Department of Cosmetic Raw Materials Chemistry, Faculty of Pharmacy, Medical University of Lodz, Muszyńskiego 1, 90-151 Łódź, Poland.
Faculty of Chemistry, University of Lodz, Pomorska 163/165, 90-236 Łódź, Poland.
Molecules. 2020 Feb 20;25(4):951. doi: 10.3390/molecules25040951.
The multifunctional profile of Zn has influenced its great popularity in various pharmaceutical, food, and cosmetic products. Despite the use of different inorganic and organic zinc derivatives, the search for new zinc-containing compounds with a safer skin profile still remains an open issue. The present paper describes the synthesis, structural characterization, and antibacterial activity of zinc(II) complexes with proteinogenic amino acids as potential candidates for dermatological treatments. The obtained complexes are of the general formula [Zn(AA)], where AA represents an amino acid (L-Glu, Gly, L-His, L-Pro, L-Met, and L-Trp). Their synthesis was designed in such a way that the final bis(aminoacidate) zinc(II) complexes did not contain any counter-ions such as Cl, NO, or SO that can cause some skin irritations. The chemical structure and composition of the compounds were identified by H NMR spectroscopy and elemental analysis, and four were also characterized by single-crystal X-ray diffraction. The Hirshfeld surface analysis for the Zn metallic center helped to determine its coordination number and geometry for each complex. Finally, the antibacterial properties of the complexes were determined with respect to three Gram-positive strains, viz. ATCC 6538, ATCC 12228, and ATCC 19615, and two Gram-negative bacteria, viz. ATCC 25992 and ATCC 27853, and were compared with the activity of zinc 2-pirrolidone 5-carboxylate (ZnPCA), commonly applied in dermatology. It was found that the Zn(II) complexes with methionine and glycine exhibited a higher antibacterial activity than the tested standard, and the antimicrobial properties of complex with Trp were satisfactory. The results of the antimicrobial activity examination allow us to postulate that the obtained zinc complexes might become new active substances for use in dermatological products.
锌的多功能特性使其在各种医药、食品和化妆品产品中广受欢迎。尽管使用了不同的无机和有机锌衍生物，但仍在寻找具有更安全皮肤特性的新型含锌化合物。本文描述了具有蛋白质氨基酸作为潜在候选药物的锌（II）配合物的合成、结构特征和抗菌活性，用于皮肤治疗。所得到的配合物的通式为[Zn(AA)]，其中 AA 代表氨基酸（L-谷氨酸、甘氨酸、L-组氨酸、L-脯氨酸、L-甲硫氨酸和 L-色氨酸）。它们的合成方式使得最终的双（氨基酸）锌（II）配合物不含任何可能引起皮肤刺激的抗衡离子，如 Cl、NO 或 SO。化合物的化学结构和组成通过 1H NMR 光谱和元素分析确定，其中四个还通过单晶 X 射线衍射进行了表征。对 Zn 金属中心的 Hirshfeld 表面分析有助于确定每个配合物的配位数和几何形状。最后，根据三个革兰氏阳性菌株（ATCC 6538、ATCC 12228 和 ATCC 19615）和两个革兰氏阴性菌（ATCC 25992 和 ATCC 27853）测定了配合物的抗菌性能，并与常用于皮肤病学的锌 2-吡咯烷酮 5-羧酸（ZnPCA）的活性进行了比较。结果发现，带有蛋氨酸和甘氨酸的 Zn(II)配合物表现出比测试标准更高的抗菌活性，而 Trp 配合物的抗菌性能令人满意。抗菌活性检测结果使我们可以假设，所获得的锌配合物可能成为皮肤科产品中使用的新活性物质。
