Series of novel amides of isoferulic acid, where the phenolic hydroxyl was replaced by a difluoromethyl group, were synthesized and their in vitro antibacterial activities assayed against fourteen bacterial strains (six Gram-positive and eight Gram-negative). A one-pot methodology was developed to obtain the 3′-(difluoromethyl)-4′-methoxycinnamoyl amides using Deoxofluor® as a fluorinating agent. The N-isopropyl, N-isopentyl, and N-(2-phenylethyl) amides 11b, 11d and 11g were the most active and selective against Mycobacterium smegmatis (MIC = 8 µg/mL) with 11b and 11g displaying negligible or no cytotoxicity against HepG2 and A549 cells. Thirteen analogs of N-isopropylamide 11b were also synthesized and their antibacterial activity assayed. Results show that the difluoromethyl moiety enhanced antibacterial activity and selectivity towards M. smegmatis, changing the microorganism inhibition profile of the parent compound. The selectivity exhibited by some of the compounds towards M. smegmatis makes them potential leads in the search for new narrow spectrum antibiotics against M. tuberculosis.
通过取代酚羟基为二氟甲基基团,合成了一系列异麦芽酸新酰胺,并对其进行了体外抗菌活性测试,针对十四种细菌菌株(六种革兰氏阳性和八种革兰氏阴性)。开发了一种一锅法,利用Deoxofluor®作为氟化试剂,获得了3′-(二氟甲基)-4′-甲氧基肉桂酰胺。N-异丙基、N-异戊基和N-(2-苯乙基)酰胺11b、11d和11g对斯米格马分枝杆菌(MIC = 8 µg/mL)具有最高活性和选择性,其中11b和11g对HepG2和A549细胞几乎没有细胞毒性或无细胞毒性。还合成了N-异丙基酰胺11b的十三个类似物,并对其抗菌活性进行了测试。结果显示,二氟甲基基团增强了抗菌活性,并增加了对斯米格马分枝杆菌的选择性,改变了母体化合物的微生物抑制谱。一些化合物对斯米格马分枝杆菌表现出的选择性使它们成为在寻找针对结核分枝杆菌的新窄谱抗生素的潜在引物。