Bencsik Ottó, Papp Tamás, Berta Máté, Zana Annamária, Forgó Péter, Dombi György, Andersson Maria A, Salkinoja-Salonen Mirja, Vágvölgyi Csaba, Szekeres András
Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged H-6726, Hungary.
Institute of Pharmaceutical Analysis, University of Szeged, Somogyi u. 4, Szeged H-6720, Hungary.
Toxins (Basel). 2014 Sep 23;6(9):2857-71. doi: 10.3390/toxins6092857.
Bipolaris oryzae is a phytopathogenic fungus causing a brown spot disease in rice, and produces substance that strongly perturbs motility and membrane integrities of boar spermatozoa. The substance was isolated from the liquid culture of the fungal strain using extraction and a multi-step semi-preparative HPLC procedures. Based on the results of mass spectrometric and 2D NMR techniques, the bioactive molecule was identified as ophiobolin A, a previously described sesterterpene-type compound. The purified ophiobolin A exhibited strong motility inhibition and viability reduction on boar spermatozoa. Furthermore, it damaged the sperm mitochondria significantly at sublethal concentration by the dissipation of transmembrane potential in the mitochondrial inner membrane, while the plasma membrane permeability barrier remained intact. The study demonstrated that the cytotoxicity of ophiobolin A toward somatic cell lines is higher by 1-2 orders of magnitude compared to other mitochondriotoxic mycotoxins, and towards sperm cells unique by replacing the progressive motility by shivering tail beating at low exposure concentration.
稻瘟病菌是一种引起水稻褐斑病的植物病原真菌，它产生的物质会严重干扰公猪精子的活力和膜完整性。该物质是通过提取和多步半制备高效液相色谱法从该真菌菌株的液体培养物中分离出来的。基于质谱和二维核磁共振技术的结果，该生物活性分子被鉴定为蛇孢菌素A，一种先前描述的倍半萜烯类化合物。纯化后的蛇孢菌素A对公猪精子表现出强烈的活力抑制和活力降低作用。此外，在亚致死浓度下，它通过耗散线粒体内膜的跨膜电位，显著损害精子线粒体，而质膜通透性屏障保持完整。该研究表明，与其他线粒体毒性霉菌毒素相比，蛇孢菌素A对体细胞系的细胞毒性高1-2个数量级，并且在低暴露浓度下通过颤抖尾巴摆动取代渐进性运动，对精子细胞具有独特的作用。
