Recent studies have revealed that there is a close relationship between neuroinflammation and Alzheimer's disease (AD) and compounds with anti-neuroinflammatory effects are potentially useful for the treatment of AD. A phytochemical investigation to obtain new neuroinflammatory inhibitors resulted in the isolation of four new and three known limonoids from Swietenia mahagoni. The structures of these limonoids were established by NMR, MS, and electronic circular dichroism (ECD) data analysis. Compounds 1-3 feature complicated polycyclic caged structures of limonoid orthoester and represent new examples of phragmalin-type limonoids. All of the isolates showed anti-neuroinflammatory activities by inhibiting nitric oxide (NO) release in LPS-induced murine microglial BV-2 cells with compounds 1 and 3-6 having IC50 values of 26.8, 26.1, 26.0, 37.1, and 16.5 μM, respectively. The possible mechanism of NO inhibition of some bioactive compounds was also investigated using molecular docking, which revealed the interactions of bioactive compounds with the inducible nitric oxide synthase (iNOS) protein.

中文翻译：

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一氧化氮抑制类柠檬酸类化合物可能是来自Swietenia mahagoni的潜在抗神经炎药。

最近的研究表明，神经炎症与阿尔茨海默氏病（AD）之间存在密切的关系，具有抗神经炎症作用的化合物可能可用于治疗AD。为了获得新的神经炎性抑制剂而进行的植物化学研究导致从马氏Swietenia中分离出四个新的和三个已知的柠檬苦素。这些柠檬苦素的结构是通过NMR，MS和电子圆二色性（ECD）数据分析建立的。化合物1-3具有柠檬苦素原酸酯的复杂多环笼状结构，并代表了芦丁类柠檬苦素的新实例。所有分离物均通过抑制LPS诱导的鼠小胶质BV-2细胞中一氧化氮（NO）的释放而显示抗神经炎活性，化合物1和3-6的IC50值分别为26.8、26.1、26.0、37.1，和16.5μM。还使用分子对接研究了某些生物活性化合物对NO抑制的可能机制，这揭示了生物活性化合物与诱导型一氧化氮合酶（iNOS）蛋白之间的相互作用。