Isolation and Identification of Flavanone Derivative Eriodictyol from the Methanol Extract of Bark and Its Antimicrobial and Antioxidant Activities.

BACKGROUND

is a plant species with well-documented ethnobotanical and medicinal properties. The plant is reported to have various secondary metabolites and had been applied for the treatment of various diseased conditions.

OBJECTIVES

The study objectives include fractionation, isolation, purification, and characterization of eriodictyol from the bark of , and the determination of its antimicrobial and antioxidant activities. . The series of methodologies that were employed include fractionations and purification (column chromatography), characterization (HPLC, LC-MS, IR, H, C, DEPT-135, HSQC, and HMBC), antimicrobial assays (microbroth dilution and checkerboard assay), and antioxidant activities assays (ABTS and DPPH scavenging capacity).

RESULTS

The study reports the identification and characterization of eriodictyol from the bark of which exhibited potent antioxidant activities against ABTS and DPPH radicals with scavenging capacities (SC) of 2.14 ± 0.05 and 2.51 ± 0.06 g/mL, respectively. The compound exhibited its antimicrobial activity by reporting good bacteriostatic activities (MBC/MIC > 4) against (SA), methicillin-resistant (MRSA), and fluconazole-resistant (CA2). Moreover, a broad spectrum of bactericidal effects (MBC/MIC ≤ 4) was reported against (SM), (EC), (BS), (KP), (PA), (ST), and standard (CA1). The compound further exhibited synergistic effects against EC, KP, ST, and MRSA; ST; and CA2 when combined with ciprofloxacin, tetracycline, and nystatin, respectively. However, antagonistic effects were observed against PA and CA1 when combined with ciprofloxacin and ketoconazole, respectively.

CONCLUSION

The study reports for the first time the identification of eriodictyol from the bark of which exhibited significant antioxidant and antimicrobial properties.