Antiplasmodial Metabolites Isolated from the Marine Octocoral <i>Muricea austera</i>
作者:Marcelino Gutiérrez、Todd L. Capson、Héctor M. Guzmán、José González、Eduardo Ortega-Barría、Emilio Quiñoá、Ricardo Riguera
DOI:10.1021/np060007f
日期:2006.10.1
Bioassay-guided fractionation of the MeOH extract from the octocoral Muricea austera collected in the Pacific coast of Panama led to the isolation of eight compounds, including three tyramine derivatives (1-3), two steroidal pregnane glycosides ( 4, 5), and three sesquiterpenoids (6-8). Compounds 2-5 are new natural products, and their structures were determined on the basis of their spectroscopic data (HRMS, 1D and 2D NMR, and CD studies). The antiprotozoal activities of the natural compounds 1-8 as well as those of a series of synthetic glycosides (11-22) and tyramine derivatives (23-35) were evaluated in vitro against a drug-resistant Plasmodium falciparum and intracellular form of Trypanosoma cruzi.
Differential scanning calorimetric studies on the thermotropic phase behavior of dry and hydrated forms of N-acyltyramines
In this paper, a homologous series of N-acyltyramine (NATA) - which is biosynthetic precursor for neuroactive lipids, N-acyldopamine - have been synthesized and their thermotropic phase transitions were characterized by differential scanning calorimetry (DSC). NATA undergoes a major sharp endothermic transition with the melting point of the hydrated samples occurs considerably at lower temperature compared to the dry samples. Thermodynamic parameters, transition enthalpy (Delta H-t) and transition entropy (Delta S-t), associated with the chain-melting phase transitions depends linearly on the number of carbon atoms. The contributions of each methylene unit to the transition enthalpy and entropy and the end contributions arising from the head group and the terminal group was determined and reported. These results are very important to understand the thermodynamics basis of NATA phase properties in other membrane lipids. (C) 2014 Elsevier B.V. All rights reserved.