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Phytochem Anal ; 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32706176


INTRODUCTION: Analysis of biochemical pathways typically involves feeding a labelled precursor to an organism, and then monitoring the metabolic fate of the label. Initial studies used radioisotopes as a label and then monitored radioactivity in the metabolic products. As analytical equipment improved and became more widely available, preference shifted the use stable 'heavy' isotopes like deuterium (2 H)-, carbon-13 (13 C)- and nitrogen-15 (15 N)-atoms as labels. Incorporation of the labels could be monitored by mass spectrometry (MS), as part of a hyphenated tool kits, e.g. Liquid chromatography (LC)-MS, gas chromatography (GC)-MS, LC-MS/MS. MS offers great sensitivity but the exact location of an isotope label in a given metabolite cannot always be unambiguously established. Nuclear magnetic resonance (NMR) can also be used to pick up signals of stable isotopes, and can give information on the precise location of incorporated label in the metabolites. However, the detection limit for NMR is quite a bit higher than that for MS. OBJECTIVES: A number of experiments involving feeding stable isotope-labelled precursors followed by NMR analysis of the metabolites is presented. The aim is to highlight the use of NMR analysis in identifying the precise fate of isotope labels after precursor feeding experiments. As more powerful NMR equipment becomes available, applications as described in this review may become more commonplace in pathway analysis. CONCLUSION AND PROSPECTS: NMR is a widely accepted tool for chemical structure elucidation and is now increasingly used in metabolomic studies. In addition, NMR, combined with stable isotope feeding, should be considered as a tool for metabolic flux analyses.

Bioorg Chem ; 81: 545-552, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30245236


Some Geranium species have been used to treat diabetes. To evaluate the scientific basis of this ethnopharmacological use, we aimed to isolate potent α-glucosidase inhibitory metabolites of Geranium asphodeloides Burm. through in vitro bioactivity-guided fractionation. All the tested extracts showed high α-glucosidase inhibitory effect compared to acarbose. Among the tested extracts, the ethyl acetate subextract showed the highest activity with an IC50 value of 0.85 ±â€¯0.01 µM. A hydrolysable tannin, 1,2,4-tri-O-galloyl-ß-d-glucopyranose (1), and five flavonoid glycosides, kaempferol-3-O-α-rhamnopyranoside (2), kaempferol-3-O-α-arabinofuranoside (3), quercetin-3-O-ß-glucopyranoside (4), quercetin-3-O-α-rhamnopyranoside (5), and quercetin-3-O-α-rhamnofuranoside (6), were isolated from the ethyl acetate subextract. Their structures were identified by 1D- and 2D-NMR experiments. 1 exhibited the highest α-glucosidase inhibitory effect, approximately 61 times more potent than positive control, acarbose, with an IC50 value of 0.95 ±â€¯0.07 µM. Also, 2 was more potent than acarbose. An enzyme kinetics analysis revealed that compounds 2, 3 and 4 were competitive, whereas 1 and 6 uncompetitive inhibitors. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolated compounds in the light of the enzyme kinetic studies using various binding sites of the enzyme model.

Geranium/química , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Polifenóis/química , Polifenóis/farmacologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimologia , alfa-Glucosidases/metabolismo , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia
Nat Prod Res ; 32(16): 1902-1910, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28758426


The present study was undertaken to evaluate the in vivo analgesic activities of the extracts prepared from the aerial parts and roots of Scrophularia kotscyhana and to isolate the bioactive metabolites from the most active extract. Analgesic activities of all extracts and subextracts at the doses of 5, 10 and 30 mg/kg (i.p.) were examined using hot plate test in mice. Among the tested extracts, MeOH extract prepared from the aerial parts and the n-butanol subextract prepared thereof displayed the best analgesic activity at all doses. Phytochemical studies on n-butanol subextract led to the isolation of two new iridoid glycosides as an inseparable mixture, 8-O-acetyl-4'-O-(E)-(p-coumaroyl)-harpagide (1) and 8-O-acetyl-4'-O-(Z)-(p-coumaroyl)-harpagide (2) along with five known secondary metabolites, ß-sitosterol 3-O-ß-glucopyranoside (3), apigenin 7-O-ß-glucopyranoside (4), apigenin 7-O-rutinoside (5), luteolin 7-O-ß-glucopyranoside (6) and luteolin 7-O-rutinoside (7). The iridoid mixture (1 and 2), 3 and 4 elicited significant inhibition of pain at 5 mg/kg dose.

Analgésicos/isolamento & purificação , Glicosídeos/química , Iridoides/química , Extratos Vegetais/química , Scrophularia/química , Analgésicos/farmacologia , Animais , Apigenina , Fracionamento Químico , Glucosídeos , Glicosídeos/isolamento & purificação , Glicosídeos/farmacologia , Glicosídeos Iridoides , Iridoides/isolamento & purificação , Iridoides/farmacologia , Luteolina , Camundongos , Dor/prevenção & controle , Componentes Aéreos da Planta/química , Extratos Vegetais/farmacologia , Piranos , Sitosteroides
Chem Biodivers ; 14(6)2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28207990


Plant phenolics are known to display many pharmacological activities. In the current study, eight phenolic compounds, e.g., luteolin 5-O-ß-glucoside (1), methyl rosmarinate (2), apigenin (3), vicenin 2 (4), lithospermic acid (5), soyasaponin II (6), rubiadin 3-O-ß-primeveroside (7), and 4-(ß-d-glucopyranosyloxy)benzyl 3,4-dihydroxybenzoate (8), isolated from various plant species were tested at 0.2 mm against carbonic anhydrase-II (CA-II) and urease using microtiter assays. Urease inhibition rate for compounds 1 - 8 ranged between 5.0 - 41.7%, while only compounds 1, 2, and 4 showed a considerable inhibition over 50% against CA-II with the IC50 values of 73.5 ± 1.05, 39.5 ± 1.14, and 104.5 ± 2.50 µm, respectively, where IC50 of the reference (acetazolamide) was 21.0 ± 0.12 µm. In silico experiments were also performed through two docking softwares (Autodock Vina and i-GEMDOCK) in order to find out interactions between the compounds and CA-II. Actually, compounds 6 (30.0%) and 7 (42.0%) possessed a better binding capability toward the active site of CA-II. According to our results obtained in this study, among the phenolic compounds screened, particularly 1, 2, and 4 appear to be the promising inhibitors of CA-II and may be further investigated as possible leads for diuretic, anti-glaucoma, and antiepileptic agents.

Inibidores da Anidrase Carbônica/farmacologia , Fenóis/farmacologia , Urease/antagonistas & inibidores , Domínio Catalítico , Simulação por Computador , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ligação Proteica , Relação Estrutura-Atividade
Nat Prod Commun ; 11(11): 1693-1696, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30475509


Sedum L. species are used for their hemostatic, antidiarrheal, antifungal, diuretic and wound healing properties, and there is growing interest in these species because of their usage in folk medicine. DPPH, SO, NO, and ABTS radical scavenging activities and protective effects against H(2)(02) induced cytotoxicity, as well as cytotoxic activities against the Hep-2 cell line of various extracts from Sedum spurium Bieb. were investigated. Besides, the total phenol, flavonoid, and flavonol contents of the extracts were determined to clarify their biological and phytochemical properties. Chromatographic studies on the most active extract led to the isolation of the major compound, identified as 2-methyl-erythritol by (1)H and (13)C NMR techniques. The EtOAc extract is found to be the most active extract in all tests. However, major compound of EtOAc extract did not possess tested activities. The EtOAC extract of S. spurium could be effective to improve antihemolytic defences of erythrocytes, and radical scavenging potential of the antioxidant mechanism. The extracts should be investigated in detail for their cytotoxic activities because of their possible pro-oxidant effects at high concentrations.

Antineoplásicos Fitogênicos/farmacologia , Antioxidantes/farmacologia , Compostos Fitoquímicos/química , Compostos Fitoquímicos/farmacologia , Sedum/química , Antineoplásicos Fitogênicos/química , Antioxidantes/química , Sobrevivência Celular/efeitos dos fármacos , Eritrócitos/efeitos dos fármacos , Radicais Livres , Humanos , Peróxido de Hidrogênio/toxicidade , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Plantas Medicinais , Sais de Tetrazólio/toxicidade , Tiazóis/toxicidade
J Ethnopharmacol ; 148(2): 423-32, 2013 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-23665056


ETHNOPHARMACOLOGICAL RELEVANCE: Trifolium species are used in Turkish folk medicine as a wound healing agent, expectorant, antiseptic, sedative and to alleviate pain in rheumatism. In the present study, the aqueous methanolic extracts (80%) of 13 Trifolium species (Trifolium ambigum, Trifolium arvense var. arvense, Trifolium campestre, Trifolium canescens, Trifolium hybridum var. anatolicum, Trifolium hybridum var. hybridum, Trifolium pannonicum, Trifolium pratense var. pratense, Trifolium purpureum var. purpureum, Trifolium repens var. repens, Trifolium resupinatum var. microcephalum, Trifolium spadiceum and Trifolium trichocephalum) collected from different regions of Anatolia were evaluated for their in vivo wound healing effects. MATERIALS AND METHODS: In vivo wound healing activities of the plant aqueous methanolic extracts were evaluated by linear incision and circular excision wound models subsequent to histopathological analysis. Active constituents were determined by a validated high performance liquid chromatographic method. Precision of the method was performed by the evaluation of intra-day and inter-day variations of the each standard at limits of quantification (LOQ) levels. RESULTS: The aqueous methanolic extracts of Trifolium canescens and Trifolium pretense var. pratense possessed better wound healing activity compared to the other extracts and control groups. The animal groups treated with the Trifolium canescens extract demonstrated increased contraction (48.96%) on excision and a significant increase in wound tensile strength (35.6%) on incision models. The main compounds were detected as genistein and biochanin A for Trifolium canescens. CONCLUSION: The results of the present study revealed the wound healing potential of Trifolium canescens. This might be due to the combined effect of the isoflavones genistein, formononetin, daidzein, and biochanin A present in the extract.

Isoflavonas/farmacologia , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Trifolium/química , Cicatrização/efeitos dos fármacos , Animais , Genisteína/química , Genisteína/farmacologia , Isoflavonas/química , Masculino , Medicina Tradicional , Metanol/química , Camundongos , Extratos Vegetais/química , Ratos , Ratos Sprague-Dawley , Turquia , Água/química