ABSTRACT
ABSTRACT Natural products have been the most valuable source of chemical compounds in the discovery of novel medicines. Secondary metabolites from terrestrial and marine organisms have found considerable use in the treatment of numerous diseases and have been considered lead molecules both in their natural form and as templates for medicinal chemistry. Brazil has an exceptionally rich biodiversity, and a valuable source of secondary metabolites that can be useful for the development of bioproducts. Ipomoea species, Convolvulaceae, are mostly found in tropical and sub-tropical regions, including South America and many are used for nutritional and medicinal purposes. Ipomoea procumbens Mart. & Choisy is endemic from South America, and this is the first study reported on the chemical composition and biological activities of this species. The present work reports the tentatively identification of natural products present in the extracts using a high performance liquid chromatography-high resolution mass spectrometry method. Additionally, the antioxidant and antifungal biological activities of the leaves, roots and steams extracts and fractions of this species were evaluated. While for the antioxidant activity the hydromethanol fractions (leaves, stem and roots) were more active, the methanol fractions of leaves and stem provided better results for the antifungal assay.
ABSTRACT
Abstract Alzheimer's disease affects nearly 36.5 million people worldwide, and acetylcholinesterase inhibition is currently considered the main therapeutic strategy against it. Seaweed biodiversity in Brazil represents one of the most important sources of biologically active compounds for applications in phytotherapy. Accordingly, this study aimed to carry out a quantitative and qualitative assessment of Hypnea musciformis (Wulfen) J.V. Lamouroux, Ochtodes secundiramea (Montagne) M.A. Howe, and Pterocladiella capillacea (S.G. Gmelin) Santelices & Hommersand (Rhodophyta) in order to determine the AChE effects from their extracts. As a matter of fact, the O. secundiramea extract showed 48% acetylcholinesterase inhibition at 400 μg/ml. The chemical composition of the bioactive fraction was determined by gas chromatography–mass spectrometry (GC–MS); this fraction is solely composed of halogenated monoterpenes, therefore allowing assignment of acetylcholinesterase inhibition activity to them.
ABSTRACT
Abstract Marine environment is one of the most important sources regarding natural products research. Besides, marine microorganisms have been denominated as a talented natural source for discovery of new leads. Although the association of macroalgae and fungi has been described regarding ecological issues, there is a lack of studies about marine seaweed endophytic fungi. In this context, the goal of this study was to evaluate cytotoxic, antifungal and antibacterial activities of endophytic fungi isolated from the Brazilian marine seaweed Bostrychia tenella (J.V. Lamouroux) J. Agardh (Ceramiales, Rhodophyta). Forty-five endophytic microorganism strains were isolated from B. tenella. Crude extracts and organic fractions of ten selected strains were obtained after growth in rice medium. Samples were evaluated for cytotoxicity, antifungal and antibacterial assays. Penicillium strains showed positive results in a diversity of assays, and other five strains were active in at least one test. In addition, cytochalasin D was isolated from Xylaria sp. This alga is composed of a microbiological potential, since its endophytic strains exhibited remarkable biological properties. Moreover, cytochalasin D isolation has confirmed chemical potential of marine endophytic strains. This is the first study in which cultured fungi isolates from the Brazilian macroalga B. tenella were evaluated concerning biological properties. Results corroborated that this species could be a pharmaceutical source from marine environment. Furthermore, Acremonium implicatum is being firstly described as marine endophyte and Xylaria sp., Trichoderma atroviride and Nigrospora oryzae as marine seaweed endophytes. Thus, this work reports the first study relating detailed isolation, cultivation and biological evaluation (cytotoxic, antifungal and antibacterial) of endophytes Penicillium decaturense and P. waksmanii from the Brazilian marine red alga B. tenella. We are also reporting the isolation of cytochalasin D, a known antitumor and antibiotic compound, from Xylaria sp. strain. Despite widespread prevalence in terrestrial and marine habitats, this present work describes the first occurrence of cytochalasin D as a metabolite from marine seaweed endophyte.
ABSTRACT
The chemical composition of volatile oils from two Myrtaceae species, Myrceugenia myrcioidesand Eugenia riedeliana, both native from the Brazilian Atlantic Rain Forest, was analyzed by GC-MS. Acetylcholinesterase inhibitory activity was colorimetrically evaluated for these oils. For M. myrcioides, monoterpene hydrocarbons represented the major class in the volatile oil, with α-pinene as the most abundant component and a weak inhibitory activity was observed, whilst for E. riedeliana sesquiterpenes were found in higher amounts, being valerianol the major compound, and this oil presented a strong acetylcholinesterase inhibition.
A composição química dos óleos voláteis de duas espécies de Myrtaceae, Myrceugenia myrcioidese Eugenia riedeliana, ambas nativas da Mata Atlântica, foi analisada por CG-EM. A atividade inibidora de acetilcolinesterase foi determinada colorimetricamente para estes óleos. Em M. myrcioides, hidrocarbonetos monoterpênicos representaram a classe majoritária de compostos presentes no óleo volátil, sendo α-pineno o componente mais abundante e a atividade inibidora de acetilcolinesterase foi baixa, enquanto para E. riedelianaos sesquiterpenos foram observados em maiores concentrações, sendo o valerianol o componente majoritário, e este óleo apresentou uma forte atividade inibidora da enzima.
ABSTRACT
The morphological parameters used to establish close connections among species taxonomically different into the Rubiaceae family is complex, mainly due to the lack of information on habitat and morphoanatomical characters in the lower hierarchic groups, for example, Chimarrhis genus. The micromolecular profile of delimited species into determined taxa can be useful to establish the boundaries among close taxonomic groups, and to indicate evolutionary phylogenetic trends into the taxa. Several indole alkaloids isolated from C. turbinata showed to be a valuable tool to support the taxonomic classification performed by Robbrecht, who established the most recent taxonomy for Rubiaceae, based on morphological characters, and concluded that Chimarrhis belong to Condamineae, and subfamily Cinchonoideae.
A utilização de parâmetros apenas morfológicos para posicionar taxonomicamente diversas espécies em sub-famílias e tribos na família Rubiaceae é bastante problemática devido à falta de informações sobre a distribuição geográfica e de características morfoanatômicas nos níveis hierárquicos mais baixos, como por exemplo, o gênero Chimarrhis. O perfil micromolecular de diferentes espécies pode auxiliar na delimitação de tribos indicando tendências filogenéticas mais completas entre as tribos das sub-famílias, já que os metabólitos secundários são expressões de adaptação, regulação e evolução de um determinado táxon. Nesse contexto, os alcalóides indólicos monoterpênicos isolados de Chimarrhis turbinata foram bastante úteis para embasar a classificação taxonômica feita por Robbrecht, em que posiciona Chimarrhis como um gênero da tribo Condamineae e subfamília Cinchonoideae.
Subject(s)
Indole Alkaloids/isolation & purification , Indole Alkaloids/chemistry , Classification , Monoterpenes/isolation & purification , Monoterpenes/chemistry , Rubiaceae/chemistryABSTRACT
Cissus verticillata L. (Vitaceae) tem sido empregada popularmente como anti-diabética. Nessa espécie foi também detectada atividade fungitóxica. O objetivo do presente trabalho foi realizar a identificação dos compostos fungitóxicos em extratos de folhas. O extrato etanólico foi submetido a fracionamento com solventes de diferentes polaridades (hexano, clorofórmio, acetato de etila e butanol) e seu efeito antifúngico foi analisado frente a Cladosporium sphaerospermum. Os extratos em clorofórmio e acetato de etila mostraram atividade, e foram fracionados por cromatografia em coluna e cromatografia preparativa em placas de sílica, respectivamente. Três terpenóides foram isolados do extrato em clorofórmio; um deles foi identificado, por análise em CG-EM, como um sesquiterpeno, o biciclogermacreno. O composto ativo do extrato em acetato de etila foi identificado, por análises em CLAE, como o estilbeno resveratrol.
Cissus verticillata L. (Vitaceae) is popularly employed as hypoglicemic and it shows fungitoxic activity. This work aims at identification of fungitoxic compounds on extracts of leaves. The ethanol extract was partitioned using solvents of different polarities (hexane, chloroform, ethyl acetate and butanol) and its fungitoxic activity was analysed upon Cladosporium sphaerospermum. The chloroform and ethyl acetate extracts showed activity and they were fractionated by column chromatography and preparative TLC, respectively. Three terpenoids were isolated from the chloroform extract, one of them identified by GLC-MS analysis as sesquiterpene bicyclogermacrene. The active compound of the ethyl acetate extract was identified by HPLC analyses as stilbene resveratrol.
Subject(s)
Cissus , Sesquiterpenes , Stilbenes , VitaceaeABSTRACT
Bioactivity-guided fractionation of several bioactive exttracts obtained from Cerrado and Atlantic Forest plant species led to the isolation of potent DNA-damaging piperidine 1-5 and guanidine alkaloids 6-9 from Cassia leptophylla and Pterogyne nitens respectively, two common Leguminosae from Atlantic Forest. By means of biotechnological approach on Maytenus aquifolium, a species from Cerrado, moderate DNA-damaging sesquiterpene pyridine alkaloid 10-11 was isolated. Bioassay-guided fractionation on Casearia sylvestris, a medicinal plant species found in Cerrado and Atlantic Forest, led to the isolation of clerodane diterpenes 12-13 which showed effect on DNA. In addition, we have reported several interesting potent antifungal iridoids: 1beta-hydroxy-dihydrocornin (14), 1alpha-hydroxy-dihydrocornin (15), alpha-gardiol (16), beta-gardiol (17), plumericin (18), isoplumericin (19), 11-O-trans-caffeoylteucrein (20); ester derivative:2-methyl-4-hydroxy-butyl-caffeoate (21), amide N-[7-(3ï, 4ï-metrylenedioxyphenyl)-2Z, 4Z-heptadienoyl] pyrrolidine (22) and triterpene viburgenin (23).