Antioxidant CMK-۵ mesoporous carbon covalently functionalized with gallic acid and ascorbic acid

Mesoporous carbon CMK-۵ was synthesized and subsequently functionalized via covalent grafting with two potent natural antioxidants, ascorbic acid (AA) and gallic acid (GA), to develop novel antioxidant-active hybrid materials. The successful covalent attachment was confirmed through comprehensive characterization techniques, including fourier-transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and transmission electron microscopy (TEM). The antioxidant performance was systematically compared using two complementary assays: the DPPH radical scavenging assay and the ferric reducing antioxidant power (FRAP) test. The results indicated that functionalization effectively enhances the antioxidant activity of CMK-۵. The DPPH scavenging capacity increased from less than ۴۲.۳% for pristine CMK-۵ to ۶۱.۵% for CMK-۵-AA, and ۷۳.۷% for CMK-۵-GA. Similarly, in the FRAP assay, CMK-۵-GA exhibited the highest reducing power. A consistent trend of CMK-۵-GA > CMK-۵-AA > CMK-۵ was observed in both methods, unequivocally proving the superior efficacy of GA, attributed to its higher number of phenolic hydroxyl groups facilitating more efficient hydrogen atom transfer and electron donation. This work presented a suitable strategy for creating advanced antioxidant carbon-based hybrids for potential applications inbiomedicine, food preservation, or catalytic systems.

کلیدواژه ها:

Antioxidant ، Ascorbic acid ، CMK-۵ ، Gallic acid