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1.
An Acad Bras Cienc ; 95(suppl 2): e20221015, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055442

RESUMO

Pollen grain morphology and the characterization of additional structures related to pollen dispersion can help to understand the strategies presented by species as well as their taxonomic circumscription. This work investigates the morphology of pollen grains and orbicules of Cedrela fissilis Vell. and Cedrela odorata L., two threatened species of the genus Cedrela P. Browne (Meliaceae A. Juss.) in Brazil. Observations of pollen grains and orbicules of the species were carried out pre- and post-chemical treatment of the samples, under light and scanning electron microscopy, aiming at recognizing structures, detailing morphological characterizations and taking measurements, the last of which were submitted to statistical treatment. The results demonstrate that the pollen grains of the two species are medium in size (measuring between 25 and 50µm), radially symmetrical, isopolar, prolate-spheroidal and 4,5-colporate with subcircular to subquadrangular amb and psilate ornamentation; the orbicules also have a smooth surface and measure about 7 to 10µm. Variation was observed in the size of pollen grains, which presented high coefficient of variation and in the orbicules, as well as in the number of apertures.


Assuntos
Cedrela , Meliaceae , Animais , Espécies em Perigo de Extinção , Especificidade da Espécie , Pólen/anatomia & histologia , Microscopia Eletrônica de Varredura
2.
Am J Bot ; 109(10): 1622-1640, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36098061

RESUMO

PREMISE: Reconciling the use of taxonomy to partition morphological variation and describe genetic divergence within and among closely related species is a persistent challenge in phylogenetics. We reconstructed phylogenetic relationships among Cedrela odorata (Meliaceae) and five closely allied species to test the genetic basis for the current model of species delimitation in this economically valuable and threatened genus. METHODS: We prepared a nuclear species tree with the program SNPhylo and 16,000 single-nucleotide polymorphisms from 168 Cedrela specimens. Based on clades present and ancestral patterns ADMIXTURE, we designed nine species delimitation models and compared each model to current taxonomy with Bayes factor delimitation. Timing of major lineage divergences was estimated with the program SNAPP. RESULTS: The resulting analysis revealed that modern C. odorata evolved from two genetically distinct ancestral sources. All species delimitation models tested better fit the data than the model representing current taxonomic delimitation. Models with the greatest marginal likelihoods separated Mesoamerican C. odorata and South American C. odorata into two species and lumped C. angustifolia and C. montana as a single species. We estimated that Cedrela diversified in South America within the last 19 million years following one or more dispersal events from Mesoamerican lineages. CONCLUSIONS: Our analyses show that the present taxonomic understanding within the genus obscures divergent lineages in C. odorata due in part to morphological differentiation and taxonomic distinctions that are not predictably associated with genetic divergence. A more accurate application of taxonomy to C. odorata and related species may aid in its conservation, management, and restoration efforts.


Assuntos
Cedrela , Cedrela/genética , Cedrela/anatomia & histologia , Filogenia , Teorema de Bayes , Especificidade da Espécie , América do Sul
3.
Magn Reson Chem ; 60(3): 275-358, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34730255

RESUMO

Cedrela genus, a member of the Meliaceae family, presents both chemical characteristics associated with and those that distinguish it from the rest of its members. The presence of triterpenes and limonoids is the characteristic of the Meliaceae family, but the class and type of these chemical constituents are distinctive for each genus. Cedrela includes cycloartane, ursane, oleanane, tirucallane, butyrospermane, and apotirucallane triterpenes, and its limonoids belongs to six class and nine types, known as class Ia-type havanensines, class Ib-type delevoyin, class II-type gedunin, class IIIb-type andirobin, class IIIg-type mexicanolide, class IVa-type evoludone, class Va-type obacunol, class V-type limonin, and class VIII. Each of these structural arrangements includes specific traits, defined by their biosynthetic origin, which can be established by means of structural elucidation techniques, particularly 1 H and 13 C NMR, which assisted by 2D NMR techniques, allowing to deduce their structures unequivocally. The constant presence of these skeletal arrangements in Cedrela ensures that they are its chemophenetic markers and their recurrence is an important criterion for their identity. This review is a compilation of the occurrence of triterpenes and limonoids in Cedrela genus, detailing their biosynthetic association and collecting and organizing their NMR data, with the purpose of facilitating its location, analysis, and use in the phytochemical study of species from this genus.


Assuntos
Cedrela , Limoninas , Meliaceae , Triterpenos , Cedrela/química , Limoninas/química , Espectroscopia de Ressonância Magnética , Meliaceae/química , Estrutura Molecular , Triterpenos/química
4.
Molecules ; 27(9)2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35566324

RESUMO

Cedrela odorata L. is a plant species from the Meliaceae family that is cultivated for timber production. Although the C. odorata essential oil (EO) contains mainly sesquiterpenes, its insecticidal potential is unknown. The lipophilic properties and high degradation capacity of EOs have limited their application for use in pest control. However, the currently available knowledge on the nanoemulsification of EOs, in addition to the possibility of improving their dispersion, would allow them to prolong their permanence in the field. The objective of the present work was to develop a nanoemulsion of the C. odorata EO and to evaluate its larvicidal activity against Spodoptera frugiperda. The EO was obtained by the hydrodistillation of C. odorata dehydrated leaves, and the nanoemulsion was prepared with non-ionic surfactants (Tween 80 and Span 80) using a combined method of agitation and dispersion with ultrasound. The stability of the nanoemulsion with a droplet diameter of <200 nm was verified in samples stored at 5 °C and 25 °C for 90 days. Both the C. odorata EO and its corresponding nanoemulsion presented lethal properties against S. frugiperda. The results obtained provide guidelines for the use of wood waste to produce sustainable and effective insecticides in the fight against S. frugiperda. In addition, considering that a phytochemical complex mixture allows the simultaneous activation of different action mechanisms, the development of resistance in insects is slower.


Assuntos
Cedrela , Inseticidas , Meliaceae , Óleos Voláteis , Animais , Inseticidas/química , Inseticidas/farmacologia , Larva , Óleos Voláteis/farmacologia , Spodoptera
5.
J Nat Prod ; 84(3): 724-737, 2021 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-33661631

RESUMO

Nine new limonoids (1-9) were isolated from the stem bark of Guarea guidonia (1-4) and Cedrela odorata (5-9). Their structures were elucidated using 1D and 2D NMR and MS data and chemical methods as three A2,B,D-seco-type limonoids (1-3), a mexicanolide (4), three nomilin-type (5-7) limonoids, and two limonol derivatives (8 and 9). A DFT/NMR procedure was used to define the relative configurations of 1 and 3. A surface plasmon resonance approach was used to screen the Hsp90 binding capability of the limonoids, and the A2,B,D-seco-type limonoid 8-hydro-(8S*,9S*)-dihydroxy-14,15-en-chisomicine A, named chisomicine D (1), demonstrated the highest affinity. By means of mass spectrometry data, biochemical and cellular assays, and molecular docking, 1 was found as a type of client-selective Hsp90 inhibitor binding to the C-terminus domain of the chaperone.


Assuntos
Cedrela/química , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Limoninas/farmacologia , Meliaceae/química , Benzoxepinas , Células HeLa , Humanos , Limoninas/isolamento & purificação , Simulação de Acoplamento Molecular , Estrutura Molecular , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Casca de Planta/química , Células U937 , Venezuela
6.
J Environ Manage ; 268: 110733, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32510453

RESUMO

Mineral exploration of copper (Cu) in the Amazon has significantly impacted the environment, leading to contamination of large areas that require remediation. Tropical tree species that can immobilize metals and restore plant cover should be selected for phytoremediation programs. The phytoremediation behavior of Khaya ivorensis and Cedrela fissilis was studied in Cu contaminated soil (60, 200, 400, and 600 mg kg-1). K. ivorensis absorbed extremely high amounts of Cu in the roots (329 mg kg-1) and excessive amounts in the shoot (52 mg kg-1), while maintaining similar growth to control plants. C. fissilis seedlings presented a higher Dickson quality index. Bioaccumulation (BCF) and translocation (TF) factors were low in both species, indicating that even with the high amounts of copper absorbed, these contents were lower than the soil concentration (BCF < 1) and that most of Cu was compartmentalized in the roots (TF < 1). The tolerance index of K. ivorensis (>1) and C. fissilis (~1) indicate their ability to grow in Cu contaminated soil. These results suggest that these species could potentially be used as phytoremediators.


Assuntos
Cedrela , Metais Pesados , Poluentes do Solo , Biodegradação Ambiental , Cobre , Solo
7.
Molecules ; 25(22)2020 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-33218181

RESUMO

The genus Cedrela P. Browne, which belongs to the Meliaceae family, has eighteen species. Trees of this genus are of economic interest due to wood quality, as well as being the focus of studies because of relevant biologic activities as in other Meliaceae species. These activities are mainly related to limonoids, a characteristic class of compounds in this family. Therefore, the aim of this review is to perform a survey of the citations in the literature on the Cedrela genus species. Articles were found on quantitative and qualitative phytochemical studies of the Cedrela species, revealing the chemical compounds identified, such as aliphatics acid and alcohol, flavonoids, tocopherol, monoterpenes, sesquiterpenes, triterpenes, cycloartanes, steroids, and limonoids. Although some activities were tested, the majority of studies focused on the insecticidal, antifeedant, or insect growth inhibitor activities of this genus. Nonetheless, the most promising activities were related to their antimalarial and antitripanocidal effects, although further investigations are still needed.


Assuntos
Cedrela/química , Compostos Fitoquímicos/farmacologia , Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Cedrela/crescimento & desenvolvimento , Concentração Inibidora 50 , Compostos Fitoquímicos/química , Desenvolvimento Vegetal/efeitos dos fármacos
8.
BMC Genomics ; 20(1): 58, 2019 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-30658593

RESUMO

BACKGROUND: Tree species in the genus Cedrela P. Browne are threatened by timber overexploitation across the Neotropics. Genetic identification of processed timber can be used to supplement wood anatomy to assist in the taxonomic and source validation of protected species and populations of Cedrela. However, few genetic resources exist that enable both species and source identification of Cedrela timber products. We developed several 'omic resources including a leaf transcriptome, organelle genome (cpDNA), and diagnostic single nucleotide polymorphisms (SNPs) that may assist the classification of Cedrela specimens to species and geographic origin and enable future research on this widespread Neotropical tree genus. RESULTS: We designed hybridization capture probes to enrich for thousands of genes from both freshly preserved leaf tissue and from herbarium specimens across eight Meliaceae species. We first assembled a draft de novo transcriptome for C. odorata, and then identified putatively low-copy genes. Hybridization probes for 10,001 transcript models successfully enriched 9795 (98%) of these targets, and analysis of target capture efficiency showed that probes worked effectively for five Cedrela species, with each species showing similar mean on-target sequence yield and depth. The probes showed greater enrichment efficiency for Cedrela species relative to the other three distantly related Meliaceae species. We provide a set of candidate SNPs for species identification of four of the Cedrela species included in this analysis, and present draft chloroplast genomes for multiple individuals of eight species from four genera in the Meliaceae. CONCLUSIONS: Deforestation and illegal logging threaten forest biodiversity globally, and wood screening tools offer enforcement agencies new approaches to identify illegally harvested timber. The genomic resources described here provide the foundation required to develop genetic screening methods for Cedrela species identification and source validation. Due to their transferability across the genus and family as well as demonstrated applicability for both fresh leaves and herbarium specimens, the genomic resources described here provide additional tools for studies examining the ecology and evolutionary history of Cedrela and related species in the Meliaceae.


Assuntos
Cedrela/genética , Perfilação da Expressão Gênica/métodos , Genoma de Cloroplastos/genética , Genômica/métodos , Árvores/genética , Região do Caribe , Cedrela/classificação , América Central , Geografia , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Meliaceae/classificação , Meliaceae/genética , Filogenia , Folhas de Planta/genética , Polimorfismo de Nucleotídeo Único , América do Sul , Especificidade da Espécie , Árvores/classificação , Clima Tropical
9.
J Immunoassay Immunochem ; 40(6): 630-641, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31544580

RESUMO

The emergence of antigenic variants and very virulent strains of infectious bursa disease virus (IBDV) in vaccinated flocks considerably stimulated research in IBDV vaccine administration. The mucoadhesive and immunopotentials of Cedrela odorata and Khaya senegalensis were explored in vaccine delivery against clinical IBDV in broiler chickens. A total of 400 chicks were successfully brooded and raised from day old for commencement of this experiment. The birds were randomly distributed into eight groups with an average of 50 birds per group comprising: Gums-Gumboro Vaccine Ocular (infected) (GGVOC), Gumboro Vaccine alone Ocular (infected) (GVOC), Gums alone Ocular (infected) (GOC), Gums-Gumboro Vaccine Oral (infected) (GGVOR), Gumboro Vaccine alone Oral (infected) (GVOR), Gums alone Oral (infected) (GOR), No-Vaccine-No-Gums (infected) (NVNG/i), and No-Vaccine-No-Gums (not infected) (NVNG). On a weekly basis, 1.5mls of blood were collected from 5 birds and 3 birds euthanized per group for serological analysis and mucosal washings (trachea and intestine) respectively. Data obtained were analyzed and sample to positive ratio calculated. The post 1st vaccination trachea IgG antibody response was moderately higher in the ocular groups than the oral groups. It was also high in the VOC, GVOC, GOC, VOR groups than the GVOR groups. The antibody response (IgG) pre and post 1st vaccination, post 2nd vaccination and post infection from serum, trachea and intestinal washes showed that by week 1 Post 1st vaccination, there was insignificant increase in titer serum response of the gum-vaccine ocular group compared to the vaccine ocular alone while both groups were insignificantly higher than the oral group. Overall, serum titer showed a rapid response with spiked significant response by 48h pi in the gum vaccine groups (especially GVOR), which peaks by day 3 and remains insignificantly higher throughout the day 7 pi compared to vaccine alone groups. In conclusion, use of the mucilage from C. odorata and K. senegalenses in equal proportion has given better enhancement of the response to IBDV vaccination and premise for further investigations for improvement against IBD.


Assuntos
Infecções por Birnaviridae/imunologia , Cedrela/imunologia , Imunidade nas Mucosas/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Meliaceae/imunologia , Doenças das Aves Domésticas/imunologia , Vacinas Virais/imunologia , Animais , Galinhas , Gomas Vegetais , Doenças das Aves Domésticas/virologia , Vacinação , Vacinas Virais/administração & dosagem
10.
J Immunoassay Immunochem ; 38(4): 378-388, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28010157

RESUMO

Immune response of challenged chickens following previous vaccinations with Newcastle disease vaccine using gums from Cedrela odorata and Khaya senegalensis as delivery agent were evaluated. Two hundred and fifty-two one-day old chickens were divided into vaccine-gum oral (GVOR), vaccine-gum ocular (GVOC), vaccine oral (VOR), vaccine ocular (VOC), gum oral (GOR), gum ocular (GOC), No-gum-no-vaccine/challenged (NGNV/C), and No-gum-no-vaccine/unchallenged (NGNV/U) groups. They were vaccinated at days 21 & 42 and challenged at day 84. Trachea and intestinal washings were collected at intervals as well as weekly serum samples. These were analyzed using enzyme-linked immunosorbent assay (ELISA) and haemagglutination inhibition (HI) test for mucosal and systemic IgG response (MA and SA). Statistical analysis was done using Omnibus one-way ANOVA. MA and SA were not different (P > 0.05) post first and second vaccination although gum-vaccine groups were marginally higher post second vaccination. Post Infection (PI), there was an early and sustained spike in both MA and SA for the GV groups especially GVOR (P < 0.05). MA and SA for the Gum alone (especially GOR) groups also spiked PI (P < 0.05). Therefore, phytogenic polymers used could be said to possess immunopotentiating property with a possible induction of immunologic memory mechanism.


Assuntos
Cedrela/química , Sistemas de Liberação de Medicamentos , Meliaceae/química , Doença de Newcastle/imunologia , Vacinas Virais/imunologia , Animais , Galinhas , Portadores de Fármacos/química , Extratos Vegetais/química , Vacinas Virais/administração & dosagem
11.
Mol Phylogenet Evol ; 102: 45-55, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27215942

RESUMO

In the Yungas of Northwestern Argentina, three endangered species of Cedrela (C. angustifolia, C. saltensis, and C. balansae) follow altitudinal gradients of distribution with contact zones between them. We sampled 210 individuals from 20 populations that spanned most of Cedrela's geographical range in the Yungas, and used Amplified Fragment Length Polymorphism (AFLP) markers and DNA sequences of the nuclear Internal Transcribed Spacer (ITS) to investigate hybrid zones. Data analyses employed an array of complementary methods, including principal coordinate analyses, Bayesian clustering analyses, maximum likelihood tree-building, and network techniques. Both nuclear molecular systems - AFLP and ITS - provided insights into the evolutionary history of Cedrela in the Yungas in a congruent manner. We uncovered strong support for the occurrence of natural hybridization between C. balansae and C. saltensis. Additionally, we identified hybrid zones in areas of sympatry (at both the Calilegua National Park and the San Andrés farm) and in transition zones from 820 to 1100meters above sea level (localities of Pintascayo and Acambuco). There was no evidence for hybridization of either C. balansae or C. saltensis with C. angustifolia. The role of hybrid populations in conservation and use of genetic resources in the Yungas were discussed.


Assuntos
Cedrela/genética , Ecossistema , Hibridização Genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Argentina , Teorema de Bayes , Análise por Conglomerados , Bases de Dados Genéticas , Genética Populacional , Geografia , Filogenia , Análise de Componente Principal
12.
Am J Bot ; 103(2): 307-16, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26838366

RESUMO

PREMISE OF THE STUDY: We investigated how genetic diversity is distributed across the range of Cedrela fissilis, a tree species associated with seasonal neotropical forests, to gain insights into competing biogeographic scenarios that explain how disjunct distributions of these forests were shaped. METHODS: A total of 250 samples were sampled from 18 sites across the species' range in Brazil and eastern Bolivia and genotyped with 10 microsatellite loci. An array of complementary methods-F statistics, analyses of molecular variance (AMOVA), and clustering analyses-assessed genetic diversity, population differentiation, and structure. KEY RESULTS: Most of the genetic diversity (82.5%) was partitioned within populations, but about 12% was due to differences among groups of populations on either side of the Cerrado or located within the Cerrado; mean expected heterozygosity and mean observed heterozygosity were 0.821 and 0.704, respectively. The 250 samples were sorted into two Bayesian groups: one group for each side of the Cerrado. The populations showed varying levels of admixture, with the greatest admixture evident in populations located toward central Brazil. CONCLUSIONS: In C. fissilis, genetic diversity is structured according to geography: the Atlantic range and the Chiquitano range each harbor a genealogical lineage. Interfertility and varying levels of admixture between lineages provide strong evidence that the lineages evolved under geographic, but not genetic, isolation. Admixture is of recent origin, owing to population expansion. Cedrela fissilis shares this dual pattern of distribution of genetic diversity with other phylogenetically unrelated taxa that are typically associated with seasonal forests.


Assuntos
Cedrela/crescimento & desenvolvimento , Florestas , Variação Genética , Bolívia , Brasil , Estações do Ano
13.
Rev Biol Trop ; 64(3): 1143-54, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29461789

RESUMO

The determination of favorable light habitat conditions per species and life stage is transcendental, for both ex situ and in situ conservation strategies of endangered forest tree species, and for their utilization as plantation trees. This becomes especially important when planting material is scarce. We studied the multivariate responses in biomass allocation and in gas exchange to light and to CO2 in Cedrela salvadorensis seedlings, grown under similar light conditions as those this species faces in nature. During a period of 135 days, groups of ten seedlings were put under 75, 45, 15 and 3.5 % of full sun exposure obtained with neutral shade cloth, under nursery conditions. A series of biomass allocation variables and detailed gas exchange parameters (photosynthesis response curves to light and to internal carbon concentration) were measured at the end of the growth period in plants of the four treatments. According to the principal component analyses, highest values of gas exchange response were associated with the lower values of biomass allocation traits. These changes can be associated with resource-conservative and resource-acquisitive strategies, where the C. salvadorensis seedlings acclimatize their traits for the exploration and exploitation of light, to high or to dim light environment, respectively. The multivariate analyses also showed that the plants had a high performance at 45 % of light environment. These results suggest that 45 % of light environment was the optimal light habitat of this species at the tested developing stage. Our results have important implications to choose the best natural habitat for a successful establishment of C. salvadorensis. We propose practical considerations for programs of reforestation or reintroduction where this species be involved.


Assuntos
Biomassa , Cedrela/fisiologia , Fotossíntese/fisiologia , Plântula/fisiologia , Luz Solar , Análise de Variância , Florestas , Folhas de Planta/fisiologia , Valores de Referência , Estações do Ano , Especificidade da Espécie , Fatores de Tempo , Clima Tropical
14.
Polim Med ; 46(1): 35-43, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28397417

RESUMO

BACKGROUND: Many excipients used in tableting exhibit some undesirable properties such as poor flow, cohesion and lubricating characteristics, thus necessitating some modification to achieve the desired product. OBJECTIVES: The objective of this study was to enhance the material, flow and compressional properties of Cedrela odorata gum (COG) (Family: Meliaceae) by co-processing with plantain starch (PS) and microcrystalline cellulose (MCC). MATERIAL AND METHODS: The COG was co-processed with PS (or MCC) by physical co-grinding at ratio 1 : 1, 1 : 2 and 1 : 4, and characterized using morphological analysis, swelling index viscosity measurements, particle size analysis and FTIR spectra. The material, flow and compressional properties of the co-processed excipients were also evaluated. Results were analyzed using mean and standard deviation of data. RESULTS: There was a decrease in the degree of agglomeration of COG and a reduction in the size of the powdered gum. The co-processed excipients were more spherical than the native excipients. The COG had the highest viscosity, while MCC and COG : PS (1 : 2) showed the highest and lowest degrees of swelling at 27.0 ± 0.05°C respectively. Water absorption capacity of the component excipients improved with co-processing COG : MCC increasing from 171.8 ± 1.54 (1 : 1) to 214.8 ± 1.07 (1 : 2), while COG : PS increased from 95.2 ± 0.08 (1 : 1) to 206.2 ± 0.13. There was a decrease in the percentage solubility of the co-processed excipients with the highest and lowest solubility observed in COG (54.1 ± 0.07%) and PS (3.7 ± 0.16%), respectively. The FTIR spectra indicate no significant interaction between the excipients. The poor flow of the component excipients did not improve with co-processing; however, there was a significant increase in compressibility. Generally, COG co-processed with MCC showed better compression properties when compared with COG co-processed with PS. CONCLUSIONS: Co-processing of COD with MC or PS enhanced the characters of the component excipients, thus making the co-processed excipients suitable for direct compression of tablets without altering the chemical nature of the component excipients.


Assuntos
Química Farmacêutica , Excipientes/química , Gomas Vegetais/química , Amido/química , Comprimidos/química , Cedrela/química , Tamanho da Partícula , Plantago/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
15.
Proc Natl Acad Sci U S A ; 109(42): 16957-62, 2012 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-23027960

RESUMO

We present a unique proxy for the reconstruction of variation in precipitation over the Amazon: oxygen isotope ratios in annual rings in tropical cedar (Cedrela odorata). A century-long record from northern Bolivia shows that tree rings preserve the signal of oxygen isotopes in precipitation during the wet season, with weaker influences of temperature and vapor pressure. Tree ring δ(18)O correlates strongly with δ(18)O in precipitation from distant stations in the center and west of the basin, and with Andean ice core δ(18)O showing that the signal is coherent over large areas. The signal correlates most strongly with basin-wide precipitation and Amazon river discharge. We attribute the strength of this (negative) correlation mainly to the cumulative rainout processes of oxygen isotopes (Rayleigh distillation) in air parcels during westward transport across the basin. We further find a clear signature of the El Niño-Southern Oscillation (ENSO) in the record, with strong ENSO influences over recent decades, but weaker influence from 1925 to 1975 indicating decadal scale variation in the controls on the hydrological cycle. The record exhibits a significant increase in δ(18)O over the 20th century consistent with increases in Andean δ(18)O ice core and lake records, which we tentatively attribute to increased water vapor transport into the basin. Taking these data together, our record reveals a fresh path to diagnose and improve our understanding of variation and trends of the hydrological cycle of the world's largest river catchment.


Assuntos
Cedrela/química , Clima , El Niño Oscilação Sul , Isótopos de Oxigênio/análise , Caules de Planta/química , Chuva/química , Bolívia , Fatores de Tempo
16.
An Acad Bras Cienc ; 86(3): 1273-86, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25140505

RESUMO

This work aimed to characterize the re-induction of desiccation tolerance (DT) in germinated seeds, using polyethylene glycol (PEG 8000). Cell changes were investigated through cytological assays (cell viability and transmission electronic microscopy) as well as DNA integrity during loss and re-establishment of DT. The loss of DT was characterized by drying germinated seeds with different radicle lengths (1, 2, 3, 4 and 5 mm) in silica gel, decreasing the moisture content to ten percentage points intervals, followed by pre-humidification (100% RH / 24 h) and rehydration. To re-induce DT, germinated seeds were treated for 72 h with PEG (-2.04 MPa) and PEG (-2.04 MPa) + ABA (100 µM) before dehydration. Germinated seeds did not tolerate desiccation to 10% moisture content, irrespectively of the radicle length. However, when incubated in PEG, those with 1 and 2 mm long radicle attained 71% and 29% survival, respectively. The PEG+ABA treatment was efficient to re-establish DT in seeds with 1 mm long radicles (100% survival). The ultrastructural assays of the cells of germinated seeds with 2 and 5 mm length confirmed the obtained physiological results. Germinated seeds of C. fissilis constitute a useful tool for desiccation tolerance investigations.


Assuntos
Cedrela/crescimento & desenvolvimento , Dessecação , Germinação/fisiologia , Sementes/fisiologia , Adaptação Fisiológica/fisiologia , Cedrela/fisiologia , Cedrela/ultraestrutura , Microscopia Eletrônica de Varredura , Polietilenoglicóis , Sementes/ultraestrutura , Fatores de Tempo
17.
J Asian Nat Prod Res ; 16(7): 709-16, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24841003

RESUMO

Two new apotirucallane-type triterpenoids, cedrodorols A-B (1 and 2), along with seven known compounds (3-9), were isolated from the twigs and leaves of Cedrela odorata. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compounds 1 and 2 showed significant inhibitory activity against protein tyrosine phosphatase 1B (PTP1B) with the IC50 values of 13.09 and 3.93 µg/ml, respectively.


Assuntos
Cedrela/química , Medicamentos de Ervas Chinesas/isolamento & purificação , Medicamentos de Ervas Chinesas/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/antagonistas & inibidores , Triterpenos/isolamento & purificação , Triterpenos/farmacologia , Medicamentos de Ervas Chinesas/química , Concentração Inibidora 50 , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Folhas de Planta/química , Caules de Planta/química , Triterpenos/química
18.
Rev Biol Trop ; 62(2): 783-93, 2014 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-25102658

RESUMO

Despite the progress made during the past 20 years, searching dendrochronological potential in tropical and subtropical tree species, tropical dendrochronology, is still in a development stage. The aim of this research was to determine the potential of C. odorata for dendrochronological studies in the Selva Central of Perú. The tree-ring anatomical characteristics were carefully examined and we were able to develop a 215 year (1795-2 009) tree-ring chronology and correlate it with precipitation records. The tree-ring chronology was developed based on 47 series of 27 trees. Tree rings are clearly delimited by large pore diameters in earlywood and small ones in latewood associated with marginal and paratracheal parenchyma. The tree-ring chronology was related to precipitation records from Satipo and significant correlations were found with the previous rainy season and late dry season of the current growth period. Moreover, we found close relationship between tree growth and total precipitations of the hydrological period (December to September) for the interval 1990-2009. These results demonstrate the influence of rainfall at different stages of C. odorata radial growth. The good discrimination of annual rings, strong relationship with precipitation, the wide range and longevity of trees (200 years) make C. odorata a very promising species for dendrochronological studies in tropical and subtropical forest of America.


Assuntos
Cedrela/crescimento & desenvolvimento , Chuva , Árvores/crescimento & desenvolvimento , Peru , Estações do Ano , Clima Tropical , Madeira/anatomia & histologia
19.
Pak J Pharm Sci ; 27(5 Spec no): 1477-82, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25176241

RESUMO

Phytochemical studies of medicinal plants are a basic and helping tool for the isolation of active secondary metabolites. The isolation of active compounds is made easy by the help of preliminary phytochemical studies, which shows the presence of a specific class or group of compounds present in these medicinal plants. Ziziphus oxyphylla and Cedrela serrata are medicinal plants with valuable local uses. The present study is for the first Phytochemical investigation of these two medicinal plants which consists of, Quantitative tests showing very good results except Ziziphus oxyphylla plants which does not showed the results for Ester value and Peroxide value. Color reactions are studied for all the crude extracts showing the presence of a number of chemical groups belonging to the class of Alkaloids, Phenol compounds, Phenothiazines, Aromatic compounds, Amino acids, Sulfur compounds etc. Brine shrimp activity was performed which showed a LD50 value of 45.74 and 53.36 in the case of Ziziphus oxyphylla roots and Cedrela serrata bark respectively, which is comparable to the standard drug Cyclophosphamide results of 16.09. Insecticidal activity did not show any promising result indicating the absence of any insect killing potency. Antioxidant activity was very positive for all the extract particularly, the Ziziphus oxyphylla roots, which showed even better results than the standard drug Ascorbic acid used in various dilutions.


Assuntos
Antioxidantes/química , Cedrela , Preparações de Plantas/química , Ziziphus , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/toxicidade , Artemia/efeitos dos fármacos , Compostos de Bifenilo/química , Cedrela/química , Cor , Dose Letal Mediana , Fitoterapia , Picratos/química , Casca de Planta , Folhas de Planta , Preparações de Plantas/isolamento & purificação , Preparações de Plantas/toxicidade , Raízes de Plantas , Plantas Medicinais , Tribolium/efeitos dos fármacos , Ziziphus/química
20.
Am J Bot ; 100(9): 1800-10, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24018859

RESUMO

PREMISE OF THE STUDY: Climatic and geological changes have been considered as major drivers of biological diversification. However, it has been generally assumed that lineages retain common environmental affinities, suggesting a limited capacity to switch their climatic niche. We tested this assumption with a study of the evolution of climatic niches in the Neotropical tree genus Cedrela (Meliaceae). • METHODS: We combined distribution models of extant Cedrela with a dated molecular phylogeny based on one nuclear (ITS) and three plastid markers (psbA-trnH, trnS-G and psbB-T-N) to reconstruct the evolutionary dynamics of climatic niches. We calculated relative disparity of climatic tolerances over time to test for niche evolution within subclades or divergence between subclades and conservatism among closely related groups. Published fossil records and studies on paleosols were evaluated for the distribution and climatic conditions of extinct Cedrela. • KEY RESULTS: The fossil record of Cedrela suggested a major biome shift from paratropical conditions into warm-temperate seasonal climates in the Early Oligocene of western North America. In the Miocene, Cedrela extended from North America (John Day Formation, Oregon, USA) to southern Central America (Gatún, Panama). Diversification in the early evolutionary history was mainly driven by changes in precipitation. Temperature had an increasing impact on ecological diversification of the genus from the Miocene onwards. Sister-species comparisons revealed that recent speciation events may be related to divergence of climatic tolerances. • CONCLUSIONS: Our study highlights the complexity of climatic niche dynamics, and shows how conservatism and evolution have acted on different temporal scales and climatic parameters in Cedrela.


Assuntos
Cedrela/genética , Especiação Genética , Sequência de Bases , América Central , Clima , DNA Intergênico/química , DNA Intergênico/genética , DNA de Plantas/química , DNA de Plantas/genética , Fósseis , Dados de Sequência Molecular , Filogenia , Plastídeos/genética , Análise de Sequência de DNA , América do Sul , Especificidade da Espécie , Fatores de Tempo
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