Sequential solvent fractionation strategies modulate polyphenol distribution and antioxidant activity of Caryota mitis seed extracts

Abstract

Seeds of Caryota mitis represent an underexplored source of bioactive polyphenols. This study investigated the influence of four extraction workflows on phenolic/flavonoid enrichment, antioxidant activity, nitric oxide (NO) inhibitory potential, and LC-MS/MS chemical profiles of C. mitis seed extracts. Total phenolic content (TPC) was expressed using both gallic acid equivalents (GAE) and ferulic acid equivalents (FAE), while total flavonoid content (TFC) was expressed as catechin equivalents (CE). Among the tested ethanol concentrations, 96% ethanol (CME96) showed the highest mean TPC values under both GAE and FAE expressions and the highest mean TFC value, and was therefore selected for ethanol-based partitioning workflows. A2-EaM showed the highest TPC and TFC among the fractions, whereas B1-M displayed the most biologically promising profile, combining strong preliminary antioxidant responses with the lowest NO IC₅₀ among the tested fractions. LC-MS/MS profiling was re-curated to retain 21 tentatively annotated compounds/features supported by accurate precursor ions and diagnostic MS/MS fragments compared with MassBank and/or MoNA records. The revised results indicate that extraction workflow affected both bulk phenolic/flavonoid enrichment and qualitative metabolite composition. Biological activity was therefore interpreted as a workflow-dependent response that cannot be explained solely by total phenolic or flavonoid content.