
A novel alkaloid isolated from Crotalaria paulina and identified by NMR and DFT calculations
2017; Elsevier BV; Volume: 1152; Linguagem: Inglês
10.1016/j.molstruc.2017.09.065
ISSN1872-8014
AutoresRamon Prata Oliveira, Antônio J. Demuner, Elson S. Alvarenga, Luiz C. A. Barbosa, Thiago de Melo Silva,
Tópico(s)Plant Toxicity and Pharmacological Properties
ResumoPyrrolizidine alkaloids (PAs) are secondary metabolites found in Crotalaria genus and are known to have several biological activities. A novel macrocycle bislactone alkaloid, coined ethylcrotaline, was isolated and purified from the aerial parts of Crotalaria paulina. The novel macrocycle was identified with the aid of high resolution mass spectrometry and advanced nuclear magnetic resonance techniques. The relative stereochemistry of the alkaloid was defined by comparing the calculated quantum mechanical hydrogen and carbon chemical shifts of eight candidate structures with the experimental NMR data. The best fit between the eight candidate structures and the experimental NMR chemical shifts was defined by the DP4 statistical analyses and the Mean Absolute Error (MAE) calculations.
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