Phytochemical analysis, antioxidant, antibacterial potentials and chemical composition of methanol extract of <i>Oscillatoria</i> sp.

Abstract

Background: Algae contains some useful phytochemicals and Oscillatoria sp. is a green microalga which has various applications

Objectives: Phytochemicals, antioxidant, antibacterial potential and chemical composition of methanol extract of Oscillatoria sp. were evaluated.

Materials and Methods: Extraction of bioactive compound from Oscillatoria sp., determination of phytochemicals, antioxidant, antibacterial potential and chemical composition of the methanol extract.

Results: Saponin, alkaloids and flavonoids were detected in the methanol extract while glycosides and phenols were absent. The scavenging assay for the antioxidant increased in a dose dependent (100 -1000 μg/mL) manner. The DPPH scavenging activity, Total phenolic content, Ferric Reducing Antioxidant Power Assay (FRAP) and hydrogen peroxide scavenging activity ranged from 21.8 - 44.9%, 9.09 -21.46%, 0.43 - 42.49% and 19.4 - 74.4% respectively. The methanol extract had inhibitory activity against the test pathogens in which Pseudomonas aeruginosa ATCC 27853 (24.0 mm) had the highest susceptibility. GCMS chromatogram of the methanol extract of Oscillatoria sp. shows fifteen major peaks which indicated the presence of Oleic acid, stearic acid, aracidic acid, methyl laurate, methyl myristate, oxirane and palmitic acid.

Conclusion: Oscillatoria sp. methanol extract contain some phytochemicals and some heterocyclic compounds. The extract had good antioxidant capability and appreciable antibacterial activity against the test pathogens.

Keywords: Oscillatoria sp.; methanol extract; Phytochemical; Antioxidant; GC-MS; Antibacterial