细胞色素P450酶（P450s / CYPs）是小分子药物吸收、分布、代谢和排泄（ADME）属性的主要贡献因素，能够介导催化多种反应类型，包括含N、S小分子化合物的代谢。本文通过对294种P450s介导的小分子底物进行统计分析，其中含N、S原子的底物占比超47%。旨在阐明五类反应类型中底物与不同CYP亚型间的广谱交叉性和专一性作用规律。总结发现，分子量大于500 Da和小于200 Da的底物主要受CYP亚型活性空腔的主导性影响；而分子量在200-400 Da范围内的中小分子化合物更多地受其所含杂原子类型的影响，酶催化空腔大小并不是底物特异性的显著决定因素。本综述从P450s介导的含N、S化合物的代谢机制出发，分析了N-脱烷基化反应、N-氧化反应和S-氧化反应的底物结构特征与P450s的代谢作用规律。这些分析为完善现有的P450s底物特异性与底物分子结构性质之间的关系提供了新的视角，也为完善基于P450s催化反应理论体系的药物设计和代谢稳定性预测提供了重要的依据。

Cytochrome P450 enzymes (P450s or CYPs) are the primary metabolic contributors to the absorption, distribution, metabolism, and excretion (ADME) properties of small-molecule drugs. These enzymes can catalyze various types of reactions, including metabolic reactions that occur at nitrogen (N) and sulfur (S) sites of small molecules. In this review, we conducted a comprehensive statistical analysis of 294 P450s-mediated small-molecule substrates, among which more than 47% substrates contained N and S. The purpose of the analysis is to elucidate the broad-spectrum cross-reactivity and specificity between these substrates and various CYP isoforms across five reaction types. Our findings reveal that substrates with molecular weights greater than 500 Da or less than 200 Da are predominantly governed by the dominant effect of the CYP isoform’s active sites. In contrast, small- to medium-sized molecules with molecular weights ranging from 200 to 400 Da exhibit a stronger dependence on the types of heteroatoms they contain, with the size of the enzyme’s catalytic site (cavity) playing a negligible role in determining substrate specificity. This review starts from the metabolic mechanisms of P450s-mediated N- and S-containing compounds, and systematically analyzes the structural characteristics of substrates involved in N-dealkylation, N-oxidation, and S-oxidation, as well as their metabolic interactions with P450s. These analyses provide a new perspective for improving the existing understanding of the relationship between the P450s substrate specificity and substrate structural characteristics, and offer a valuable perspective for enhancing drug design and predicting metabolic stability based on the P450s-catalyzed reaction framework.