Extraction of phenolic and flavonoids compounds from kenaf (Hibiscus Cannabinus L.) using ultrasound assisted extraction

Abstract

The objective of this research is to conduct the preliminary phytochemical screening of phenolic and flavonoid compounds from leaves and bast fibres of Hibiscus Cannabinus L that been extracted using Ultrasound Assisted Extraction (UAE). This study was conducted to evaluate the comparative phytochemical screening test of kenaf leaves and kenaf bast fibres using Ultrasound Assisted Extraction (UAE) with water and absolute ethanol as extraction solvent and different extraction times. Phytochemical screening was carried out with the crude extracts by tested with ferric chloride test for phenolic compounds meanwhile sodium hydroxide 10% test for flavonoid compounds. The major finding of this research is the presences of phenolic and flavonoid compounds by the colour changes using the phytochemical screening test. In phenolic compound test, bast fibres shown the orange colour for ethanol solvents while for water shows dark orange with precipitate. Meanwhile, leaves give dark green colours for water and for ethanol the dark green colour was more intense. In flavonoid compound test, both water and ethanol solvent for bast fibres samples shows pale yellow while leaves show yellow for water and bright yellow for ethanol. Overall, the presence of phenolic and flavonoid compounds was confirmed in Hibiscus Cannabinus L. The result shown the kenaf leaves gives the most positives presences of both compounds according by the colour changes in water and ethanol solvents. The extracts from locally grown kenaf shows the presences of phenolic and flavonoid compounds which can be used as antibiotics for diseases.