Virola Sebifera Research Articles

Divergent patterns of intraspecific trait variation among floral and vegetative characters in the hyperdominant dioecious Neotropical treeVirola sebifera(Myristicaceae)

AbstractMany Neotropical tree species are widespread at continental and even inter-continental scales, but phenotypic variation across their respective ranges has rarely been quantified. We measured traits in the widespread, unisexual Neotropical tree Virola sebifera (Myristicaceae) across its continental-scale range, and predicted that, given its hyperdominant status, generalist-pollinated flower type, high dispersal capacity and wide ecological amplitude there would be: (1) a weak relationship among and within reproductive and vegetative characters with environmental, spatial and biome correlates; (2) undetectable canalization of reproductive traits; and (3) high phenotypic variation of vegetative characters. We measured five foliar and seven floral traits from 187 male-expressing individuals of V. sebifera in specimens collected from Central to South America. Spatial regression models were employed to test for the importance of distance, elevation, mean annual rainfall and temperature on phenotypic variation. Pairwise correlations of vegetative and reproductive characters were calculated to examine intraspecific trait variation among and within these two classes. We found that most phenotypic variation was weakly explained by spatial predictors such as certain major South American domains like the Andes Cordillera and the Amazon Basin. Within-class comparisons of floral characters were no different than among-class (floral-foliar) correlates, suggesting the absence of canalization of reproductive structures. Greater phenotypic variation in flowers relative to leaves may be due to the generalist pollinator regime and high dispersal capacity thus relaxing divergences in the evolutionary process of its floral morphology. The results of these morphometric analyses (e.g. weak signals of isolation by distance) in combination with the biology of this Neotropical tree suggest that V. sebifera operates as a well-dispersed metapopulation across most of its range.

In Vitro Antibacterial Activity and in Silico Analysis of the Bioactivity of Major Compounds Obtained from the Essential Oil of Virola surinamensis Warb (Myristicaceae)

Essential oils are well known for their antimicrobial activity and they are used as an effective food preservative. Virola is one of the five genera of Myristicaceae and this genus is native to the American continent, especially in neotropical regions. The largest number of species of this genus is found in the Amazon region and the most important species include Virola surinamensis Warb. and Virola sebifera Aubl. In the present study, we describe the chemical composition of the essential oil of the V. surinamensis obtained at two different periods of the day in two seasons (rainy and dry), as well as their antimicrobial activity against pathogenic bacterial strains of Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. In addition, we investigated, using in silico tools, the antimicrobial activity of the major chemical compounds present in the essential oil of V. surinamensis. The samples collected at different seasons and times showed a similar chemical profile, characterized by the major constituents α-pinene (>33%) and β-pinene (>13%). The essential oil of V. surinamensis showed an interesting antibacterial activity, exhibiting low inhibitory concentrations against the tested bacterial species. The computational investigation indicated that limonene, myrcene, and β-pinene could be related to the antibacterial activity against the tested pathogenic bacterial strains. Our results shed light on the possible constituents of essential oil that could be related to its activity against bacterial species and might be useful for further experimental tests that aim to discover new potential antibacterial agents for food preservation.

Chemical assessment, antioxidant and antimicrobial of leafs extracts of Virola sebifera, an Amazonian medicinal plant

The high biodiversity of Amazon forest implies in a great number of plants with ethnopharmacological utilization. V. sebifera is one of the most important species of Virola genus, used in treatment of rheumatism, arthritis, dyspepsia, malaria, muscle pain and erysipelas. This study aimed to investigate its chemical composition, antioxidant and antimicrobial properties. For this, leafs extracts i) 70% ethanol in ultrasound bath (CEU); ii) 70% ethanol in Soxhlet (CES); and iii) sequential extraction in Soxhlet apparatus, starting with hexane (HE), followed by methanol (ME), and 70% ethanol extract (EE). Phenolic concentration, total flavonoid and antioxidant activity were assessed. The highest phenolic and total flavonoid contents were found in CEU and EE showed the best antioxidant activity. The most relevant substances identified by GC-MS analysis were the Kusunokinin, Hinokinin and catechol, among others first time related in V. sebifera. The antimicrobial activity was tested against Staphylococcus aureus, S. epidermidis, Salmonella typhimurium, Escherichia coli, and Candida albicans. The CEU, CES, EM, and EE obtained positive results against S. aureus and S. epidermidis. CES and EM also inhibited S. typhimurium and E. coli. Based on these results, V. sebifera can be recognized as a promising source of antioxidant and antimicrobial compounds.

Chemical characterization and cytotoxicity of extracts of leaves of Virola sebifera of the cerrado tocantinense

Virola sebifera (Aubl.), belonging to the Myristicaceae family, popularly known as mucuíba, and ucuúba, is among the various species with medicinal use found in the Cerrado, has several ethnobotanical uses and medicinal benefits, being applied in folk medicine for the treatment of various illnesses. Based on this, the present study aimed to investigate the chemical composition of Virola sebifera using high performance liquid chromatography and analyze the cytotoxic activity of its leaf extracts. The leaf extracts were prepared using different methodologies: i) 70% ethanol in an ultrasonic bath, originating the crude ultrasonic extract (CEU); ii) 70% ethanol, in a soxhlet apparatus, originating the crude soxhlet extract (CES); and iii) sequential extraction in a soxhlet apparatus, starting with the hexane solvent, followed by methanol and 70% ethanol, originating, respectively, the hexane extract (HE), methanol extract (ME) and ethanol extract (EE). HPLC analyzes showed that extracts from V. sebifera leaves have a diverse matrix of phenolic compounds, including phenolic acids (syringic acid, p-coumaric acid, rosmarinic acid and chlorogenic acid) and flavonoids (morina, quercetin, catechin, hesperidin, naringin and rutin). The in vitro toxic activities were analyzed in CEU, CES, and EE and observed a great inhibition of Allium strain, this suggest an anticarcinogenic activity. The results obtained indicate that V. sebifera has potential antioxidant activity, due to the presence of a diversity of phenolic compounds, thus evidencing its medicinal potential, requiring further studies with the species in order to confirm the results obtained and direct its use safe.

Evaluation of the quality of Amazonian butters as sustainable raw materials for applications in bioproducts

A new consumer profile for pharmaceutical and cosmetic products has motivated research into natural raw materials in the development of “green” products such as herbal medicines and biocosmetics. However, various limitations have been encountered in the marketing of these products, for example the quality control of the natural raw materials used by the industrial market. This study aims to evaluate the sensory and physicochemical parameters of murumuru (Astrocaryum murumuru Mart.), bacuri (Platonia insignis Mart.), tucuma (Astrocaryum vulgare Mart.), and ucuuba (Virola sebifera Aubl.) butters for applications in pharmaceutical and cosmetic bioproducts. The acidity and saponification as well as the iodine and peroxide indexes were evaluated and fatty acid profiles for the samples obtained by GC-MS. The sensory properties of the butters showed the appearance of solid to soft cream, color (yellow, brown, buttercup, and ochre), and characteristic odor. The melting temperatures of all butters ranged between 31 oC and 49 °C. The acidity, saponification, iodine and peroxide indexes for the butters were of 5.82 – 17.73 mg (NaOH or KOH) g−1, 181.10 – 573.55 mg KOH g−1, 2.78 – 44.96 gl2 100 g−1, and 1.39 – 9.30 meq kg−1, respectively. From analyses of the fatty acid profiles, the major components identified were lauric acid in murumuru (40%) and ucuuba butters (73%), myristic acid in tucuma butter (53%), and palmitic acid in bacuri butter (42%). In general, the results of the analyses differed from the specifications of the supplier reports and official compendia. These findings highlight the importance of quality control in natural raw materials to ensure their functionality in pharmaceutical and cosmetic bioproducts.

Allelophatic and Antioxidant Activity of Eight Amazon Species from De Tamshiyacu Tahuayo Reserve.

Allelophatic and Antioxidant Activity of Eight Amazon Species from De Tamshiyacu Tahuayo Reserve. Úrsula Monteiro, Blanca Diaz, Robinson Saldaña, Víctor Sotero, Dora García Abstract In this study were evaluated the antioxidant activity (AAO), allelopathic (ALL) and bioactive substances present in leaves of eight plant species from the Tamshiyacu-Tahuayo Community (Loreto-Peru). The AAO evaluation was performed by the free radical DPPH capture method, using dry and pulverized leaves, macerated in methanol for fifteen days, solutions of 0.01- 5.0 mg/mL and 0.1 mM DPPH were prepared, reading was performed in the UV/vis spectrometer at 517 nm, for the ALL was performed by the Petri plates method, using methanolics extracts of fresh leaves with concentrations of 0.1- 50.0 mg/mL against the growth of pregerminated seeds of Latuca sativa , the reading was made by measuring the hypocotyl and radicle of the seedling. In the results of species with high AAO were Virola sebifera, Caryocar glabrum and Tapirira guianensis, which present a percentage of inhibition superior to 50% in concentrations of 5.0 mg/mL. The species with high ALL are Xylopia benthami, Malouetia naias and Virola surinamensis, reaching an EC50 for the radicle at concentrations lower than 1.0 - 50.0 mg/L. The concentration of phenolic compounds for these species varied from 115217,18-321815,14 mg/kg, flavonoids from 1030,79-1441,16 mg/kg and proanthocyanidins from 0.65-1,77 mg / 100g. Total alkaloids range from 0,0 - 68,2 m/g evaluation, presenting differences between them. Full Text: PDF DOI: 10.15640/jns.v7n1a4

Evaluation of the Antioxidant Activity of 31 Amazonian Vegetable Species of Tamshiyacu Loreto-Peru

Evaluation of the Antioxidant Activity of 31 Amazonian Vegetable Species of Tamshiyacu Loreto-Peru Dora García1, Blanca Díaz, Robinson Saldaña, Úrsula Monteiro, Víctor Sotero, Jorge Chavez Abstract The aim of this study was evaluate the antioxidant capacity of the extracts of the leaves of 31 vegetable species collected at the vicinity of the town of Tamshiyacu, in the department of Loreto, Peru. The percentage of inhibition of free radicals of 2,2-diphenyl-1-picrylhydrazyl (DPPH) was calculated. From the concentration of the best species with high activity, which were three, it was realized the analysis of total concentration of phenolic compounds and alkaloids was analyzed by UV/Vis spectrophotometry. Besides the metanolics extracts were submitted to fractionation in chromatographic column and the fractions with similar molecules, grouped by thin layer chromatography. The final fractions were analyzed by a Gas Chromatograph coupled to mass spectrometry (CG-MS), to identify the molecules present in them and causing this activity. According to the results, the species that showed the best activity at concentrations lower than 5.0 mg/ml were Virola sebifera, Caryocar glabrum and Tapirira guianensis. The concentration of total phenolic compounds was 18580.9, 15180.7 and 11568.7 mg/100g for V. sebifra, C. glabrum and T. guiannensis, and total alkaloids were 36.6, 0.0 and 74.0 mg/100g for these same species. The main secondary metabolites are 3,5-di-tert-butyl-4-hydroxyanisole and normolatedol and caryophyllene, in V. sebifera, diisooctyl dicarboxylate.1,2-benzene and 3, 5-bis (1,1-dimetyl etill-phenol in C. glabrum and diisoctylphthalate, α-panasinseno, and vitamin E in T. guianensis. Full Text: PDF DOI: 10.15640/jns.v7n1a3

AMAZON RAINFOREST COSMETICS: CHEMICAL APPROACH FOR QUALITY CONTROL

The market for natural cosmetics featuring ingredients derived from Amazon natural resources is growing worldwide. However, there is neither enough scientific basis nor quality control of these ingredients. This paper is an account of the chemical constituents and their biological activities of fourteen Amazonian species used in cosmetic industry, including acai (Euterpe oleracea), andiroba (Carapa guianensis), bacuri (Platonia insignis), Brazil nut (Bertholletia excelsa), buriti (Mauritia vinifera or M. flexuosa), cumaru (Dipteryx odorata), cupuacu (Theobroma grandiflorum), guarana (Paullinia cupana), mulateiro (Calycophyllum spruceanum), murumuru (Astrocaryum murumuru), patawa (Oenocarpus bataua or Jessenia bataua), pracaxi (Pentaclethra macroloba), rosewood (Aniba rosaeodora), and ucuuba (Virola sebifera). Based on the reviewed articles, we selected chemical markers for the quality control purpose and evaluated analytical methods. Even though chromatographic and spectroscopic methods are major analytical techniques in the studies of these species, molecular approaches will also be important as used in food and medicine traceability. Only a little phytochemical study is available about most of the Amazonian species and some species such as acai and andiroba have many reports on chemical constituents, but studies on biological activities of isolated compounds and sampling with geographical variation are limited.

In-Vitro Antiviral Activities of Extracts of Plants of The Brazilian Cerrado against the Avian Metapneumovirus (aMPV)

Avian metapneumovirus (aMPV) is a negative-sense single-stranded RNA enveloped virus of the Metapneumovirus genus belonging to theParamyxoviridae family. This virus may cause significant economic losses to the poultry industry, despite vaccination, which is the main tool for controlling and preventing aMPV. The aim of this study was to evaluate the antiviral activity of extracts of four different native plants of the Brazilian Cerrado against aMPV. The antiviral activity against aMPV was determined by titration. This technique measures the ability of plant extract dilutions (25 to 2.5 µg mL-1) to inhibit the cytopathic effect (CPE) of the virus, expressed as inhibition percentage (IP). The maximum nontoxic concentration (MNTC) of the extracts used in antiviral assay was 25 µg mL-1for Aspidosperma tomentosumand Gaylussacia brasiliensis, and 2.5 µg mL-1for Arrabidaea chicaand Virola sebifera. Twelve different extracts derived from four plant species collected from the Brazilian Cerrado were screened for antiviral activity against aMPV. G. brasiliensis, A. chica,and V. sebifera extracts presented inhibition rates of 99% in the early viral replication stages, suggesting that these extracts act during the adsorption phase. On the other hand, A. tomentosum inhibited 99% virus replication after the virus entered the cell. The biomonitored fractioning of extracts active against aMPV may be a tool to identify the active compounds of plant extracts and to determine their precise mode of action.

Polymorphic microsatellite loci for Virola sebifera (Myristicaceae) derived from shotgun 454 pyrosequencing.

• Premise of the study: Polymorphic microsatellite loci were characterized in the dioecious neotropical rainforest tree Virola sebifera. The markers will be used to study ecological and genetic impacts of hunting and landscape change in this vertebrate-dispersed, insect-pollinated tree species.• Methods and Results: Simple sequence repeat (SSR) markers were screened from genomic libraries of South American V. sebifera obtained by shotgun 454 pyrosequencing. Primer pairs were tested on Panamanian samples (N = 42). Approximately 52% of the 61 tested SSR markers amplified, and 16% were polymorphic. Ten selected polymorphic SSR loci contained seven to 15 alleles per locus, and polymorphic information content averaged 0.694. Observed heterozygosity ranged from 0.465 to 0.905, and expected heterozygosity was between 0.477 and 0.876.• Conclusions: The 10 polymorphic loci will be useful in studying gene flow and genetic structure at local and regional spatial scales in V. sebifera.

Evaluation of the Toxicity ofVirola sebiferaCrude Extracts, Fractions and Isolated Compounds on the Nest of Leaf-Cutting Ants

The phytochemical study ofVirola sebiferaleaves led to the isolation of three lignans: (+)-sesamin, (−)-hinokinin, and (−)-kusunokinin and three flavonoids: quercetin-3-O-α-L-rhamnoside, quercetin-3-O-β-D-glucoside, and quercetin-3-methoxy-7-O-β-D-glucoside by using techniques as high-speed counter-current chromatography and high-performance liquid chromatography. The crude extracts, fractions, and isolated compounds were evaluated for their insecticidal and fungicidal potential againstAtta sexdens rubropilosaand its symbiotic fungusLeucoagaricus gongylophorus. The bioassay results showed a high insecticidal activity for the methanol crude extract of the leaves ofV. sebiferaand itsn-hexane, dichloromethane and ethyl acetate fractions. The fungicidal bioassay revealed high toxicity of the lignans againstL. gongylophorus.

High-temperature tolerance of a tropical tree, Ficus insipida: methodological reassessment and climate change considerations

In view of anthropogenic global warming, heat tolerance of a neotropical pioneer tree, Ficus insipida Willd., was determined. Sections of sun leaves from a mature tree and from seedlings cultivated at ambient and elevated temperatures were heated to 42–53°C. Leaves from a late-successional tree species, Virola sebifera Aubl., were also studied. Widely used chlorophyll a fluorescence methods based on heat-induced rise of initial fluorescence emission, Fo, and decrease in the ratio of variable to maximum fluorescence, Fv/Fm, were reassessed. Fv/Fm determined 24 h after heat treatment was the fluorescence parameter most suitable to assess the lethal temperature causing permanent tissue damage. Thermo-tolerance was underestimated when Fo and Fv/Fm were recorded immediately after the heat treatment. The limit of thermo-tolerance was between 50 and 53°C, only a few °C above peak leaf temperatures measured in situ. The absence of seasonal changes in thermo-tolerance and only marginal increases in thermo-tolerance of plants grown under elevated temperatures suggest little capacity for further heat acclimation. Heat-stress experiments with intact potted seedlings also revealed irreversible leaf damage at 51–53°C, but plants survived and developed new leaves during post-culture.

Atividade antiproliferativa dos extratos e da fração orgânica obtidos das folhas de Virola sebifera Aubl. (Myristicaceae)

As cascas de Virola sebifera (Myristicaceae) são utilizadas por populações indígenas amazônicas em preparações alucinógenas, nas quais foram encontrados alcalóides como a dimetiltriptamina e seus derivados. Considerando a enorme importância dos alcalóides isolados de plantas na terapêutica do câncer e a presença desses compostos em espécies de Virola, o presente trabalho teve por objetivo o estudo da atividade antiproliferativa em cultura de células tumorais humanas de extratos e da fração orgânica, obtidos das folhas de Virola sebifera. O extrato bruto diclorometânico (EBD) foi considerado o mais ativo, com seletividade principalmente para a linhagem de pulmão (NCI-460) - IC50: 4,46 µg/mL e para a fração orgânica (FO) obtida por extração ácido-base - IC50; 6,91 µg/mL. A atividade observada possivelmente pode ser atribuída a alcalóides ou compostos nitrogenados que foram evidenciados pelo corante Dragendorff. Assim, a purificação da FO será necessária a fim de comprovar a presença de compostos nitrogenados, através de isolamento e determinação estrutural, bem como a participação desses compostos na atividade antiproliferativa observada.

Antiproliferative properties of polyketides isolated from Virola sebifera leaves

An activity-guided fractionation of Virola sebifera Aubl. methylene chloride-soluble fraction provided novel 3,5-dihydro-2-(1'-oxo-3'-hexadecenyl)-2-cyclohexen-1-one (3), two known lignans (1, 2) and dehydro hexadecanoyl resorcinol (4). Isolation and purification were conducted with the application of column chromatography and structures were assigned by spetral analysis (1D and 2D NMR, HREIMS). Compounds 1-4 were evaluated for cytotoxic activities against human tumour cell lines UACC62 (melanoma), MCF-7 (breast), NCI 460 (lung, non-small cells), OVCAR03 (ovarian), PC-03 (prostate), HT-29 (colon), 786-0 (renal) and NCI-ADR (breast expressing phenotype multiple drugs resistance) in vitro. The new polyketide (3) showed selectivity against human OVCAR03 and NCI-ADR cell lines, ranging from 2 to 4 microg/mL.

Solubility of triacylglycerols in supercritical carbon dioxide

The solubility of refined corn and sunflower seed oils, babassu ( Attalea funifera) and ucuuba ( Virola sebifera) fats in supercritical carbon dioxide (SC-CO 2) were measured in a temperature range from 40 to 80 °C and pressure between 200 and 350 bar. Under working conditions, the values of solubility showed retrograde behavior. Experimental SC-CO 2 solubility data were collected from the literature for the following systems: tricaprylin (CCC), trilaurin (LLL), trimyristin (MMM), tripalmitin (PPP), tristearin (SSS), triolein (OOO), blackcurrant seed oil and canola seed oil, and analyzed together with the values obtained in this work. Chrastil's equation was used to correlate the solubility of oils in CO 2 as a function of the temperature and density of the SC-CO 2. An analysis of the results showed that the parameters of Chrastil's equation could be correlated to the fatty acid composition of the triacylglycerols.

Análise florística e estrutural do componente arbustivo-arbóreo de uma floresta de galeria no Município de Cristais Paulista, SP, Brasil

Remanescentes florestais na porção nordeste do Estado de São Paulo são ainda pouco estudados quanto à composição florística. Foi realizado o levantamento florístico e fitossociológico de uma floresta de galeria no Município de Cristais Paulista visando à caracterização da flora do remanescente e o estudo das relações florísticas com outras formações ribeirinhas. Para o levantamento fitossociológico foi utilizado o método de ponto-quadrante. Em quatro transeções paralelas ao curso d'água, foram estabelecidos 90 pontos eqüidistantes em 10 metros e amostrados os indivíduos com PAP > 15 cm. Espécies em estágio reprodutivo, não amostradas no levantamento fitossociológico, foram coletadas e identificadas. Foram encontradas 68 espécies, distribuídas em 37 famílias, das quais 53 espécies e 34 famílias foram amostradas no levantamento fitossociológico. O índice de diversidade (H') para as espécies foi de 3,17 nats indivíduo-1 e as espécies mais importantes (em VI) foram Virola sebifera, Protium heptaphyllum, Tapirira guianensis e Copaifera langsdorffii. A comparação com outras florestas ribeirinhas evidenciou uma maior semelhança florística com as florestas situadas principalmente na bacia do Rio Grande, possivelmente devido às condições semelhantes de clima, e no Brasil Central, devido à rede de drenagem que atua como rota migratória das espécies. Foram encontradas também muitas espécies compartilhadas com os cerrados, evidenciando a contribuição da flora desse domínio para a floresta de galeria estudada.

Biologia reprodutiva e fenologia de Virola sebifera Aubl. (Myristicaceae) em mata mesofítica de Uberlândia, MG, Brasil

We studied some aspects of the floral and reproductive biology of Virola sebifera Aubl., a dioecious woody species of mesophytic forest in Uberlândia, Minas Gerais. The sex of 54 individuals in the study area was determined in three consecutive reproductive periods. Reproductive phenology of 11 individuals of each sex was followed from October 1998 to April 2000. The sex ratio was always male biased and no sex change was observed, which indicates sexual stability. The flowering was annual, relatively long and massive (cornucopia type) with male individuals blooming earlier and for a longer period than the female ones. Flowers, grouped in paniculate inflorescences, were small (3 and 4 mm long for male and female flowers respectively) and inconspicuous, with an infundibuliforme periant and inserted reproductive whorls. Both male and female flowers have long lifespan (ca. one week). Pollen in male flowers is the sole floral reward. Strong scent and similar flower morphology between sexes may lead to visits to rewardless female flowers (floral self-mimicry). Natural pollination resulted in relatively low number of initiated fruits (5.8%). Fruit-set from bagged unpollinated flowers (apomixis) were much lower than from natural pollination. These results show that V. sebifera depends upon pollination services for seed production although flower visitors were rarely seen during the study and effective pollinators of the species could not be clearly defined.

Antioxidant activity of aryltetralone lignans and derivatives from Virola sebifera (Aubl.)

Aryltetralone lignans bearing methylenedioxy groups (1a–b; 2a–b) were isolated from seeds of Virola sebifera. Their antioxidant activities were evaluated by inhibition of lipid peroxidation as indicated by TBARS and chemiluminescence emission (CL) assays. The lignan 1c, 'having a 2′-hydroxy-4′,5′-methylenedioxyphenyl group, was the most active compound with TBARS/CL Q 1/2 values of 0.89 and 0.10 µg/mL, respectively. The catechol derivatives 3 and 4, obtained by demethylenation of lignans 1a and 2a, were of similar activity to 1c, and all were much more effective as antioxidants than α-tocopherol.

First Asymmetric Synthesis and Determination of the Absolute Configuration of a Lignan Isolated from Virola sebifera

AbstractThe first asymmetric synthesis of a lignan isolated from the seeds of Virola sebifera, one of the most widely spread Myristicaceae species in Brazil, in four steps (48 % overall yield) and with excellent stereoselectivity (de, ee ≥ 96 %) is described. The key step is the asymmetric Michael addition of a lithiated enantiopure α‐amino nitrile to an enone, followed by α‐methylation and cleavage of the amino nitrile. The absolute configuration of the naturally occurring 1,4‐diketone was determined by polarimetry as well as by CD spectroscopy and quantum chemical calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Caracterização florística, fitossociológica e regeneração natural do sub-bosque da reserva genética florestal Tamanduá, DF.

O presente trabalho, desenvolvido na Reserva Genética Florestal Tamanduá, DF, teve como objetivo efetuar o levantamento fitossociológico, composição florística e distribuição espacial dos indivíduos das espécies arbóreas ocorrentes no sub-bosque da Reserva, focalizando Cariniana estrellensis (Raddi) O. Kuntze, Apuleia leiocarpa (Vogel) J. F.Macbr., Copaifera langsdorffii Desf., Anadenanthera macrocarpa (Benth.) Brenan, Virola sebifera Aubl., Hymenaea courbaril var. stilbocarpa (Hayne) Lee & Lang., Aspidosperma discolor A. St. Hil., Astronium fraxinifolium Schott e Schefflera morototoni B. Maguire, Stey. & Frodin, consideradas prioritárias para conservação in situ. Foram utilizados cinco transectos com 10 m de largura cada, alocados eqüidistantes e de comprimento variável, demarcados perpendicularmente ao curso da drenagem principal. Foram encontrados 21.482 regenerantes ha-1 em 69 espécies vegetais, 53 gêneros e 39 famílias botânicas. Em número de espécies, as famílias que mais se destacaram entre os regenerantes foram, em ordem decrescente, Leguminosae, Rubiaceae, Sapindaceae e Meliaceae. Entre os jovens, as famílias com maiores valor de importância (VI) foram pela ordem Meliaceae (32,78 %), Rubiceae (13,92 %), Burseraceae (13,76 %), Rutaceae (8,54 %) e Hippocrateaceae (6,36), totalizando 75,36 % de valor de importância e 78,56 % de valor de cobertura. Todas as espécies objeto deste trabalho ocorreram entre os regenerantes, destacando-se Cariniana estrellensis, porém, apenas Copaifera lagsdorffii e Virola sebifera ocorreram entre os indivíduos jovens. O quociente de mistura de 1:3 indicou tratar-se de uma mata rica em espécies, comparativamente a outros tipos florestais. A distribuição espacial dos regenerantes das espécies em questão mostrou padrões diferenciados.