Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics
Ipomoea aquatica Forssk. (morning glory) is a green leafy vegetable that is rich in minerals, proteins, vitamins, amino acids and secondary metabolites. The aims of the study were to discriminate Ipomoea extracts by 1H NMR spectroscopy in combination with chemometrics method and to determine thei...
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my-upm-ir.694152019-07-10T01:02:28Z Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics 2016-03 Lawal, Umar Ipomoea aquatica Forssk. (morning glory) is a green leafy vegetable that is rich in minerals, proteins, vitamins, amino acids and secondary metabolites. The aims of the study were to discriminate Ipomoea extracts by 1H NMR spectroscopy in combination with chemometrics method and to determine their antioxidant and α-glucosidase inhibitory activities. In the first part of the study, different types of I. aquatica cultivar such as the upland type has narrow leaves (K-11), the low-land and aquatic type, have broader, arrow-shaped leaves, (K-25) and bamboo shaped leaves (K-88), extracted using water and methanol at various concentrations were investigate for their effects on the total phenolics, antioxidant and α-glucosidase inhibitory activities. This study indicates that 70% methanol was the most efficient solvent for the extraction of phenolic compounds from I. aquatica cultivars. Thus, for the second part of the study 1H NMR combined with multivariate data analysis was applied for the metabolic profiling of three cultivars of I. aquatica extracted with 70% methanol. The orthogonal partial least squares discriminant analysis (OPLS-DA) indicated a clear separation among cultivars. The relative levels of various compounds such as amino acids, organic acids, sugars and phenolic compounds were specific to each cultivar. Among the three cultivars, the K-11 was the most active for the antioxidant and α-glucosidase inhibitory activities and was selected for the third part of the study. Proton nuclear magnetic resonance (1H NMR) spectroscopy was combined with multivariate data analyses to distinguish the K-11 cultivar at different developmental stages. A principal component analysis (PCA) of I. aquatica provides clusters based on the different developmental stages by combining principal components PC1 and PC2 with a total variance of 65.1%. The initial stages (weeks 3 and 4) showed comparatively low contents of phenolic and organic acids, such as citric and maleic acid; the latter stages (weeks 5 and 6) exhibited higher glucose and phenolic compound contents. The sugar, phenolic compound, fatty and formic acid contents increased based on the developmental stages of the I. aquatica. The latent structures were projected using a partial least squares (PLS) model to predict the biological activity of the Ipomoea extracts based on their 1H NMR spectra. The results showed that six-week-old plants were the most active, showing an accumulation of epicatechin, protocatechuic acid, rutin and maleic acid. In addition, three compounds namely 3,5-di-O-caffeoylquinic acid (83) and 4,5-di-O-caffeoylquinic acid (84) and quercetin-3-O-β-glucoside (85) were isolated from six-week-old of the K-11 cultivar. The structures of these compounds were elucidated using various spectroscopic techniques including UV, ESIMS, 1D- and 2D-NMR. Compounds (83) and (84) exhibited good antioxidant activity with IC50 values of 4.85±0.06 μg/mL and 6.65±0.12 μg/mL, respectively, and compound (85) exhibited the lowest activity with IC50 values of 7.66±0.19 μg/mL compared to standard BHT; 6.25±0.15 μg/mL. A similar trend was observed for α- glucosidase inhibitory activity. In conclusion, this study may serve as a starting point for further research on phytochemicals from I. aquatica and can aid in the development of medicinal preparation, nutraceutical and functional food. Ipomoea aquatica Plant metabolites Antioxidants 2016-03 Thesis http://psasir.upm.edu.my/id/eprint/69415/ http://psasir.upm.edu.my/id/eprint/69415/1/FSTM%202016%204%20-%20IR.pdf text en public doctoral Universiti Putra Malaysia Ipomoea aquatica Plant metabolites Antioxidants |
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Universiti Putra Malaysia |
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PSAS Institutional Repository |
| language |
English |
| topic |
Ipomoea aquatica Plant metabolites Antioxidants |
| spellingShingle |
Ipomoea aquatica Plant metabolites Antioxidants Lawal, Umar Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| description |
Ipomoea aquatica Forssk. (morning glory) is a green leafy vegetable that is rich in
minerals, proteins, vitamins, amino acids and secondary metabolites. The aims of the
study were to discriminate Ipomoea extracts by 1H NMR spectroscopy in combination
with chemometrics method and to determine their antioxidant and α-glucosidase
inhibitory activities. In the first part of the study, different types of I. aquatica cultivar
such as the upland type has narrow leaves (K-11), the low-land and aquatic type, have
broader, arrow-shaped leaves, (K-25) and bamboo shaped leaves (K-88), extracted
using water and methanol at various concentrations were investigate for their effects on
the total phenolics, antioxidant and α-glucosidase inhibitory activities. This study
indicates that 70% methanol was the most efficient solvent for the extraction of
phenolic compounds from I. aquatica cultivars. Thus, for the second part of the study
1H NMR combined with multivariate data analysis was applied for the metabolic
profiling of three cultivars of I. aquatica extracted with 70% methanol. The orthogonal
partial least squares discriminant analysis (OPLS-DA) indicated a clear separation
among cultivars. The relative levels of various compounds such as amino acids,
organic acids, sugars and phenolic compounds were specific to each cultivar. Among
the three cultivars, the K-11 was the most active for the antioxidant and α-glucosidase
inhibitory activities and was selected for the third part of the study. Proton nuclear
magnetic resonance (1H NMR) spectroscopy was combined with multivariate data
analyses to distinguish the K-11 cultivar at different developmental stages. A principal
component analysis (PCA) of I. aquatica provides clusters based on the different
developmental stages by combining principal components PC1 and PC2 with a total
variance of 65.1%. The initial stages (weeks 3 and 4) showed comparatively low
contents of phenolic and organic acids, such as citric and maleic acid; the latter stages
(weeks 5 and 6) exhibited higher glucose and phenolic compound contents. The sugar,
phenolic compound, fatty and formic acid contents increased based on the
developmental stages of the I. aquatica. The latent structures were projected using a
partial least squares (PLS) model to predict the biological activity of the Ipomoea extracts based on their 1H NMR spectra. The results showed that six-week-old plants
were the most active, showing an accumulation of epicatechin, protocatechuic acid,
rutin and maleic acid. In addition, three compounds namely 3,5-di-O-caffeoylquinic
acid (83) and 4,5-di-O-caffeoylquinic acid (84) and quercetin-3-O-β-glucoside (85)
were isolated from six-week-old of the K-11 cultivar. The structures of these
compounds were elucidated using various spectroscopic techniques including UV,
ESIMS, 1D- and 2D-NMR. Compounds (83) and (84) exhibited good antioxidant
activity with IC50 values of 4.85±0.06 μg/mL and 6.65±0.12 μg/mL, respectively, and
compound (85) exhibited the lowest activity with IC50 values of 7.66±0.19 μg/mL
compared to standard BHT; 6.25±0.15 μg/mL. A similar trend was observed for α-
glucosidase inhibitory activity. In conclusion, this study may serve as a starting point
for further research on phytochemicals from I. aquatica and can aid in the development
of medicinal preparation, nutraceutical and functional food. |
| format |
Thesis |
| qualification_level |
Doctorate |
| author |
Lawal, Umar |
| author_facet |
Lawal, Umar |
| author_sort |
Lawal, Umar |
| title |
Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| title_short |
Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| title_full |
Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| title_fullStr |
Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| title_full_unstemmed |
Correlation between metabolite profile and phytochemical characteristics of Ipomoea aquatica Forssk. with its antioxidant and α-glucosidase inhibitory activities using NMR-based metabolomics |
| title_sort |
correlation between metabolite profile and phytochemical characteristics of ipomoea aquatica forssk. with its antioxidant and α-glucosidase inhibitory activities using nmr-based metabolomics |
| granting_institution |
Universiti Putra Malaysia |
| publishDate |
2016 |
| url |
http://psasir.upm.edu.my/id/eprint/69415/1/FSTM%202016%204%20-%20IR.pdf |
| _version_ |
1747812694330703872 |