Background: The MAO enzyme is presented in the brain and peripheral tissues and is a significant enzyme that is responsible for the deamination of biogenic amines and thus the regulation of neurotransmitter levels. The reaction of these neurotransmitters with the MAO enzyme produces aldehyde and free amine. MAO enzyme consists of two isoforms, MAO-A and MAO-B, which are characterized by amino acid sequence, three-dimensional structure, substrate preference, and inhibitor selectivity. Dopamine, tyramine, and tryptamine are substrates of both MAO isoforms and MAO inhibitors such as clorgiline and selegiline, which are used as medications in neurodegenerative and neurological diseases. In particular, MAO-A inhibitors are used in the treatment of depression, while MAO-B inhibitors are used in the treatment of Parkinson's disease. It is also investigated whether MAO-B inhibitors are effective in the treatment of Alzheimer's disease. Nowadays, life expectancy has increased, as a result, neurodegenerative diseases such as Parkinson's and Alzheimer's disease have started to occur more frequently. The elderly population is increasing day by day. As a result of these common diseases in elderly people, these people are unable to do their jobs and need care. Therefore, these diseases have become a significant health problem in society.

Methods: In this study, review, inclusion, and exclusion criteria were used. Peer-reviewed research articles were searched. The quality of the examined articles was evaluated with standard tools. The information obtained was analyzed conceptually by using qualitative content analysis methodology.

Results: One hundred and five papers were included in the review. The current MAO-B inhibitors and their usage areas are discussed together with the structures of the drugs; also, their possible effects in Alzheimer’s and Parkinson’s treatment are evaluated. In addition, different articles have been compiled in which structures such as arylalkylamines, chalcones, benzoquinone, benzoxazinone, and chromen are substituted with various functional groups and aromatic rings, along with thestructures of 44 different compounds that have recently been developed and their inhibitory effects on MAO-B enzyme. As a result, the structure required for MAO-B inhibition and SAR studies is discussed.

Conclusion: Many studies demonstrate that MAO-B activity increases with age in brain tissue, cerebrospinal fluid (CSF), and platelets in Alzheimer's patients. This suggests that MAO-B inhibitor drugs, which may be effective in the treatment of Parkinson's disease, may also be effective in the treatment of Alzheimer's disease. This article was written to explain the multifaceted MAO-B inhibitor molecules.

背景：MAO 酶存在于大脑和外周组织中，是一种重要的酶，负责生物胺的脱氨基作用，从而调节神经递质水平。这些神经递质与 MAO 酶的反应产生醛和游离胺。MAO 酶由 MAO-A 和 MAO-B 两种异构体组成，具有氨基酸序列、三维结构、底物偏好和抑制剂选择性等特点。多巴胺、酪胺和色胺是 MAO 同种型和 MAO 抑制剂（如克乐吉兰和司来吉兰）的底物，可用作神经退行性疾病和神经系统疾病的药物。具体而言，MAO-A抑制剂用于治疗抑郁症，而MAO-B抑制剂用于治疗帕金森病。还研究了 MAO-B 抑制剂是否有效治疗阿尔茨海默病。如今，预期寿命增加了，因此，帕金森氏症和阿尔茨海默氏症等神经退行性疾病开始更加频繁地发生。老年人口日益增多。由于老年人的这些常见疾病，这些人无法完成工作并需要护理。因此，这些疾病已成为社会的重大健康问题。由于老年人的这些常见疾病，这些人无法完成工作并需要护理。因此，这些疾病已成为社会的重大健康问题。由于老年人的这些常见疾病，这些人无法完成工作并需要护理。因此，这些疾病已成为社会的重大健康问题。

方法：在本研究中，使用了审查、纳入和排除标准。搜索了同行评议的研究文章。使用标准工具评估检查文章的质量。使用定性内容分析方法对获得的信息进行概念分析。

结果：105篇论文被纳入审查。结合药物结构，讨论了目前的MAO-B抑制剂及其应用领域；此外，还评估了它们在阿尔茨海默氏症和帕金森氏症治疗中可能产生的影响。此外，还汇编了不同的文章，其中芳烷基胺、查耳酮、苯醌、苯并恶嗪酮和色烯等结构被各种官能团和芳环取代，以及最近开发的44种不同化合物的结构及其抑制作用。 MAO-B酶。因此，讨论了 MAO-B 抑制和 SAR 研究所需的结构。

结论：许多研究表明，阿尔茨海默病患者的脑组织、脑脊液 (CSF) 和血小板中的 MAO-B 活性随着年龄的增长而增加。这表明可能对治疗帕金森病有效的MAO-B抑制剂药物也可能对治疗阿尔茨海默病有效。本文旨在解释多方面的 MAO-B 抑制剂分子。