Solvent-dependent bioactivity profiling and comparative analysis of Croton macrostachyus bark extracts
Year: 2026
Type: article
Abstract: Solvent choice strongly influences which phytochemicals are extracted and their biological effectiveness, an important consideration in natural product research. Croton macrostachyus bark was extracted sequentially with cyclohexane, chloroform, and methanol, and the resulting extracts were comparatively evaluated for antioxidant, antibacterial, and antifungal activity. The methanolic extract showed the strongest antioxidant activity (DPPH IC50 = 138.87 ± 0.090 µg/mL), followed by chloroform (178.21 ± 0.12 µg/mL) and cyclohexane (IC50 > 400 µg/mL). This was corroborated quantitatively: total phenolic content was highest in the methanolic extract (188.8 ± 14.0 mg GAE/g) and lowest in the cyclohexane extract (80.8 ± 20.5 mg GAE/g), with total flavonoid content following the same order; an HPLC-DAD fingerprint of the methanolic extract confirmed a phenolic-dominated profile. Antimicrobial assays showed a similar polarity-dependent trend: the methanolic extract produced the broadest and strongest inhibition against both Gram-positive and Gram-negative bacteria, including the largest zone (17.2 ± 1.0 mm) against Streptococcus pneumoniae. Antifungal activity varied by extract and pathogen, reflecting both extract composition and fungal susceptibility. The methanolic extract consistently outperformed the chloroform and cyclohexane extracts, indicating that polar and moderately polar phytochemicals are the major contributors to antioxidant and antimicrobial activity. Solvent selection is therefore a key determinant of bioactivity.
Source: Cogent Food & Agriculture
Institutions: University of Gondar, Addis Ababa University
Language: English
Topic: Medicinal Plant Research
Subfield: Plant Science
Domain: Life Sciences
Open Access status: diamond
OpenAlex ID: W7164687048