henolic compounds and flavonoids from kinnow peel and their microbial activity
Loading...
Date
2014
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University Ludhiana
Abstract
The objectives of the study were to determine phenolics in kinnow peel and to determine its
antimicrobial potential. The effect of different solvents (Methanol, Ethanol, Ethyl acetate,
Isopropyl alcohol, Dichloromethane and Petroleum ether) for extraction of phenolics were
studied. Further, the extraction was done by two methods- Soxhlet extraction and
Conventional extraction. Results revealed that yield of kinnow peel extract were higher with
methanol i.e. 54.0%, whereas 2.3% in case of petroleum ether extract with Soxhlet extraction.
The total phenolic content ranged from 2.37 to 42.78 mg/g DW and total flavonoid content
ranged from 0.39 to 5.40 mg/g DW in petroleum ether and ethanolic extract, respectively.
Hesperidin which is a dominant flavanone in citrus was isolated and investigated for its antimicrobial
potential. Hesperidin was isolated by extracting the peel powder first with
petroleum ether and then with methanol and it was confirmed by TLC, IR and 1H NMR.
Acetylated Hesperidin was synthesized by reaction of hesperidin with glacial acetic acid and
it was identified by TLC and IR spectra. Antimicrobial activity of different kinnow peel
extracts, hesperidin and acetylated hesperidin was done by disc plate method against Bacillus
sp., Acinetobacter sp. and Pseudomonas sp. The highest antimicrobial activity was shown by
isopropyl alcohol extract with diameter of zone of inhibition of 17mm, 15mm and 16mm at
2500 µg/disc against Bacillus sp., Acinetobacter sp. and Pseudomonas sp. respectively.
Hesperidin was found to be less effective than its derivative. Results showed that all extracts,
hesperidin and its derivative could be used as antimicrobial agents except petroleum ether
extract. The minimum inhibitory concentrations (MIC) were evaluated for all extracts,
hesperidin and its derivative. The lowest MIC value was obtained for isopropyl alcohol
extract i.e.100 µg/disc, 120 µg/disc and 125 µg/disc, whereas MIC value was highest in case
of dichloromethane extract i.e. 400 µg/disc, 425 µg/disc and 450 µg/disc against Bacillus sp.,
Acinetobacter sp. and Pseudomonas sp. respectively.