Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith

Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith

Zerumbone, a sesquiterpenoid from the essential oil of Zingiber zerumbet, Smith has been isolated in 0.33% by recrystallization from n-hexane. Treatment of zerumbone with m-chloroperbenzoic acid (MCPBA), followed by methanolysis with N-bromosuccinimide (NBS) and methanol gave 2-hydroxy-3-methoxy-6,9...

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Main Author: Ahmad, Mohamad Syahrizal
Format: Thesis
Language:English
Published: 2006
Subjects:
QD Chemistry
Online Access:http://eprints.utm.my/id/eprint/5325/1/MohamadSyahrizalAhmadMFS2006.pdf
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spelling my-utm-ep.53252018-03-07T20:56:31Z Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith 2006-03 Ahmad, Mohamad Syahrizal QD Chemistry Zerumbone, a sesquiterpenoid from the essential oil of Zingiber zerumbet, Smith has been isolated in 0.33% by recrystallization from n-hexane. Treatment of zerumbone with m-chloroperbenzoic acid (MCPBA), followed by methanolysis with N-bromosuccinimide (NBS) and methanol gave 2-hydroxy-3-methoxy-6,9-humuladien-8-one, while acetylation of 2-hydroxy-3-methoxy-6,9-humuladien-8-one afforded 2-acetoxy-3-methoxy-6,9-humuladien-8-one. Reaction of zerumbone with bromine (Br2) at -5ºC to -10ºC in carbon tetrachloride (CCl4) gave 6,7-dibromo-2,9-humuladien-8-one. Further treatment of 6,7-dibromo-2,9-humuladien-8-one with m-chloroperbenzoic acid (MCPBA) gave 6,7-dibromo-2,3-epoxy-9-humulen-8-one. Under nitrogen, zerumbone was reduced with lithium aluminium hydride (LiAlH4) at -5ºC to -10ºC to afford zerumbol. Acetylation and methylation of zerumbol gave 8-acetoxy-2,6,9-humulatriene and 8-methoxy-2,6,9-humulatriene, respectively. 2,3-Epoxy-6-ethoxy-9-humulen-8-one has been obtained by treating zerumbone with ethanol at 10°C to 15°C in the presence of boron trifluoride-etherate as catalyst, followed by epoxidation with m-chloroperbenzoic acid (MCPBA). 6,10-Dicyano-2-humulen-8-one was prepared by treatment of zerumbone with potassium cyanide at 15ºC to 20ºC in the presence of a-cyclodextrin. The deoxygenation of the zerumbone under the Clemmensen reduction, followed by Sharpless asymmetric dihydroxylation yielded (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one and (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one as the major and minor compounds respectively. Acetylation of (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one afforded (6S,7S)-6-acetoxy-7-hydroxy-2,9-humuladien-8-one, while further treatment of the acetoxy compound in the presence of 4-N,N-dimethylaminopyridine (DMAP) as catalyst gave (6S,7S)-6,7-diacetoxy-2,9-humuladien-8-one. (9S,10S)-9,10-Diacetoxy-2,6-humuladien-8-one has been obtained by acetylation of (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one in the presence of 4-N,N-dimethylaminopyridine (DMAP) as catalyst. Antibacterial screening showed that zerumbol gave a moderate inhibition to Bacillus subtilis with minimum concentration of 0.025 µg/µL and Pseudomonas aeruginosa with minimum concentration of 0.05 µg/µL. The results showed that 6,10-dicyano-2-humulen-8-one, (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one and (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one gave the highest antioxidant activity with the IC50 were 0.0171, 0.0227 and 0.0259 respectively. 2006-03 Thesis http://eprints.utm.my/id/eprint/5325/ http://eprints.utm.my/id/eprint/5325/1/MohamadSyahrizalAhmadMFS2006.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 QD Chemistry
spellingShingle QD Chemistry
Ahmad, Mohamad Syahrizal
Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
description Zerumbone, a sesquiterpenoid from the essential oil of Zingiber zerumbet, Smith has been isolated in 0.33% by recrystallization from n-hexane. Treatment of zerumbone with m-chloroperbenzoic acid (MCPBA), followed by methanolysis with N-bromosuccinimide (NBS) and methanol gave 2-hydroxy-3-methoxy-6,9-humuladien-8-one, while acetylation of 2-hydroxy-3-methoxy-6,9-humuladien-8-one afforded 2-acetoxy-3-methoxy-6,9-humuladien-8-one. Reaction of zerumbone with bromine (Br2) at -5ºC to -10ºC in carbon tetrachloride (CCl4) gave 6,7-dibromo-2,9-humuladien-8-one. Further treatment of 6,7-dibromo-2,9-humuladien-8-one with m-chloroperbenzoic acid (MCPBA) gave 6,7-dibromo-2,3-epoxy-9-humulen-8-one. Under nitrogen, zerumbone was reduced with lithium aluminium hydride (LiAlH4) at -5ºC to -10ºC to afford zerumbol. Acetylation and methylation of zerumbol gave 8-acetoxy-2,6,9-humulatriene and 8-methoxy-2,6,9-humulatriene, respectively. 2,3-Epoxy-6-ethoxy-9-humulen-8-one has been obtained by treating zerumbone with ethanol at 10°C to 15°C in the presence of boron trifluoride-etherate as catalyst, followed by epoxidation with m-chloroperbenzoic acid (MCPBA). 6,10-Dicyano-2-humulen-8-one was prepared by treatment of zerumbone with potassium cyanide at 15ºC to 20ºC in the presence of a-cyclodextrin. The deoxygenation of the zerumbone under the Clemmensen reduction, followed by Sharpless asymmetric dihydroxylation yielded (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one and (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one as the major and minor compounds respectively. Acetylation of (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one afforded (6S,7S)-6-acetoxy-7-hydroxy-2,9-humuladien-8-one, while further treatment of the acetoxy compound in the presence of 4-N,N-dimethylaminopyridine (DMAP) as catalyst gave (6S,7S)-6,7-diacetoxy-2,9-humuladien-8-one. (9S,10S)-9,10-Diacetoxy-2,6-humuladien-8-one has been obtained by acetylation of (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one in the presence of 4-N,N-dimethylaminopyridine (DMAP) as catalyst. Antibacterial screening showed that zerumbol gave a moderate inhibition to Bacillus subtilis with minimum concentration of 0.025 µg/µL and Pseudomonas aeruginosa with minimum concentration of 0.05 µg/µL. The results showed that 6,10-dicyano-2-humulen-8-one, (6S,7S)-6,7-dihydroxy-2,9-humuladien-8-one and (9S,10S)-9,10-dihydroxy-2,6-humuladien-8-one gave the highest antioxidant activity with the IC50 were 0.0171, 0.0227 and 0.0259 respectively.
format Thesis
qualification_level Master's degree
author Ahmad, Mohamad Syahrizal
author_facet Ahmad, Mohamad Syahrizal
author_sort Ahmad, Mohamad Syahrizal
title Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
title_short Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
title_full Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
title_fullStr Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
title_full_unstemmed Kajian kimia zerumbon daripada Zingiber Zerumbet, Smith
title_sort kajian kimia zerumbon daripada zingiber zerumbet, smith
granting_institution Universiti Teknologi Malaysia, Faculty of Science
granting_department Faculty of Science
publishDate 2006
url http://eprints.utm.my/id/eprint/5325/1/MohamadSyahrizalAhmadMFS2006.pdf
_version_ 1747814580032110592

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