ABSTRACT
Objective: To study the chemical constituents from the inflorescence bracts of Arctii Fructus. Methods: The compounds were isolated and purified by the methods of silica gel column chromatography, HPLC, and recrystallization, and the structures were elucidated by the means of spectral analysis. Results: Twelve compounds were isolated and identified as daucosterol (1), isofouquierol (2), (22E)-5α, 8-epidioxyergosta-6, 22-dien-3β-ol (3), 3β-hydroxy-21, 22-epoxyursa-20(30)-en (4), 3β, 21β-dihydroxy-20(30)-en-taraxastane (5), oleanolic acid (6), arctigenin (7), carthamogenin (8), caffeic acid (9), 4(14)-eudesmene-8α, 11-diol (10), monogynol A (11), and lupeol (12). Conclusion; Compounds 2-3, 5, 6, 10-11 are obtained from the plants of Arctium L. for the first time, and compound 12 is isolated from the inflorescence bracts of Arctii Fructus for the first time.
ABSTRACT
Mapania belongs to Mapanioideae, a quite controversial subfamily in Cyperaceae due to the existence of unusual characters in both reproductive and vegetative organs. The genus is represented by seven species in Northern Brazil but taxonomic valuable information related to the leaf organs is still unknown. The present study aimed the anatomical description of the leaf organs (either basal leaves or cataphylls and involucral bracts) of three representative Brazilian species of Mapania. Samples of cataphylls, basal leaves and involucral bracts were sectioned and stained for observations under light microscopy. The involucral bracts provide the most elucidative characters (ten) to distinguish the three species The basal leaves provides six distinguishing characters and are useful to M. macrophylla and M. pycnostachya, as they are absent in M. sylvatica. Mesophyll arrangement in the involucral bracts supports the circumscription of M. macrophylla and M. pycnostachya in M. sect. Pycnocephala and of M. sylvatica in M. sect. Mapania. Some features as thin-walled epidermal cells, stomata level and aerenchyma were considered to be adaptive to the humid environment in which the species occur. The translucent cells are here considered as aerenchyma precursors and a supportive function is assumed for the bulliform cells on the basal leaves and involucral bracts. No silica bodies were found which confirm it as a diagnostic character of Mapania among Hypolytreae genera.
Mapania pertence à subfamília Mapanioideae que apresenta caracteres incomuns às demais Cyperaceae, tanto vegetativos como reprodutivos. O gênero é representado por sete espécies no norte do Brasil e apresenta ainda lacunas de informações especialmente relacionadas aos órgãos foliares. O presente estudo objetivou a descrição anatômica dos órgãos foliares (folhas basais, ou catafilos, e brácteas involucrais) de três espécies representativas de Mapania no território brasileiro. Amostras de catafilos, folhas basais e brácteas involucrais foram seccionadas e coradas para observações em microscopia de luz. As brácteas involucrais foram as mais elucidativas na separação das espécies, com dez caracteres variáveis, uma vez que ocorrem em todas as espécies durante o estágio reprodutivo. As folhas basais forneceram seis caracteres úteis na distinção de M. macrophylla e M. pycnostachya, já que não ocorrem em M. sylvatica. seguidas das folhas basais. O arranjo do mesofilo das brácteas involucrais suporta a circunscrição de M. macrophylla e M. pycnostachya em M. sect. Pycnocephala e de M. sylvatica em M. sect. Mapania. Características adaptativas ao ambiente úmido também foram encontradas, como epiderme com paredes delgadas, níveis dos estômatos e presença de aerênquima. As células translúcidas do mesofilo foram descritas como precursoras de aerênquima e considerou-se que as células buliformes presentes nas folhas e brácteas involucrais apresentam função de suporte desses órgãos. Corpos silicosos não foram encontrados sustentando o seu uso na delimitação de Mapania e dos demais gêneros de Hypolytreae.
ABSTRACT
Members of the genus Passiflora are reported to have evolved modifications which kill insects; they have however never been tested for carnivorous syndrome. The flowers of Passiflora foetida consists of highly reticulate bracts which cover and grow along with the buds and fruits. Removal of bracts from developing bud and fruit resulted in higher predatory damage compared to those where the bracts were intact. These bracts also possess a large number of minute glands which ooze sticky secretion. A variety of tiny insects were found trapped by the secretion of the bracts. The secretion of these glands show high proteases and acid phosphatase activity, two common digestive enzymes found in traps of true carnivorous plants. A high quantity of aminoacids were released from freshly freeze killed ants when incubated in buffer extract of bracts· [14C] phenylalanine smeared on the glandular surface of bracts was recovered from ovules suggesting potential for absorption of aminoacids. These results suggest a novel role for bracts where primary function is to minimize predatory damage to developing flowers and fruits. The bracts serve as insect traps and also possess the mechanism to digest the trapped insects to obtain free aminoacids.