Phytochemical Properties of Silk Floss Tree Stem Bark Extract and Its Potential as an Eco-Friendly Biocontrol Agent against Potato Phytopathogenic Microorganisms

In the current study, the ethanolic extract of the stem bark of Ceiba speciosa, the silk floss tree (SFSB), was evaluated against various phytopathogenic microorganisms, including Ralstonia solanacearum, Dickeya solani, Pectobacterium atrosepticum, P. carotovorum, Fusarium oxysporum, and Rhizoctonia solani. At 300 µg/mL concentration, the SFSB extract exhibited the highest inhibition percentages of 83.33 and 86.67 for R. solani and F. oxysporum, respectively. In addition to its antimicrobial activity, SFSB extract exhibited strong antioxidant activity (IC50 value of 140.88 g/mL). HPLC analysis of the extract revealed the presence of various phenolic acids and flavonoids. Among these compounds, naringenin (18,698.83 µg/g), chlorogenic acid (2727.49 µg/g), ferulic acid (1276.18 µg/g), syringic acid (946.26 µg/g), gallic acid (812.34 µg/g), and methyl gallate (651.73 µg/g) were found to be the most abundant constituents. GCMS analysis showed that there were antimicrobial compounds like terpenoids, benzoic acid derivatives, phthalate esters, and different fatty acids. Isopropyl myristate was the most common compound, with a relative abundance of 55.61%. To our knowledge, this is the first investigation on the phytochemical composition and antimicrobial properties of SFSB extract. Consequently, utilizing SFSB extract could hold significant potential as a sustainable and natural approach for controlling and mitigating plant diseases.