Phytochemical profiling and antifungal activity of ethanolic root extract of water hyacinth (Eichhornia crassipes) against selected fungal pathogens

Abstract

The present study aimed to investigate the phytochemical composition and antifungal potential of ethanolic root extracts from water hyacinth (Eichhornia crassipes), along with spectroscopic and chromatographic profiling to identify bioactive constituents. The extract exhibited a moderately acidic pH of 4.5. Qualitative phytochemical screening confirmed the presence of secondary metabolites including tannins, lysine, flavonoids, saponins, alkaloids, and terpenes, highlighting the efficiency of ethanol as a solvent for extracting semi-polar compounds. Antifungal activity was assessed via the well diffusion method against several phytopathogenic fungi. Notably, 30% and 40% ethanol extracts significantly inhibited the growth of Curvularia sp., Fusarium errundifyme, and F. moniliforme, showing superior performance over standard antibiotics such as amoxicillin and gentamicin. However, minimal inhibitory effects were observed against F. proliferatum, F. oxysporum, and Sclerotium rolfsii. GC-MS analysis identified approximately 21 organic compounds, primarily long-chain aldehydes and complex ethers, which are commonly associated with plant-based bioactivity. UV-visible spectrophotometry revealed three major absorption peaks (232.5 nm, 287.5 nm, and 322.0 nm), indicative of π→π* transitions and extended conjugated systems typical of aromatic compounds with antioxidant potential. FTIR spectral analysis further confirmed the presence of carbonyl (C=O), hydroxyl (C–H and COH), and carboxylate (COO⁻) functional groups, all of which are characteristic of bioactive plant constituents. Collectively, these findings suggest that water hyacinth roots are a promising source of phytochemicals with significant antifungal and potential medicinal properties, offering a basis for further development of natural antifungal agents.