Enhancing the Solubility and Bioactivity of Phenolic Acids by Their Conversion into Supramolecular Ionic Salts
256
Presented by: Jiaheng Zhang
Phenolic acid is a kind of phenolic compound typically containing a carboxyl group and one or more hydroxyl groups bonded to the aromatic ring. As a prominent class of bioactive substances, phenolic acids present in various plant sources such as fruits, vegetables, spices, grains and beverages. For their great amount of bioactive properties as antioxidants, antibacterial and anti-inflammatory, phenolic acids are extensively used in cosmetic, medicine, food, and other fields. However, the limited aqueous solubility of some of these phenolic compounds represents a major drawback when envisaging their incorporation into water-rich dermatological formulations or for their absorption and transport in body fluids.
To overcome this limitation, the formulation of supramolecular ionic salts appears as a promising approach aiming at enhancing their water solubility. Matrine is a key tetracyclo-quinolizidine alkaloid isolated from the roots of Sophora flavescens Aiton, a Chinese therapeutic herb with a variety of pharmacological effects, including antibacterial, immunityregulatory, antiviral, anticancer, antipyretic, antiallergic, antidiarrheal, analgesic and anti-inflammatory, etc. Furthermore, matrine and its derivatives have been used extensively in traditional Chinese medicine (TCM) to treat several ailments, as well as in cosmetic formulations.
Herein, a novel family of matrinium-based supramolecular ionic salts, were designed and synthesized, featuring a series of phenolic acid anions derived from natural plants, i.e., gallic acid, vanillic acid, caffeic acid, syringic acid, etc. The structure of resulting supramolecular ionic salts was confirmed by NMR spectroscopy, X-ray crystallography, infrared spectroscopy, and elemental analysis, showing a high purity level of all synthesized ionic structures. Results of the water solubility experiments showed that these new salts were significantly more soluble in water (up to 3 orders of magnitude higher) than the corresponding phenolic acids. The antioxidant properties were evaluated by using the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays in the solutions. The IC50 values of the supramolecular ionic salts were significantly lower than that for the phenolic acids. Hence, it reveals that these new salts display a superior antioxidant activity when compared with the respective acidic precursor. Furthermore, the prepared salts were shown to have better antibacterial activities, as well as lower cytotoxicity profiles than their acidic precursors. Consequently, the bio-renewable supramolecular phenolic compounds should have potential applications as bioactive substances for use in cosmetic, food, pharmacy, etc.
To overcome this limitation, the formulation of supramolecular ionic salts appears as a promising approach aiming at enhancing their water solubility. Matrine is a key tetracyclo-quinolizidine alkaloid isolated from the roots of Sophora flavescens Aiton, a Chinese therapeutic herb with a variety of pharmacological effects, including antibacterial, immunityregulatory, antiviral, anticancer, antipyretic, antiallergic, antidiarrheal, analgesic and anti-inflammatory, etc. Furthermore, matrine and its derivatives have been used extensively in traditional Chinese medicine (TCM) to treat several ailments, as well as in cosmetic formulations.
Herein, a novel family of matrinium-based supramolecular ionic salts, were designed and synthesized, featuring a series of phenolic acid anions derived from natural plants, i.e., gallic acid, vanillic acid, caffeic acid, syringic acid, etc. The structure of resulting supramolecular ionic salts was confirmed by NMR spectroscopy, X-ray crystallography, infrared spectroscopy, and elemental analysis, showing a high purity level of all synthesized ionic structures. Results of the water solubility experiments showed that these new salts were significantly more soluble in water (up to 3 orders of magnitude higher) than the corresponding phenolic acids. The antioxidant properties were evaluated by using the 1,1-Diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azino-bis-(3-ethylbenzothiazoline)-6-sulfonic acid (ABTS) assays in the solutions. The IC50 values of the supramolecular ionic salts were significantly lower than that for the phenolic acids. Hence, it reveals that these new salts display a superior antioxidant activity when compared with the respective acidic precursor. Furthermore, the prepared salts were shown to have better antibacterial activities, as well as lower cytotoxicity profiles than their acidic precursors. Consequently, the bio-renewable supramolecular phenolic compounds should have potential applications as bioactive substances for use in cosmetic, food, pharmacy, etc.