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1.
An Acad Bras Cienc ; 93(4): e20200443, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495202

RESUMO

Phytochemical studies of Cespedesia spathulata (Ochnaceae) leaves using 1H, 13C NMR, and GC-MS have led to the isolation of some metabolites identified for the first time in these species such as cathechin, epicatechin, vitexin, orientin, 6''-O-acetyl-vitexin, sitosterol, stigmasterol, phytol, 4,5-dihydrovomifoliol and a mixture of aliphatic methyl esters, together with ochnaflavone, which was previously isolated from this plant. The modulating activity of some fractions and compounds from Cespedesia spathulata towards tyrosinase enzyme was assayed by spectroscopic and theoretical means/experiments. The dichloromethane fraction (133 µg mL-1) and ochnaflavone (333 µM) inhibited tyrosinase activity by 20 % and 2.0 %, respectively, whereas the ethyl acetate fraction (666 µg mL-1) and ±catechins (catechin and epicatechin - 800 µM) activated it by 104 % and 384 %, respectively. Quantum chemical calculations suggested that catechin and epicatechin are better activators than L-DOPA by interacting with Cu (II) ions. Molecular docking results suggested that hydrogen bonding and hydrophobic interactions are the main binding forces between each tyrosinase activator and the amino acid residues inside the active protein binding pocket.


Assuntos
Ochnaceae , Simulação de Acoplamento Molecular , Monofenol Mono-Oxigenase , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/farmacologia , Folhas de Planta
2.
An Acad Bras Cienc ; 91(1): e20180312, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30994764

RESUMO

This study aims to identify phenolic compounds in dichloromethane and methanolic extracts of the rhizome of Renealmia nicolaioides collected in the North Region of Brazil. Two known diarylheptanoids, 1,7-bis(4-hydroxyphenyl)-(1E)-1-hepten-3-one (1), and 5R-1,7-bis(4-hydroxyphenyl)-1E-hepten-5-ol (2), and a new one (1R,2S,5S)-2-hydroxy-1,7(p-hydroxyphenyl)-centrolobine (3), as well as one flavonoid, 3-metoxi-quercetin (4) were isolated by chromatographic procedure and identified by spectroscopic techniques (1H and13C NMR, HRMS and CD). The acetyl derivative of 2 was used to confirm its structure. All four compounds are reported for the first time for this genus, and this is the first occurrence of compound 1 as a natural metabolite. The results reported here are unprecedented for the genus Renealmia.


Assuntos
Diarileptanoides/química , Fenóis/química , Extratos Vegetais/química , Rizoma/química , Zingiberaceae/química , Brasil , Cromatografia Líquida de Alta Pressão , Diarileptanoides/isolamento & purificação , Estrutura Molecular , Fenóis/isolamento & purificação , Espectroscopia de Prótons por Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray
3.
An Acad Bras Cienc ; 89(2): 789-797, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28640339

RESUMO

This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-ß-d-glucopyranoside and methyl quercetin-3-O-ß-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-ß-d-glucopyranosyl-penogenin, as well as catechin-7-O-ß-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.


Assuntos
Brachiaria/química , Flavonoides/isolamento & purificação , Extratos Vegetais/química , Cromatografia em Camada Fina , Crotonatos/química , Crotonatos/isolamento & purificação , Flavonoides/química , Glicosídeos/química , Glicosídeos/isolamento & purificação , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Parabenos/química , Parabenos/isolamento & purificação , Folhas de Planta/química , Raízes de Plantas/química , Quercetina/análogos & derivados , Quercetina/química , Quercetina/isolamento & purificação , Saponinas/química , Saponinas/isolamento & purificação , Ácido Vanílico/química , Ácido Vanílico/isolamento & purificação
4.
An. acad. bras. ciênc ; 89(2): 789-797, Apr.-June 2017. graf
Artigo em Inglês | LILACS | ID: biblio-886693

RESUMO

ABSTRACT This study aims to identify special metabolites in polar extracts from Urochloa humidicola (synonym Brachiaria humidicola) that have allelopathic effects and induce secondary photosensitization in ruminants. The compounds were isolated and identified via chromatographic and spectroscopic techniques. The compounds 4-hydroxy-3-methoxy-benzoic acid, trans-4-hydroxycinnamic acid, and p-hydroxy-benzoic acid; the flavonols isorhamnetin-3-O-β-d-glucopyranoside and methyl quercetin-3-O-β-d-glucuronate; and kaempferitrin, quercetin-3-O-α-l-rhamnopyranoside, and tricin were identified in the extract from the leaves of Urochloa humidicola. Two furostanic saponins, namely, dioscin and 3-O-α-l-rhamnopyranosyl-(1-4)-[α-l-rhamnopyranosyl-(1-2)]-β-d-glucopyranosyl-penogenin, as well as catechin-7-O-β-d-glucopyranoside were identified in the methanolic extract obtained from the roots of this plant. This species features a range of metabolites that may be toxic for animals if used in food and may interfere with the growth medium, thereby inhibiting the development of other species.


Assuntos
Flavonoides/isolamento & purificação , Extratos Vegetais/química , Brachiaria/química , Parabenos/isolamento & purificação , Parabenos/química , Saponinas/química , Ácido Vanílico/química , Flavonoides/química , Crotonatos/isolamento & purificação , Crotonatos/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Cromatografia em Camada Fina , Glicosídeos/isolamento & purificação , Glicosídeos/química
5.
Mem. Inst. Oswaldo Cruz ; 112(1): 63-69, Jan. 2017. tab, graf
Artigo em Inglês | LILACS | ID: biblio-841750

RESUMO

The aim of this study was to identify the composition of the essential oil from leaves of Lippia sidoides (EOLS), a typical shrub commonly found in the dry northeast of Brazil, popularly known as “alecrim-pimenta”. Additionally, we investigated the nymphicidal, ovicidal, phagoinhibitory and excretion effects of EOLS, its major constituent thymol and its isomer carvacrol, on fourth instar nymphs and eggs of Rhodnius prolixus, the Chagas’ disease vector. The nymphicidal and ovicidal activity of thymol, carvacrol, and EOLS was assessed by tests using impregnated Petri dishes. The lethal concentration values (LC50) for EOLS, carvacrol, and thymol were 54.48, 32.98, and 9.38 mg/cm2, respectively. The ovicidal test showed that both carvacrol and thymol (50 mg/cm2) inhibited hatching (50% and 23.3%, respectively), while treatments with 10 mg/cm2 or 50 mg/cm2 EOLS did not affect the hatching rate at all (80% and 90%, respectively). We observed an anti-feeding effect in insects fed with blood containing natural products at the higher concentrations (100 µg/mL). Finally, excretion rate was affected by EOLS and carvacrol, but not by thymol. These findings offer novel insights into basic physiological processes that make the tested natural compounds interesting candidates for new types of insecticides.


Assuntos
Animais , Rhodnius/parasitologia , Citotoxinas/química , Lippia , Disponibilidade Biológica
6.
Mem Inst Oswaldo Cruz ; 112(1): 63-69, 2017 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-27878214

RESUMO

The aim of this study was to identify the composition of the essential oil from leaves of Lippia sidoides (EOLS), a typical shrub commonly found in the dry northeast of Brazil, popularly known as "alecrim-pimenta". Additionally, we investigated the nymphicidal, ovicidal, phagoinhibitory and excretion effects of EOLS, its major constituent thymol and its isomer carvacrol, on fourth instar nymphs and eggs of Rhodnius prolixus, the Chagas' disease vector. The nymphicidal and ovicidal activity of thymol, carvacrol, and EOLS was assessed by tests using impregnated Petri dishes. The lethal concentration values (LC50) for EOLS, carvacrol, and thymol were 54.48, 32.98, and 9.38 mg/cm2, respectively. The ovicidal test showed that both carvacrol and thymol (50 mg/cm2) inhibited hatching (50% and 23.3%, respectively), while treatments with 10 mg/cm2 or 50 mg/cm2 EOLS did not affect the hatching rate at all (80% and 90%, respectively). We observed an anti-feeding effect in insects fed with blood containing natural products at the higher concentrations (100 µg/mL). Finally, excretion rate was affected by EOLS and carvacrol, but not by thymol. These findings offer novel insights into basic physiological processes that make the tested natural compounds interesting candidates for new types of insecticides.


Assuntos
Lippia/química , Monoterpenos/administração & dosagem , Óleos Voláteis/administração & dosagem , Rhodnius/efeitos dos fármacos , Timol/administração & dosagem , Animais , Doença de Chagas/transmissão , Cimenos , Relação Dose-Resposta a Droga , Dose Letal Mediana
7.
Rev. bras. farmacogn ; 26(3): 321-325, May-June 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-784288

RESUMO

Abstract The aim of the current study is to evaluate the effect of Acmella oleracea (L.) R.K. Jansen, Asteraceae, methanolic extract, hexane (84.28% spilanthol) and dichloromethane (approximately 100% spilanthol) fractions on the tyrosinase enzyme. The dehydrated jambu extract was obtained through maceration using methanol. The extract residue was solubilized in MeOH/H2O (8:2) and subjected to liq.–liq. partition in organic solvents. Both the extraction and the partition procedures were conducted with three replicates. The analyses were performed using GC–MS, 1H and 13C NMR. The hexane fraction provided samples containing 84.28, 82.91 and 62.83% spilanthol in repetitions 1, 2 and 3, respectively. The dichloromethane fraction showed 88.55% spilanthol in repetition 1, and approximately 100% spilanthol in repetitions 2 and 3. The jambu extract as well as the hexane fraction (84.28% spilanthol) were able to activate the oxidizing activity of the tyrosinase enzyme for L-DOPA. The dichloromethane fraction (approximately 100% spilanthol) showed stronger inhibition effect on the tyrosinase enzyme in the first 10 min. The results raise the interest in study in spilanthol formulations for topical use, since it may prevent and/or slow skin hyperpigmentation or depigmentation processes. Furthermore, spilanthol may be used to control the enzymatic browning in fruits and vegetables.

8.
J Nat Prod ; 79(5): 1454-8, 2016 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-27082849

RESUMO

A new orbitide named [1-8-NαC]-zanriorb A1 (1) was isolated and characterized from the leaves of Zanthoxylum riedelianum using NMR and mass spectrometry. The absolute configuration of the amino acids was determined using Marfey's method on the acid hydrolysates. Compound 1 induced cell death by apoptosis in Jurkat leukemia T cells (IC50 218 nM).


Assuntos
Apoptose/efeitos dos fármacos , Peptídeos Cíclicos/isolamento & purificação , Folhas de Planta/química , Zanthoxylum/química , Brasil , DNA/análise , Humanos , Células Jurkat , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacologia
9.
Rev. bras. farmacogn ; 26(1): 128-133, Jan.-Feb. 2016. tab, graf
Artigo em Inglês | LILACS | ID: lil-772644

RESUMO

Abstract Spilanthol (C14H23NO, 221.339 g/mol) is a bioactive compound that is found in many different plants that are used as traditional remedies throughout the world. It is present in Heliopsis longipes and several species in the genus Acmella, including A. oleracea L., also known as paracress and jambu. Its leaves and flowers have sensory properties (pungency, tingling, numbing, mouth-watering) that make it a popular spice and ingredient in several Brazilian dishes. Spilanthol can exert a variety of biological and pharmacological effects including analgesic, neuroprotective, antioxidant, antimutagenic, anti-cancer, anti-inflammatory, antimicrobial, antilarvicidal and insecticidal activities. So, the aim of this review is to present a literature review on the spilanthol that describes its occurrence, chemistry, extraction and biological activities.

10.
Rev. bras. farmacogn ; 24(6): 617-625, Nov-Dec/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-741842

RESUMO

Essential oils of galled and non-galled leaves of Clusia lanceolata Cambess., Clusiaceae, were obtained by hydrodistillation and analyzed by GC and GC/MS. The chemical composition of both oils was similar, with a predominance of sesquiterpene caryophyllenes. The extracts from the leaves were evaluated regarding total phenols, flavonoids and proanthocyanidins. Galled leaves showed higher levels of phenolics and proanthocyanidins, since the content of flavonoids was higher in non-galled leaves. The chromatographic profiles of extracts were obtained by using HPLC/DAD and LC-ESI-MS. Electrospray ionisation (ESI) in positive and negative ion mode was used to identify four flavones C-glycosides in both extracts. The study constitutes a first report on the chemical research of C. lanceolata. The extract from galled leaves had a higher antioxidant activity.

11.
Rev. bras. farmacogn ; 24(1): 1-19, Jan-Feb/2014. tab, graf
Artigo em Inglês | LILACS | ID: lil-710157

RESUMO

Ouratea and the other genera of the Ochnaceae family are a rich source of flavonoids and biflavonoids. These can be used as chemotaxonomic markers of Ouratea. Some biflavonoids, as well as extracts of the Ouratea species show important biological activities, such as antitumour, antiviral, vasodilation, antimicrobial and DNA topoisomerase inhibition. On the other hand species of this genus are used in folk medicine for gastric distress, dysentery, and diarrhea; as an astringent, a tonic, and for the treatment of inflammation-related diseases. The information collected in this review attempts to summarise the phytochemical and biological activities studied in Ouratea species that may be helpful to guide researches, to undertake further investigation concerning the common properties of Ouratea species and evaluation as a source of active compounds.

12.
Rev. bras. farmacogn ; 21(3): 397-401, maio-jun. 2011. ilus
Artigo em Inglês | LILACS | ID: lil-593288

RESUMO

The phytochemical investigation of the roots of Piptadenia rigida Benth., Fabaceae, known as "angico", afforded sitosterol, lupeol, betuline, the chalcone isoliquiritigenin, the flavonoids, 7,4'-dihydroxyflavone, 7,3',4'-trihydroxyflavone, 7,8,3',4'-tetrahydroxyflavanone, 4-hydroxy-3,5-dimethoxybenzaldehyde and methyl-3,4-dihydroxy-benzoate. Both flavones were also isolated from the branches of this plant. Five derivatives of the aldehyde were obtained by diazomethane treatment. The structures of compounds were identified by IR, NMR and mass spectral data analysis of natural compounds and some derivatives, and by comparison with literature data.

13.
An. acad. bras. ciênc ; 82(3): 561-567, Sept. 2010. ilus
Artigo em Inglês | LILACS | ID: lil-556791

RESUMO

The phytochemical investigation of Piptadenia gonoacantha (Mart.) J.F. Macbr. (Leguminosae-Mimosoideae), commonly known as "pau jacaré" (alligator stick), afforded sitosterol, campesterol, stigmasterol, the N-benzoylphenylalanine-2-benzoylamide-3-phenylpropyl ester, known as asperphenamate, sitosterol-3-O-β-D-glucopyranoside, besides three flavonoids, apigenin, 5-O-methylapigenin and 7,4'-dihydroxy-3',5-dimethoxyflavone from its branches. From its leaves, the methyl gallate and two flavonoids, vitexin and isovitexin, were isolated. From its bark, a mixture of sitosterol, campesterol, and stigmasterol, besides a mixture of cycloartenone, cycloartan-25-en-3-one, and 24-methylene-cycloartenone, and the pure triterpenes 24-methylenecycloartanol, friedelin, lupeol and lupenone, were isolated. Their structures were established on the basis of spectral analysis, comparison with literature data and GC-MS analysis of the mixtures. The ester, flavonoids and the cycloartanes are been identified for first time in the genus Piptadenia.


O estudo fitoquímico de galhos de Piptadenia gonoacantha (Mart.) J.F. Macbr. (Leguminosae-Mimosoideae), comumente conhecida como "pau jacaré", forneceu sitosterol, estigmasterol, o éster N-benzoilfenilalaninato de 2-N-benzoil-3-fenilpropila, conhecido como asperfenamato, 3-O-β-D-glicopiranosil-sitosterol, além de três flavonóides, apigenina (5,7,4'-triidroxiflavona), apigenina-5-O-metil éter e 7,4'-dihidroxi-3' , 5-dimetoxiflavona. Das folhas isolaram-se galato de metila e dois flavonóides, 8-C-glicopiranosil-5,7,4' -trihidroxiflavona e 6-C-glicopiranosil-5,7,4'-trihidroxiflavona, conhecidas como vitexina e isovitexina. Das cascas desta planta isolaram-se uma mistura de sitosterol, campesterol e estigmasterol; mistura de cicloartenona, cicloartan-25,26-en-3-ona e 24-metileno-cicloartanona, além dos triterpenos, 24-metilenocicloartenol, fridelina, lupeol e lupenona. As estruturas foram estabelecidas através de análise de espectros de IV, RMN ¹H e 13C e massas, além de análise com CG-EM para identificar os componentes das misturas de cicloartanos e esteróides. O éster conhecido como asperfenamato, os flavonóides e os cicloartanos estão sendo registrados pela primeira vez em Piptadenia.


Assuntos
Fabaceae/química , Casca de Planta/química , Extratos Vegetais/química , Folhas de Planta/química , Cromatografia em Gel , Fabaceae/classificação , Espectrometria de Massas
14.
An Acad Bras Cienc ; 82(3): 561-7, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21562684

RESUMO

The phytochemical investigation of Piptadenia gonoacantha (Mart.) J.F. Macbr. (Leguminosae-Mimosoideae), commonly known as "pau jacaré" (alligator stick), afforded sitosterol, campesterol, stigmasterol, the N-benzoylphenylalanine-2-benzoylamide-3-phenylpropyl ester, known as asperphenamate, sitosterol-3-O-ß-D-glucopyranoside, besides three flavonoids, apigenin, 5-O-methylapigenin and 7,4'-dihydroxy-3',5-dimethoxyflavone from its branches. From its leaves, the methyl gallate and two flavonoids, vitexin and isovitexin, were isolated. From its bark, a mixture of sitosterol, campesterol, and stigmasterol, besides a mixture of cycloartenone, cycloartan-25-en-3-one, and 24-methylene-cycloartenone, and the pure triterpenes 24-methylenecycloartanol, friedelin, lupeol and lupenone, were isolated. Their structures were established on the basis of spectral analysis, comparison with literature data and GC-MS analysis of the mixtures. The ester, flavonoids and the cycloartanes are been identified for first time in the genus Piptadenia.


Assuntos
Fabaceae/química , Casca de Planta/química , Extratos Vegetais/química , Folhas de Planta/química , Cromatografia em Gel , Fabaceae/classificação , Espectrometria de Massas
15.
Rev. bras. farmacogn ; 19(4): 823-827, out.-dez. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-542694

RESUMO

This paper presents the chemical investigation of the leaves and stems of Ouratea castaneifolia (DC.) Engl.. There are no chemical or pharmacological studies with this species. Classic phytochemical investigation of the organic extracts together with high pressure liquid chromatography (HPLC) procedures lead to the identification of seventeen metabolites: seven triterpenes (friedelin, 3β-friedelinol, α-amyrin, β-amyrin, lupeol, germanicol and taraxerol), four steroids (sitosterol, stigmasterol and the glycosides sitosteryl 3-O-β-D-glucopyranoside and stigmasteryl 3-O-β-D-glucopyranoside), one isoflavone (5,7,4'-trimethoxyisoflavone), one flavone (5,4'-dihydroxy-7,3',5'-trimethoxyflavone) and four biflavones (amenthoflavone, 7,7"-O-dimethylamenthoflavone, heveaflavone and tetramethylamenthoflavone). The structures of the compounds were established by the analysis of ¹H, 13C NMR spectra including bidimensional techniques. The classes of the identified metabolites are in agreement with previous studies of the Ouratea genus.


O presente trabalho trata da investigação química das folhas e caule da espécie Ouratea castaneifolia (DC.) Engl., sobre a qual não há registros de estudos químicos ou farmacológicos anteriores. O estudo fitoquímico clássico dos extratos orgânicos do caule e das folhas de O. castaneifolia foi aliado à técnica da cromatografia líquida de alta eficiência (CLAE) e resultou na identificação de dezessete metabólitos: sete triperpenos (friedelina, 3β-friedelinol, α-amirina, β-amirina, lupeol, taraxerol e germanicol), quatro esteróides (sitosterol, estigmasterol e os glucosídeos sitosteril 3-O-β-D-glicopiranosídeo e estigmasteril 3-O-β-D-glicopiranosídeo), uma isoflavona (5,7,4´-trimetoxiisoflavona), uma flavona (5,4´-diidroxi-7,3´,5´-trimetoxiflavona), quatro biflavonas (amentoflavona, 7,7"-O-dimetil-amentoflavona, heveaflavona e tetrametilamentoflavona). A identificação das substâncias foi feita com base na análise de espectros de RMN de ¹H, 13C e técnicas bidimensionais. As classes dos metabólitos identificados estão de acordo com aquelas citadas em estudos químicos do gênero Ouratea.

16.
An Acad Bras Cienc ; 81(1): 21-8, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19274328

RESUMO

The reaction of the flavonol 3,7,3', 4'-tetra-O-methylquercetin (1) and of the isoflavone 7,4'-di-O-methylgenistein (2) with alkaline iodine in methanol afforded four new iodine derivatives: 8-iodo-5-hydroxy-3,7,3', 4'-tetramethoxy- flavone (1a) and 6-iodo-5-hydroxy-3,7,3', 4'-tetramethoxyflavone (1b) from 1; 2 afforded a mixture of two compounds, identified as a racemic mixture of (+/-)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-8-iodo-isoflavanone (2a) and (+/-)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-6,8-diiodo-isoflavanone (2b). The formation of these different products reveals a significant difference involving the chemical interaction between the reactive site of alpha, beta-unsaturated ketones of flavonol and isoflavone under the tested reaction conditions (using I2/KOH/MeOH). Furthermore, the trans stereo selectivity is noteworthy in the nucleophylic addition of methanol at the isoflavone alpha, beta-unsaturated system. The structures were identified on the basis of spectral data, mainly 1D and 2D NMR and mass spectra.


Assuntos
Flavonoides/química , Iodo/química , Isoflavonas/química , Análise Espectral
17.
An. acad. bras. ciênc ; 81(1): 21-28, Mar. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-506849

RESUMO

The reaction of the flavonol 3,7,3', 4'-tetra-O-methylquercetin (1) and of the isoflavone 7,4'-di-O-methylgenistein (2) with alkaline iodine in methanol afforded four new iodine derivatives: 8-iodo-5-hydroxy-3,7,3', 4'-tetramethoxy- flavone (1a) and 6-iodo-5-hydroxy-3,7,3', 4'-tetramethoxyflavone (1b) from 1; 2 afforded a mixture of two compounds, identified as a racemic mixture of (±)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-8-iodo-isoflavanone (2a) and (±)-trans-5-hydroxy-2,3,7,4'-tetramethoxy-6,8-diiodo-isoflavanone (2b). The formation of these different products reveals a significant difference involving the chemical interaction between the reactive site of α, β-unsaturated ketones of flavonol and isoflavone under the tested reaction conditions (using I2/KOH/MeOH). Furthermore, the trans stereo selectivity is noteworthy in the nucleophylic addition of methanol at the isoflavone α, β-unsaturated system. The structures were identified on the basis of spectral data, mainly 1D and 2D NMR and mass spectra.


A reação do flavonol 3,7,3',4'-tetra-O-metilquercetina (1) e da isoflavona 7,4'-di-O-metilgenisteina (2) com iodo/KOH em metanol forneceu como produto quatro derivados iodados: 8-iodo-5-hidroxi-3,7,3',4'-tetrametoxiflavona (1a) e 6-iodo-5-hidroxi-3,7,3',4'-tetrametoxiflavona (1b) a partir da iodação de 1; a partir de 2 foi obtida uma mistura racêmica composta de (±)-trans-5-hidroxi-2,3,7,4'-tetrametoxi-8-iodo-isoflavanona (2a) e (±)-trans-5-hidroxi-2,3,7,4'-tetrametoxi-6,8-diiodo-isoflavanona (2b). A formação destes diferentes produtos revela a significante diferença envolvendo a interação química entre o sitio reativo de cetonas α, β-insaturadas de flavonol e de isoflavonas nas condições experimentais testadas (usando I2/KOH/MeOH). Além disso, ressalta-se a estereosseletividade trans na adição de metanol ao sistema α, β-insaturado da isoflavona. As estruturas foram identificadas com análise nos dados espectrométricos de RMN 1D e 2D e massas.


Assuntos
Flavonoides/química , Iodo/química , Isoflavonas/química , Análise Espectral
18.
Rev. bras. farmacogn ; 19(1a): 33-35, Jan.-Mar. 2009. ilus, tab
Artigo em Inglês | LILACS | ID: lil-522417

RESUMO

The biflavonoid 2",3"-dihydroochnaflavone, isolated from the Luxemburgia species (Ochanaceae), was treated with diazomethane to obtain the trimethyl-ether that was treated with pyridine/acetic anhydride to yield a new derivative, 5-acetil-7,4'-dimethyl-flavone-(3'→O-4'")-5"-acetil-7"-methyl-flavanone. The complete ¹H and 13C NMR data assignments of the new derivative were made by the one- and two-dimensional spectral analysis.


O biflavonóide 2",3"-diidroochnaflavona, isolada de espécies de Luxemburgia (Ochanaceae), foi tratada com diazometano e forneceu o éter trimetílico que, em seguida, foi tratado com anidrido acético/piridina obtendo-se um novo derivado, 5-acetil-7,4'-dimetil-flavona-(3'→O-4'")-5"-acetil-7"-metil-flavanona. Fez-se o completo assinalamento dos dados de RMN ¹H e 13C através da análise dos espectros uni- e bidimensionais do derivado.

19.
Rev. bras. farmacogn ; 19(1b): 290-293, Jan.-Mar. 2009. ilus, tab
Artigo em Português | LILACS | ID: lil-523096

RESUMO

O ácido flavona-6-sulfônico, 4'-O-metil-5,7-diidroxi-flavona-6-sulfonato, conhecido como niruriflavona, e a saponina, ácido 3-O-[6'-O-4-hidroxibenzoil]-²-D-galactopiranosil-ursa-12-en-28-óico, foram isolados, respectivamente, de madeira e folhas de Licania arianeae. As estruturas foram estabelecidas através da análise de espectros de massas e RMN incluindo experimentos bidimensionais.


The flavone-6-sulfonic acid, 4'-metil-5,7-dihydroxy-flavone-6-sulfonic acid, known as niruriflavone, and the saponin 3-O-[6'-O-4-hydroxybenzoyl]-²-D-galactopyranosyl-ursa-12-en-28-oic acid were isolated, respectively, from wood and leaves of Licania arianeae. The structures were established from the NMR and mass spectra data analysis including two-dimensional NMR experiments.

20.
Rev. bras. farmacogn ; 18(4): 573-576, Oct.-Dec. 2008. ilus, graf, tab
Artigo em Português | LILACS | ID: lil-509051

RESUMO

As cascas e as raízes de A. anthelmia têm sido utilizadas tradicionalmente como vermífugas. Um estudo biomonitorado do extrato metanólico das raízes de A. anthelmia conduziu ao isolamento das isoflavonas biochanina A e genisteína da fração acetato de etila; biochanina A 7-O-β-D-glicopiranosídeo, biochanina A 7-O-α-L-rhamnopiranosil-(1→6)-β-D-glicopiranosídeo e biochanina A 7-O-β-D-apiofuranosil-(1→5)-β-D-apiofuranosil-(1→6)-β-D-glicopiranosídeo da fração n-butanólica e catequina da fração metanólica. Suas estruturas foram elucidadas com base em dados espectrométricos. A atividade anti-helmíntica foi investigada em camundongos naturalmente infectados por Aspiculuris tetraptera. Os compostos isolados aplicados nos animais por via intragástrica na dose de 2,0 mg.kg-1 durante três dias consecutivos revelaram percentuais significativos na eliminação de A. tetraptera, quando comparados com o lote controle.


Bioactivity-guided fractions of the methanol extract from the roots of Andira anthelmia led the isolation of the isoflavones biochanin A and genistein from the ethyl acetate fraction; biochanin A 7-O-β-D-glucopyranoside, biochanin A 7-O-α-L-rhamnopyranosyl-(1→6)β-D-glucopyranoside and biochanin A 7-O-β-D-apiofuranosyl-(1→5)-β-D-apiofuranosyl-(1→6)β-D-glucopyranoside from the n-butanol fraction and catechin from the methanol one. Their structures were elucidated on the basis of spectroscopy data. The anthelmintic activity was investigated in mice naturally infected by Aspiculuris tetraptera. The compounds administered in the animals by intragastric route in doses of 2.0 mg.kg-1, were effective in the removal of the total number of the A. tetraptera when compared with the control group.

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