随着免疫缺陷人群规模的迅速增长、抗真菌药物的长期使用，以及以耳念珠菌（Candida auris）为代表的多重耐药真菌的持续涌现，真菌感染已演变为一个与高发病率和死亡率以及毁灭性的社会经济后果相关的全球性健康危机。2024年流行病学数据显示，全球每年因侵袭性真菌感染直接导致约250万人死亡，总死亡人数达375万，远超2017年统计的170万人^[1]。

第一部分研究通过整合生物信息学与天然产物化学的研究策略，聚焦于抗真菌化合物生产菌株，建立了基于抗白色念珠菌（Candida albicans）的活性追踪体系，综合运用硅胶柱层析、半制备HPLC等多种分离技术，成功实现了不易检测的抗真菌化合物的靶向分离。从Pseudofabraea citricarpa strain WZH菌株中挖掘具有抗白色念珠菌活性的新颖化合物，分离鉴定了2个fellutamides类化合物，其中化合物1目前未有报道，将其命名为Fellutamide E。后续将对其余化合物进一步纯化、结构鉴定及活性机制探究。

第二部分从真菌Dictyochaeta simplex中分离获得一个新的聚酯类化合物（Dictpolyester A）。通过多种色谱技术结合核磁共振、质谱等波谱学方法解析了其结构特征，发现其含有独特的2,4-二羟基-6-(2-氧代-3-戊烯-1-基)苯甲酸单元。活性评价显示该化合物抗真菌活性有限，但深入分析发现其生物合成途径与抗真菌天然产物阜孢杀酵素（Papulacandins）存在竞争关系。由此，我们设想通过敲除合成该类化合物的核心基因，增加生物合成前体来实现阜孢杀酵素产量的提升。目前已成功建立了该菌的遗传操纵体系，后续将对突变体进行验证，发酵检测阜孢杀酵素的产量。

本研究通过整合天然产物化学、生物信息学和合成生物技术，不仅发现了结构新颖的抗真菌候选分子，更通过基因簇分析为定向改造产抗真菌化合物的生产菌提供了理论依据。我们的研究为开发新一代抗真菌药物提供了重要的物质基础和研究思路，对日益严峻的真菌耐药性挑战具有一定的借鉴意义。

With the rapid expansion of immunocompromised populations, prolonged use of antifungal agents, and the continuous emergence of multidrug-resistant fungi represented by Candida auris, fungal infections have evolved into a global health crisis associated with high morbidity and mortality rates as well as devastating socioeconomic consequences. Epidemiological data from 2024 reveal that invasive fungal infections directly cause approximately 2.5 million deaths annually worldwide, with total mortality reaching 3.75 million—significantly higher than the 1.7 million deaths recorded in 2017.

In Part I, we established an integrated bioinformatics and natural product chemistry approach to investigate antifungal compound-producing strains. By developing a Candida albicans activity-guided tracking system and employing multiple separation techniques including silica gel column chromatography and semi-preparative HPLC, we successfully achieved targeted isolation of trace antifungal compounds that are difficult to detect. From Pseudofabraea citricarpa strain WZH, we discovered and characterized two novel fellutamide-class compounds with anti-C.albicans activity. Notably, compound 1 represents a previously unreported structure, which we designated as Fellutamide E. Further purification, structural elucidation, and mechanistic studies will be conducted on the remaining compounds.

In Part II, a novel polyester compound (Dictpolyester A) was isolated from Dictyochaeta simplex. Structural characterization by NMR and MS revealed a unique 2,4-dihydroxy-6-(2-oxo-3-pentenyl)benzoic acid moiety. Although showing limited antifungal activity, biosynthetic analysis indicated its competitive relationship with antifungal natural product papulacandin production. Based on this, we aim to enhance the production of papulacandin by knocking out key genes involved in the biosynthesis of this compound, thereby increasing the availability of biosynthetic precursors. We have optimized the genetic manipulation methods in Dictyochaeta simplex, and subsequent steps will include validation of the mutants and fermentation-based analysis of papulacandin production.

This study integrates methodologies from natural product chemistry, bioinformatics, and synthetic biology, leading to the discovery of structurally novel antifungal candidate molecules while establishing a theoretical foundation for targeted genetic modification of antifungal compound-producing strains through biosynthetic gene cluster analysis. The findings establish both chemical and biological foundations for developing next-generation antifungals to combat the growing threat of drug-resistant fungal infections.