Partial isolation and characterization of secondary metabolites of Selliguea taeniata and its antioxidant and antibacterial activity
Date
2019
Authors
Abigail L. Dela Cruz
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Abstract
This current study presents chemical exploration on the methanolic leaf extract of Selliguea taeniata, a fern species endemic in certain regions in the Philippines, such as Ifugao where it is used to treat cough. Although botanical data of this fern are reported, there are still no reports, as of the time this thesis was conducted, regarding its chemical properties, such as phytochemicals and biological activities. For this to be conducted, the air-dried leaves of S. taeniata were extracted using absolute methanol. Crude extract was concentrated and subjected to Folin-Ciocalteu method to determine the total phenolic content (TPC), 2.2diphenyl-1 picrylhydrazyl (DPPH) free radical scavenging assay to evaluate its antioxidant activity, disc diffusion method to assess antibacterial activity, and phytochemical screening. Subsequently, various chromatographic techniques and 1H Nuclear Magnetic Resonance spectroscopy were applied to partially isolate and characterize its secondary metabolites. Methanolic leaf extract of S. taeniata had TPC of 1669.11±0.07 mg GAE/gram of dried sample. It also exhibited antioxidant activity of (EC50=85.79±0.023 ppm), which was lower than ascorbic acid (EC50 = 0.51±0.66ppm). However, it was found ineffective against Escherichia coli and Staphylococcus aureus. The crude extract was found to contain alkaloids, falvonoids, cardiac glycosides, saponins, phenols and tannins. Partial isolation of its secondary metabolites suggested that the crude extract may contain a mixture of proanthrocyandins and/ or its monomer units, and glycosides. In conclusions, S. taeniata was considered as strong antioxidant, but was inactive against E. coli and S. aureus. It contained high amount of phenolic compounds that could be proanthrocyanidins and/or monomer units of it and glycosides.
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Research Subject Categories::NATURAL SCIENCES::Chemistry