A new Schiff base ligand (E)-2,6-dimethoxy-4-((quinolin-3-ylimino)methyl)phenol (HL) and its Cu(II), Co(II), Ni(II) and Zn(II) metal complexes have been synthesized and characterized by various spectroscopic (UV-visible, IR, NMR and mass), SEM and magnetic susceptibility measurement. The ligand (HL) have been synthesized by condensation of 4-hydroxy-3,5-dimethoxybenzaldehyde and 3-aminoquinoline. Based on electronic spectral data and magnetic susceptibility measurement the tetrahedral geometry is proposed for all the complexes. The ligand and metal complexes are screened for their antimicrobial activities against bacteria (Staphylococcus aureus, Escherichia coli) and antifungal activity against the fungi (Candida albicans). Further, the ligand and its Cu(II) complex are also screened for anticancer activity on human breast (MCF7) cancer cell lines by the MTT assay method. Interestingly, Cu(II) complex shows better anticancer activity than the free Schiff base ligand. The in vitro anti-inflammatory and anti-diabetic activities of the ligand and Cu(II) complex are studied. The Cu(II) complex show higher inhibition activity than that of the free ligand.

中文翻译：

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4-羟基-3,5-二甲氧基苯甲醛和3-氨基喹啉衍生的席夫碱金属(II)配合物的合成、表征和生物活性

一种新的席夫碱配体 (E)-2,6-二甲氧基-4-((quinolin-3-ylimino)methyl)phenol (HL) 及其 Cu(II)、Co(II)、Ni(II) 和 Zn( II) 金属配合物已被合成并通过各种光谱（紫外-可见光、红外、核磁共振和质谱）、扫描电镜和磁化率测量表征。配体 (HL) 是通过 4-羟基-3,5-二甲氧基苯甲醛和 3-氨基喹啉缩合合成的。基于电子光谱数据和磁化率测量，提出了所有配合物的四面体几何形状。筛选配体和金属配合物对细菌（金黄色葡萄球菌、大肠杆菌）的抗微生物活性和对真菌（白色念珠菌）的抗真菌活性。更远，还通过 MTT 分析方法筛选配体及其 Cu(II) 复合物对人乳腺癌 (MCF7) 癌细胞系的抗癌活性。有趣的是，Cu(II) 配合物显示出比游离希夫碱配体更好的抗癌活性。研究了配体和 Cu(II) 复合物的体外抗炎和抗糖尿病活性。Cu(II) 配合物显示出比游离配体更高的抑制活性。