RESUMO
Abstract Marine algae have been the focus of important studies over the past fifty years, with a considerable number of components important to chemists and taxonomists having been isolated and characterized. The scientific data available on Sargassum polyceratium are extremely limited. The objective of the present study was to evaluate the antinociceptive activity of an ethanol extract of S. polyceratium and to isolate its components. Intraperitoneal treatment with ethanol extract of S. polyceratium reduced the number of acetic acid-induced writhes and the amount of time spent in paw-licking in the second phase of the formalin test. Ethanol extract of S. polyceratium also reduced the amount of time spent in paw-licking in the glutamate test; however, there was no difference in the reaction time in the hot plate test at any of the doses tested. The chemical components isolated from ethanol extract of S. polyceratium were identified using one- and two-dimensional spectroscopic methods such as infrared spectroscopy, mass spectrometry and 1H and 13C nuclear magnetic resonance spectroscopy. The analytical results were also compared with data obtained in the literature. The following porphyrin derivatives were isolated from S. polyceratium: 132-hydroxy-(132-R)-pheophytin-a, 132-hydroxy-(132-S)-pheophytin-a, pheophytin-a, and the steroid fucosterol. The present results indicate that the ethanol extract of S. polyceratium has antinociceptive activity. In addition, four new substances were isolated from the species evaluated.
RESUMO
Objective To study the molecular recognition of porphyrin compounds with carbohydrate molecular. Methods Fluorescent titration method was developed to explore the porphyrin and its metal porphyrin compounds interaction with carbohydrate compounds. Results The binding constants indicated that porphyrin and its metal compounds involved in this experiment could recognize carbohydrate compounds respectively, and interaction with lactose is stronger than glucose; Comparison with free porphyrin, metal ion Zn~(2+) and Fe~(3+) in the core of porphyrin compounds could enhance the binding capability with carbohydrate. Conclusion Porphyrin compounds has selective molecular recognition abilityto sugar molecular.