Evaluation of the Antioxidant Potential of Citrus medica from Different Geographical Regions and Characterization of Phenolic Constituents by LC–MS

Abstract

The varying antioxidant potential of Citrus medica associated with different geographical regions makes the evaluation of C. medica for natural antioxidants essential. This work aimed to compare the antioxidant potential of the phenolic constituents from different geographical regions. The chemical compositions were characterized by ultra-high-performance liquid chromatography (UPLC) coupled with mass spectrometry (MS). A total of 67 compounds including 29 coumarin derivatives and 38 flavonoids were tentatively identified by UPLC–quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). To evaluate the quality of C. medica from seven different geographical regions, water and 80% methanol fractions were subjected to quantitative analysis. Antioxidant potentials were determined by 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), iron chelation, and reduction methods. The samples collected from Sichuan province showed the highest content of total phenolic compounds. Combined with antioxidant results, the sample from Sichuan province presented good antioxidant activity. This study also showed that total phenolic compounds significantly contributed to the antioxidant activities (2,2-azinobis(3-ethyl-benzothiazoline-6-sulphonic acid) and radical scavenging activity) of C. medica samples ( p < 0.01). These results provided chemical information and potential antioxidant value for further research, providing ideal evidence for the quality evaluation and exploitation of the source.

Investigation of pectin deficiency in modulating the bioflavonoid profile of orange processing waste: A sustainable valorization of industrial waste

“…From hesperidin, the fragment ions at m / z 465 [M−C 6 H 10 O 4 + H] + and at m / z 449 [M−C 6 H 10 O 5 + H] + , by the loss of 146 and 162 Da are observed, indicating the loss of rhamnose and glucose, respectively. Also, the fragment at m / z 303 is observed, related to hesperetin, the basic nucleus of this flavanone ( Xia et al, 2023 , Cuyckens and Claeys, 2004 ). In the case of sinesentin, a polymethoxylated flavonoid, the common fragment generated at low collision energy is O-methyl.…”

“…The usual method for flavonoid quantification is HPLC coupled with a UV detector (DAD). Xia et al, 2023 , for example, quantified some flavonoids in Citrus medica using UHPLC-DAD. Omoba, Obafaye, Salawu, Boligon, & Athayde, 2015 another example of the use of HPLC-DAD for flavonoid quantification in citrus.…”

Combined transcriptome and widely targeted metabolome analysis reveals the potential mechanism of HupA biosynthesis and antioxidant activity in Huperzia serrata

“…The FRAP assay was performed using the methodology described by Xia et al (2023), with minor modification. Firstly, 300 mM acetate buffer, 25 mL 10 mM TPTZ (2,4,6-tri-pyridyl-striazine) solution and 2.5 mL of 20 mM FeCl 3 •6H 2 O solution were fully mixed to prepare the stock solution.…”

Table_3.xls

“…The FRAP assay was performed using the methodology described by Xia et al (2023), with minor modification. Firstly, 300 mM acetate buffer, 25 mL 10 mM TPTZ (2,4,6-tri-pyridyl-striazine) solution and 2.5 mL of 20 mM FeCl 3 •6H 2 O solution were fully mixed to prepare the stock solution.…”