Anti-inflammatory and immune properties of the peltatoside, isolated from the leaves of Annona crassiflora Mart., in a new experimental model zebrafish.

Establishing new animal models for the study of inflammation is very important in the process of discovering new drugs, since the inflammatory event is the basis of many pathological processes. Whereas rodent models have been the primary focus of inflammation research, we defend the zebrafish (Danio rerio) test as a feasible alternative for preclinical studies. Moreover, despite all the technological development already achieved by humanity, nature can still be considered a relevant source of new medicines. In this context, the aim of this work was to evaluate the anti-inflammatory effect of a substance isolated from the medicinal plant Annona crassilfora Mart, the peltatoside, in an inflammatory model of zebrafish. It was determined: (i) total leukocyte count in the coelomate exudate; (ii) N-acetyl-ß-d-glucuronidase (NAG); (iii) myeloperoxidase (MPO); (iv) and the histology of liver, intestine and mesentery. Peltotoside (25, 50 and 100 µg) and dexamethasone (25 µg) were administered intracelomatically (i.c.) 30 min before carrageenan (i.c.). Pretreatment with peltatoside at three doses significantly inhibited leukocyte recruitment in the coelomic cavity, and inhibited NAG and MPO activity against the action of Cg, in a similar manner as dexamethasone. However, some microlesions in the evaluated organs were detected. The dose of 25 µg showed an anti-inflammatory effect with lower undesirable effects in the tissues. Our results suggest that the zebrafish test was satisfactory in performing our analyzes and that the peltotoside has a modulatory action in reducing leukocyte migration.

Aporphine alkaloids and feruloylamides from the bark of Xylopia benthamii R.E. Fries (Annonaceae).

The bark of Xylopia benthamii R.E. Fries was investigated in a search for new bioactive compounds. The ethanolic extract of the air-dried bark of X. benthamii was obtained and submitted to an acidic extraction procedure to obtain an alkaloid mixture. Chromatographic fractionation led to the isolation of two aporphine alkaloids, nornantenine and laurotetanine, and a mixture of trans- and cis-feruloyltyramine, isolated for the first time in this genus. Structures were established by spectroscopic methods as NMR (1D and 2D) and mass spectrometry (ESI-MS).

Avaliação da atividade citotóxica das sementes de Annona cornifolia A. St.-Hil. (Annonaceae) / Evaluation of the cytotoxic activity of seeds of Annona cornifolia A. St.-Hil. (Annonaceae)

Na família Annonaceae, especialmente o gênero Annona é muito apreciado por fornecer frutos comestíveis. Espécies desse gênero são utilizadas na medicina popular contra diabetes, malária e infecções. Muitas dessas atividades biológicas têm sido relacionadas às acetogeninas de anonáceas. O objetivo deste estudo foi avaliar a atividade citotóxica dos grupos e de uma acetogenina pura (cornifolina) obtidos a partir do extrato etanólico das sementes de Annona cornifolia A. St.-Hil. (Annonaceae). Esta atividade foi avaliada pelo ensaio colorimétrico MTT. Cornifolina (1), a única substância pura testada, apresentou citotoxicidade positiva sobre todas as linhagens tumorais avaliadas. Os grupos testados, todos caracterizados por espectroscopia no infravermelho (IV), apresentaram 68,7% dos valores de CI50 menores que 20,0 µg mL-1, sendo também considerados citotóxicos. As amostras testadas foram mais ativas que o taxol sobre melanoma humano (MeWo) e, ainda, o grupo G10-5 apresentou melhor atividade sobre fibroblasto tumorigênico de camundongo (L929). Além disso, os grupos mostraram menor citotoxidade do que o taxol sobre a linhagem normal (CHO).

The family Annonaceae, especially the genus Annona, is greatly appreciated for providing edible fruits. Species of this genus are used in folk medicine against diabetes, malaria and infections. Many of these biological activities have been related to annonaceous acetogenins. The aim of this study was to evaluate the cytotoxic activity of groups and a pure acetogenin (cornifolin) obtained from the ethanol extract of the seeds of Annona cornifolia A. St.-Hil. (Annonaceae). This activity was evaluated by using MTT colorimetric assay. Cornifolin (1), the only tested substance that was pure, showed positive cytotoxicity on all evaluated tumor cell lines. The tested groups, all characterized by infrared spectroscopy (IR), showed 68.7% of the IC50 values lower than 20.0 µg mL-1, also considered cytotoxic. The tested samples were more active than taxol on human melanoma (MeWo) and the group G10-5 showed better activity on mouse tumorigenic fibroblast (L929). In addition, the tested groups showed less cytotoxicity than taxol on the normal line (CHO).

Decarboxylation of oxidized single-wall carbon nanotubes.

A classical protocol widely used in organic chemistry of aromatic and polyaromatic molecules has been successfully applied in this work for the decarboxylation of oxidized single-wall carbon nanotube (SWNT) to rend C-H SWNT derivatives. SWNT produced by arc discharge method have been oxidized during a purification process using strongly oxidant agents, such as hydrogen peroxide and nitric acid. The decarboxylation of oxidized SWNT has been conduced with copper(I) oxide in a 50:50 solution of N-methylpyrrolidone and quinoline. Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and acid-base potentiometric titration analyses were carried out to characterize quali and quantitatively the changes in the chemical environment on the SWNT surface in each step of the purification and the decarboxylation process. Those techniques showed the appearance of mainly carboxylic and phenolic groups after the purification process and the disappearance of the carboxylic groups after the decarboxylation reaction. Fourier transform infrared spectroscopy analysis indicated also the formation of aliphatic and aromatic C-H groups. X-ray photoelectron spectroscopy and potentiometric titration results determined an efficiency higher than 90% for our decarboxylation procedure. The purity and structural quality of the SWNT sample used in the decarboxylation process were evaluated by thermogravimetry and Raman spectroscopy. Thermogravimetric analysis identified a purified sample with approximately 80 wt% of SWNT, in fractions distributed in highly structured SWNTs (25 wt%), with distribution in composition, length and structural quality (35 wt%) and with very defective and short tubes (25 wt%). The damages on the purified SWNT walls were characterized by the Raman scattering analysis.