phytochemical analysis, antibacterial and antioxidant activities of essential oil from hibiscus sabdariffa (l) seeds, (sudanese karkadi)

In this study we investigated the chemical constituents, phytochemical screening of the essential oil from h. sabdariffa (l) seeds, (sudanese karkadi) and evaluated its potential antibacterial and antioxidant activities, using soxhlet method to extract the essential oil. the chemical constituents of h. sabdariffa (l) oil were identified and quantified by gc-ms, where dpph and paper, disc diffusion assay were employed to evaluate the antioxidant and antibacterial activities respectively. phytochemical screening showed that alkaloids, flavonoids, carbohydrates, saponins, triterpens, streols, tannins and phenolic compounds are present in seeds of the h. sabdariffa. thirty eight components have been identified which classified in to four categories; 31 fatty acid ester derivatives , the majority of them are; hexadecanoic acid, methyl ester (16.94%), 9,12- octadecadienoic acid (z,z), methyl ester (21.93%), 9, -octadecadienoic acid (z), methyl ester (30.11%), methyl stearate(7.39%), cyclopropaneoctanoic acid (3.17 %), dotriacontane(2.17 %), two phenolic derivatives; 1,3-benzodioxole, 4methoxy-6-(2-propenyl) (0.01 %) and apiol (0.04 %), two steroidal derivatives; 17-androstannone, 3-(3, 4-dimethylphenyl) (1.81%) and stigmasta-4,7,22-trien-3.beta.-ol (0.41%) and three pentacyclic triterpenes derivatives; beta.-amyrin (3.82%), alpha.-amyrin (1.65 %) urs-12-en-3-ol, acetate,(3.beta.) (1.17%). the dpph assay, showed moderate antioxidant potential (50 ± 0.01 compared with standard 89 ± 0.01; the antibacterial showed high inhibitory effect against bacillus subtilis (13mm). in conclusion, the study showed that the oil of h. sabdariffa seed is a good source of antioxidants due to the presence of phenolic compounds, also is a potential source of natural antibacterial, and justify its uses in folkloric medicines.