Carboni Davide, Cadeddu Marta, Olia Federico, Fiori Federico, Anedda Roberto, Carraro Massimo, Malfatti Luca, Innocenzi Plinio
Laboratory of Materials Science and Nanotechnology, CR-INSTM, Department of Biomedical Sciences, University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy.
Porto Conte Ricerche, Strada Provinciale 55, Porto Conte Capo Caccia, Km. 8400, 07041 Alghero, Italy.
Molecules. 2025 Apr 17;30(8):1802. doi: 10.3390/molecules30081802.
The class of diamino-naphthalene exhibits antioxidant properties, which are partly related to the relative positions of the two amino groups. This study demonstrates how the reactivity of one of these compounds, 1,5-diamino-naphthalene (DAN), can be adjusted by introducing a single amide bond through a simple thermal coupling with l-pyroglutamic acid (PyroGlu). The solventless thermal reaction between PyroGlu and DAN at 160 °C yielded a new mono-pyroglutanilide compound (PyroDAN) that was characterized using various analytical techniques, including a thermal and infrared analysis, HRMS (ESI), and one- (1D) and two-dimensional (2D) NMR. The optical properties were investigated using UV-Vis and fluorescence spectroscopy. Additionally, two chemical standard assays were used to measure both the antioxidant and pro-oxidant properties of PyroDAN. The molecule has shown nearly negligible pro-oxidant activity, while a mild antioxidant activity is still retained. These findings indicate that the transformation of DAN into a mono-pyroglutanilide derivative breaks the original molecular symmetry and effectively modifies the electronic distribution of the aromatic system, suppressing the oxidant properties while keeping a mild antioxidant activity. Furthermore, the tuneable fluorescent properties of PyroDAN-the mild antioxidant activity and the inhibition of the cytologically harmful pro-oxidant properties-suggest promising applications in bioimaging and other biological fields.
二氨基萘类化合物具有抗氧化特性，这部分与两个氨基的相对位置有关。本研究表明，通过与L-焦谷氨酸（PyroGlu）进行简单的热偶联引入单个酰胺键，可以调节其中一种化合物1,5-二氨基萘（DAN）的反应活性。PyroGlu与DAN在160°C下进行无溶剂热反应，生成了一种新的单焦谷氨酰化化合物（PyroDAN），并使用各种分析技术对其进行了表征，包括热分析和红外分析、高分辨质谱（电喷雾电离）以及一维（1D）和二维（2D）核磁共振。使用紫外可见光谱和荧光光谱研究了其光学性质。此外，还使用了两种化学标准测定法来测量PyroDAN的抗氧化和促氧化性质。该分子的促氧化活性几乎可以忽略不计，同时仍保留了温和的抗氧化活性。这些发现表明，将DAN转化为单焦谷氨酰化衍生物打破了原有的分子对称性，有效地改变了芳香体系的电子分布，抑制了氧化性质，同时保持了温和的抗氧化活性。此外，PyroDAN的可调荧光性质——温和的抗氧化活性以及对细胞有害的促氧化性质的抑制——表明其在生物成像和其他生物领域具有广阔的应用前景。
