 alkaloids, 13 of Sceletium-type were detected. Two new alkaloids were identified as 2-oxo-mesembrine and 2-oxo-epi-mesembrenol. Lycorine was found as a major compound (43.5%) in the crude silylated methanol extract. After the elimination of lycorine by pre-crystallization, the major alkaloids were 40.8% 6-epi-mesembranol, 16.2% 6-epi-mesembrenol, and 13.8% sanguinine. This fraction showed anxiolytic and antidepressant-like activities as well as potent AChE inhibitory and antineoplastic activities. CONCLUSIONS: Silylation of the alkaloid fractions from Narcissus cv. Hawera provides better separation, structural information, and improved sensitivity for compounds with two and more hydroxyl groups. The lycorine-free alkaloid fraction shows a great potential for further pharmacological studies.
Assuntos
Alcaloides , Cromatografia Gasosa-Espectrometria de Massas/métodos , Narcissus/química , Extratos Vegetais/química , Aizoaceae , Alcaloides/análise , Alcaloides/farmacologia , Alcaloides/toxicidade , Amaryllidaceae , Animais , Ansiolíticos/análise , Ansiolíticos/farmacologia , Ansiolíticos/toxicidade , Comportamento Animal/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICRRESUMO
BACKGROUND: Altered glycosylation associated with hepatocellular carcinoma (HCC) is well documented. However, few reports have investigated the association between dedifferentiation and glycosylation. Therefore, the aim of this study was to analyze glycosylation associated with dedifferentiation of HCC within the same nodule and to investigate glycosyltransferase related to the glycosylation. METHODS: We analyzed resected HCC specimens (n = 50) using lectin microarray to comprehensively and sensitively analyze glycan profiles, and identify changes to glycosylation between well- and moderately-differentiated components within the same nodule. Moreover, we performed immunohistochemical staining of mannosyl(α-1,3-)-glycoprotein ß-1,2-N-acetylglucosaminyltransferase (MGAT1), which is an essential glycosyltransferase that converts high-mannose glycans to complex- or hybrid-type N-glycans. RESULTS: Four lectins from Narcissus pseudonarcissus agglutinin (NPA), Concanavalin A, Galanthus nivalis agglutinin, and Calystegia sepium agglutinin were significantly elevated in moderately-differentiated components of HCC compared with well-differentiated components, and all lectins showed binding specificity to high-mannose glycans. Therefore, these structures were represented to a greater extent in moderately-differentiated components than in well-differentiated ones. Immunohistochemical staining revealed significantly increased NPA expression and decreased MGAT1 expression in moderately-differentiated components. Low MGAT1 expression in moderately-differentiated components of tumors was associated with intrahepatic metastasis and had tendency for poor prognosis. CONCLUSION: Dedifferentiation of well-differentiated HCC is associated with an increase in high-mannose glycans. MGAT1 may play a role in the dedifferentiation of HCC.
Assuntos
Carcinoma Hepatocelular/metabolismo , Concanavalina A/metabolismo , Neoplasias Hepáticas/metabolismo , Lectinas de Ligação a Manose/metabolismo , Lectinas de Plantas/metabolismo , Idoso , Calystegia/química , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/cirurgia , Intervalo Livre de Doença , Feminino , Glicosilação , Humanos , Imuno-Histoquímica/métodos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/cirurgia , Masculino , N-Acetilglucosaminiltransferases/metabolismo , Narcissus/química , Imagem Óptica/métodos , Polissacarídeos/química , Coloração e Rotulagem/métodosRESUMO
A new N-oxide, Pseudolycorine N-oxide (1) was characterised along with eleven known alkaloids homolycorine (2), O-methylmaritidine (3), 8-O-demethylhomolycorine (4), homolycorine N-oxide (5), lycorine (6), narciclasine (7), pseudolycorine (8), ungeremine (9), 8-O-demethylmaritidine (10), zefbetaine (11) and lycorine N-oxide (12), from Narcissus tazetta. Their structures were established on the basis of spectroscopic data analysis. The extract, fractions and isolated compounds were screened for in vitro cytotoxicity against two human cancer cell lines, human cervical cancer (SiHa) and human epidermoid carcinoma (KB) cells. The study demonstrated the cytotoxic potential of extract and its chloroform and n-butanol fractions. Further, the results revealed the bioactive potential of narciclasine, pseudolycorine and homolycorine alkaloids. However, new N-oxide (1) was not active against these cell lines.
Assuntos
Alcaloides/isolamento & purificação , Alcaloides de Amaryllidaceae/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Narcissus/química , Óxidos/isolamento & purificação , Fenantridinas/isolamento & purificação , Extratos Vegetais/química , Alcaloides/química , Alcaloides de Amaryllidaceae/análise , Alcaloides de Amaryllidaceae/química , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Humanos , Indolizinas/análise , Óxidos/química , Fenantridinas/análise , Fenantridinas/químicaRESUMO
Narcissus tazetta is used traditionally for treatment of sores, wounds, skin diseases, cancer in different parts of world. Present study focus on the analysis of amaryllidaceae alkaloids in this plant using an ultra-performance liquid chromatography-diode array detection method. The method was developed for simultaneous quantification of eight Amaryllidaceae alkaloids i.e. pseudolycorine (1), lycorine (2), galanthamine (3), 8-O-demethylhomolycorine (4), N-methylhaemanthidine chloride (5), homolycorine (6), narciclasine (7) and zefbetaine (8) in Narcissus tazetta. The method was validated using a BEH C18 column with linear gradient. Standard calibration curve for the analytes showed good linearity (â¯r2≥0.999). The method was validated for intra-day (RSDs<0.91%) and inter-day (RSDs<0.65%) precisions and accuracy (recovery 92.2-112.5%). The developed method was successively applied for studying the variation of alkaloids in different parts of Narcissus tazetta, i.e. bulbs, roots, flowers, flower stalks and leaves. The study showed a significant variation of these alkaloids in different parts of the plant. Among the alkaloids under investigation, pseudolycorine had highest content in all the parts. Furthermore, application of the developed method to the identification of phytocomponents allowed the identification of sixteen alkaloids.
Assuntos
Alcaloides de Amaryllidaceae/química , Narcissus/química , Extratos Vegetais/química , Cromatografia Líquida de Alta Pressão/métodos , Flores/química , Galantamina/química , Fenantridinas/química , Folhas de Planta/química , Raízes de Plantas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Espectrometria de Massas em Tandem/métodosRESUMO
Two new flavan derivatives tazettones C-D (1-2), one new ß-coumaranone (tazettone E, 3), one new flavan (tazettone F, 4), and one new phenylpropanoid (tazettone G, 5), together with six known flavonoids (6-11), were isolated from the bulbs of Narcissus tazetta var. chinensis Roem. Their structures were elucidated by spectroscopic analysis. In addition, the structures of 1-3 were confirmed by single crystal X-ray diffraction. All isolated compounds were tested for antioxidant activity by Cell Counting Kit-8 (CCK-8) assay. Compounds 6-8 and 10-11 exhibited potent antioxidant activity against H2O2-induced impairment in human SH-SY5Y neuroblastoma cells at tested concentrations.
Assuntos
Antioxidantes/química , Flavanonas/química , Narcissus/química , Raízes de Plantas/química , Antioxidantes/isolamento & purificação , Linhagem Celular Tumoral , Flavanonas/isolamento & purificação , Humanos , Peróxido de Hidrogênio , Estrutura MolecularRESUMO
The isocarbostyril alkaloid narciclasine, also known as lycoricidinol, was discovered in Narcissus species (Amaryllidaceae) in 1967. A few years later, the 60S subunit of ribosomes, and thus protein biosynthesis, were shown to be directly targeted by narciclasine. Due to its selective and highly potent cytotoxic action on cancer cells, narciclasine was intensively investigated as an antitumor compound both in vitro and in vivo. However, narciclasine did not show a strong pharmacological activity in animal tumor models. During the last decade, new fascinating actions, mechanisms, and targets of narciclasine have emerged. This review intends to present a brief but comprehensive overview of these novel insights. Beneficial therapeutical actions have been reported particularly in brain tumor models. The translation elongation factor eEF1A, which does not only participate in protein biosynthesis but also in the regulation of the actin cytoskeleton, was discovered as new direct target. Moreover, narciclasine was found to trigger actin stress fiber formation via the activation of the small GTPase RhoA. Progress has also been made regarding the pharmacokinetic characterization of the alkaloid. The synthesis of a great number of narciclasine derivatives led to a substantial understanding of its pharmacophore and of the structure-activity relationships. However, an optimized compound did not result from these efforts. Most importantly, a new field of indication has emerged: Narciclasine was proven to exert profound anti-inflammatory actions in vivo. Taken together, there has been a strong advance in the preclinical knowledge about the alkaloid. Nevertheless, narciclasine has not been tested in human clinical trials up to now.
Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Anti-Inflamatórios/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Narcissus/química , Fenantridinas/farmacologia , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/metabolismo , Animais , Anti-Inflamatórios/química , Anti-Inflamatórios/metabolismo , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/metabolismo , Fenantridinas/química , Fenantridinas/metabolismoRESUMO
A methanol extract of the flowers of Narcissus tazetta var. chinensis Roem. (Amaryllidaceae) demonstrated inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the extract, four new phenylethanoid glycosides, tazettosides AD (14), and a new phenylpropanoid glycoside, tazettoside E (5), were isolated along with 23 known compounds (628). Of the isolates, 1 (IC50 = 22.0 µM) and 4 (82.5 µM), 3-methoxy-8,9-methylenedioxy-3,4-dihydrophenanthridine (13, IC50 = 28.5 µM), 5,6-dihydrobicolorine (14, 23.7 µM), tazettine (16, 60.8 µM), benzyl ß-D-glucopyranosyl-(1â6)-ß-D-glucopyranoside (18, 27.8 µM), 2-(3,4-dimethoxyphenyl)ethyl ß-D-glucopyranosyl-(1â6)-ß-D-glucopyranoside (21, 74.6 µM), 3-phenylpropyl ß-D-glucopyranoside (22, 59.0 µM), and cinnamyl ß-D-glucopyranosyl-(1â6)-ß-D-glucopyranoside (24, 88.0 µM) showed inhibitory effects without notable cytotoxicity at the effective concentrations.
Assuntos
Glicosídeos/farmacologia , Melaninas/biossíntese , Melanoma Experimental/metabolismo , Narcissus/química , Extratos Vegetais/farmacologia , Animais , Linhagem Celular Tumoral , Flores/química , Glicosídeos/química , Camundongos , Monofenol Mono-Oxigenase/metabolismoRESUMO
A new alkaloid, belonging to the pretazettine group of Amaryllidaceae alkaloids, was isolated from dried bulbs of Narcissus jonquilla quail and named jonquailine. Its structure, including the absolute configuration, was elucidated using various NMR, ECD and ESI MS techniques. Initial biological evaluation revealed significant antiproliferative effects against glioblastoma, melanoma, uterine sarcoma and non-small-cell lung cancer cells displaying various forms of drug resistance, including resistance to apoptosis and multi-drug resistance. Jonquailine was also found to synergize with paclitaxel in its antiproliferative action against drug-resistant lung cancer cells. The results obtained compared with literature data also showed that the hydroxylation at C-8 is an important feature for the anticancer activity but this seems unaffected by the stereochemistry or the acetalization of the lactol.
Assuntos
Alcaloides/farmacologia , Alcaloides de Amaryllidaceae/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Narcissus/química , Raízes de Plantas/química , Alcaloides/isolamento & purificação , Alcaloides de Amaryllidaceae/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Humanos , Estrutura MolecularRESUMO
This study compares the chloroform extracts of bulbs and roots of Narcissus papyraceus Ker Gawl. and Narcissus tazetta L. The cytotoxicity of the plant extracts was evaluated against human hepatocellular carcinoma cell line (HEPG2) and colon carcinoma cell line (HCT116) in comparison to doxorubicin. The extracts from the after-flowering (AF) bulbs of N. tazetta L. and N. papyraceus exhibited strong cytotoxic activity against HEPG2 (IC50: 2.2, 3.5 µg mL(-1)) and HCT116 (IC50: 4.2, 3.9 µg mL(-1)) cell lines, respectively. N. tazetta L. bulbs exhibited the least cell viability percentage in HepG-2 cell line (5.32%), while the AF root extracts of N. papyraceus exhibited the least cell viability percentage in HCT116 cell line (4.93%), when applied at a concentration of 50 µg mL(-1), thereby being more active than doxorubicin at the same concentration.
Assuntos
Antineoplásicos Fitogênicos/química , Narcissus/química , Extratos Vegetais/química , Células HCT116 , Células Hep G2 , Humanos , Narcissus/classificação , Raízes de Plantas/químicaRESUMO
Galanthamine is an Amaryllidaceae alkaloid used to treat the symptoms of Alzheimer's disease. This compound is primarily isolated from daffodil (Narcissus spp.), snowdrop (Galanthus spp.), and summer snowflake (Leucojum aestivum). Despite its importance as a medicine, no genes involved in the biosynthetic pathway of galanthamine have been identified. This absence of genetic information on biosynthetic pathways is a limiting factor in the development of synthetic biology platforms for many important botanical medicines. The paucity of information is largely due to the limitations of traditional methods for finding biochemical pathway enzymes and genes in non-model organisms. A new bioinformatic approach using several recent technological improvements was applied to search for genes in the proposed galanthamine biosynthetic pathway, first targeting methyltransferases due to strong signature amino acid sequences in the proteins. Using Illumina sequencing, a de novo transcriptome assembly was constructed for daffodil. BLAST was used to identify sequences that contain signatures for plant O-methyltransferases in this transcriptome. The program HAYSTACK was then used to identify methyltransferases that fit a model for galanthamine biosynthesis in leaf, bulb and inflorescence tissues. One candidate gene for the methylation of norbelladine to 4'-O-methylnorbelladine in the proposed galanthamine biosynthetic pathway was identified. This methyltransferase cDNA was expressed in E. coli and the protein purified by affinity chromatography. The resulting protein was found to be a norbelladine 4'-O-methyltransferase (NpN4OMT) of the proposed galanthamine biosynthetic pathway.
Assuntos
Alcaloides/metabolismo , Galantamina/metabolismo , Narcissus/enzimologia , Proteína O-Metiltransferase/genética , Alcaloides/genética , Alcaloides/uso terapêutico , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Sequência de Aminoácidos , Clonagem Molecular , DNA Complementar , Escherichia coli , Galantamina/genética , Galantamina/uso terapêutico , Humanos , Narcissus/química , Narcissus/genética , Proteína O-Metiltransferase/isolamento & purificação , Proteína O-Metiltransferase/metabolismoRESUMO
Narcissus pseudonarcissus (L.) cv. Carlton is being cultivated as a main source of galanthamine from the bulbs. After galanthamine, haemanthamine and narciclasine are the next most abundant alkaloids in this cultivar. Both these compounds are promising chemical scaffolds for potential anticancer drugs. For further research and drug development, a reliable supply of these compounds will be needed. In this study a field experiment was conducted to investigate the levels of galanthamine, haemanthamine and narciclasine in plants of N. pseudonarcissus cv. Carlton. In a field experiment alkaloids in the bulbs, leaves and roots were analyzed by quantitative (1)H NMR to monitor the variations during the growing season. Major primary and secondary metabolites were identified in the various plant parts. Multivariate data analysis was performed on the (1)H NMR spectra to investigate how metabolites changed in the plant organs over time. The results show that the leaves have relatively high concentrations of the alkaloids before flowering. The bulbs had lower concentrations of the compounds of interest but would have a higher total yield of alkaloids due to bigger biomass. Narcissus pseudonarcissus cv. Carlton represents a good source of galanthamine, and can potentially be a source of the other major alkaloids depending on choice of organ and harvest time.
Assuntos
Alcaloides/química , Narcissus/química , Estações do Ano , Alcaloides de Amaryllidaceae/química , Descoberta de Drogas , Galantamina/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Análise Multivariada , Narcissus/crescimento & desenvolvimento , Narcissus/metabolismo , Fenantridinas/química , Folhas de Planta/química , Raízes de Plantas/química , Fatores de TempoRESUMO
Plants of the Amaryllidaceae family are a well-known source of tetrahydroisoquinoline alkaloids with a wide range of biological activities, including antiviral, antitumoral, antiparasitic, psychopharmacological, and acetylcholinesterase inhibitory, among others. Recent advances in the use of GC or LC coupled to MS have allowed a chemically guided isolation of uncommon and bioactive alkaloids. In the present work, analytical methods were applied to study the alkaloid profile of Narcissus broussonetii, a plant endemic to North Africa. Using the GC-MS technique and an in-home mass fragmentation database, twenty-three alkaloids were identified, including the very rare dinitrogenous alkaloids obliquine, plicamine, and secoplicamine. Applying LC-ESI-LTQ-Orbitrap-MS, fragmentation profiles were found to be similar for obliquine and plicamine but different for secoplicamine. Pretazettine, a potent cytotoxic alkaloid, was also isolated from N. broussonetii, although its identification by GC-MS was only possible after a BSTFA-derivatization. The silylated crude methanolic extract only showed the presence of pretazettine-TMS, confirming that tazettine was formed after the alkaloid extraction. The same observation was made in Narcissus cultivars in which tazettine had been detected as the major alkaloid. As part of an ongoing project on MS of Amaryllidaceae alkaloids, the silylated tazettine and pretazettine were studied by GC-MS/MS, and found to differ in their fragmentation routes. Finally, the EtOAc extract of N. broussonetii showed notable in vitro activity against Trypanosoma cruzi, with an IC(50) value of 1.77 µg/ml.
Assuntos
Alcaloides de Amaryllidaceae/química , Antiparasitários/química , Cromatografia Gasosa-Espectrometria de Massas , Narcissus/química , Extratos Vegetais/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Alcaloides de Amaryllidaceae/isolamento & purificação , Alcaloides de Amaryllidaceae/farmacologia , Animais , Antiparasitários/isolamento & purificação , Antiparasitários/farmacologia , Linhagem Celular , Compostos Heterocíclicos de 4 ou mais Anéis/química , Concentração Inibidora 50 , Isoquinolinas/química , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Camundongos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Raízes de Plantas , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/crescimento & desenvolvimento , Ratos , Solventes/química , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/crescimento & desenvolvimentoRESUMO
Bioassay-guided (cancer cell line) separation of an extract prepared from Narcissus cv. Ice Follies (from The Netherlands) led to the isolation of a new Amaryllidaceae isocarbostiryl, 3-epipancratistatin (1b), as well as narciclasine (2). This Narcissus cultivar was found to be a good source of narciclasine. The structure of 1b was established by high-resolution mass and high-field 2D NMR spectroscopic analyses. Against a panel of murine and human cancer cell lines, 3-epipancratistatin (1b) led to cell growth inhibition (GI(50) 2.2-0.69 µg/mL) some 100× less than that found for pancratistatin (1a) and narciclasine (2), thereby revealing an important configurational requirement in 1a for strong cancer cell growth inhibition.
Assuntos
Alcaloides de Amaryllidaceae/isolamento & purificação , Alcaloides de Amaryllidaceae/farmacologia , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Narcissus/química , Fenantridinas/isolamento & purificação , Fenantridinas/farmacologia , Alcaloides de Amaryllidaceae/química , Animais , Antineoplásicos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Leucemia P388 , Camundongos , Estrutura Molecular , Fenantridinas/químicaRESUMO
Narciclasine (NCS) is a plant growth inhibitor isolated from the secreted mucilage of Narcissus tazetta bulbs. It is a commonly used anticancer agent in animal systems. In this study, we provide evidence to show that NCS also acts as an agent in inducing programmed cell death (PCD) in tobacco Bright Yellow-2 (TBY-2) cell cultures. NCS treatment induces typical PCD-associated morphological and biochemical changes, namely cell shrinkage, chromatin condensation and nuclear DNA degradation. To investigate possible signaling events, we analyzed the production of reactive oxygen species (ROS) and the function of mitochondria during PCD induced by NCS. A biphasic behavior burst of hydrogen peroxide (H(2)O(2)) was detected in TBY-2 cells treated with NCS, and mitochondrial transmembrane potential (MTP) loss occurred after a slight increase. Pre-incubation with antioxidant catalase (CAT) and N-acetyl-L-cysteine (NAC) not only significantly decreased the H(2)O(2) production but also effectively retarded the decrease of MTP and reduced the percentage of cells undergoing PCD after NCS treatment. In conclusion, our results suggest that NCS induces PCD in plant cells; the oxidative stress (accumulation of H(2)O(2)) and the MTP loss play important roles during NCS-induced PCD.
Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Apoptose/efeitos dos fármacos , Mitocôndrias/fisiologia , Nicotiana/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fenantridinas/farmacologia , Acetilcisteína/metabolismo , Antioxidantes/metabolismo , Catalase/metabolismo , Células Cultivadas , Peróxido de Hidrogênio/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Narcissus/química , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Nicotiana/crescimento & desenvolvimento , Nicotiana/metabolismoRESUMO
The cytochrome P45O activities of the naturally occurring Amaryllidaceae alkaloid narciclasine (3), isolated from Narcissus pseudonarcissus, and synthetic derivative trans-dihydronarciclasine (5) are reported. While narciclasine was found to possess potent inhibitory activity to human CYP3A4, its dihydro analogue was inactive. This study revealed that the C1-C10b double bond is required for inhibition of this crucial metabolizing enzyme. Compound 5 also demonstrated no inhibition of the related human cytochromes CYP19 and CYP1A1. This study elevates the status of trans-dihydronarciclasine (5) as a highly privileged, readily available molecule, with potent and selective anticancer activity.
Assuntos
Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Alcaloides de Amaryllidaceae/isolamento & purificação , Alcaloides de Amaryllidaceae/farmacologia , Antineoplásicos Fitogênicos/isolamento & purificação , Antineoplásicos Fitogênicos/farmacologia , Citocromo P-450 CYP1A1/antagonistas & inibidores , Inibidores do Citocromo P-450 CYP3A , Narcissus/química , Fenantridinas/isolamento & purificação , Fenantridinas/farmacologia , Alcaloides/química , Alcaloides de Amaryllidaceae/química , Antineoplásicos Fitogênicos/química , Cristalografia por Raios X , Citocromo P-450 CYP3A , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Estrutura Molecular , Fenantridinas/química , EstereoisomerismoRESUMO
To further pursue the antineoplastic leads offered by our isolation of trans-dihydronarciclasine (1a) and 7-deoxy-trans-dihydronarciclasine (1c) from two medicinal plant species of the Amaryllidaceae family, a practical palladium-catalyzed hydrogenation procedure was developed for the synthesis of these isocarbostyrils from narciclasine (2a) and 7-deoxynarciclasine (2c).
Assuntos
Alcaloides/síntese química , Alcaloides/farmacologia , Antineoplásicos Fitogênicos/síntese química , Isoquinolinas/síntese química , Isoquinolinas/farmacologia , Narcissus/química , Plantas Medicinais/química , Alcaloides/química , Alcaloides de Amaryllidaceae , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/farmacologia , Catálise , Isoquinolinas/química , Estrutura Molecular , Paládio/química , Fenantridinas , EstereoisomerismoRESUMO
A fetuin-binding peptide with a molecular mass of about 9kDa (designated NTP) was isolated and purified from the bulbs of Chinese daffodil, Narcissus tazetta var. chinensis L., by gel filtration and high-performance liquid chromatography, after removing the mannose-binding proteins by mannose-agarose column. Molecular cloning revealed that NTP contained an open reading frame of 354bp encoding a polypeptide of 118 amino acids which included a 26-amino-acid signal peptide. An analysis of the deduced amino acid sequence of NTP shows considerable sequence homology to the non-specific lipid transfer proteins (nsLTPs) of certain plants. Model of the three-dimensional (3D) structure of NTP exhibits an internal hydrophobic cavity which can bind lipid-like molecules and transfer a wide range of ligands. As a member of the putative non-specific lipid transfer protein of N. tazetta, NTP did not possess hemagglutinating activity toward rabbit erythrocytes. In a cell-free system, it could arrest the protein synthesis of rabbit reticulocytes. Using the in vitro antiviral assays, NTP could significantly inhibit the plaque formation by respiratory syncytial virus (RSV) and the cytopathic effect induced by influenza A (H1N1) virus, as well as the proliferation of human acute promyelocytic leukemia cells (HL-60).
Assuntos
Antivirais/farmacologia , Proteínas de Transporte/farmacologia , Proliferação de Células/efeitos dos fármacos , Narcissus/química , Proteínas de Plantas/farmacologia , Sequência de Aminoácidos , Animais , Antivirais/química , Antivirais/isolamento & purificação , Proteínas de Transporte/química , Proteínas de Transporte/isolamento & purificação , DNA Complementar/isolamento & purificação , DNA Complementar/metabolismo , Eritrócitos/efeitos dos fármacos , Células HL-60 , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Vírus da Influenza A Subtipo H1N1/metabolismo , Dados de Sequência Molecular , Proteínas de Plantas/isolamento & purificação , Biossíntese de Proteínas/efeitos dos fármacos , Conformação Proteica , Coelhos , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/metabolismo , Replicação Viral/efeitos dos fármacosRESUMO
Our study has shown that the Amaryllidaceae isocarbostyril narciclasine induces marked apoptosis-mediated cytotoxic effects in human cancer cells but not in normal fibroblasts by triggering the activation of the initiator caspases of the death receptor pathway (caspase-8 and caspase-10) at least in human MCF-7 breast and PC-3 prostate carcinoma cells. The formation of the Fas and death receptor 4 (DR4) death-inducing signaling complex was clearly evidenced in MCF-7 and PC-3 cancer cells. Caspase-8 was found to interact with Fas and DR4 receptors on narciclasine treatment. However, narciclasine-induced downstream apoptotic pathways in MCF-7 cells diverged from those in PC-3 cells, where caspase-8 directly activated effector caspases such as caspase-3 in the absence of any further release of mitochondrial proapoptotic effectors. In contrast, in MCF-7 cells, the apoptotic process was found to require an amplification step that is mitochondria-dependent, with Bid processing, release of cytochrome c, and caspase-9 activation. It is postulated that the high selectivity of narciclasine to cancer cells might be linked, at least in part, to this activation of the death receptor pathway. Normal human fibroblasts appear approximately 250-fold less sensitive to narciclasine, which does not induce apoptosis in these cells probably due to the absence of death receptor pathway activation.
Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/patologia , Carcinoma/patologia , Mitocôndrias/fisiologia , Fenantridinas/farmacologia , Neoplasias da Próstata/patologia , Receptores do Fator de Necrose Tumoral/fisiologia , Alcaloides de Amaryllidaceae/isolamento & purificação , Antineoplásicos Fitogênicos/isolamento & purificação , Apoptose/fisiologia , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/fisiologia , Neoplasias da Mama/metabolismo , Carcinoma/metabolismo , Caspases/fisiologia , Citocromos c/análise , Fragmentação do DNA , Resistencia a Medicamentos Antineoplásicos , Ativação Enzimática/efeitos dos fármacos , Feminino , Fibroblastos/efeitos dos fármacos , Humanos , Masculino , Mitocôndrias/enzimologia , Narcissus/química , Proteínas de Neoplasias/efeitos dos fármacos , Proteínas de Neoplasias/fisiologia , Fenantridinas/isolamento & purificação , Neoplasias da Próstata/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF , Receptor fas/efeitos dos fármacos , Receptor fas/fisiologiaRESUMO
By means of a five-step reaction sequence, narciclasine (2a), isolated from Narcissus sp., was converted to 10b(S)-epipancratistatin (3a) in 5.7% overall yield. The key step entailed a radical-initiated 10b,1 C-O cleavage employing tributyltin hydride to yield a B/C cis ring juncture (3b). Biological evaluation of 10b(S)-epipancratistatin (3a) provided evidence that antineoplastic activity was reduced by a factor of 10 when the B/C trans juncture was replaced with a B/C cis ring juncture.