Phang, Siew Thing (2014) Study of the effects of L-Ascorbic acid and Ferrous Ions on Myrosinase Enzyme Activtiy by using Spectrophotometric method. Universiti Malaysia Sabah. (Unpublished)
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Study of the effects of L Ascorbic acid and Ferrous Ions on Myrosinase Enzyme Activtiy by using Spectrophotometric method.pdf Download (2MB) | Preview |
Abstract
Glucosinolates (GS) are sulphur-containing secondary metabolites found largely in Brassicaceae family. GS undergo hydrolysis readily upon cell rupture by the naturallyoccurring enzyme myrosinase to form mainly isothiocyanates and/or simple nitriles. Isothiocyanates are known to possess anti-carcinogenic properties. An enzymatic assay of glucosinolate degradation requires an optimized condition for sensitive and reliable methods. In this study, two main experiments have been carried out. Firstly, an optimized spectrophotometric method for enzyme-substrate assay using standard myrosinase (enzyme) and sinigrin (substrate) have been systematically developed. Secondly, by using the developed method, the effects of L-ascorbic acid and ferrous ions on the myrosinase activity were studied. The results showed that the optimum composition of sinigrin and myrosinase were 0.20 mM and 0.065 mM, respectively. The other optimum conditions were at pH 6.5 (in phosphate buffer) and at room temperature in the range of 22-25°C. The optimum UV detection wavelength was at 234 nm. It was shown that, low concentration of ascorbic acid enhanced the myrosinase activity but eventually inhibited it as the concentration increased. The highest myrosinase activity by L-ascorbic was at the concentration of 0.5 mM.Ferrous ions impacted on myrosinase activity significantly even with a trace amount. At 10 mM ferrous ions, the myrosinase activity was inhibited almost 100%. The newly-developed method using UV-Vis spectrophotometer appears easy, rapid and cost-effective for determination of myrosinase activity.
| Item Type: | Academic Exercise |
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| Keyword: | Glucosinolates (GS) , enzyme , anti-carcinogenic properties |
| Subjects: | Q Science > QD Chemistry |
| Department: | FACULTY > Faculty of Science and Natural Resources |
| Depositing User: | NORAINI LABUK - |
| Date Deposited: | 07 Mar 2018 17:10 |
| Last Modified: | 07 Mar 2018 17:10 |
| URI: | https://eprints.ums.edu.my/id/eprint/19104 |
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