Nematostatic activity of isoprenylated guanidine alkaloids from Pterogyne nitens and their interaction with acetylcholinesterase.

Although new nematicides have appeared, the demand for new products less toxic and more efficient for the control of plant-parasitic nematodes are still high. Consequently, studies on natural secondary metabolites from plants, to develop new nematicides, have increased. In this work, nineteen extracts from eleven Brazilian plant species were screened for activity against Meloidogyne incognita. Among them, the extracts of Piterogyne nitens showed a potent nematostatic activity. The alkaloid fraction obtained from the ethanol extract of leaves of P. nitens was more active than the coming extract. Due to the promising activity from the alkaloid fraction, three isoprenylated guanidine alkaloids isolated from this fraction, galegine (1), pterogynidine (2), and pterogynine (3) were tested, showing similar activity to the alkaloid fraction, which was comparable to that of the positive control Temik at 250 µg/mL. At lower concentrations (125-50 µg/mL), compound 2 showed to be the most active one. As several nematicides act through inhibition of acetylcholinesterase (AChE), the guanidine alkaloids were also employed in two in vitro AChE assays. In both cases, compound 2 was more active than compounds 1 and 3. Its activity was considered moderated compared to the control (physostigmine). Compound 2 was selected for an in silico study with the electric eel (Electrophorus electricus) AChE, showing to bind mostly to the same site of physostigmine in the AChEs, pointing out that this could be the mechanism of action for this compound. These results suggested that the guanidine alkaloids 1,2 and 3 from P. nitens are promising for the development of new products to control M. incognita, especially guanidine 2, and encourage new investigations to confirm the mechanism of action, as well as to determine the structure-activity relationship of the guanidine alkaloids.

Cytogenotoxic evaluation of the acetonitrile extract, citrinin and dicitrinin-A from Penicillium citrinum.

Endophytic fungi are promising sources of bioactive substances; however, their secondary metabolites are toxic to plants, animals, and humans. This study aimed toevaluate the toxic, cytotoxic, mutagenic and oxidant/antioxidant activities of acetonitrile extract (AEPc), citrinin (CIT) and dicitrinin-A (DIC-A) of Penicillium citrinum. For this, the test substances at 0.5; 1.0; 1.5 and 2 µg/mLwere exposed for 24 and 48 h in Artemia salina, and 48 h in Allium cepa test systems. The oxidant/antioxidant test was evaluated in pre-, co- and post-treatment with the stressor hydrogen peroxide (H2O2) in Saccharomyces cerevisiae. The results suggest that the AEPc, CIT and DIC-A at 0.5; 1.0; 1.5 and 2 µg/mL showed toxicity in A. saline, with LC50 (24 h) of 2.03 µg/mL, 1.71 µg/mL and 2.29 µg/mL, and LC50 (48 h) of 0.51 µg/mL, 0.54 µg/mL and 0.54 µg/mL, respectively.In A. cepa, the test substances also exerted cytotoxic and mutagenic effects. The AEPc, CIT and DIC-A at lower concentrations modulated the damage induced by H2O2 in the proficient and mutant strains of S. cerevisiae for cytoplasmic and mitochondrial superoxide dismutase. Moreover, the AEPc at 2 µg/mL and CIT at the two highest concentrations did not affect the H2O2-induced DNA damage in the test strains. In conclusion, AEPc, CIT and DIC-A of P. citrinum may exert their toxic, cytotoxic and mutagenic effects in the test systems possibly through oxidative stress induction pathway.

Bioprospecting as a strategy for conservation and sustainable use of the Brazilian Flora / Bioprospecção como estratégia para a conservação e uso sustentável da Flora Brasileira

Abstract In Brazil, research with natural products had a strong impulse when FAPESP supported the creation of the Laboratory of Chemistry of Natural Products of the Institute of Chemistry of USP (1966). In 1999, FAPESP launched the Research Program in the Characterization, Conservation, Restoration and Sustainable Use of Biodiversity (BIOTA-FAPESP), which intensified the sustainable exploitation of biodiversity, and which evolved to form the Biota Network for Bioprospection and Bioassays (BIOprospecTA), which integrates groups from all over the country, optimizing the use of the skills already installed for the bioprospecting of microorganisms, plants, invertebrates, vertebrates and marine organisms. Of the 104 projects related to plant sciences, 35 carried out bioprospection of Brazilian flora, belonging to the areas of Chemistry, Botany, Genetics, Plant Physiology, Plant Morphology, Plant (Chemo)taxonomy, Ecosystem Ecology, Plant Genetics. Physical Sciences, Forest Resources, Forestry Engineering, Agronomy, leading to thousands of publications, engagement of hundreds of students and a deeper understanding of natural products in different biological models through macromolecules analysis aided by computational and spectrometric strategies, in addition to pharmacological evaluations. The development of omics approaches led to a more comprehensive view of the chemical profile of an organism, and enabled integrated and concomitant studies of several samples, and faster annotation of known molecules, through the use of hyphenated and chemometric techniques, and molecular networking. This also helped to overcome the lack of information on the safety and efficacy of herbal preparations, in projects dealing with the standardization of herbal products, according to international standards. The BIOTA-FAPESP program has also focused on environmental aspects, in accordance with the principles of Green Chemistry and has had positive effects on international collaboration, on the number and impact of scientific publications and on partnership with companies, a crucial step to add value and expand the production chain of bioproducts. Also, the compilation, systematization and sharing of data were contemplated with the creation of the NUBBEDB database, of free access, and that integrates with international databases (ACD/labs, American Chemical Society - ACS), helping researchers and companies in the development from different areas of science, technology, strengthening the bioeconomy and subsidizing public policies.

Resumo No Brasil, as pesquisas com produtos naturais tiveram um forte impulso quando a FAPESP apoiou a criação do Laboratório de Química de Produtos Naturais do Instituto de Química da USP (1966). Em 1999, a FAPESP lançou o Programa de Pesquisa em Caracterização, Conservação, Restauração e Uso Sustentável da Biodiversidade (BIOTA-FAPESP), que intensificou a exploração sustentável da biodiversidade, e que evoluiu para formar a Rede Biota de Bioprospecção e Bioensaios (BIOprospecTA), que integra grupos de todo o país, otimizando o aproveitamento das competências já instaladas para a bioprospecção de microrganismos, plantas, invertebrados, vertebrados e organismos marinhos. Dos 104 projetos relacionados às ciências vegetais, 35 realizaram a bioprospecção da flora brasileira, em diversas áreas como Química, Botânica, Fisiologia e Morfologia Vegetal, (Quimio)taxonomia Vegetal, Ecologia de Ecossistemas, Genética Vegetal, Recursos Florestais, Engenharia Florestal, dentre outros, levando a milhares de publicações, ao engajamento de centenas de estudantes e ao entendimento mais profundo dos produtos naturais em diferentes modelos biológicos por meio da análise de micromoléculas auxiliada por estratégias computacionais e espectrométricas, além de avaliações farmacológicas. O desenvolvimento de abordagens ômicas ampliou a visão sobre perfil químico dos organismos, possibilitou o estudo integrado e concomitante de várias amostras, e a anotação mais rápida de moléculas conhecidas, por meio do uso de técnicas hifenadas, quimiométricas e redes moleculares. Isso também contribuiu para superar a falta de informação sobre a segurança e eficácia dos fitopreparados, em projetos que tratam da padronização de produtos fitoterápicos, de acordo com normas internacionais. O programa BIOTA-FAPESP também tem focado em aspectos ambientais, de acordo com os princípios da Química Verde e teve reflexos positivos na colaboração internacional, no número e no impacto das publicações científicas e na parceria com empresas, etapa crucial para agregar valor e expandir a cadeia produtiva de bioprodutos. Ainda, a compilação, sistematização e compartilhamento de dados foram contemplados com a criação da base de dados NUBBEDB, de livre acesso, e que se integra com bases internacionais (ACD/labs, American Chemical Society - ACS), auxiliando pesquisadores e empresas no desenvolvimento de diferentes áreas da ciência, tecnologia, fortalecendo a bioeconomia e subsidiando políticas públicas.

Citrinin against breast cancer: A cytogenotoxicological study.

Breast cancer is one of the most lethal types of cancer and a leading cause of mortality among Women worldwide. Citrinin (CIT), a polyketide extracted from the fungus Penicillium citrinum, exhibits a wide range of biological activities such as antibacterial, antifungal, and cytotoxic effects. The aim of the current study was to evaluate the antitumoral effects of CIT against 7,12-dimethylbenzanthracene (DMBA)-induced mammary carcinoma in Swiss mice For this, CIT, DMBA and the standard cyclophosphamide (CPA) induced behavioral changes in experimental animals, and these changes were screened by using the rota rod and open field tests. Additionally, hematological, biochemical, immuno-histochemical, and histopathological analyses were carried out. Results suggest that CIT did not alter behavioral, hematological, and biochemical parameters in mice. DMBA induced invasive mammary carcinoma and showed genotoxic effects in the breasts, bone marrow, lymphocytes, and hepatic cells. It also caused mutagenic effects in the formation of micronuclei, bridges, shoots, and binucleate cells in bone marrow and liver. CIT and CPA genotoxic effects were observed after 3 weeks of therapy, where CIT exhibited a repair capacity and induced significant apoptotic damage in mouse lymphocytes. In conclusion, CIT showed antitumoral effects in Swiss mice, possibly through induction of apoptosis.

Antifungal Activity of Decyl Gallate against Several Species of Pathogenic Fungi.

This work aims to demonstrate that the gallic acid structure modification to the decyl gallate (G14) compound contributed to increase the antifungal activity against several species of pathogenic fungi, mainly, Candida spp., Cryptococcus spp., Paracoccidioides spp., and Histoplasma capsulatum, according to standardized microdilution method described by Clinical Laboratory Standard Institute (CLSI) documents. Moreover this compound has a particularly good selectivity index value, which makes it an excellent candidate for broad-spectrum antifungal prototype and encourages the continuation of subsequent studies for the discovery of its mechanism of action.

Anti-trichophyton activity of protocatechuates and their synergism with fluconazole.

Dermatophytosis and superficial mycosis are a major global public health problem that affects 20-25% of the world's population. The increase in fungal resistance to the commercially available antifungal agents, in conjunction with the limited spectrum of action of such drugs, emphasises the need to develop new antifungal agents. Natural products are attractive prototypes for antifungal agents due to their broad spectrum of biological activities. This study aimed to verify the antifungal activity of protocatechuic acid, 3,4-diacetoxybenzoic, and fourteen alkyl protocatechuates (3,4-dihydroxybenzoates) against Trichophyton rubrum and Trichophyton mentagrophytes and to further assess their activities when combined with fluconazole. Susceptibility and synergism assays were conducted as described in M38-A2 (CLSI), with modifications. Three strains of Trichophyton rubrum and three strains of Trichophyton mentagrophytes were used in this work. The pentyl, hexyl, heptyl, octyl, nonyl, and decyl protocatechuates showed great fungicidal effects, with minimum inhibitory concentration (MIC) values ranging from 0.97 to 7.8 mg/L. Heptyl showed a synergistic activity (FIC index = 0.49), reducing the MIC of fluconazole by fourfold. All substances tested were safe, especially the hexyl, heptyl, octyl, and nonyl compounds, all of which showed a high selectivity index, particularly in combination with fluconazole. These ester associations with fluconazole may represent a promising source of prototypes in the search for anti-Trichophyton therapeutic agents.

Chemical and antifungal investigations of six Lippia species (Verbenaceae) from Brazil.

The Lippia genus is used in ethnobotany as food, beverages, seasoning and antiseptic remedies, among others. The chemical compositions of fifteen extracts of six Lippia species were investigated comparatively by HPLC-PDA. To avoid data replication of previous works on this genus, Lippia lupulina Cham. root ethanol extract was selected for isolation procedures based on Principal Component Analyses (PCA) of such data. Seven compounds previously unreported in this genus were isolated from this extract (a triterpene, two furanonaphtoquinones, a furanochromone, an isoflavone, a stilbene and an iridoid). The activities of extracts, fractions and pure compounds towards Candida albicans, Candida krusei, Candida parapsilosis and Cryptococcus neoformans were investigated. Two fractions from the extract of Lippia salviaefolia leaves showed marked inhibition of fungal growth, in addition to verbascoside and asebogenin, which showed MICs lower than 15.6µg/ml and may be promising leads for the development of new antifungal agents, especially against C. neoformans.

Interconverting flavanone glucosides and other phenolic compounds in Lippia salviaefolia Cham. ethanol extracts.

Four interconverting flavanone glycosides [(2R)- and (2S)-3',4',5,6-tetrahydroxyflavanone 7-O-ß-D-glucopyranoside, and (2R)- and (2S)-3',4',5,8-tetrahydroxyflavanone 7-O-ß-D-glucopyranoside], in addition to eight known flavonoids [naringenin, asebogenin, sakuranetin, 6-hydroxyluteolin 7-O-ß-D-glucoside, (2R)- and (2S)-eriodictyol 7-O-ß-D-glucopyranoside, aromadendrin and phloretin], three phenylpropanoid glycosides [forsythoside B, alyssonoside and verbascoside] and the epoxylignan lariciresinol 4'-O-ß-D-glucopyranoside were isolated and identified in the EtOH extract of the aerial parts of Lippia salviaefolia Cham. The phytochemical study herein was guided by preliminary antioxidant tests, namely, ß-carotene protection and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity. The crude extracts, their active fractions and the isolated compounds were assayed against intracellular reactive oxygen species (ROS) and human embryonic kidney HEK-293 and human melanoma M14 cancer cell growth. Aromadendrin and phloretin were able to counteract elevation of ROS induced by the oxidant t-butylhydroperoxide (t-BOOH) in HEK-293 cells, whereas phloretin strongly protected HEK-293 cells from ROS damage at 1 µM. Additionally, phloretin exhibited a significant growth inhibitory effect at 20-40 µM in both HEK-293 and M14 cells and induced a concentration dependent apoptosis at 20 µM in M14 cells, suggesting a selective action towards malignant cells. Due to their equilibria, the four interconverting flavanone glycosides were studied using 1D and 2D NMR, HPLC-CD-PDA and HRMS analyses.

Antibacterial activity of labdane diterpenoids from Stemodia foliosa.

As part of a continuing interest in exploring the chemistry of Brazilian medicinal plants, three new labdane diterpenoids, 6alpha-acetoxymanoyl oxide (1), 6alpha-malonyloxymanoyl oxide (2), and 6alpha-malonyloxy-n-butyl ester manoyl oxide (3), together with the known betulinic acid, lupeol, sitosterol, and stigmasterol, were isolated from the aerial parts of Stemodia foliosa. The structures of 1-3 were established on the basis of interpretation of spectroscopic data, including HRESIMS, and 1D and 2D NMR techniques. All compounds were tested against a bacteria panel consisting of Staphylococcus aureus, Bacillus cereus, B. subtilis, B. anthracis, Micrococcus luteus, Mycobacterium smegmatis, and M. phlei. Compound 2 showed moderate activity against these strains, with MIC values in the range 7-20 microg/mL.

Flavonols from Pterogyne nitens and their evaluation as myeloperoxidase inhibitors.

A myeloperoxidase inhibitory kaempferol derivative, namely pterogynoside (1), was isolated from fruits of Pterogyne nitens, along with six known flavonols, kaempferol, afzelin, kaempferitrin, quercetin, isoquercetrin and rutin. The structures of all compounds were elucidated primarily from 1D and 2D NMR spectroscopic analyses, as well as by high resolution mass spectrometry. All flavonols were screened to identify secondary metabolites as potential myeloperoxidase (MPO) inhibitors, and at concentrations of 0.50-50nM, quercetin (5), isoquercitrin (6) and rutin (7) exhibited strong inhibitory effects with IC50 values of 1.22+/-0.01, 3.75+/-0.02 and 3.60+/-0.02, respectively. The MPO activity detected for the new derivative 1 was markedly decreased (IC(50) 10.3+/-0.03) when compared with known flavonols 5-7, and interestingly increased when tested against ABTS scavenging activity.

Evaluation of micronuclei frequency in Tradescantia pallida pollen mother cells treated with ethanolic extracts isolated from Cryptocarya mandioccana, Cryptocarya moschata and Pterogyne nitens

Apesar de extratos vegetais possuírem uma série de compostos com atividade farmacológica, eles podem também apresentar substâncias com potencial mutagênico. O objetivo do atual estudo é avaliar a mutagenicidade do extrato etanólico das plantas: Cryptocarya mandioccana, Cryptocarya moschta e Pterogyne nitens utilizando o ensaio do micronúcleo em células mãe de grão de pólen (tétrades) de Tradescantia pallida (Trad-MCN). Inflorescências de T. pallida foram tratadas com diferentes concentrações do extrato etanólico das plantas selecionadas. Para C. mandioccana, C. moschata e P. nitens o ensaio Trad-MCN foi executado os tratamentos, controle positivo (formaldeido 10000 ppm), controle negativo (solução de Hoagland), e controle de veículo (Tween 20 por cento ou DMSO 3 por cento). Os micronúcleos foram quantificados em 300 tétrades/inflorescência, a média e o erro padrão foram estabelecidos no mínimo para 10 inflorescências/tratamento. Os extratos avaliados demonstraram efeito clastogênico dose resposta, respectivamente: C. mandioccana (0.5, 1.0 e 2.0 mg/mL) e P. nitens (1.0 and 2.0 mg/mL). Entretanto, C. moschata não demonstrou atividade clastogênica/aneugênica nas concentrações avaliadas no presente estudo. A partir desses resultados foi possível concluir que os extratos de C. mandioccana and P. nitens apresentaram atividade clastogênica/aneugênica nas maiores concentrações enquanto o extrato C. moschata não apresentou o mesmo efeito.

Although herbal extracts contain several classes of compounds with pharmacological activity, they also present toxic substances with mutagenic effects. The aim of the present study was to verify the mutagenicity of Cryptocarya moschata, Cryptocarya mandioccana and Pterogyne nitens using micronucleus assay in pollen mother cells (tetrads) in Tradescantia pallida (Trad-MCN). T. pallida inflorescences were treated with different concentrations of ethanolic extracts from the selected plant species. For C. mandioccana C. moschata and P. nitens, Trad-MCN assays were carried out simultaneoulsly, followed by positive control (formaldehyde 10000 ppm), negative control (Hoagland's solution), and vehicle control (Tween 20 20 percent or DMSO 3 percent). MCN present in tetrads were quantified in 300 tetrads/inflorescence and the mean(percent) and standard error (SE) were established for at least 10 inflorescences per treatment. The extracts demonstrated dose response mutagenicity (clastogenic/aneugenic effects), respectively, C. mandioccana (0.5, 1.0 and 2.0 mg/mL) and P. nitens (1.0 and 2.0 mg/mL) However, no mutagenic effect was observed to C. moschata at the concentrations evaluated in the present study. We can conclude that the C. mandioccana and P. nitens extracts demonstrated clastogenic/aneugenic effects in highest concentrations whereas C. moschata extract did not demonstrate the same effect.

The use of standard methodology for determination of antifungal activity of natural products against medical yeasts Candida sp and Cryptococcus sp

Methodology for testing natural compounds for determination of antifungal activity had been developed with adaptations. The most used are bioautography and agar diffusion with a complex and no defined media. In this study, different methods for determination of antifungal activity of natural products are discussed and the use of M27-A2 microdilution test from CLSI (Clinical and Laboratory Standards Institute, 2002), as general standard methodology for testing plant extracts activity is recommended.

Metodologias para determinar atividade antifúngica foram desenvolvidas com adaptações para avaliar produtos naturais. As mais usadas são bioautografia e o método de difusão em agar, que empregam meios de cultura complexos, não definidos. Neste estudo são discutidos os métodos para determinação de atividade antifúngica de produtos naturais e é recomendado o uso do micrométodo modificado segundo o documento M27A2 do CLSI.

The absolute configuration of 1-(3',4'-dihydroxycinnamoyl)cyclopentane-2,3-diol from the amazonian tree Chimarrhis turbinata.

An antioxidant, 1-(3',4'-dihydroxycinnamoyl)cyclopentane-2,3-diol [or (E)-2,3-dihydroxycyclopentyl-3-(3',4'-dihydroxyphenyl)acrylate (1)], and two known trans- and cis-chlorogenic acid methyl esters were isolated from the ethanolic extract of the leaves of Chimarrhis turbinata. The relative configuration of 1 was determined by NMR and by comparison of the circular dichroic spectrum (CD) with those of the enantiomers of synthetic 3',4'-dimethoxycinnamoyl analogues. The absolute configuration of one of the synthetic enantiomers was determined using the CD exciton chirality method. This established the structure of naturally occurring 1 as (E)-2,3-dihydroxycyclopentyl-3-(3',4'-dihydroxyphenyl)acrylate.

Antioxidant flavan-3-ols and flavonol glycosides from Maytenus aquifolium.

TLC autographic assay revealed, in the EtOAc extract obtained from leaves and root bark of Maytenus aquifolium (Celastraceae), the presence of fi ve compounds exhibiting antioxidant properties towards beta-carotene. They were isolated and identified as epigallocatechin (1), (+) ouratea-catechin (2), proanthocyanidin (3), kaempferol 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (4) and quercetin 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (5). The isolates were investigated for their redox properties using cyclic voltammetry and for their radical scavenging abilities through spectrophotometric assay on the reduction of 2,2-diphenyl-pycryl hydrazyl (DPPH). These results were correlated to the inhibition of beta-carotene bleaching on TLC autographic assay and to structural features of the flavonoids.