Abstract Flavonoids belong to the extensive group of polyphenols and have several biological activities such as anti-inflammatory, anti-ulcer, anticancer, antiviral, antibacterial, and antispasmodic. These compounds can thus be explored as a tool against multidrug resistant bacteria, as nosocomial infections now constitute a major public health problem worldwide. We have carried out a structural characterization by nuclear magnetic resonance and FT-IR of fisetinidol, a flavonoid isolated from B. pentandra stems. In addition, this flavonoid was tested for antibacterial and modulatory activities, as well as inhibition of the NorA efflux pump. Fisetinidol has no intrinsic antibacterial activity. However, there is synergism in association with norfloxacin, with a two-fold decrease in MIC. When compared to chlorpromazine, a standard efflux pump inhibitor, a two-fold decrease in MIC was also verified when used against S. aureus SA-1199B, which over expresses the NorA gene encoding the NorA efflux protein. As such, it could become an alternative source to reverse the bacterial resistance if administered in association with antibiotics.

中文翻译：

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黄酮类漆黄酮的结构表征、抗菌活性和 NorA 外排泵抑制

摘要 黄酮类化合物属于广泛的多酚类化合物，具有抗炎、抗溃疡、抗癌、抗病毒、抗菌、解痉等多种生物学活性。因此，可以探索这些化合物作为对抗多药耐药细菌的工具，因为医院感染现在构成了世界范围内的主要公共卫生问题。我们已经通过核磁共振和 FT-IR 对 fisetinidol 进行了结构表征，fisetinidol 是一种从 B. pentandra 茎中分离出来的黄酮类化合物。此外，还测试了这种黄酮类化合物的抗菌和调节活性，以及​​对 NorA 外排泵的抑制作用。非塞替尼醇没有内在的抗菌活性。然而，与诺氟沙星相关有协同作用，MIC 降低两倍。与氯丙嗪相比，作为一种标准的外排泵抑制剂，当针对金黄色葡萄球菌 SA-1199B 使用时，也证实了 MIC 降低了两倍，该 SA-1199B 过表达编码 NorA 外排蛋白的 NorA 基因。因此，如果与抗生素联合使用，它可能成为逆转细菌耐药性的替代来源。