Abstract The present work aimed to isolate secondary metabolites from Myrcia insularis Gardner (Myrtaceae) wood and to evaluate the anti-Candida activity and further extracts obtained by partition and the respective main isolated compounds. Wood was collected in a Seasonal Semideciduous Forest remnant of the Atlantic Forest of northern Rio de Janeiro State, Brazil. Chromatographic and spectrographic techniques were used to isolate and identify secondary metabolites. Methanol extract inhibited the growth of Candida buinensis and Candida tropicalis, with inhibition being approximately 82% for the latter. The main compound isolated from the ethyl acetate partitions was arjunolic acid, a triterpene. The antimicrobial activity was first observed with the wood metabolites of M. insularis adds to our understanding of the antifungal properties of this species and other species within the Myrtaceae family, including the presence of arjunolic acid, which may play a role in this activity.

ABSTRACT Secretory structures are formed by many types of plants and are present on numerous different organs. Among the many types of known secretory structures, colleters are predominant on plants of the Rubiaceae. One remarkable characteristic of secretory tissues is the export of exudates; however, the precise mechanism involved in this process is still unclear. To better understand the mechanisms of exudate externalization it is necessary to understand the ultrastructure and dynamics of the outer cell wall of the secretory structures during the secretory process, and so we investigated these aspects of the colleters of Bathysa nicholsonii. The outer cell wall (OCW) exhibits multiple layers: a basal polysaccharide rich layer; a cuticular membrane, which is subdivided into arborescent and reticulated layers; and a thin cuticle proper. The structural organization of the OCW is changed during secretion passage, which is mainly related to the development of a secretion accumulation site on the polysaccharide rich layer. Secretion dynamics is driven by the organization and disruption of the secretion accumulation site. The results show that the OCW of the colleters of B. nicholsonii is a dynamic structure with an active role in secretion externalization via constant structural reorganization directly related to secretion passage.

Pachystroma longifolium é uma espécie perenifólia de Euphorbiaceae presente na floresta de tabuleiros, uma formação de floresta estacional semidecidual de terras baixas da Mata Atlântica. A área de estudo é um fragmento de floresta de tabuleiros com histórico de corte seletivo de madeira, na qual P. longifolium apresenta grande sucesso na colonização de áreas perturbadas em comparação com outras áreas mais preservadas dentro deste fragmento. No presente trabalho nós caracterizamos a estrutura foliar e látex de P. longifolium e sua importância como mecanismos de defesa contra dessecação e herbivoria a partir de diferentes técnicas de microscopia (microscopia eletrônica, microanálise e microscopia óptica) e bioquímicas. Nossos resultados sugerem que a riqueza de P. longifolium, nas áreas perturbadas do estudo, é primariamente em conseqüência de folhas impalatáveis devido à abundância de cristais de oxalato de cálcio no tecido parenquimático subjacente a epiderme; presença de compostos fenólicos na face adaxial da epiderme; um sistema laticífero contendo uma mistura de proteínas, a qual confere resistência aos herbívoros. Adicionalmente, esta espécie apresenta resistência à dessecação durante os períodos de seca devido a uma extensa camada lipídica na parede periclinal externa da epiderme, e a habilidade de reter água propiciada pela epiderme bisseriada.

Pachystroma longifolium is an evergreen species of Euphorbiaceae that occurs in tabuleiro forest, a type of lowland Atlantic Forest. The site chosen for this study was a fragment of tabuleiro forest that has a history of being selectively logged for timber. P. longifolium is very successful at colonizing disturbed areas in this forest fragment in comparison with preserved fragments. In the present work, which was based on using different microscopy (electron and light microscopy, X-ray analysis) and biochemistry techniques, we describe the leaf and latex traits of P. longifolium and their role as defense mechanisms against desiccation and herbivory. Our results suggest the richness of P. longifolium populations, in the disturbed forest area studied, is primarily a consequence of unpalatable leaves because of an abundance of calcium oxalate crystals in the subjacent epidermis; the presence of phenolic compounds in the adaxial surface; and a laticifer system that contains a complex mixture of proteins, which provides resistance to herbivores. In addition, this species is resistant to desiccation during dry periods because of an extensive amount of wax that occurs on the outer cell walls of the epidermis, and its ability to retain water because of a biseriate epidermis.

Simira is a predominantly woody Neotropical genus comprising 41 taxa, 16 of which occur in Brazil and eight of them in the southeastern region of Brazil. Leaf blades of Simira eliezeriana Peixoto, S. glaziovii (K. Schum.) Steyerm., S. grazielae Peixoto, S. pikia (K. Schum.) Steyerm., S. rubra (Mart.) Steyerm., S. sampaioana (Standl.) Steyerm.were collected in the southeastern region of Brazil and fixed according to usual methods for light and electron microscopy. The leaf blades show typical characteristics of the Rubiaceae family as dorsiventral mesophyll and paracytic stomata. The presence of two bundle sheaths that extend to the upper epidermal layer, prismatic crystal and crystal-sand, alkaloids in the mesophyll and the organization micromorphological of the outer periclinal wall are considered characteristics representative for the genus. This study also demonstrates some leaf blade characteristics that can be used to Simira species identification (leaf surface, domatia types, epicuticular wax types and patterns of epidermis anticlinal cell walls).

Uma fração protéica, rica em lectina, obtida por precipitação com sulfato de amônia (F40/70), da alga marinha vermelha Hypnea musciformis foi avaliada quanto à presença de atividade quitinásica e beta-1,3-glucanásica e potencial antifúngico contra as leveduras patogênicas Candida albicans e C. guilliermondii. A fração F40/70 mostrou ambas as atividades enzimáticas, com atividades específicas de 276,43 e 1880,7 Unidades.mg-1 proteína, respectivamente. Essa fração foi capaz de inibir de forma significativa o crescimento da levedura C. guilliermondii nas concentrações de 45, 100 e 450 µg proteína.ml -1 porém mostrou apenas uma discreta ação contra C. albicans, independente das concentrações testadas. A ação inibitória foi fungistática e a presença da glicoproteína fetuína, para a qual a lectina na fração tem afinidade, aboliu a ação antifúngica. A recuperação completa do crescimento das leveduras após tratamento com fetuína indicou que as atividades quitinásica e beta-1,3-glucanásica não estão envolvidas na inibição do crescimento dessas leveduras.

A protein fraction, rich in lectin, obtained from the red seaweed Hypnea musciformis by precipitation with ammonium sulfate (F40/70) was screened for chitinase and beta-1,3-glucanase activity and assessed for antifungal potential against the human pathogen yeasts Candida albicans and C. guilliermondii. The F40/70 fraction showed chitinase and beta-1,3-glucanase enzymes, with specific activities of 276.43 and 1880.7 Units.mg -1 protein, respectively. It was capable of inhibiting the growth of C. guilliermondii at the concentrations of 45, 100 and 450 µg protein.ml -1 but it showed only a discrete inhibition against C. albicans irrespective of the tested concentrations. The inhibitory action was shown to be fungistatic and the presence of the glycoprotein fetuin, for which the lectin in the fraction had affinity, abolished the antifungal action. The complete growth recovery following fetuin treatment indicated that chitinase and beta-1,3-glucanase were not involved in the growth inhibition of these yeasts.

Uma beta-1,3-glucanase foi purificada a partir da secreção de Simira glaziovii, através de vários processos cromatográficos, tendo a análise do perfil protéico acompanhado de SDS-PAGE. A enzima purificada apresentou uma massa molecular estimada de 35 kDa. O pH ótimo obtido para a enzima foi de 5,2.

In this study, beta-1,3-glucanase was isolated from Simira glaziovii secretion. The purification process was achieved by a combination of chromatographic methods and was analyzed by SDS-PAGE. The purified enzyme presented an estimated molecular mass of 35 kDa. The optimum pH of enzyme was 5.2