Synthesis and bioactivity studies of flavonoid and its derivatives

Flavonoids are the most widespread class of plants constituents. Most flavonoids are produced in biosynthetic pathways of secondary metabolites in plants and chalcones constituent as the important intermediate in flavonoid biosynthesis. In this study, eleven flavonoid derivatives were synthesized na...

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Main Author:	Hashim, Nur Athirah
Format:	Thesis
Language:	English
Published:	2012
Subjects:	QK Botany
Online Access:	http://eprints.utm.my/id/eprint/31956/1/NurAthirahHashimMFS2012.pdf
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spelling	my-utm-ep.319562018-04-12T05:05:55Z Synthesis and bioactivity studies of flavonoid and its derivatives 2012-09 Hashim, Nur Athirah QK Botany Flavonoids are the most widespread class of plants constituents. Most flavonoids are produced in biosynthetic pathways of secondary metabolites in plants and chalcones constituent as the important intermediate in flavonoid biosynthesis. In this study, eleven flavonoid derivatives were synthesized namely 2',3,4-trihydroxy-4',6'-dimethoxychalcone (110), 2',4',6'-trihydroxy-4,6-dimethoxychalcone (120), along with new compounds of 4',5,7-trimethoxy-3'-O-prenylflavanone (123), 4',5,7-trimethoxy-3'-O-6-C-diprenylflavanone (126), 2'-hydroxy- 4',6'- dimethoxy-3,4-methylenedioxy -3'-C-prenylchalcone (127), 5,6- chroman- 7-methoxy- 3',4'-methylenedioxyflavone (130), 5,6,7,8- dichroman- 3',4'- methylenedioxyflavone (132), 5',6'- chroman-2',3,4- trihydroxy- 4'-methoxychalcone (134), 3',4',5',6'-dichroman- 2',3,4-trihydroxychalcone (137), 3',4',5',6'-dichroman-3,4-dimethoxy-2'-hydroxychalcone (138) and 5',6'- chroman-2'- hydroxy-4'- methoxy-3,4-O-diprenylchalcone (139). The initial step in the synthesis was to prepare various derivatives of 2,4,6-trihydroxyacetophenone and 3,4-dihydroxybenzaldehyde by methylation, methylenation, protection and prenylation of the phenolic hydroxyl groups. The derivatives of both ketone and aldehyde were coupled and reacted using Claisen-Schmidt condensation to obtain the desired 2'-hydroxychalcone. 2'-Hydroxy-4,4',6'-trimethoxy-3-O-prenylchalcone (122) and 4,4',6'-trimethoxy-3-O-5'-C-diprenylchalcone (125) underwent an acid hydrolysis to yield flavanones (123) and (126), respectively. In addition, 2'-hydroxy- 4-methoxy- 5,6-chroman- 3,4-methylenedioxychalcone (129) and 2'- hydroxy- 3',4',5',6'- dichroman- 3,4-methylenedioxychalcone (131) were converted to flavones (130) and (132) using iodine in dimethylsulfoxide as an oxidative agent The structures of all compounds were confirmed spectroscopically by UV, IR, NMR and MS analysis. The biological studies of all the synthetic compounds were tested towards antioxidant, anti-inflammatory and antibacterial properties. The hydroxylated flavonoids with 3,4-dihydroxyl substituents were tested positive in 2,2-diphenyl-1-dipicrylhydrazyl (DPPH) assay and the highest antioxidant activity was exhibited by chalcone (110) with IC50 19.3 µg/mL. Two assays were used to evaluate the potential of the compounds as anti-inflammation agents. The results showed that chalcones (110) (IC50 2.4 µg/mL), (134) (IC50 1.94 µg/mL) and (137) (IC50 20.8 µg/mL) which possessed 3,4-dihydroxyl substituents exhibited good activity in the 13-lipooxygenase (LOX) assay. For xanthine oxidase assay, chalcone (120) with 4',6'-dihydroxyl showed a significant activity with IC50 6.83 µg/mL. All the synthesized flavonoids were found inactive towards the tested bacteria in the antibacterial assay. 2012-09 Thesis http://eprints.utm.my/id/eprint/31956/ http://eprints.utm.my/id/eprint/31956/1/NurAthirahHashimMFS2012.pdf application/pdf en public masters Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QK Botany
spellingShingle	QK Botany Hashim, Nur Athirah Synthesis and bioactivity studies of flavonoid and its derivatives
description	Flavonoids are the most widespread class of plants constituents. Most flavonoids are produced in biosynthetic pathways of secondary metabolites in plants and chalcones constituent as the important intermediate in flavonoid biosynthesis. In this study, eleven flavonoid derivatives were synthesized namely 2',3,4-trihydroxy-4',6'-dimethoxychalcone (110), 2',4',6'-trihydroxy-4,6-dimethoxychalcone (120), along with new compounds of 4',5,7-trimethoxy-3'-O-prenylflavanone (123), 4',5,7-trimethoxy-3'-O-6-C-diprenylflavanone (126), 2'-hydroxy- 4',6'- dimethoxy-3,4-methylenedioxy -3'-C-prenylchalcone (127), 5,6- chroman- 7-methoxy- 3',4'-methylenedioxyflavone (130), 5,6,7,8- dichroman- 3',4'- methylenedioxyflavone (132), 5',6'- chroman-2',3,4- trihydroxy- 4'-methoxychalcone (134), 3',4',5',6'-dichroman- 2',3,4-trihydroxychalcone (137), 3',4',5',6'-dichroman-3,4-dimethoxy-2'-hydroxychalcone (138) and 5',6'- chroman-2'- hydroxy-4'- methoxy-3,4-O-diprenylchalcone (139). The initial step in the synthesis was to prepare various derivatives of 2,4,6-trihydroxyacetophenone and 3,4-dihydroxybenzaldehyde by methylation, methylenation, protection and prenylation of the phenolic hydroxyl groups. The derivatives of both ketone and aldehyde were coupled and reacted using Claisen-Schmidt condensation to obtain the desired 2'-hydroxychalcone. 2'-Hydroxy-4,4',6'-trimethoxy-3-O-prenylchalcone (122) and 4,4',6'-trimethoxy-3-O-5'-C-diprenylchalcone (125) underwent an acid hydrolysis to yield flavanones (123) and (126), respectively. In addition, 2'-hydroxy- 4-methoxy- 5,6-chroman- 3,4-methylenedioxychalcone (129) and 2'- hydroxy- 3',4',5',6'- dichroman- 3,4-methylenedioxychalcone (131) were converted to flavones (130) and (132) using iodine in dimethylsulfoxide as an oxidative agent The structures of all compounds were confirmed spectroscopically by UV, IR, NMR and MS analysis. The biological studies of all the synthetic compounds were tested towards antioxidant, anti-inflammatory and antibacterial properties. The hydroxylated flavonoids with 3,4-dihydroxyl substituents were tested positive in 2,2-diphenyl-1-dipicrylhydrazyl (DPPH) assay and the highest antioxidant activity was exhibited by chalcone (110) with IC50 19.3 µg/mL. Two assays were used to evaluate the potential of the compounds as anti-inflammation agents. The results showed that chalcones (110) (IC50 2.4 µg/mL), (134) (IC50 1.94 µg/mL) and (137) (IC50 20.8 µg/mL) which possessed 3,4-dihydroxyl substituents exhibited good activity in the 13-lipooxygenase (LOX) assay. For xanthine oxidase assay, chalcone (120) with 4',6'-dihydroxyl showed a significant activity with IC50 6.83 µg/mL. All the synthesized flavonoids were found inactive towards the tested bacteria in the antibacterial assay.
format	Thesis
qualification_level	Master's degree
author	Hashim, Nur Athirah
author_facet	Hashim, Nur Athirah
author_sort	Hashim, Nur Athirah
title	Synthesis and bioactivity studies of flavonoid and its derivatives
title_short	Synthesis and bioactivity studies of flavonoid and its derivatives
title_full	Synthesis and bioactivity studies of flavonoid and its derivatives
title_fullStr	Synthesis and bioactivity studies of flavonoid and its derivatives
title_full_unstemmed	Synthesis and bioactivity studies of flavonoid and its derivatives
title_sort	synthesis and bioactivity studies of flavonoid and its derivatives
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2012
url	http://eprints.utm.my/id/eprint/31956/1/NurAthirahHashimMFS2012.pdf
_version_	1747815886339702784

Synthesis and bioactivity studies of flavonoid and its derivatives

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