Synthesis and Antifungal Activity of Derivatives of 2- and 3-Benzofurancarboxylic Acids
作者:Elżbieta Hejchman、Kinga Ostrowska、Dorota Maciejewska、Jerzy Kossakowski、William E. Courchesne
DOI:10.1124/jpet.112.196980
日期:2012.11
We found that amiodarone has potent antifungal activity against a broad range of fungi, potentially defining a new class of antimycotics. Investigations into its molecular mechanisms showed amiodarone mobilized intracellular Ca2+, which is thought to be an important antifungal characteristic of its fungicidal activity. Amiodarone is a synthetic drug based on the benzofuran ring system, which is contained in numerous compounds that are both synthetic and isolated from natural sources with antifungal activity. To define the structural components responsible for antifungal activity, we synthesized a series of benzofuran derivatives and tested them for the inhibition of growth of two pathogenic fungi, Cryptococcus neoformans and Aspergillus fumigatus , to find new compounds with antifungal activity. We found several derivatives that inhibited fungal growth, two of which had significant antifungal activity. We were surprised to find that calcium fluxes in cells treated with these derivatives did not correlate directly with their antifungal effects; however, the derivatives did augment the amiodarone-elicited calcium flux into the cytoplasm. We conclude that antifungal activity of these new compounds includes changes in cytoplasmic calcium concentration. Analyses of these benzofuran derivatives suggest that certain structural features are important for antifungal activity. Antifungal activity drastically increased on converting methyl 7-acetyl-6-hydroxy-3-methyl-2-benzofurancarboxylate ( 2b ) into its dibromo derivative, methyl 7-acetyl-5-bromo-6-hydroxy-3-bromomethyl-2-benzofurancarboxylate ( 4 ).
我们发现,胺碘酮对广泛的真菌具有强效的抗真菌活性,可能定义了一类新的抗真菌药物。对其分子机制的研究显示,胺碘酮能调动细胞内Ca2+,这被认为是其杀菌活性的重要抗真菌特性。胺碘酮是一种基于苯并呋喃环系统的合成药物,该环系统存在于许多既有合成来源又从天然来源分离出的具有抗真菌活性的化合物中。为了确定负责抗真菌活性的结构成分,我们合成了一系列苯并呋喃衍生物,并测试了它们对两种病原真菌——新生隐球菌和烟曲霉的生长抑制作用,以寻找具有抗真菌活性的新化合物。我们发现了几种抑制真菌生长的衍生物,其中两种具有显著的抗真菌活性。我们惊讶地发现,这些衍生物处理细胞中的钙流并不直接与它们的抗真菌效果相关;然而,这些衍生物确实增强了胺碘酮引发的细胞质钙流入。我们得出结论,这些新化合物的抗真菌活性包括细胞质钙浓度的变化。对这些苯并呋喃衍生物的分析表明,某些结构特征对抗真菌活性是重要的。将甲基7-乙酰基-6-羟基-3-甲基-2-苯并呋喃羧酸酯(2b)转化为其二溴衍生物——甲基7-乙酰基-5-溴-6-羟基-3-溴甲基-2-苯并呋喃羧酸酯(4),其抗真菌活性显著增加。