Isolation and Characterization of polyphenolic compounds from Ethanolic Extract of Hibiscus syriacus

Abstract

Background:Polyphenolic compounds are known for their structural diversity and potential therapeutic
applications. Hibiscus syriacus, a plant traditionally used in herbal medicine, contains a rich profile of
phytoconstituents, including polyphenols. This study aimed to isolate and structurally characterize
polyphenolic compounds from the ethanolic extract of H. syriacus flowers using advanced
spectroscopic techniques.
Methods: Flowers of H. syriacus were collected, shade-dried, powdered, and extracted using Soxhlet
extraction with ethanol. The crude extract was partitioned and subjected to column chromatography and
Sephadex LH-20 for fractionation. Final purification was achieved using reversed-phase semi-
preparative high-performance liquid chromatography (HPLC). Isolated compounds were characterized
by Fourier Transform Infrared Spectroscopy (FTIR), Proton and Carbon Nuclear Magnetic Resonance
(¹H and ¹³C NMR), and Mass Spectrometry (MS) for detailed structural elucidation.
Results: Two distinct polyphenolic compounds (Compound 1 and Compound 2) were successfully
isolated and identified. FTIR analysis confirmed the presence of key functional groups such as
hydroxyl, aromatic rings, and carbonyl groups. NMR spectra provided detailed insights into the
structural framework, revealing substitution patterns consistent with known polyphenolic structures.
Mass spectrometry determined the molecular weights of Compound 1 (MW 164.16; m/z 165.05) and
Compound 2 (MW 194.18; m/z 195.06), confirming their purity and identity.
Conclusion:The study successfully demonstrated the extraction, isolation, and spectroscopic
characterization of two polyphenolic compounds from Hibiscus syriacus flowers. These findings
contribute to the phytochemical profiling of the species and provide a foundation for future research into
their potential biological or pharmaceutical applications.