Selected Physicochemical and Biological Properties of Ethyl Ascorbic Acid Compared to Ascorbic Acid.

Area of Science:

• Biochemistry and Materials Science
• Chemical analysis and biological properties evaluation

Background:

• Ascorbic acid (AA) is a vital nutrient with antioxidant properties, but its stability can be a limitation.
• Ethylated ascorbic acid (AAE) is a derivative of AA, and its properties require comprehensive evaluation for potential applications.

Purpose of the Study:

• To compare the biological and physicochemical properties of ethylated ascorbic acid (AAE) with ascorbic acid (AA).
• To evaluate the thermal stability, antioxidant activity, antimicrobial effects, and cytotoxicity of AAE.

Main Methods:

• Thermogravimetry (TG), differential thermogravimetry (DTG), and differential thermal analysis (DTA) for thermal properties.
• UV-Vis spectroscopy to assess decomposition under varying temperature and pH.
• Free-radical scavenging assays (DPPH), antimicrobial activity tests, and in vitro cytotoxicity assays (L929 fibroblasts).

Main Results:

• AAE demonstrated significantly higher thermal stability than AA, with a 30% difference in mass loss observed via TG.
• AAE exhibited potent antioxidant activity with prolonged free-radical scavenging kinetics and stronger antimicrobial action against Candida albicans compared to AA.
• AAE displayed lower cytotoxicity, with a 10% concentration being cytotoxic compared to AA's ≥2.5% threshold.

Conclusions:

• Ethylated ascorbic acid (AAE) offers superior thermal stability and enhanced antioxidant and antimicrobial properties compared to ascorbic acid (AA).
• The reduced in vitro toxicity of AAE, coupled with its biological activities, supports its potential utility in the pharmaceutical and cosmetic industries.
• DTG analysis effectively differentiates between AA and AAE, highlighting AAE's enhanced stability in aqueous solutions.