Abstract
Background: Dioscorea dumetorum (bitter yam) is an underutilized West African species valued for its nutritional and ethnomedicinal importance. While its tubers have been extensively studied, the essential oils of its aerial parts remain largely unexplored. This study investigated the chemical composition, antimicrobial activity, and antioxidant potential of essential oils extracted from the leaves and stems of Dioscorea dumetorum, to provide scientific insight into their bioactive properties and industrial relevance. Methods: Leaves and stems were air-dried, pulverized, and hydro distilled using a Clevenger-type apparatus. Oil yields and physicochemical properties were determined, while chemical constituents were characterized by Gas Chromatography–Mass Spectrometry (GC-MS). Antimicrobial activity was evaluated against selected bacterial (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, Pseudomonas aeruginosa, Klebsiella pneumoniae) and fungal (Candida albicans, Aspergillus niger, Penicillium notatum, Rhizopus stolonifer) pathogens using the agar well diffusion method. Antioxidant potential was assessed by Ferric Reducing Antioxidant Power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assays. Results: The leaf and stem oils yielded 0.50% and 1.07%, respectively. GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil. Both oils exhibited broad-spectrum antimicrobial effects, with leaf oil showing larger inhibition zones (18–26 mm) than stem oil (14–24 mm). Antioxidant assays demonstrated concentration-dependent activities: leaf oil showed stronger ferric-reducing power, whereas stem oil displayed higher radical-scavenging potential. Conclusions: These findings demonstrated that Dioscorea dumetorum essential oils possess significant antimicrobial and antioxidant properties with distinct phytochemical profiles, supporting their potential applications as natural sources of bioactive compounds in nutraceutical, pharmaceutical, and cosmetic formulations.
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Claims 12
Claim · model-written summary
Leaf oil yield was 0.50%.
- Taxon
- Dioscorea dumetorum
Dioscorea dumetorume1 - Organ / stage
- leafe0
- Outcome
- leaf and stem oils yieldede0
- Value
- 0.50%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf and stem oils yielded 0.50% and 1.07%, respectively.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Stem oil yield was 1.07%.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- leaf and stem oils yieldede0
- Value
- 1.07%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The leaf and stem oils yielded 0.50% and 1.07%, respectively.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
GC-MS found 23 compounds in leaf oil.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- leafe0
- Outcome
- compoundse0
- Value
- 23e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
GC-MS found 20 compounds in stem oil.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- compoundse0
- Value
- 20e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Leaf oil contained 20.64% 2-pentadecanone.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- leafe0
- Outcome
- 2-pentadecanonee0
- Value
- 20.64%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Leaf oil contained 16.74% phytol.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- leafe0
- Outcome
- phytole0
- Value
- 16.74%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Stem oil contained 34.43% di-n-octyl phthalate.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- di-n-octyl phthalatee0
- Value
- 34.43%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Stem oil contained 15.97% eicosanoic acid esters.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- eicosanoic acid esterse0
- Value
- 15.97%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“GC-MS analysis revealed 23 and 20 compounds dominated by 2-pentadecanone (20.64%) and phytol (16.74%) in the leaf oil, and di-n-octyl phthalate (34.43%) and eicosanoic acid esters (15.97%) in the stem oil.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Leaf oil had inhibition zones of 18–26 mm.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- leafe0
- Outcome
- inhibition zonese0
- Direction
- largere0
- Value
- 18–26 mme0
- Comparator
- stem oile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both oils exhibited broad-spectrum antimicrobial effects, with leaf oil showing larger inhibition zones (18–26 mm) than stem oil (14–24 mm).”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Stem oil had inhibition zones of 14–24 mm.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- inhibition zonese0
- Value
- 14–24 mme0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Both oils exhibited broad-spectrum antimicrobial effects, with leaf oil showing larger inhibition zones (18–26 mm) than stem oil (14–24 mm).”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Leaf oil showed stronger ferric-reducing power.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- leafe0
- Outcome
- ferric-reducing powere0
- Direction
- strongere0
- Qualifier
- concentration-dependente0
- Comparator
- stem oile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Antioxidant assays demonstrated concentration-dependent activities: leaf oil showed stronger ferric-reducing power, whereas stem oil displayed higher radical-scavenging potential.”
e1“Dioscorea dumetorum (bitter yam)”
Claim · model-written summary
Stem oil showed higher radical-scavenging potential.
- Taxon
- Dioscorea dumetorumDioscorea dumetorume1
- Organ / stage
- steme0
- Outcome
- radical-scavenging potentiale0
- Direction
- highere0
- Qualifier
- concentration-dependente0
- Comparator
- leaf oile0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Antioxidant assays demonstrated concentration-dependent activities: leaf oil showed stronger ferric-reducing power, whereas stem oil displayed higher radical-scavenging potential.”
e1“Dioscorea dumetorum (bitter yam)”