Green synthesis of new and natural diester based on gallic acid and polyethylene glycol [version 1; peer review: 1 approved, 2 approved with reservations]

Abstract

Background Antioxidant polyphenols like gallic acid (GA) and its esters called “gallates”, which have health advantages for humans, have grown in significance in maintaining a healthy lifestyle and eating a significant amount of secondary plant phytochemicals. Here, for the first time, we suggest a green synthesis of a brand-new, all-natural diester based on gallic acid and polyethylene glycol. Methods This di-gallate is created in a single step without the use of a solvent (solid-solid reaction). This reaction has a potential yield of up to 90%. The bathochromic shift of the absorption bands from 277 nm to 295 nm in the UV-VIS spectra was caused by the addition of PEG to gallic acid. To confirm the structure of this di-gallate; Fourier-transform infrared (FTIR) spectroscopy, proton and carbon nuclear magnetic resonance (1H and 13C NMR), the thermal stability identified by thermogravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM) were all used to thoroughly analyze the manufactured product. Results and conclusions The acquired results, when compared to the literature spectrums, supported the establishment of the di-ester structure and created new opportunities for a large number of applications.

Keywords

• Gallicacid; polyethylene glycol; di-gallate; biopolymer; green synthesis; solid-solid reaction; esterification.
• eng