Department of Chemical Sciences, University of Naples Federico II, 80126 Naples, Italy.
Institute for Sustainable Plant Protection, National Research Council, 80055 Portici, Italy.
Molecules. 2022 Mar 17;27(6):1959. doi: 10.3390/molecules27061959.
Rare-earth elements are emerging contaminants of soil and water bodies which destiny in the environment and effects on organisms is modulated by their interactions with natural ligands produced by bacteria, fungi and plants. Within this framework, coordination by harzianic acid (HL), a secondary metabolite, of a selection of tripositive rare-earth cations Ln (Ln = La, Nd, Sm and Gd) was investigated at 25 °C, and in a CHOH/0.1 M NaClO (50/50 ) solvent, using mass spectrometry, circular dichroism, UV-Vis spectrophotometry, and pH measurements. Experimental data can be satisfactorily explained by assuming, for all investigated cations, the formation of a mono-complex (LnL) and a bis-complex (LnL). Differences were found between the formation constants of complexes of different Ln cations, which can be correlated with ionic radius. Since gadolinium is the element that raises the most concern among lanthanide elements, its effects on organisms at different levels of biological organization were explored, in the presence and absence of harzianic acid. Results of ecotoxicological tests suggest that harzianic acid can decrease gadolinium biotoxicity, presumably because of complex formation with Gd.
稀土元素是土壤和水体中的新兴污染物，其在环境中的命运和对生物体的影响受其与细菌、真菌和植物产生的天然配体相互作用的调节。在这一框架内，研究了哈茨木霉酸 (HL) 对一系列三价稀土阳离子 Ln（Ln = La、Nd、Sm 和 Gd）的配位作用，在 25°C 下，在 CHOH/0.1 M NaClO（50/50）溶剂中，使用质谱、圆二色性、紫外可见分光光度法和 pH 值测量。通过假设所有研究的阳离子都形成单核配合物 (LnL) 和双核配合物 (LnL)，可以很好地解释实验数据。发现不同 Ln 阳离子的配合物形成常数存在差异，这可以与离子半径相关联。由于钆是镧系元素中最令人关注的元素，因此在存在和不存在哈茨木霉酸的情况下，研究了其对不同生物组织层次生物体的影响。生态毒理学测试的结果表明，哈茨木霉酸可以降低钆的生物毒性，这可能是因为与 Gd 形成了配合物。
