Evaluation of the antitrypanosoma activity and SAR study of novel LINS03 derivatives
摘要:
Chagas' disease is a parasitic infection caused by Trypanosoma cruzi that is still treated by old and toxic drugs. In the search for novel alternatives, natural sources are an important source for new drug prototypes against T. cruzi to further structural exploitation. A set of natural-based compounds (LINS03) was designed, showing promising antitrypanosoma activity and low cytotoxicity to host cells. In this paper, nine novel LINS03 derivatives were evaluated against T. cruzi trypomastigotes and amastigotes. The selectivity was assessed through cytotoxicity assays using NCTC mammalian cells and calculating the CC50/IC50 ratio. The results showed that compounds 2d and 4c are noteworthy, due their high activity against amastigotes (IC50 13.9 and 5.8 mu M) and low cytotoxicity (CC50 107.7 mu M and > 200 mu M, respectively). These compounds did not showed alteration on plasma membrane permeability in a Sytox green model. SAR analysis suggested an ideal balance between hydrosolubility and lipophilicity is necessary to improve the activity, and that insertion of a meta-substituent is detrimental to the activity of the amine derivatives but not to the neutral derivatives, suggesting different mechanisms of actions. The results presented herein are valuable for designing novel compounds with improved activity and selectivity to be applied in future studies.
Highly Selective Catalytic Intermolecular Reductive Coupling of Alkynes and Aldehydes
作者:Wei-Sheng Huang、Johann Chan、Timothy F. Jamison
DOI:10.1021/ol006781q
日期:2000.12.1
Alkynes (internal and terminal) and aldehydes (aromatic and aliphatic) are reductively coupled in a single catalytic reaction to yield di- and trisubstituted allylic alcohols with high stereoselectivity and regioselectivity. In most cases, a 1:1 ratio of alkyne to aldehyde is sufficient for efficient coupling. The yield and regioselectivity are strongly dependent on the phosphine ligand, but the allylic