Cecchini Martina Maya, Reale Samantha, Manini Paola, d'Ischia Marco, De Angelis Francesco
Department of Physical and Chemical Sciences, University of L'Aquila, Via Vetoio, Coppito, L'Aquila, Italy.
Department of Chemical Sciences, University of Naples "Federico II"-, Faculties of Monte Sant'Angelo, Via Cinthia, Naples, Italy.
Chemistry. 2017 Jun 12;23(33):8092-8098. doi: 10.1002/chem.201701951. Epub 2017 May 29.
Due to the emerging biomedical relevance and technological potential of fungal melanins, and prompted by the virtual lack of information about their structural arrangement, an optimized synthetic protocol has been devised for a potential structural model of Ascomyces allomelanin through enzyme-catalyzed oxidative polymerization of 1,8-dihydroxynaphthalene (1,8-DHN). Electrospray ionization mass spectrometry (ESI-MS) measurements of freshly synthesized DHN-polymer recorded in the negative ion mode allowed detection of oligomers up to m/z 4000, separated by 158 Da, corresponding to the in-chain DHN-unit. The dominant peaks were assigned to singly-charged distribution, up to 23 repeating units, whereas a doubly charged polymer distribution was also detectable. Chemical derivatization, ultra-performance liquid chromatography (UPLC)-ESI MS, and MS/MS data confirmed that oxidative polymerization of 1,8-DHN proceeds through C-C coupling of the naphthalene rings. The new insights reported here into synthetic 1,8-DHN oligomers/polymers as a mimic of fungal melanins may guide novel interesting advances and applications in the field of biomimetic functional materials.
由于真菌黑色素在生物医学方面的相关性不断显现以及其技术潜力，同时鉴于关于它们结构排列的信息几乎空白，我们设计了一种优化的合成方案，通过1,8 - 二羟基萘（1,8 - DHN）的酶催化氧化聚合反应来构建子囊菌全黑色素的潜在结构模型。在负离子模式下对新合成的DHN - 聚合物进行电喷雾电离质谱（ESI - MS）测量，可检测到分子量高达4000的寡聚物，相邻寡聚物分子量相差158 Da，对应于链内的DHN单元。主要峰被归为单电荷分布，包含多达23个重复单元，同时也可检测到双电荷聚合物分布。化学衍生化、超高效液相色谱（UPLC） - ESI MS以及MS/MS数据证实，1,8 - DHN的氧化聚合反应是通过萘环的C - C偶联进行的。本文报道的关于合成1,8 - DHN寡聚物/聚合物作为真菌黑色素模拟物的新见解，可能会为仿生功能材料领域带来新的有趣进展和应用。
