Juceni David | Federal University of Bahia (original) (raw)

Papers by Juceni David

Research paper thumbnail of Ryanodane diterpenes from two Erythroxylum species

Phytochemistry, 2007

Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit ... more Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit of Erythroxylum passerinum. Compound 2 was also found in the leaves of this species, while 1 was obtained from the leaves of E. nummularia. Compound 1 showed insecticidal activity against Aedes aegypti larvae.

Research paper thumbnail of Antileishmanial and immunomodulatory activities of extracts from Portulaca hirsutissima and Portulaca werdermannii

Fitoterapia, 2007

Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutis... more Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies.

Research paper thumbnail of CHEMICAL COMPOSITION OF BIOLOGICAL ACTIVE EXTRACTS OF Tapirira guianensis (ANACARDIACEAE)

Química Nova

Recebido em 25/03/2020; aceito em 22/06/2020; publicado na web em 07/08/2020 This work describes ... more Recebido em 25/03/2020; aceito em 22/06/2020; publicado na web em 07/08/2020 This work describes the chemical composition of MeOH seeds and flowers extracts of Tapirira guianensis, a known tree that occurs in the Brazilian Atlantic forest. The CH 2 Cl 2 soluble fraction of seeds extract was submitted to chromatographic procedures to obtain a mixture of new alkenyl dihydrobenzofuranoids which were identified as 2-[

Research paper thumbnail of Agathisflavone, a flavonoid derived from Poincianella pyramidalis (Tul.), enhances neuronal population and protects against glutamate excitotoxicity

Neurotoxicology, Jan 6, 2018

Flavonoids are bioactive compounds that are known to be neuroprotective against glutamate-mediate... more Flavonoids are bioactive compounds that are known to be neuroprotective against glutamate-mediated excitotoxicity, one of the major causes of neurodegeneration. The mechanisms underlying these effects are unresolved, but recent evidence indicates flavonoids may modulate estrogen signaling, which can delay the onset and ameliorate the severity of neurodegenerative disorders. Furthermore, the roles played by glial cells in the neuroprotective effects of flavonoids are poorly understood. The aim of this study was to investigate the effects of the flavonoid agathisflavone (FAB) in primary neuron-glial co-cultures from postnatal rat cerebral cortex. Compared to controls, treatment with FAB significantly increased the number of neuronal progenitors and mature neurons, without increasing astrocytes or microglia. These pro-neuronal effects of FAB were suppressed by antagonists of estrogen receptors (ERα and ERβ). In addition, treatment with FAB significantly reduced cell death induced by gl...

Research paper thumbnail of Atividade antioxidante de subst�ncias presentes em Dioclea violacea e Erythroxylum nummularia

Research paper thumbnail of New flavonoids of Cratylia mollis (Leguminosae)

Research paper thumbnail of Sesquiterpene Lactones from Ambrosia artemisiaefolia (Asteraceae)

Pharmaceutical Biology, 1999

... unsaturated--lactone moiety with an -exo-methylene was essential for cytotoxicity (Kupchan et... more ... unsaturated--lactone moiety with an -exo-methylene was essential for cytotoxicity (Kupchan et al., 1970, 1971; Lee et al., 1975; Rodríguez et al ... Alessandro J. de O. Santos1, Maria L. da S. Guedes2, Jorge M. David3, Hee-Byung Chai4, John M. Pezzuto4, Cindy K. Angerhofer4 ...

Research paper thumbnail of Antinoceptive and Anti-inflammatory Activities of the Ethanolic Extract, Fractions and Flavones Isolated from Mimosa tenuiflora (Willd.) Poir (Leguminosae)

PloS one, 2016

The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as "jure... more The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as "jurema preta" in Brazil, is used by the population of Contendas of Sincorá (Bahia State, Brazil) for the treatment of coughs and wound healing. Thus, the aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the bark ethanol extract (EEMT) and solvent soluble fractions (hexane-H, DCM-D, EtOAc-E and BuOH-B) of the extract in vivo. Additionally, we synthesized 5,7-dihidroxy-4'-methoxyflavanone (isosakuranetin) and isolated the compound sakuranetin, and both compounds were also tested. The anti-inflammatory and antinociceptive assays performed were: writhing test; nociception induced by intraplantar formalin injection; leukocyte recruitment to the peritoneal cavity; evaluation of vascular permeability (Evans blue test); and evaluation of mechanical hypernociception (von Frey test). Production of TNF-α, IL-10, myeloperoxidase and the expression of ICA...

Research paper thumbnail of Secundary metabolites from species of Anacardiaceae

Química Nova

SECUNDARY METABOLITES FROM SPECIES OF ANACARDIACEAE. This review describes some aspects of the fa... more SECUNDARY METABOLITES FROM SPECIES OF ANACARDIACEAE. This review describes some aspects of the family Anacardiaceae dealing with the presence and distribution of secondary metabolites in the main genera of this family and their biological activities. It reports the occurrence of different natural compounds present in their species with special emphasis on phenolic lipids, flavonoids and triterpenes that are typical metabolites of this family.

Research paper thumbnail of Utilização de RMN de ¹H na determinação da configuração absoluta de álcoois

Química Nova, 2005

Recebido em 12/7/04; aceito em 17/3/05; publicado na web em 24/8/05 UTILIZATION OF 1 H NMR IN THE... more Recebido em 12/7/04; aceito em 17/3/05; publicado na web em 24/8/05 UTILIZATION OF 1 H NMR IN THE DETERMINATION OF ABSOLUTE CONFIGURATION OF ALCOHOLS. This review reports the determination of absolute configuration of primary and secondary alcohols by 1 H NMR spectroscopy, using the Mosher method. This method consists in the derivatization of an alcohol possessig unknown absolute configuration with one or both enantiomers of an auxiliary reagent. The resulting diastereoisomer spectra are registered and compared, and the chemical shift differences (Δδ R,S = δ Rδ S) are measured. The determination of the absolute configuration of the alcohol molecule is based on the correlation between its chiral center and the auxiliary reagent's chiral center. Therefore, the determination of the absolute configuration depends on aromatic ring shielding effects on the substituents of the alcohol as evidenced by the 1 H NMR spectrum.

Research paper thumbnail of Métodos para determinação de atividade antioxidante in vitro em substratos orgânicos

Química Nova, 2010

Recebido em 21/6/10; aceito em 17/8/10; publicado na web em 20/10/10 METHODS FOR DETERMINATION OF... more Recebido em 21/6/10; aceito em 17/8/10; publicado na web em 20/10/10 METHODS FOR DETERMINATION OF IN VITRO ANTIOXIDANT ACTIVITY FOR EXTRACTS AND ORGANIC COMPOUNDS. In the literature there are a considerable number of chemical and biochemical tests for evaluation of in vitro antioxidant activities of pure compounds or fractions and organic extracts. These tests are important tools for screening of synthetic and natural bioactive compound as well as they can be employed in food chemistry. This work is a critical review of the main methods employed for in vitro antioxidant determination.

Research paper thumbnail of In Vitro Effects of Arylhydrocoumarin on Free Radicals and Oxidative Stress in Erythrocytes and Saccharomyces cerevisiae

Current Pharmaceutical Biotechnology, 2014

Neoflavonoids comprise a group of natural compounds with varied chemical structures and promising... more Neoflavonoids comprise a group of natural compounds with varied chemical structures and promising pharmacological properties, including antioxidant capacity. This work describes an evaluation of the in vitro antioxidant capacity of a new coumarin derivative, i.e., 7-acetoxy-4-aryl-3,4-dihydrocoumarin, in terms of its ability to quench the 2,2- diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), hydroxyl (OH•) and superoxide anion (O2(•-)) radicals, as well as its capacity to initiate electron transfer by reducing potential and inhibit lipid peroxidation by TBARS (thiobarbituric acid reactive substances) method. In addition, the antioxidant capacity of 7-acetoxy-4-aryl-3,4-dihydrocoumarin was evaluated against oxidative damage induced by hydrogen peroxide in erythrocyte suspensions and S. cerevisiae strains. In all methodologies investigated, high antioxidant capacities above 65% were demonstrated by 7-acetoxy-4-aryl-3,4-dihydrocoumarin against the DPPH(•), ABTS(•+), OH(•) and O2(•-) radicals. The ability of 7-acetoxy-4-aryl-3,4-dihydrocoumarin to inhibit oxidative damage induced by hydrogen peroxide in erythrocytes and S. cerevisiae strains demonstrates the importance of this compound in the protection against oxidative stress at the cellular level. Thus, the results obtained in this study suggest that 7-acetoxy-4-aryl-3,4-dihydrocoumarin can assist the development of new antioxidant products for possible use in the prevention or reduction of diseases related to oxidative stress.

Research paper thumbnail of Triterpenos e ferulatos de alquila de Maprounea guianensis

Recebido em 20/3/03; aceito em 13/6/03 TRITERPENES AND ALKYL FERULATES FROM MAPROUNEA. This work ... more Recebido em 20/3/03; aceito em 13/6/03 TRITERPENES AND ALKYL FERULATES FROM MAPROUNEA. This work describes the phytochemical study of hexane extracts from the stem of Maprounea guianensis. Besides 3-oxo-21α-H-hop-22(29)-en (moretenone), β-sitosterol, lupenone and lupeol, a mixture of dodecosyl, tetracosyl, hexacosyl, octacosyl and triacontyl ferulates was also isolated, as well as 3-β-acetoxylup-20(29)-en-28-oic acid, 3β-O-trans-p-coumaroyl-lup-20(29)-en-28-oic acid and 3β-O-trans-p-coumaroyl-urs-12-en-28-oic acid. The structures of these compounds were established by spectroscopic analysis.

Research paper thumbnail of Review of the genus Ipomoea: traditional uses, chemistry and biological activities

Approximately 600-700 species of Ipomoea, Convolvulaceae, are found throughout tropical and subtr... more Approximately 600-700 species of Ipomoea, Convolvulaceae, are found throughout tropical and subtropical regions of the world. Several of those species have been used as ornamental plants, food, medicines or in religious ritual. The present work reviews the traditional uses, chemistry and biological activities of Ipomoea species and illustrates the potential of the genus as a source of therapeutic agents. These species are used in different parts of the world for the treatment of several diseases, such as, diabetes, hypertension, dysentery, constipation, fatigue, arthritis, rheumatism, hydrocephaly, meningitis, kidney ailments and infl ammations. Some of these species showed antimicrobial, analgesic, spasmolitic, spasmogenic, hypoglycemic, hypotensive, anticoagulant, anti-infl ammatory, psychotomimetic and anticancer activities. Alkaloids, phenolics compounds and glycolipids are the most common biologically active constituents from these plant extracts.

Research paper thumbnail of Flavonóides galoil e p-cumaruil glicosilados de Cenostigma gardnerianum Tul

Research paper thumbnail of Immunomodulatory and antibacterial activities of extracts from Rutaceae species

Revista Brasileira de Farmacognosia, 2010

RESUMO: "Atividade imunomoduladora e antibacteriana de extratos de espécies da família Rutaceae."... more RESUMO: "Atividade imunomoduladora e antibacteriana de extratos de espécies da família Rutaceae." A família Rutaceae apresenta espécies vegetais muito bem distribuídas no Semi-Árido Brasileiro e comumente usadas em medicina popular. Espécies dessa família tem diversas atividades biológicas descritas na literatura. Neste trabalho, atividades imunomoduladora e bactericida são descritas para o extrato acetato de etila e clorofórmico de três espécies da família (Esenbeckia grandiflora Mart., Pilocarpus spicatus A.St.-Hil. e Galipea simplicifolia Schult.). Todas as amostras foram inicialmente avaliadas quanto à sua citotoxicidade, com objetivo de determinar a LC50. O potencial imunomodulador foi avaliado em culturas de esplenócitos murinos estimulados ou não com concanavalina A e também em reação mista linfocitária (RML),usando também esplenócitos de camundongos BALB/c (H-2 d) imunizados com esplenócitos de camundongos C57Bl/6 (H-2 b). Quatro amostras tiveram os mais elevados valores percentuais de inibição da proliferação de linfócitos ativados pela concanavalina A e foram avaliados em RML. A atividade antibacteriana dos extratos foi também avaliada e a concentração mínima inibitória (CMI) para duas amostras ativas foi de 1.0 e 5.0 mg/mL, respectivamente para as espécies Esenbeckia grandiflora Mart. and Galipea simplicifolia Schult. Assim, os dados aqui apresentados reforçam informações da literatura científica relacionados à atividade biológica para muitas espécies da família Rutaceae e incentivam outros estudos com estas visando descobrir substâncias ativas, potenciais candidatas a novos fármacos.

Research paper thumbnail of Lignanas e triterpenos do extrato citotóxico de Eriope blanchetii

Química Nova, 2001

Recebido em 6/7/00; aceito em 21/3/01 LIGNANS AND TRITERPENES FROM CYTOTOXIC EXTRACT OF ERIOPE BL... more Recebido em 6/7/00; aceito em 21/3/01 LIGNANS AND TRITERPENES FROM CYTOTOXIC EXTRACT OF ERIOPE BLANCHETII. This phytochemical study performed with the cytotoxic chloroformic extract of Eriope blanchetii (Benth.) Harley was the first work with this species and describes from aerial parts the isolation of two lignans of podophylotoxin type named β-peltatin and α-peltatin. Besides them it was obtained four triterpenes; oleanolic acid, ursolic acid, 2α,3β-dihydroxy-urs-12-en-28-olic acid, 2α,3β,19α-trihydroxy-urs-12-en-28-olic acid, named tormentic acid and 3β-glucosyl-sitosterol. The compounds were identified by analysis of their spectral data.

Research paper thumbnail of Atividade anticolinesterásica e perfil químico de uma fração cromatográfica ativa do extrato etanólico das flores Bellis perennis L. (Asteraceae)

Química Nova, 2013

Recebido em 2/7/12; aceito em 14/11/12; publicado na web em 21/2/13 ANTICHOLINESTERASE ACTIVITY A... more Recebido em 2/7/12; aceito em 14/11/12; publicado na web em 21/2/13 ANTICHOLINESTERASE ACTIVITY AND CHEMICAL PROFILE OF AN ACTIVE CHROMATOGRAPHIC FRACTION OF ETHANOLIC EXTRACT FROM Bellis perennis L. (Asteraceae) FLOWERS. This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-β-D-(6''-acetyl)-galactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE) activity of ethanolic extract from flowers (EEF) and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic 1 H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 mM for 50% inhibitory concentration (IC 50), suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer's disease.

Research paper thumbnail of An unusual coumarin derivative from Polygala boliviensis A.W. Benn (Polygalaceae)

Research paper thumbnail of A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

Phytochemistry Letters, 2013

ABSTRACT A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated... more ABSTRACT A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, kaempferol-3-O-α-l-arabinofuranoside, (+)-catechin, epicatechin, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-α-arabinopyranoside, quercetin-3-O-β-arabinopyranoside, quercetin-3-β-glucopyranoside, kaempferol, quercetin-3-O-β-galactopyranoside, β-sitosterol, α-amyrin, β-amyrin, and the ester derivatives of these two amyrins. Compound 1 exhibited weak inhibition of acetylcholinesterase. Structural identification was performed using IR, ESIHRMS and one- and two-dimensional NMR data analyses and confirmed by comparison with literature data.

Research paper thumbnail of Ryanodane diterpenes from two Erythroxylum species

Phytochemistry, 2007

Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit ... more Ryanodane diterpenes, named 14-O-methyl-ryanodanol and ryanodanol, were isolated from ripe fruit of Erythroxylum passerinum. Compound 2 was also found in the leaves of this species, while 1 was obtained from the leaves of E. nummularia. Compound 1 showed insecticidal activity against Aedes aegypti larvae.

Research paper thumbnail of Antileishmanial and immunomodulatory activities of extracts from Portulaca hirsutissima and Portulaca werdermannii

Fitoterapia, 2007

Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutis... more Ethyl acetate and chloroform extracts from aerial parts of Portulaca werdermannii and P. hirsutissima were tested in lymphoproliferation assays and axenic cultures of Leishmania amazonensis and Trypanosoma cruzi. Both extracts of P. werdermannii and P. hirsutissima had a potent inhibitory activity on lymphocyte proliferation. On the contrary, only the chloroformic extract of both plants inhibited L. amazonensis growth, without effect on T. cruzi cultures. These results indicate these Portulaca species as potential sources of new active molecules for the treatment of leishmaniasis and immune-mediated pathologies.

Research paper thumbnail of CHEMICAL COMPOSITION OF BIOLOGICAL ACTIVE EXTRACTS OF Tapirira guianensis (ANACARDIACEAE)

Química Nova

Recebido em 25/03/2020; aceito em 22/06/2020; publicado na web em 07/08/2020 This work describes ... more Recebido em 25/03/2020; aceito em 22/06/2020; publicado na web em 07/08/2020 This work describes the chemical composition of MeOH seeds and flowers extracts of Tapirira guianensis, a known tree that occurs in the Brazilian Atlantic forest. The CH 2 Cl 2 soluble fraction of seeds extract was submitted to chromatographic procedures to obtain a mixture of new alkenyl dihydrobenzofuranoids which were identified as 2-[

Research paper thumbnail of Agathisflavone, a flavonoid derived from Poincianella pyramidalis (Tul.), enhances neuronal population and protects against glutamate excitotoxicity

Neurotoxicology, Jan 6, 2018

Flavonoids are bioactive compounds that are known to be neuroprotective against glutamate-mediate... more Flavonoids are bioactive compounds that are known to be neuroprotective against glutamate-mediated excitotoxicity, one of the major causes of neurodegeneration. The mechanisms underlying these effects are unresolved, but recent evidence indicates flavonoids may modulate estrogen signaling, which can delay the onset and ameliorate the severity of neurodegenerative disorders. Furthermore, the roles played by glial cells in the neuroprotective effects of flavonoids are poorly understood. The aim of this study was to investigate the effects of the flavonoid agathisflavone (FAB) in primary neuron-glial co-cultures from postnatal rat cerebral cortex. Compared to controls, treatment with FAB significantly increased the number of neuronal progenitors and mature neurons, without increasing astrocytes or microglia. These pro-neuronal effects of FAB were suppressed by antagonists of estrogen receptors (ERα and ERβ). In addition, treatment with FAB significantly reduced cell death induced by gl...

Research paper thumbnail of Atividade antioxidante de subst�ncias presentes em Dioclea violacea e Erythroxylum nummularia

Research paper thumbnail of New flavonoids of Cratylia mollis (Leguminosae)

Research paper thumbnail of Sesquiterpene Lactones from Ambrosia artemisiaefolia (Asteraceae)

Pharmaceutical Biology, 1999

... unsaturated--lactone moiety with an -exo-methylene was essential for cytotoxicity (Kupchan et... more ... unsaturated--lactone moiety with an -exo-methylene was essential for cytotoxicity (Kupchan et al., 1970, 1971; Lee et al., 1975; Rodríguez et al ... Alessandro J. de O. Santos1, Maria L. da S. Guedes2, Jorge M. David3, Hee-Byung Chai4, John M. Pezzuto4, Cindy K. Angerhofer4 ...

Research paper thumbnail of Antinoceptive and Anti-inflammatory Activities of the Ethanolic Extract, Fractions and Flavones Isolated from Mimosa tenuiflora (Willd.) Poir (Leguminosae)

PloS one, 2016

The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as "jure... more The bark of Mimosa tenuiflora (Willd.) Poiret (Leguminosae family), popularly known as "jurema preta" in Brazil, is used by the population of Contendas of Sincorá (Bahia State, Brazil) for the treatment of coughs and wound healing. Thus, the aim of this study was to evaluate the antinociceptive and anti-inflammatory activities of the bark ethanol extract (EEMT) and solvent soluble fractions (hexane-H, DCM-D, EtOAc-E and BuOH-B) of the extract in vivo. Additionally, we synthesized 5,7-dihidroxy-4'-methoxyflavanone (isosakuranetin) and isolated the compound sakuranetin, and both compounds were also tested. The anti-inflammatory and antinociceptive assays performed were: writhing test; nociception induced by intraplantar formalin injection; leukocyte recruitment to the peritoneal cavity; evaluation of vascular permeability (Evans blue test); and evaluation of mechanical hypernociception (von Frey test). Production of TNF-α, IL-10, myeloperoxidase and the expression of ICA...

Research paper thumbnail of Secundary metabolites from species of Anacardiaceae

Química Nova

SECUNDARY METABOLITES FROM SPECIES OF ANACARDIACEAE. This review describes some aspects of the fa... more SECUNDARY METABOLITES FROM SPECIES OF ANACARDIACEAE. This review describes some aspects of the family Anacardiaceae dealing with the presence and distribution of secondary metabolites in the main genera of this family and their biological activities. It reports the occurrence of different natural compounds present in their species with special emphasis on phenolic lipids, flavonoids and triterpenes that are typical metabolites of this family.

Research paper thumbnail of Utilização de RMN de ¹H na determinação da configuração absoluta de álcoois

Química Nova, 2005

Recebido em 12/7/04; aceito em 17/3/05; publicado na web em 24/8/05 UTILIZATION OF 1 H NMR IN THE... more Recebido em 12/7/04; aceito em 17/3/05; publicado na web em 24/8/05 UTILIZATION OF 1 H NMR IN THE DETERMINATION OF ABSOLUTE CONFIGURATION OF ALCOHOLS. This review reports the determination of absolute configuration of primary and secondary alcohols by 1 H NMR spectroscopy, using the Mosher method. This method consists in the derivatization of an alcohol possessig unknown absolute configuration with one or both enantiomers of an auxiliary reagent. The resulting diastereoisomer spectra are registered and compared, and the chemical shift differences (Δδ R,S = δ Rδ S) are measured. The determination of the absolute configuration of the alcohol molecule is based on the correlation between its chiral center and the auxiliary reagent's chiral center. Therefore, the determination of the absolute configuration depends on aromatic ring shielding effects on the substituents of the alcohol as evidenced by the 1 H NMR spectrum.

Research paper thumbnail of Métodos para determinação de atividade antioxidante in vitro em substratos orgânicos

Química Nova, 2010

Recebido em 21/6/10; aceito em 17/8/10; publicado na web em 20/10/10 METHODS FOR DETERMINATION OF... more Recebido em 21/6/10; aceito em 17/8/10; publicado na web em 20/10/10 METHODS FOR DETERMINATION OF IN VITRO ANTIOXIDANT ACTIVITY FOR EXTRACTS AND ORGANIC COMPOUNDS. In the literature there are a considerable number of chemical and biochemical tests for evaluation of in vitro antioxidant activities of pure compounds or fractions and organic extracts. These tests are important tools for screening of synthetic and natural bioactive compound as well as they can be employed in food chemistry. This work is a critical review of the main methods employed for in vitro antioxidant determination.

Research paper thumbnail of In Vitro Effects of Arylhydrocoumarin on Free Radicals and Oxidative Stress in Erythrocytes and Saccharomyces cerevisiae

Current Pharmaceutical Biotechnology, 2014

Neoflavonoids comprise a group of natural compounds with varied chemical structures and promising... more Neoflavonoids comprise a group of natural compounds with varied chemical structures and promising pharmacological properties, including antioxidant capacity. This work describes an evaluation of the in vitro antioxidant capacity of a new coumarin derivative, i.e., 7-acetoxy-4-aryl-3,4-dihydrocoumarin, in terms of its ability to quench the 2,2- diphenyl-1-picrylhydrazyl (DPPH•), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+), hydroxyl (OH•) and superoxide anion (O2(•-)) radicals, as well as its capacity to initiate electron transfer by reducing potential and inhibit lipid peroxidation by TBARS (thiobarbituric acid reactive substances) method. In addition, the antioxidant capacity of 7-acetoxy-4-aryl-3,4-dihydrocoumarin was evaluated against oxidative damage induced by hydrogen peroxide in erythrocyte suspensions and S. cerevisiae strains. In all methodologies investigated, high antioxidant capacities above 65% were demonstrated by 7-acetoxy-4-aryl-3,4-dihydrocoumarin against the DPPH(•), ABTS(•+), OH(•) and O2(•-) radicals. The ability of 7-acetoxy-4-aryl-3,4-dihydrocoumarin to inhibit oxidative damage induced by hydrogen peroxide in erythrocytes and S. cerevisiae strains demonstrates the importance of this compound in the protection against oxidative stress at the cellular level. Thus, the results obtained in this study suggest that 7-acetoxy-4-aryl-3,4-dihydrocoumarin can assist the development of new antioxidant products for possible use in the prevention or reduction of diseases related to oxidative stress.

Research paper thumbnail of Triterpenos e ferulatos de alquila de Maprounea guianensis

Recebido em 20/3/03; aceito em 13/6/03 TRITERPENES AND ALKYL FERULATES FROM MAPROUNEA. This work ... more Recebido em 20/3/03; aceito em 13/6/03 TRITERPENES AND ALKYL FERULATES FROM MAPROUNEA. This work describes the phytochemical study of hexane extracts from the stem of Maprounea guianensis. Besides 3-oxo-21α-H-hop-22(29)-en (moretenone), β-sitosterol, lupenone and lupeol, a mixture of dodecosyl, tetracosyl, hexacosyl, octacosyl and triacontyl ferulates was also isolated, as well as 3-β-acetoxylup-20(29)-en-28-oic acid, 3β-O-trans-p-coumaroyl-lup-20(29)-en-28-oic acid and 3β-O-trans-p-coumaroyl-urs-12-en-28-oic acid. The structures of these compounds were established by spectroscopic analysis.

Research paper thumbnail of Review of the genus Ipomoea: traditional uses, chemistry and biological activities

Approximately 600-700 species of Ipomoea, Convolvulaceae, are found throughout tropical and subtr... more Approximately 600-700 species of Ipomoea, Convolvulaceae, are found throughout tropical and subtropical regions of the world. Several of those species have been used as ornamental plants, food, medicines or in religious ritual. The present work reviews the traditional uses, chemistry and biological activities of Ipomoea species and illustrates the potential of the genus as a source of therapeutic agents. These species are used in different parts of the world for the treatment of several diseases, such as, diabetes, hypertension, dysentery, constipation, fatigue, arthritis, rheumatism, hydrocephaly, meningitis, kidney ailments and infl ammations. Some of these species showed antimicrobial, analgesic, spasmolitic, spasmogenic, hypoglycemic, hypotensive, anticoagulant, anti-infl ammatory, psychotomimetic and anticancer activities. Alkaloids, phenolics compounds and glycolipids are the most common biologically active constituents from these plant extracts.

Research paper thumbnail of Flavonóides galoil e p-cumaruil glicosilados de Cenostigma gardnerianum Tul

Research paper thumbnail of Immunomodulatory and antibacterial activities of extracts from Rutaceae species

Revista Brasileira de Farmacognosia, 2010

RESUMO: "Atividade imunomoduladora e antibacteriana de extratos de espécies da família Rutaceae."... more RESUMO: "Atividade imunomoduladora e antibacteriana de extratos de espécies da família Rutaceae." A família Rutaceae apresenta espécies vegetais muito bem distribuídas no Semi-Árido Brasileiro e comumente usadas em medicina popular. Espécies dessa família tem diversas atividades biológicas descritas na literatura. Neste trabalho, atividades imunomoduladora e bactericida são descritas para o extrato acetato de etila e clorofórmico de três espécies da família (Esenbeckia grandiflora Mart., Pilocarpus spicatus A.St.-Hil. e Galipea simplicifolia Schult.). Todas as amostras foram inicialmente avaliadas quanto à sua citotoxicidade, com objetivo de determinar a LC50. O potencial imunomodulador foi avaliado em culturas de esplenócitos murinos estimulados ou não com concanavalina A e também em reação mista linfocitária (RML),usando também esplenócitos de camundongos BALB/c (H-2 d) imunizados com esplenócitos de camundongos C57Bl/6 (H-2 b). Quatro amostras tiveram os mais elevados valores percentuais de inibição da proliferação de linfócitos ativados pela concanavalina A e foram avaliados em RML. A atividade antibacteriana dos extratos foi também avaliada e a concentração mínima inibitória (CMI) para duas amostras ativas foi de 1.0 e 5.0 mg/mL, respectivamente para as espécies Esenbeckia grandiflora Mart. and Galipea simplicifolia Schult. Assim, os dados aqui apresentados reforçam informações da literatura científica relacionados à atividade biológica para muitas espécies da família Rutaceae e incentivam outros estudos com estas visando descobrir substâncias ativas, potenciais candidatas a novos fármacos.

Research paper thumbnail of Lignanas e triterpenos do extrato citotóxico de Eriope blanchetii

Química Nova, 2001

Recebido em 6/7/00; aceito em 21/3/01 LIGNANS AND TRITERPENES FROM CYTOTOXIC EXTRACT OF ERIOPE BL... more Recebido em 6/7/00; aceito em 21/3/01 LIGNANS AND TRITERPENES FROM CYTOTOXIC EXTRACT OF ERIOPE BLANCHETII. This phytochemical study performed with the cytotoxic chloroformic extract of Eriope blanchetii (Benth.) Harley was the first work with this species and describes from aerial parts the isolation of two lignans of podophylotoxin type named β-peltatin and α-peltatin. Besides them it was obtained four triterpenes; oleanolic acid, ursolic acid, 2α,3β-dihydroxy-urs-12-en-28-olic acid, 2α,3β,19α-trihydroxy-urs-12-en-28-olic acid, named tormentic acid and 3β-glucosyl-sitosterol. The compounds were identified by analysis of their spectral data.

Research paper thumbnail of Atividade anticolinesterásica e perfil químico de uma fração cromatográfica ativa do extrato etanólico das flores Bellis perennis L. (Asteraceae)

Química Nova, 2013

Recebido em 2/7/12; aceito em 14/11/12; publicado na web em 21/2/13 ANTICHOLINESTERASE ACTIVITY A... more Recebido em 2/7/12; aceito em 14/11/12; publicado na web em 21/2/13 ANTICHOLINESTERASE ACTIVITY AND CHEMICAL PROFILE OF AN ACTIVE CHROMATOGRAPHIC FRACTION OF ETHANOLIC EXTRACT FROM Bellis perennis L. (Asteraceae) FLOWERS. This work describes the isolation of an active flavonoid fraction and identification of isorhamnetin 3-O-β-D-(6''-acetyl)-galactopyranoside from flowers of B. perennis, and also the evaluation of anticholinesterase (AChE) activity of ethanolic extract from flowers (EEF) and the active fraction. The chemical structure of the flavonoid was defined on the basis of spectroscopic 1 H NMR, IR and UV data. EEF or flavonoid reduces AChE activity in vivo, while flavonoid also reduces AChE activity in vitro, showing a value of 1.49 mM for 50% inhibitory concentration (IC 50), suggesting potential use as an insecticide or in the treatment of neurodegenerative diseases such as Alzheimer's disease.

Research paper thumbnail of An unusual coumarin derivative from Polygala boliviensis A.W. Benn (Polygalaceae)

Research paper thumbnail of A new tropane alkaloid and other constituents of Erythroxylum rimosum (Erythroxylaceae)

Phytochemistry Letters, 2013

ABSTRACT A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated... more ABSTRACT A new tropane alkaloid, named the 7β-acetoxy-3β,6β-dibenzoyloxytropane (1), was isolated from a methanol extract of Erythroxylum rimosum O.E. Schulz leaves. Other known compounds were detected, including quercetin, kaempferol-3-O-α-l-arabinofuranoside, (+)-catechin, epicatechin, quercetin-3-O-α-arabinofuranoside, quercetin-3-O-α-arabinopyranoside, quercetin-3-O-β-arabinopyranoside, quercetin-3-β-glucopyranoside, kaempferol, quercetin-3-O-β-galactopyranoside, β-sitosterol, α-amyrin, β-amyrin, and the ester derivatives of these two amyrins. Compound 1 exhibited weak inhibition of acetylcholinesterase. Structural identification was performed using IR, ESIHRMS and one- and two-dimensional NMR data analyses and confirmed by comparison with literature data.