Synthesis, spectroscopic characterization, Hirshfeld surface analysis, biological activity studies, and molecular docking investigation of a cobalt (II) porphyrin complex

This work involved spectroscopic studies, Hirshfeld surface analysis and antimicrobial evaluation against bacterial and fungal species, and computational docking analysis of the [Co^II(OEP)]^.2NBA complex (I), where (OEP is 2,3,7,8,12,13,17,18-octaethylporphyrin) and (NBA is 2-nitrobenzaldehyde). The structure of complex (I) reveals an interaction between the Co(II) center and the NBA ring, with a centroid–metal separation of 3.508(6) Å. Furthermore, the NBA molecule exhibits an intramolecular C—H…O hydrogen bond. Bioactivity studies concluded that cobalt porphyrin holds promise as an important new antibacterial agent, generating outstanding inhibition zones measuring 22.5 mm was observed for <i>Bacillus subtilis</i> and 20 mm observed for <i>Staphylococcus aureus</i>. Molecular docking analysis was conducted to determine how strongly complex (I) interacts with the catalytic sites of bacterial proteins, including <i>Bacillus subtilis</i> (1C9E), <i>Staphylococcus aureus</i> (8ADR), <i>Pseudomonas aeruginosa</i> (7EMR), <i>Escherichia coli</i> (1ECL), <i>Candida Albicans</i> (5FSA), and <i>Aspergillus fumigatus</i> (4UYL). The analysis was conducted to determine the level of interaction involved in antibacterial recognition.

本研究针对[Co(II)(OEP)]·2NBA配合物（I，其中OEP即2,3,7,8,12,13,17,18-八乙基卟啉（2,3,7,8,12,13,17,18-octaethylporphyrin），NBA即2-硝基苯甲醛（2-nitrobenzaldehyde））开展了光谱学研究、希尔施费尔德表面分析（Hirshfeld surface analysis）、针对细菌与真菌菌株的抗菌活性评价，以及计算分子对接分析。配合物（I）的结构显示，Co(II)中心与NBA环之间存在相互作用，其质心-金属间距为3.508(6) Å。此外，该NBA分子存在分子内C—H…O氢键。生物活性研究表明，钴卟啉类化合物有望成为一类重要的新型抗菌剂：对枯草芽孢杆菌（Bacillus subtilis）的抑菌圈直径可达22.5 mm，对金黄色葡萄球菌（Staphylococcus aureus）的抑菌圈直径可达20 mm。为探究配合物（I）与各类细菌及真菌蛋白催化位点的结合强度，本研究开展了分子对接分析，所涉及的蛋白来源包括枯草芽孢杆菌（Bacillus subtilis，1C9E）、金黄色葡萄球菌（Staphylococcus aureus，8ADR）、铜绿假单胞菌（Pseudomonas aeruginosa，7EMR）、大肠埃希菌（Escherichia coli，1ECL）、白色念珠菌（Candida albicans，5FSA）以及烟曲霉（Aspergillus fumigatus，4UYL）。本分析旨在明确抗菌识别过程中的相互作用程度。