Abstract: This study aims to identify phenolic compounds in dichloromethane and methanolic extracts of the rhizome of Renealmia nicolaioides collected in the North Region of Brazil. Two known diarylheptanoids, 1,7-bis(4-hydroxyphenyl)-(1E)-1-hepten-3-one (1), and 5R-1,7-bis(4-hydroxyphenyl)-1E-hepten-5-ol (2), and a new one (1R,2S,5S)-2-hydroxy-1,7(p-hydroxyphenyl)-centrolobine (3), as well as one flavonoid, 3-metoxi-quercetin (4) were isolated by chromatographic procedure and identified by spectroscopic techniques (1H and13C NMR, HRMS and CD). The acetyl derivative of 2 was used to confirm its structure. All four compounds are reported for the first time for this genus, and this is the first occurrence of compound 1 as a natural metabolite. The results reported here are unprecedented for the genus Renealmia.

Este trabalho objetiva caracterizar a estrutura anatômica do lenho de Mollinedia glabra, ocorrente em duas formações vegetais contíguas na restinga da Praia Virgem, município de Rio das Ostras, RJ. Essas formações Arbustiva Aberta de Pal-mae (AAP) e Arbustiva Fechada do Cordão Arenoso (AFCA) estão sobre cordão arenoso e recebem precipitações anuais de 1.100-1.300 mm. Foram obtidas amostras do lenho das duas forações. São características anatôicas gerais da espécie: elementos de vasos solitários, em arranjos radiais ou cachos, de seção de circular a angular; placa de perfuração es-calariforme, com 5-15 barras; parênquima axial escasso; fibro-traqueídes septadas e raios multisseriados largos, com cristais prismáticos. A análise estatística evidenciou aumento significativo na frequência dos elementos de vasos e aumento no diâmetro das fibrotraqueídes nos indivíduos de AAP. Essas características são consideradas adaptações estruturais ao aumento da necessidade de água causada por maior exposição à luz solar. A realização de podas frequentes pode ter relação com a formação de tilos nesses indivíduos. O aumento significativo no comprimento e frequência de raios podem representar uma resposta ao maior diâmetro dos indivíduos em AFCA. Os resultados obtidos sugerem que M. glabra desenvolve adaptações estruturais às variações micro-ambientais da restinga durante seu desenvolvimento.

This paper aimed to characterize the anatomical structure of the wood of specimens of Mollinedia glabra (Spreng.) Perkins growing in two contiguous formations of restinga vegetation at Praia Virgem, in the municipality of Rio das Ostras, RJ. Both the Open Palmae (OPS) and the Sandy Strip Closed Shrub (SSCS) formations are found in coastal regions that receive between 1,100 and 1,300 mm of rainfall per year. Sapwood samples were collected in both formations. Typical anatomical features for this species include: solitary vessels, radial multiples or clusters elements, that are circular to angular in outline, 5-15 barred scalarifor perforation plates, ood parenchya scanty, septate fiber-tracheids, and wide multiseriate rays with prismatic crystals. Statistical analyses indicated a significant increase in the frequency of vessel elements and an increase in fiber-tracheid diameters in OPS individuals. These characteristics are considered structural adaptations to increased water needs caused by a greater exposure to sunlight. Continuous pruning may be responsible for the tyloses observed in OPS plants. The greater lengths and higher frequencies of the rays in SSCS trees ay be due to the greater diaeters of their branches. ur results suggest that . glabra develops structural adaptations to the restinga micro-environmental variations during its development.