Determination of Bioactive Polyphenols in Mangrove Species and Their in-Vitro anti-Candida Activities by Ultra-High-Performance Liquid Chromatography – Electrospray Ionization – Tandem Mass Spectrometry (UPLC-ESI-MS/MS)

Abstract

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-Candida activities 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 (R2 ) 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, the Sonneratia species showed potent anti-Candida effects while the flavonoids showed higher anti-Candida activity 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.