Vanderlan da Silva Bolzani - Academia.edu (original) (raw)

Papers by Vanderlan da Silva Bolzani

Revista Brasileira de Farmacognosia, 2011

Química Nova, 2006

Recebido em 4/5/05; aceito em 27/1/06; publicado na web em 11/8/06 ETHNOPHARMACOLOGICAL, BIOLOGIC... more Recebido em 4/5/05; aceito em 27/1/06; publicado na web em 11/8/06 ETHNOPHARMACOLOGICAL, BIOLOGICAL AND CHEMICAL ASPECTS OF THE Cassia GENUS. Species of Cassia are widely distributed in tropical and subtropical regions throughout the world, and have been extensively investigated chemically and pharmacologically.They are known to be a rich source of phenolic derivatives, most of them with important biological and pharmacological properties. Some Asian, African and Indian tribes use these species as a laxative, purgative, antimicrobial, antipyretic, antiviral and anti-inflammatory agent. Among a number of other classes of secondary metabolites, such as anthracene derivatives, antraquinones, steroids and stilbenoids, biologically active piperidine alkaloids are an especially important bioactive class of compounds that showed to be restricted to a small group of Cassia species. In this paper we present an overview of the chemical, biological and ethnopharmacological data on Cassia piblished in the literature.

Quim Nova, 2006

Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE... more Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE MODERN MEDICINAL CHEMISTRY. Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

Eclética Química, 2011

The aim of the present study was to investigate a cytotoxic oxidative cell stress related and the... more The aim of the present study was to investigate a cytotoxic oxidative cell stress related and the antioxidant profile of kaempferol, quercetin, and isoquercitrin. The flavonol compounds were able to act as scavengers of superoxide anion (but not hydrogen peroxide), hypochlorous acid, chloramine and nitric oxide. Although flavonoids are widely described as antioxidants and this activity is generally related to beneficial effects on human health, here we show important cytotoxic actions of three well known flavonoids. They were able to promote hemolysis which one was exacerbated on the presence of hypochlorous acid but not by AAPH radical. Therefore, despite they expected scavenger action over free radicals an oxidants, these compounds could be very lesive to living organisms by acting over erythrocytes and maybe other cellular types.

Revista Brasileira de Farmacognosia, 2012

Chagas disease is one of the main public health problems in Latin America. Since the available tr... more Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fi broblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.

Biota Neotropica, 2004

I. Atlantic Rain Forest-Ecological Station Juréia-Itatins) Crude extracts from 88 plant species o... more I. Atlantic Rain Forest-Ecological Station Juréia-Itatins) Crude extracts from 88 plant species occurring in São Paulo State (Brazil), collected in an Atlantic Forest region, have been screened for antimicrobial and DNA-damaging activities. Of the 114 extracts assayed for antibacterial activity, only the extracts from leaves and stems of Aspidosperma ramiflorum (Apocynaceae) showed a slight activity against Escherichia coli. In the antifungal assay with Candida albicans, no active extract was observed, while in the bioautography assay with Cladosporium sphaerospermum and C. cladosporioides 12% were active. However, only the extract of Psychotria mapoureoides (Rubiaceae) stems showed a strong inhibition of both fungi. The DNA-damaging assay with mutant strains of Saccharomyces cerevisiae resulted in 17.5 % of active extracts. The majority (55 %) of the active extracts showed selectivity for the DNA-repair mechanism of topoisomerase II and only 20 % showed a selective response for the mechanism of topoisomerase I.

Revista Brasileira de Farmacognosia, 2009

Considering the traditional use of Casearia sylvestris Sw., Salicaceae, to threat gastric injurie... more Considering the traditional use of Casearia sylvestris Sw., Salicaceae, to threat gastric injuries and the pre-clinical studies showing its efficacy we aimed to screen other species to explore the biological activity of some species of this family. For this, we used a protease inhibition assay as a model for searching gastric anti-ulcer plant extracts. The ethanolic and aqueous extracts from branches and leafs of C. gossypiosperma, C. decandra and C. rupestris showed high percentage inhibition of pepsin, approximately 50%, with 1 µg/mL concentration. Curiously, C. obliquoa and Flacourtia ramontchi did not inhibit pepsin, but its most apolar extract showed inhibitory activity in the subtilisin assay. The enriched fraction of clerodane diterpenes inhibited the activity (42.75%) of pepsin with 1 ug/mL, but it did not inhibit subtilisin (23.76%). The results obtained with apolar and polar extracts from branches and leaves of some species of Salicaceae showed a different pattern of inhibition of two proteases, the aspartic pepsin and the serinic subtilisin, related with different biological activities. The results with the enriched fraction of clerodane diterpenes suggests that the activity observed with the C. sylvestris may be related with the presence of these substances in the crude extract.

Química Nova, 2013

Recebido em 9/9/13; aceito em 8/10/13; publicado na web em 24/10/13 METABOLOMICS, AN OPTIMIZED AP... more Recebido em 9/9/13; aceito em 8/10/13; publicado na web em 24/10/13 METABOLOMICS, AN OPTIMIZED APPROACH FOR THE RATIONAL EXPLOITATION OF BRAZILIAN BIODIVERSITY: STATE OF THE ART, NEW SCENARIOS, AND CHALLENGES. Brazilian biodiversity is a colossal source of secondary metabolites with remarkable structural features, which are valuable in further biodiscovery studies. In order to fully understand the relations and interactions of a living system with its surroundings, efforts in natural product chemistry are directed toward the challenge of detecting and identifying all the molecular components present in complex samples. It is plausible that this endeavor was born out of recent technological sophistication in secondary metabolite identification with sensitive spectroscopic instruments (MS and NMR) and higher resolving power of chromatographic systems, which allow a decrease in the amount of required sample and time to acquire data. Nevertheless, the escalation of data acquired in these analyses must be sorted with statistical and multi-way tools in order to select key information. Chromatography is also of paramount importance, more so when selected compounds need to be isolated for further investigation. However, in the course of pursuing a "greener" environment, new policies, with an aim to decrease the use of energy and solvents, are being developed and incorporated into analytical methods. Metabolomics could be an effective tool to answer questions on how living organisms in our huge biodiversity work and interact with their surroundings while also being strategic to the development of high value bio-derived products, such as phytotherapeutics and nutraceuticals. The incorporation of proper phytotherapeutics in the so-called Brazilian Unified Health System is considered an important factor for the urgent improvement and expansion of the Brazilian national health system. Furthermore, this approach could have a positive impact on the international interest toward scientific research developed in Brazil as well as the development of high value bio-derived products, which appear as an interesting economic opportunity in national and global markets. Thus, this study attempts to highlight the recent advances in analytical tools used in detection of secondary metabolites, which can be useful as bioproducts. It also emphasizes the potential avenues to be explored in Brazilian biodiversity, known for its rich chemical diversity.

Química Nova, 2005

Recebido em 19/4/04; aceito em 15/12/04; publicado na web em 13/4/05 TRITERPENOID SAPONINS FROM T... more Recebido em 19/4/04; aceito em 15/12/04; publicado na web em 13/4/05 TRITERPENOID SAPONINS FROM Tocoyena brasiliensis MART. (RUBIACEAE). The present communication reports the isolation and identification of four triterpenoid saponins from the chloroform extract of the leaves of Tocoyena brasiliensis: 3-O-β-Dquinovopyranosyl quinovic acid, 3-O-β-D-quinovopyranosyl cincholic acid, 3-O-β-D-glucopyranosyl quinovic acid and the 28-O-β-D-glucopyranosyl ester derivative of quinovic acid as binary mixtures, respectively. From the ethanol extract a flavonoid identified as ramnazin-3-O-rutinoside was obtained. The structures of these compounds were assigned by data analysis of 1D and 2D NMR spectrometry and comparison with data recorded in the literature for these compounds.

Química Nova, 2006

Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE... more Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE MODERN MEDICINAL CHEMISTRY. Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

Química Nova, 2009

In economic terms, biodiversity transcends the boundaries usually given to conventional industrie... more In economic terms, biodiversity transcends the boundaries usually given to conventional industries because it is a valuable source of biological and chemical data of great use to drug discovery. Certainly, the use of natural products has been the single most successful strategy in the discovery of novel medicines, and most of the medical breakthroughs are based on natural products. Half of the top 20 best-selling drugs are natural products, and their total sales amounted to US$ 16 billions shows the importance of natural products, which is evidenced by the new chemical entities (NCE) approved by regulatory authorities around the world in the past decade. Recently, the approval of the alkaloid galanthamine as a medicine to treat Alzheimer's disease shows that natural compounds from plants will continue to reach the market. The huge biological diversity of the Brazilian biomes, by its ability to generate new knowledge and technological innovation can be a fantastic alternative as raw material for drug discovery.

Journal of the Brazilian Chemical Society, 2005

Dois novos metabólitos, 2,4-diidroxi-5,6-dimetil benzoato de etila (1) e phomopsilactona (2) fora... more Dois novos metabólitos, 2,4-diidroxi-5,6-dimetil benzoato de etila (1) e phomopsilactona (2) foram isolados de Phomopsis cassiae, um fungo endofítico de Cassia spectabilis. As estruturas destes compostos foram elucidadas por dados espectrométricos de 1D e 2D RMN, EM e IV. As substâncias 1 e 2 exibiram forte atividade antifúngica contra os fungos fitopatogênicos Cladosporium cladosporioides e C. sphaerospermum, bem como citotoxidade contra a linhagem celular de tumor cervical humano (HeLa), em experimentos in vitro. Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays.

Journal of the Brazilian Chemical Society, 2009

Este trabalho apresenta um estudo comparativo da atividade antioxidante dos extratos de nove espé... more Este trabalho apresenta um estudo comparativo da atividade antioxidante dos extratos de nove espécies de plantas pertencentes à flora brasileira-Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum-neutralizando os radicais livres DPPH (2,2-difenil-1-picrilhidrazil) e TEMPOL (4-hidróxi-2,2,6,6-tetrametil-1-piperidiniloxi-1-oxil) utilizando ressonância paramagnética eletrônica (RPE), e agindo sobre os radicais hidroxila (OH•) gerados por uma reação Fenton, através da técnica de spin-trapping. Os melhores resultados foram obtidos para os extratos de Iryanthera juruensis e Chrysophyllum inornatum. Os resultados dos testes foram acompanhados por cálculos computacionais dos compostos, utilizando a teoria do funcional da densidade (TFD), com aproximação local da densidade (ALD), e o código SIESTA. Os resultados indicaram que a energia liberada na reação de redução TEMPOL é inferior a DPPH. Como o DPPH é um composto de menor custo e mais disponível tem um uso mais amplo que o TEMPOL, entretanto este último deve ser considerado quando se quer estudar processos que envolvam menores energias. This work presents a comparative study of the antioxidant activity of extracts from nine plant species belonging to the Brazilian flora-Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum-acting on the free-radicals DPPH (2,2-diphenyl-1-picrylhydrazyl) and TEMPOL (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy-1-oxyl) by electron paramagnetic resonance (EPR), and acting on the hydroxyl radical (OH•) by the spintrapping technique generated by a Fenton reaction. Results showed that the extracts of Iryanthera juruensis and Chrysophyllum inornatum display the strongest antioxidant activities. The results of scavenging tests were clarified by computational calculations-density functional theory (DFT), local density approximation (LDA) with SIESTA code-indicating that the energy released in the reduction reaction of TEMPOL is less than DPPH. Due to its availability and cost DPPH is more often used in these tests than TEMPOL, however TEMPOL should be considered when studying processes dealing with smaller energies.

Journal of Natural Products, 2009

Pteridium aquilinum : Natural source of pteridic acid ND-not determined. a Jurkat-immortalized li... more Pteridium aquilinum : Natural source of pteridic acid ND-not determined. a Jurkat-immortalized line of T lymphocyte cells cell line. b HL60-acute myeloid leukemia cell line. c HL60.Bcl-XL cell line-HL60 cells ectopically expressing the anti-apoptotic protein Bcl-XL. Representative data of at least three independent experiments performed in triplicate.

Revista Brasileira de Ciências Farmacêuticas, 2007

Várias hipóteses e constantes estudos são realizados com o intuito de elucidar o envelhecimento c... more Várias hipóteses e constantes estudos são realizados com o intuito de elucidar o envelhecimento cutâneo. Para prevenir e contornar este processo torna-se necessário reforçar nossas defesas naturais antioxidantes endógenas. Diversas substâncias antioxidantes exógenas, como vitaminas, extratos vegetais, dentre outras, são utilizadas pela Cosmetologia nos produtos antienvelhecimento. O objetivo deste artigo é apresentar de que forma a Modelagem Molecular pode ser uma ferramenta útil na pesquisa por novas substâncias cosméticas antioxidantes para combater o envelhecimento cutâneo.

Química Nova, 2002

Batista, s/n, 24210-150 Niterói-RJ CURRENT STATUS, CHALLENGES AND TRENDS ON NATURAL PRODUCTS IN B... more Batista, s/n, 24210-150 Niterói-RJ CURRENT STATUS, CHALLENGES AND TRENDS ON NATURAL PRODUCTS IN BRAZIL. This article offers an overview on the historical facts and the recent state of art of Chemistry of Natural Products which, in the course of 25 years of SBQ, have led to the present development of this area in Brazil. In addition, this article deals with the last trends on Natural Products in Brazil and also in developed countries.

Química Nova, 2004

Recebido em 28/7/03; aceito em 20/10/03; publicado na web em 27/05/04 NATURAL PRODUCTS AS CANDIDA... more Recebido em 28/7/03; aceito em 20/10/03; publicado na web em 27/05/04 NATURAL PRODUCTS AS CANDIDATES FOR USEFUL DRUGS IN THE TREATMENT OF ALZHEIMER'S DISEASE. Alzheimer's disease (AD) is a progressive neurodegenerative pathology with severe economic and social impact. There is currently no cure, although cholinesterase inhibitors provide effective temporary relief of symptoms in some patients. Nowadays drug research and development are based on the cholinergic hypothesis that supports the cognition improvement by regulation of the synthesis and release of acetylcholine in the brain. There are only four commercial medicines approved for treatment of AD and natural products have played an important role in the research for new acetylcholinesterase inhibitors.

Revista Brasileira de Farmacognosia, 2011

Química Nova, 2006

Recebido em 4/5/05; aceito em 27/1/06; publicado na web em 11/8/06 ETHNOPHARMACOLOGICAL, BIOLOGIC... more Recebido em 4/5/05; aceito em 27/1/06; publicado na web em 11/8/06 ETHNOPHARMACOLOGICAL, BIOLOGICAL AND CHEMICAL ASPECTS OF THE Cassia GENUS. Species of Cassia are widely distributed in tropical and subtropical regions throughout the world, and have been extensively investigated chemically and pharmacologically.They are known to be a rich source of phenolic derivatives, most of them with important biological and pharmacological properties. Some Asian, African and Indian tribes use these species as a laxative, purgative, antimicrobial, antipyretic, antiviral and anti-inflammatory agent. Among a number of other classes of secondary metabolites, such as anthracene derivatives, antraquinones, steroids and stilbenoids, biologically active piperidine alkaloids are an especially important bioactive class of compounds that showed to be restricted to a small group of Cassia species. In this paper we present an overview of the chemical, biological and ethnopharmacological data on Cassia piblished in the literature.

Quim Nova, 2006

Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE... more Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE MODERN MEDICINAL CHEMISTRY. Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

Eclética Química, 2011

The aim of the present study was to investigate a cytotoxic oxidative cell stress related and the... more The aim of the present study was to investigate a cytotoxic oxidative cell stress related and the antioxidant profile of kaempferol, quercetin, and isoquercitrin. The flavonol compounds were able to act as scavengers of superoxide anion (but not hydrogen peroxide), hypochlorous acid, chloramine and nitric oxide. Although flavonoids are widely described as antioxidants and this activity is generally related to beneficial effects on human health, here we show important cytotoxic actions of three well known flavonoids. They were able to promote hemolysis which one was exacerbated on the presence of hypochlorous acid but not by AAPH radical. Therefore, despite they expected scavenger action over free radicals an oxidants, these compounds could be very lesive to living organisms by acting over erythrocytes and maybe other cellular types.

Revista Brasileira de Farmacognosia, 2012

Chagas disease is one of the main public health problems in Latin America. Since the available tr... more Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fi broblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.

Biota Neotropica, 2004

I. Atlantic Rain Forest-Ecological Station Juréia-Itatins) Crude extracts from 88 plant species o... more I. Atlantic Rain Forest-Ecological Station Juréia-Itatins) Crude extracts from 88 plant species occurring in São Paulo State (Brazil), collected in an Atlantic Forest region, have been screened for antimicrobial and DNA-damaging activities. Of the 114 extracts assayed for antibacterial activity, only the extracts from leaves and stems of Aspidosperma ramiflorum (Apocynaceae) showed a slight activity against Escherichia coli. In the antifungal assay with Candida albicans, no active extract was observed, while in the bioautography assay with Cladosporium sphaerospermum and C. cladosporioides 12% were active. However, only the extract of Psychotria mapoureoides (Rubiaceae) stems showed a strong inhibition of both fungi. The DNA-damaging assay with mutant strains of Saccharomyces cerevisiae resulted in 17.5 % of active extracts. The majority (55 %) of the active extracts showed selectivity for the DNA-repair mechanism of topoisomerase II and only 20 % showed a selective response for the mechanism of topoisomerase I.

Revista Brasileira de Farmacognosia, 2009

Considering the traditional use of Casearia sylvestris Sw., Salicaceae, to threat gastric injurie... more Considering the traditional use of Casearia sylvestris Sw., Salicaceae, to threat gastric injuries and the pre-clinical studies showing its efficacy we aimed to screen other species to explore the biological activity of some species of this family. For this, we used a protease inhibition assay as a model for searching gastric anti-ulcer plant extracts. The ethanolic and aqueous extracts from branches and leafs of C. gossypiosperma, C. decandra and C. rupestris showed high percentage inhibition of pepsin, approximately 50%, with 1 µg/mL concentration. Curiously, C. obliquoa and Flacourtia ramontchi did not inhibit pepsin, but its most apolar extract showed inhibitory activity in the subtilisin assay. The enriched fraction of clerodane diterpenes inhibited the activity (42.75%) of pepsin with 1 ug/mL, but it did not inhibit subtilisin (23.76%). The results obtained with apolar and polar extracts from branches and leaves of some species of Salicaceae showed a different pattern of inhibition of two proteases, the aspartic pepsin and the serinic subtilisin, related with different biological activities. The results with the enriched fraction of clerodane diterpenes suggests that the activity observed with the C. sylvestris may be related with the presence of these substances in the crude extract.

Química Nova, 2013

Recebido em 9/9/13; aceito em 8/10/13; publicado na web em 24/10/13 METABOLOMICS, AN OPTIMIZED AP... more Recebido em 9/9/13; aceito em 8/10/13; publicado na web em 24/10/13 METABOLOMICS, AN OPTIMIZED APPROACH FOR THE RATIONAL EXPLOITATION OF BRAZILIAN BIODIVERSITY: STATE OF THE ART, NEW SCENARIOS, AND CHALLENGES. Brazilian biodiversity is a colossal source of secondary metabolites with remarkable structural features, which are valuable in further biodiscovery studies. In order to fully understand the relations and interactions of a living system with its surroundings, efforts in natural product chemistry are directed toward the challenge of detecting and identifying all the molecular components present in complex samples. It is plausible that this endeavor was born out of recent technological sophistication in secondary metabolite identification with sensitive spectroscopic instruments (MS and NMR) and higher resolving power of chromatographic systems, which allow a decrease in the amount of required sample and time to acquire data. Nevertheless, the escalation of data acquired in these analyses must be sorted with statistical and multi-way tools in order to select key information. Chromatography is also of paramount importance, more so when selected compounds need to be isolated for further investigation. However, in the course of pursuing a "greener" environment, new policies, with an aim to decrease the use of energy and solvents, are being developed and incorporated into analytical methods. Metabolomics could be an effective tool to answer questions on how living organisms in our huge biodiversity work and interact with their surroundings while also being strategic to the development of high value bio-derived products, such as phytotherapeutics and nutraceuticals. The incorporation of proper phytotherapeutics in the so-called Brazilian Unified Health System is considered an important factor for the urgent improvement and expansion of the Brazilian national health system. Furthermore, this approach could have a positive impact on the international interest toward scientific research developed in Brazil as well as the development of high value bio-derived products, which appear as an interesting economic opportunity in national and global markets. Thus, this study attempts to highlight the recent advances in analytical tools used in detection of secondary metabolites, which can be useful as bioproducts. It also emphasizes the potential avenues to be explored in Brazilian biodiversity, known for its rich chemical diversity.

Química Nova, 2005

Recebido em 19/4/04; aceito em 15/12/04; publicado na web em 13/4/05 TRITERPENOID SAPONINS FROM T... more Recebido em 19/4/04; aceito em 15/12/04; publicado na web em 13/4/05 TRITERPENOID SAPONINS FROM Tocoyena brasiliensis MART. (RUBIACEAE). The present communication reports the isolation and identification of four triterpenoid saponins from the chloroform extract of the leaves of Tocoyena brasiliensis: 3-O-β-Dquinovopyranosyl quinovic acid, 3-O-β-D-quinovopyranosyl cincholic acid, 3-O-β-D-glucopyranosyl quinovic acid and the 28-O-β-D-glucopyranosyl ester derivative of quinovic acid as binary mixtures, respectively. From the ethanol extract a flavonoid identified as ramnazin-3-O-rutinoside was obtained. The structures of these compounds were assigned by data analysis of 1D and 2D NMR spectrometry and comparison with data recorded in the literature for these compounds.

Química Nova, 2006

Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE... more Recebido em 10/12/04; aceito em 29/6/05; publicado na web em 20/1/06 THE NATURAL PRODUCTS AND THE MODERN MEDICINAL CHEMISTRY. Natural products have been utilized by humans since ancient times and the relief and cure of their diseases was the first purpose for using natural products in medicine. The history of the oriental and occidental civilizations is very rich in examples of the utilization of natural products in medicine and health care. Chinese traditional medicine is one of the most important examples of how natural products can be efficient in the treatment of diseases, and it points to the importance of scientific research on natural products, concerning the discovery of new active chemical entities. The complexity, chemical diversity and biological properties of natural products always fascinated people, and during the last 200 years, this led to the discovery of important new drugs. In the last 30 years, the development of new bioassay techniques, biotechnology methods, bio-guided phytochemical studies, automated high throughput screening and high performance analytical methods, have introduced new concepts and possibilities of rational drug design and drug discovery. In this context, natural products have played an important and decisive role in the development of modern medicinal chemistry.

Química Nova, 2009

In economic terms, biodiversity transcends the boundaries usually given to conventional industrie... more In economic terms, biodiversity transcends the boundaries usually given to conventional industries because it is a valuable source of biological and chemical data of great use to drug discovery. Certainly, the use of natural products has been the single most successful strategy in the discovery of novel medicines, and most of the medical breakthroughs are based on natural products. Half of the top 20 best-selling drugs are natural products, and their total sales amounted to US$ 16 billions shows the importance of natural products, which is evidenced by the new chemical entities (NCE) approved by regulatory authorities around the world in the past decade. Recently, the approval of the alkaloid galanthamine as a medicine to treat Alzheimer's disease shows that natural compounds from plants will continue to reach the market. The huge biological diversity of the Brazilian biomes, by its ability to generate new knowledge and technological innovation can be a fantastic alternative as raw material for drug discovery.

Journal of the Brazilian Chemical Society, 2005

Dois novos metabólitos, 2,4-diidroxi-5,6-dimetil benzoato de etila (1) e phomopsilactona (2) fora... more Dois novos metabólitos, 2,4-diidroxi-5,6-dimetil benzoato de etila (1) e phomopsilactona (2) foram isolados de Phomopsis cassiae, um fungo endofítico de Cassia spectabilis. As estruturas destes compostos foram elucidadas por dados espectrométricos de 1D e 2D RMN, EM e IV. As substâncias 1 e 2 exibiram forte atividade antifúngica contra os fungos fitopatogênicos Cladosporium cladosporioides e C. sphaerospermum, bem como citotoxidade contra a linhagem celular de tumor cervical humano (HeLa), em experimentos in vitro. Two new metabolites, ethyl 2,4-dihydroxy-5,6-dimethylbenzoate (1) and phomopsilactone (2) were isolated from Phomopsis cassiae, an endophytic fungus in Cassia spectabilis. Their structures were elucidated by 1D and 2D NMR, MS and IR spectral data. Compounds 1 and 2 displayed strong antifungal activity against the phytopatogenic fungi Cladosporium cladosporioides and C. sphaerospermum, as well as cytotoxicity against human cervical tumor cell line (HeLa), in in vitro assays.

Journal of the Brazilian Chemical Society, 2009

Este trabalho apresenta um estudo comparativo da atividade antioxidante dos extratos de nove espé... more Este trabalho apresenta um estudo comparativo da atividade antioxidante dos extratos de nove espécies de plantas pertencentes à flora brasileira-Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum-neutralizando os radicais livres DPPH (2,2-difenil-1-picrilhidrazil) e TEMPOL (4-hidróxi-2,2,6,6-tetrametil-1-piperidiniloxi-1-oxil) utilizando ressonância paramagnética eletrônica (RPE), e agindo sobre os radicais hidroxila (OH•) gerados por uma reação Fenton, através da técnica de spin-trapping. Os melhores resultados foram obtidos para os extratos de Iryanthera juruensis e Chrysophyllum inornatum. Os resultados dos testes foram acompanhados por cálculos computacionais dos compostos, utilizando a teoria do funcional da densidade (TFD), com aproximação local da densidade (ALD), e o código SIESTA. Os resultados indicaram que a energia liberada na reação de redução TEMPOL é inferior a DPPH. Como o DPPH é um composto de menor custo e mais disponível tem um uso mais amplo que o TEMPOL, entretanto este último deve ser considerado quando se quer estudar processos que envolvam menores energias. This work presents a comparative study of the antioxidant activity of extracts from nine plant species belonging to the Brazilian flora-Swartzia langsdorffii, Machaerium villosum, Pterogyne nitens, Pera glabrata, Aegiphyla sellowiana, Copaifera langsdorffii, Chrysophyllum inornatum, Iryanthera juruensis, Didymopanax venosum-acting on the free-radicals DPPH (2,2-diphenyl-1-picrylhydrazyl) and TEMPOL (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy-1-oxyl) by electron paramagnetic resonance (EPR), and acting on the hydroxyl radical (OH•) by the spintrapping technique generated by a Fenton reaction. Results showed that the extracts of Iryanthera juruensis and Chrysophyllum inornatum display the strongest antioxidant activities. The results of scavenging tests were clarified by computational calculations-density functional theory (DFT), local density approximation (LDA) with SIESTA code-indicating that the energy released in the reduction reaction of TEMPOL is less than DPPH. Due to its availability and cost DPPH is more often used in these tests than TEMPOL, however TEMPOL should be considered when studying processes dealing with smaller energies.

Journal of Natural Products, 2009

Pteridium aquilinum : Natural source of pteridic acid ND-not determined. a Jurkat-immortalized li... more Pteridium aquilinum : Natural source of pteridic acid ND-not determined. a Jurkat-immortalized line of T lymphocyte cells cell line. b HL60-acute myeloid leukemia cell line. c HL60.Bcl-XL cell line-HL60 cells ectopically expressing the anti-apoptotic protein Bcl-XL. Representative data of at least three independent experiments performed in triplicate.

Revista Brasileira de Ciências Farmacêuticas, 2007

Várias hipóteses e constantes estudos são realizados com o intuito de elucidar o envelhecimento c... more Várias hipóteses e constantes estudos são realizados com o intuito de elucidar o envelhecimento cutâneo. Para prevenir e contornar este processo torna-se necessário reforçar nossas defesas naturais antioxidantes endógenas. Diversas substâncias antioxidantes exógenas, como vitaminas, extratos vegetais, dentre outras, são utilizadas pela Cosmetologia nos produtos antienvelhecimento. O objetivo deste artigo é apresentar de que forma a Modelagem Molecular pode ser uma ferramenta útil na pesquisa por novas substâncias cosméticas antioxidantes para combater o envelhecimento cutâneo.

Química Nova, 2002

Batista, s/n, 24210-150 Niterói-RJ CURRENT STATUS, CHALLENGES AND TRENDS ON NATURAL PRODUCTS IN B... more Batista, s/n, 24210-150 Niterói-RJ CURRENT STATUS, CHALLENGES AND TRENDS ON NATURAL PRODUCTS IN BRAZIL. This article offers an overview on the historical facts and the recent state of art of Chemistry of Natural Products which, in the course of 25 years of SBQ, have led to the present development of this area in Brazil. In addition, this article deals with the last trends on Natural Products in Brazil and also in developed countries.

Química Nova, 2004

Recebido em 28/7/03; aceito em 20/10/03; publicado na web em 27/05/04 NATURAL PRODUCTS AS CANDIDA... more Recebido em 28/7/03; aceito em 20/10/03; publicado na web em 27/05/04 NATURAL PRODUCTS AS CANDIDATES FOR USEFUL DRUGS IN THE TREATMENT OF ALZHEIMER'S DISEASE. Alzheimer's disease (AD) is a progressive neurodegenerative pathology with severe economic and social impact. There is currently no cure, although cholinesterase inhibitors provide effective temporary relief of symptoms in some patients. Nowadays drug research and development are based on the cholinergic hypothesis that supports the cognition improvement by regulation of the synthesis and release of acetylcholine in the brain. There are only four commercial medicines approved for treatment of AD and natural products have played an important role in the research for new acetylcholinesterase inhibitors.