Claim Missing Document
Check
Articles

Found 2 Documents
Search

Phytochemical Characterization and Evaluation of Antioxidant Activity in Sorghum bicolor Leaves Extracts Clark, Poro David; Ndukwe, Gloria Ihuoma; Awatefe, Kehinde Jonathan
Sciences of Phytochemistry Volume 5 Issue 1
Publisher : ETFLIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58920/sciphy0501459

Abstract

This study investigated the phytochemical composition and in-vitro antioxidant potential of leaves extracts from Sorghum bicolor, which were obtained through sequential maceration with solvents of different polarities (n-hexane and methanol). The extraction yields revealed a predominance of polar compounds, with methanol extract (12.5% w/w) significantly higher than the n-hexane extract (1.7% w/w). Gas chromatography–mass spectrometry (GC–MS) profiling, using NIST library matching (similarity scores >80%) without reference standards, showed distinct patterns based on solvent use: the n-hexane extract contained nine primarily lipophilic compounds, mainly consisting of Z-2-octadecen-1-ol and octadecenoic acid derivatives, whereas the methanol extract yielded fifteen characterized by polar fatty acids and oxygenated derivatives. Identifications were tentative; those with lower match scores or inconsistent retention times required confirmation through alternative methods. Antioxidant capacity was evaluated via 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, hydroxyl radical inhibitory activity (HRIA), and ferric reducing antioxidant power (FRAP) assays. The methanol extract demonstrated concentration-dependent DPPH scavenging (IC₅₀ = 0.1402 mg/L), comparable to vitamin C (0.1369 mg/L) in this assay, while the n-hexane extract showed weaker activity (IC₅₀ 3.22 mg/L). In HRIA and FRAP assays, vitamin C consistently showed greater activity than either extract, with n-hexane IC50 estimates constrained by poor curve fits (R2<0.9). Overall, the methanol extract surpassed the n-hexane extract across all assays but did not match the effectiveness of vitamin C. These in-vitro results suggest that S. bicolor leaves contain polar phytochemicals that merit further fractionation, compound-level characterization, and evaluation in biologically relevant models to elucidate their potential as sources of natural antioxidants.
Optimization of Extraction Conditions and Kinetics of Antioxidant Compounds from Polyalthia longifolia Leaves Clark, Poro David
Sciences of Phytochemistry Volume 5 Issue 2 (2026)
Publisher : ETFLIN

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58920/sciphy0402625

Abstract

This study aimed to optimize phenolic antioxidant extraction from Polyalthia longifolia leaves using hot maceration with 70% ethanol and to characterize the extraction kinetics under optimal conditions. Response surface methodology was used to evaluate the effects of extraction time and temperature on extraction yield, total phenolic content (TPC), and ferric reducing antioxidant power (FRAP). Both factors significantly influenced all responses, with the extraction yield and TPC increasing progressively with temperature and time. FRAP, however, exhibited a dome-shaped response, peaking at intermediate temperatures before declining under prolonged high-temperature conditions, consistent with the thermal degradation of heat-labile antioxidants. The highest phenolic recovery and antioxidant activity were achieved at the upper boundary of the experimental domain, suggesting that the true optimum may lie beyond the conditions tested. Kinetic analysis further revealed that antioxidant-active compounds were mobilized faster than the bulk extractable mass, with implications for reducing extraction time and energy consumption at scale. These findings provide a statistically guided and kinetically informed foundation for the valorization of Polyalthia longifolia leaves, supporting future process optimization across broader solvent systems and extraction techniques for functional food and nutraceutical applications.