| 摘要: |
| 本研究旨在挖掘徐闻石珊瑚共附生真菌资源，筛选出具有显著抑菌活性的菌株，并进一步研究其次级代谢产物的化学多样性。实验采用马铃薯葡萄糖肉汤（potato dextrose broth, PDB）和糙米培养基（brown rice medium, BRM），并设置0.3%、3.0%、10.0%三个盐度对29株真菌进行发酵。运用牛津杯扩散法评估真菌次级代谢产物的抑菌活性，通过薄层色谱法（thin-layer chromatography, TLC）、高效液相色谱法(high performance liquid chromatography，HPLC)、超高效液相色谱串联四极杆飞行时间质谱（ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry, UPLC-QTOF-MS）以及基于特征的分子网络（feature-based molecular networking, FBMN）、MSFINDER等技术手段分析活性次级代谢产物的化学多样性。抑菌结果显示，8株真菌的次级代谢产物表现出较强的抑菌活性（抑菌直径>15.0 mm），其中菌株C14-19 3.0% PDB次级代谢产物在5 mg/mL的浓度条件下对副溶血性弧菌和溶藻弧菌表现出了显著的抑菌活性（抑菌直径>24.5 mm）。化学多样性结果显示，不同培养条件对菌株次级代谢产物抑菌活性的影响较大，其中菌株C14-19在PDB培养基中能够产生更多的酚类和生物碱类物质，且在3.0%盐度下，菌株C14-19能产生更多的抑菌活性化合物。通过与数据库收录的二级质谱匹配以指认化合物，共从中注释出6个化合物，分别为canthin-6-one、meleagrin、oxaline、roquefortine C、glycyrrhetinic acid、4-hydroxy-3-(3-methyl-2-butenyl)acetophenone。本研究表明菌株C14-19次级代谢产物具有显著的抑菌活性和化学多样性，为发掘南海石珊瑚来源的抑菌药物先导化合物提供科学依据。 |
| 关键词: 石珊瑚 共附生真菌 抑菌活性 分子网络分析 化学多样性 |
| DOI： |
| 投稿时间：2024-12-04修订日期：2025-01-27 |
| 基金项目:湛江市非资助科技攻关专题项目（2023B010008）；广东海洋大学大学生创新创业训练计划项目（S202110566017）；国家自然科学基金（21807015）；广东省基础与应用基础研究基金自然科学基金（2022A1515010783）；广东省科技专项资金-基础与应用基础研究专题（2021A05240）；广东省普通高校重点领域专项（生物医药与健康）（2021ZDZX2064）；广东海洋大学博士科研启动项目（R18008，060302042201）；深圳市科创委基础研究面上项目（JCYJ20220530162014032）；湛江市海洋青年人才创新项目（2022E05010）。 |
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| Mass Spectrometry-Based Molecular Network Analysis of Antimicrobial Active Secondary Metabolites and Their Chemical Diversities in Symbiotic Fungi from Stony Corals |
|
HUANG Yijun1, ZHONG Yuejia1, ZHOU Longjian2, FENG Yunkai1, LIAOQingnan1, Huang Yilong1, ZHANG Yi2, LIU Yayue2
|
| (1.College of Food Science and Technology,Guangdong Ocean University,Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety,Shenzhen Institute of Guangdong Ocean University,Zhanjiang Municipal Key Laboratory of Marine Drugs and Nutrition for Brain Health,Zhanjiang,Guangdong;2.College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Shenzhen Institute of Guangdong Ocean University, Zhanjiang Municipal Key Laboratory of Marine Drugs and Nutrition for Brain Health, Zhanjiang, Guangdong// Southern Marine Science and Engineering Guangdong Laboratory（Zhanjiang）, Zhangjiang, Guangdong//Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian, Liaoning) |
| Abstract: |
| The aim of this study was to excavate the co-epiphytic fungal resources of Xuwen stony coral, to screen out strains with significant antibacterial activity, and to further investigate the chemical diversity of their secondary metabolites. Potato dextrose broth (PDB) and brown rice medium (BRM) with three salinity levels of 0.3%, 3.0%and 10.0% were used for the fermentation of 29 fungal strains. The antibacterial activities of the fungal secondary metabolites were evaluated by the Oxford cup diffusion method, and the chemical diversity of the active secondary metabolites was analyzed by thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS), and feature-based molecular networking (FBMN), MSFINDER to analyze the chemical diversity of active secondary metabolites. The inhibition results showed that the secondary metabolites of eight fungal strains exhibited strong inhibitory activities (inhibitory diameter >15.0 mm), among which strain C14-19 3.0% PDB secondary metabolite exhibited significant inhibitory activities against Vibrio parahaemolyticus and Vibrio alginolyticus at a concentration of 5 mg/mL (inhibitory diameter >24.5 mm). The results of chemical diversity showed that different culture conditions had a greater effect on the inhibitory activity of secondary metabolites of strains, in which strain C14-19 produced more phenolics and alkaloids in the PDB medium. At 3.0% salinity, strain C14-19 could produce more inhibitory active compounds. A total of six compounds were annotated from the database by matching with secondary mass spectra included in the database to identify the compounds, which were canthin-6-one, meleagrin, oxaline, roquefortine C, glycyrrhetinic acid, 4-hydroxy-3-(3-methyl-2- butenyl)acetophenone. The present study demonstrated that strain C14-19 secondary metabolites possessed significant bacteriostatic activity and chemical diversity, providing a scientific basis for the discovery of bacteriostatic drug lead compounds of stony coral origin in the South China Sea. |
| Key words: Stony coral symbiotic fungi antibacterial activity molecular network analysis chemical diversity |
