Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity
Kaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Ka...
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MDPI AG
2019-02-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | https://www.mdpi.com/1422-0067/20/4/975 |
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| author | Sui-Ping Deng Yi-Li Yang Xing-Xing Cheng Wen-Rong Li Ji-Ye Cai |
| author_facet | Sui-Ping Deng Yi-Li Yang Xing-Xing Cheng Wen-Rong Li Ji-Ye Cai |
| author_sort | Sui-Ping Deng |
| collection | DOAJ |
| description | Kaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Kae (Kae-SO<sub>3</sub>), gallium (Ga) complexes with Kae (Kae-Ga) and Kae-SO<sub>3</sub> (Kae-SO<sub>3</sub>-Ga). The compound structures were characterized by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and thermal methods (TG/DSC). The results showed that a sulfonic group (-SO<sub>3</sub>) was successfully tethered on the C3’ of Kae to form Kae-SO<sub>3</sub>. And in the metal complexation, 4-CO and 3-OH of the ligand participated in the coordination with Ga(III). The metal-to-ligand ratio 1:2 was suggested for both complexes. Interestingly, Kae-SO<sub>3</sub>-Ga was obviously superior to other compounds in terms of overcoming the poor water-solubility of free Kae, and the solubility of Kae-SO<sub>3</sub>-Ga was about 300-fold higher than that of Kae-Ga. Furthermore, the evaluation of antioxidant activities in vitro was carried out for Kae derivatives by using α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging. The results showed that Kae-SO<sub>3</sub>-Ga was also optimal for scavenging free radicals in a dose-dependent manner. These data demonstrate that sulfonate kaempferol-gallium complex has a promising future as a potential antioxidant and as a potential therapeutic agent for further biomedical studies. |
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| issn | 1422-0067 |
| language | English |
| last_indexed | 2024-04-12T21:54:44Z |
| publishDate | 2019-02-01 |
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| spelling | doaj.art-11196552e445409eb1d654c9eb836d5a2022-12-22T03:15:21ZengMDPI AGInternational Journal of Molecular Sciences1422-00672019-02-0120497510.3390/ijms20040975ijms20040975Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant ActivitySui-Ping Deng0Yi-Li Yang1Xing-Xing Cheng2Wen-Rong Li3Ji-Ye Cai4Department of Chemistry, Jinan University, Guangzhou 510632, ChinaDepartment of Chemistry, Jinan University, Guangzhou 510632, ChinaDepartment of Chemistry, Jinan University, Guangzhou 510632, ChinaDepartment of Chemistry, Jinan University, Guangzhou 510632, ChinaDepartment of Chemistry, Jinan University, Guangzhou 510632, ChinaKaempferol (Kae) is a natural flavonoid with potent antioxidant activity, but its therapeutic use is limited by its low aqueous solubility. Here, a series of Kae derivatives were synthesized to improve Kae dissolution property in water and antioxidant activity. These compounds included sulfonated Kae (Kae-SO<sub>3</sub>), gallium (Ga) complexes with Kae (Kae-Ga) and Kae-SO<sub>3</sub> (Kae-SO<sub>3</sub>-Ga). The compound structures were characterized by high-resolution mass spectrometry (HRMS), nuclear magnetic resonance (NMR) spectroscopy, ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and thermal methods (TG/DSC). The results showed that a sulfonic group (-SO<sub>3</sub>) was successfully tethered on the C3’ of Kae to form Kae-SO<sub>3</sub>. And in the metal complexation, 4-CO and 3-OH of the ligand participated in the coordination with Ga(III). The metal-to-ligand ratio 1:2 was suggested for both complexes. Interestingly, Kae-SO<sub>3</sub>-Ga was obviously superior to other compounds in terms of overcoming the poor water-solubility of free Kae, and the solubility of Kae-SO<sub>3</sub>-Ga was about 300-fold higher than that of Kae-Ga. Furthermore, the evaluation of antioxidant activities in vitro was carried out for Kae derivatives by using α,α-diphenyl-β-picrylhydrazyl (DPPH) and 2,2’-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) free radical scavenging. The results showed that Kae-SO<sub>3</sub>-Ga was also optimal for scavenging free radicals in a dose-dependent manner. These data demonstrate that sulfonate kaempferol-gallium complex has a promising future as a potential antioxidant and as a potential therapeutic agent for further biomedical studies.https://www.mdpi.com/1422-0067/20/4/975kaempferolgallium complexwater solubilityantioxidant activityflavonoid |
| spellingShingle | Sui-Ping Deng Yi-Li Yang Xing-Xing Cheng Wen-Rong Li Ji-Ye Cai Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity International Journal of Molecular Sciences kaempferol gallium complex water solubility antioxidant activity flavonoid |
| title | Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity |
| title_full | Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity |
| title_fullStr | Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity |
| title_full_unstemmed | Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity |
| title_short | Synthesis, Spectroscopic Study and Radical Scavenging Activity of Kaempferol Derivatives: Enhanced Water Solubility and Antioxidant Activity |
| title_sort | synthesis spectroscopic study and radical scavenging activity of kaempferol derivatives enhanced water solubility and antioxidant activity |
| topic | kaempferol gallium complex water solubility antioxidant activity flavonoid |
| url | https://www.mdpi.com/1422-0067/20/4/975 |
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