Determination of Bioactive Polyphenols in Mangrove Species and Theirin-Vitroanti-CandidaActivities by Ultra-High-Performance Liquid Chromatography - Electrospray Ionization - Tandem Mass Spectrometry (UPLC-ESI-MS/MS)

Mangroves were reported as a source of bioactive compounds that include subgroups of polyphenols with various therapeutic activities. A new, sensitive and selective ultra-high-performance liquid chromatography - electrospray ionization - tandem mass spectrometry (UPLC-ESI-MS/MS) method was developed and validated for the determination of phenolic acids and flavonoids in fourteen mangrove species. Furthermore, anti-Candidaactivities were evaluated for the mangroves and selected compounds. The selectivity and sensitivity provided by multiple reactions monitoring mode allowed the separation of analytes within 14 minutes using the optimized conditions. The method exhibited excellent linearity for all analytes with correlation coefficient (R-2) values of at least 0.991. The limits of detection and quantification were between 0.24 and 15.62 ng/ml and 0.48 and 31.25 ng/mL. The intra- and inter-day precision values characterized by the relative standard deviation were from 3.27 to 8.05% and 3.02 to 8.83%. The corresponding accuracy values were from -6.81 to 9.49% and -4.07 to 7.99%, respectively. Among the selected polyphenols, chlorogenic acid was the dominant compound at concentrations between 8.13 ng/mg and 5690 ng/mg. The phenolic acid (p-coumaric acid, caffeic acid and ferulic acid), flavonol (quercetin, rutin, myricetin), flavanone (naringenin), and flavone (apigenin) concentrations varied as per the mangrove species. The mean recoveries of selected analytes were from 88.8% to 101.9%. Additionally, among the selected mangroves, theSonneratiaspecies showed potent anti-Candidaeffects while the flavonoids showed higher anti-Candidaactivity than the phenolic acids. The selected polyphenols were successfully identified and quantified by UPLC-ESI-MS/MS in mangroves and this method can be used for the analysis of other biological extracts.

Automated summary

A sensitive UPLC-ESI-MS/MS method was developed and validated for the determination of phenolic acids and flavonoids in fourteen mangrove species. Chlorogenic acid was identified as the dominant compound among selected polyphenols, with concentrations varying across different mangrove species. Sonneratia species exhibited potent anti-Candida effects, while flavonoids showed higher anti-Candida activity compared to phenolic acids.