Synthesis and biological activities of O- and C-prenylated flavonoid derivatives

Chalcones scaffolds have attracted many researchers to investigate their synthetic routes, potential biological activities and their roles as intermediates for naturally occurring flavanoid skeletons. This study focused on the synthesis of chalcones bearing the O-, C-prenyl and chromane as substitue...

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Main Author: Mohd. Fauzi, Nur Edelin
Format: Thesis
Language:English
Published: 2017
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Online Access:http://eprints.utm.my/id/eprint/77808/1/NurEdelinMohdMFS20171.pdf
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spelling my-utm-ep.778082018-07-04T11:46:05Z Synthesis and biological activities of O- and C-prenylated flavonoid derivatives 2017-03 Mohd. Fauzi, Nur Edelin QD Chemistry Chalcones scaffolds have attracted many researchers to investigate their synthetic routes, potential biological activities and their roles as intermediates for naturally occurring flavanoid skeletons. This study focused on the synthesis of chalcones bearing the O-, C-prenyl and chromane as substituents. The target compounds were purified by chromatographic methods and the structures of these compounds were determined by using infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectroscopies. The prenylated precursors were synthesized starting from 2,4-dihydroxyacetophenone (65) and 2,4,6-trihydroxyacetophenone (93). Prenylation of 2,4-dihydroxyacetophenone using prenyl bromide has been successfully accomplished to produce 2-hydroxy-4-O-prenylacetophenone (101). A reaction of 2,4,6-trihydroxyacetophenone with prenyl bromide in the presence of base resulted in a mixture and the chromatographic purification gave 2,4,6-trihydroxy-3-C-prenylacetophenone (132) and 2,4-dihydroxy-5,6-chromanacetophenone (133). Compound (133) was prenylated into 2-hydroxy-4-O-prenyl-5,6-chromanacetophenone (136). C-prenylated acetophenone (132) was then converted to 2-hydroxy-3-C-prenyl-4,6-dimethoxyacetophenone (137) using methyl iodide in the presence of potassium carbonate. Claisen-Schmidt condensation of O- and C-prenylated acetophenone with individual benzaldehydes, namely 4-(N,N-dimethyl)aminobenzaldehyde (61), 2-methoxybenzaldehyde (126), 4-isopropylbenzaldehyde (127), 3,4-dimethoxybenzaldehyde (128) and 4-chlorobenzaldehyde (129) resulted in the formation of two series of chalcones, each consisting of five chalcones. These two series differ in the existence of prenyl substituents on ring A of the chalcone structure. Five chalcones bear O-prenyl and five others bear C-prenyl substituent with both series having the same substituents on ring B consisting of 4-(N,N-dimethyl)amino, 2-methoxy, 4-isopropyl, 3,4-dimethoxy and 4-chloro substituents. Chromanochalcone (152) was the sole compound successfully synthesized with the aid of prenylation of free hydroxyl group of the chromanacetophenone (133) precursor. All the synthetic compounds were screened for antibacterial activity by the micro dilution method against two bacteria strains, namely Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative (Pseudomonas aeruginosa and Escherichia coli). The compounds were also tested for 15-LOX assay using Lipoxygenase inhibitory screening assay kit (Item No. 760700). All the synthetic compounds did not show activity against the bacteria tested, while compound (138) and (145) showed moderate lypoxygenase activity at 100 M concentration with 53.9% and 50.9% inhibition, respectively. 2017-03 Thesis http://eprints.utm.my/id/eprint/77808/ http://eprints.utm.my/id/eprint/77808/1/NurEdelinMohdMFS20171.pdf application/pdf en public http://dms.library.utm.my:8080/vital/access/manager/Repository/vital:105101 masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution Universiti Teknologi Malaysia
collection UTM Institutional Repository
language English
topic QD Chemistry
spellingShingle QD Chemistry
Mohd. Fauzi, Nur Edelin
Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
description Chalcones scaffolds have attracted many researchers to investigate their synthetic routes, potential biological activities and their roles as intermediates for naturally occurring flavanoid skeletons. This study focused on the synthesis of chalcones bearing the O-, C-prenyl and chromane as substituents. The target compounds were purified by chromatographic methods and the structures of these compounds were determined by using infrared (IR), nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectroscopies. The prenylated precursors were synthesized starting from 2,4-dihydroxyacetophenone (65) and 2,4,6-trihydroxyacetophenone (93). Prenylation of 2,4-dihydroxyacetophenone using prenyl bromide has been successfully accomplished to produce 2-hydroxy-4-O-prenylacetophenone (101). A reaction of 2,4,6-trihydroxyacetophenone with prenyl bromide in the presence of base resulted in a mixture and the chromatographic purification gave 2,4,6-trihydroxy-3-C-prenylacetophenone (132) and 2,4-dihydroxy-5,6-chromanacetophenone (133). Compound (133) was prenylated into 2-hydroxy-4-O-prenyl-5,6-chromanacetophenone (136). C-prenylated acetophenone (132) was then converted to 2-hydroxy-3-C-prenyl-4,6-dimethoxyacetophenone (137) using methyl iodide in the presence of potassium carbonate. Claisen-Schmidt condensation of O- and C-prenylated acetophenone with individual benzaldehydes, namely 4-(N,N-dimethyl)aminobenzaldehyde (61), 2-methoxybenzaldehyde (126), 4-isopropylbenzaldehyde (127), 3,4-dimethoxybenzaldehyde (128) and 4-chlorobenzaldehyde (129) resulted in the formation of two series of chalcones, each consisting of five chalcones. These two series differ in the existence of prenyl substituents on ring A of the chalcone structure. Five chalcones bear O-prenyl and five others bear C-prenyl substituent with both series having the same substituents on ring B consisting of 4-(N,N-dimethyl)amino, 2-methoxy, 4-isopropyl, 3,4-dimethoxy and 4-chloro substituents. Chromanochalcone (152) was the sole compound successfully synthesized with the aid of prenylation of free hydroxyl group of the chromanacetophenone (133) precursor. All the synthetic compounds were screened for antibacterial activity by the micro dilution method against two bacteria strains, namely Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram negative (Pseudomonas aeruginosa and Escherichia coli). The compounds were also tested for 15-LOX assay using Lipoxygenase inhibitory screening assay kit (Item No. 760700). All the synthetic compounds did not show activity against the bacteria tested, while compound (138) and (145) showed moderate lypoxygenase activity at 100 M concentration with 53.9% and 50.9% inhibition, respectively.
format Thesis
qualification_level Master's degree
author Mohd. Fauzi, Nur Edelin
author_facet Mohd. Fauzi, Nur Edelin
author_sort Mohd. Fauzi, Nur Edelin
title Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
title_short Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
title_full Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
title_fullStr Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
title_full_unstemmed Synthesis and biological activities of O- and C-prenylated flavonoid derivatives
title_sort synthesis and biological activities of o- and c-prenylated flavonoid derivatives
granting_institution Universiti Teknologi Malaysia, Faculty of Science
granting_department Faculty of Science
publishDate 2017
url http://eprints.utm.my/id/eprint/77808/1/NurEdelinMohdMFS20171.pdf
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