Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites

Red algae genus Laurencia is known to be prolific producer of halogenated metabolites such as brominated indoles, terpenes and C15 acetogenins. Malaysian waters are rich with many species of Laurencia, but very few are documented and published. In this investigation, we have analyzed the chemical co...

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Main Author:	Takashi Kamada
Format:	Thesis
Language:	English English
Published:	2013
Subjects:	QK504-(638) Cryptogams
Online Access:	https://eprints.ums.edu.my/id/eprint/41888/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/41888/2/FULLTEXT.pdf
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spelling	my-ums-ep.418882024-12-10T02:46:28Z Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites 2013 Takashi Kamada QK504-(638) Cryptogams Red algae genus Laurencia is known to be prolific producer of halogenated metabolites such as brominated indoles, terpenes and C15 acetogenins. Malaysian waters are rich with many species of Laurencia, but very few are documented and published. In this investigation, we have analyzed the chemical composition of L. similis, L. snackeyi, L. majuscula and L. nangii. A total of 72 secondary metabolites including 17 new compounds were isolated. Laurencia similis contained 1 new and 6 known metabolites that belongs to brominated indoles and non-halogenated aristolan type. Laurencia snackeyi contained 2 new and 15 known metabolites of snyderane, monocyclofarnesol, cuparane, cyclolaurane and chamigrene types. Laurencia majuscula produced 12 new and 14 known metabolites of chamigrene, rhodolaurane and omphalane types. Laurencia nangii contained 2 new and 20 known metabolites of acetogenins, sesquiterpenes, diterpenes and triterpenes chemical types. It also revealed the possible presence of "chemical race" in L. snackeyi with the isolation of chamigrene, cuparane and cyclolaurane type compounds. First record of Laurencia derived omphalane type halogenated secondary metabolites were isolated from populations of L. majuscula. It was also clear that L. majuscula is present in two chemical types; 1) population that produces elatol, laurencenone B and 2-chloro-3-hydroxy-α-chamigren-9-one, 2) population that produces (E)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene and (Z)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene. Laurencia nangii consist of two chemical races; 1) race that produces C15 acetylenes and terpenes, 2) race that produces C15 bromoallenes and terpenes. All the isolated compounds were subjected to biological activity evaluations such as antibacterial, cytotoxic and antiinflammatory activities. Potent antibacterial activities were observed in α-chamigrenes and brominated indole. Cytotoxic activities, particularly against Adult T-Cell Leukemia were seen in α-chamigrene, β-chamigrene, rhodolaurane and snyderane type compounds. While, strong anti-inflammatory activity was exhibited by aplysistatin, 5β- hydroxypalisadin B and nangiol. Hence, secondary metabolites from Laurencia have potential to be developed into a lead pharmaceutical metabolites. 2013 Thesis https://eprints.ums.edu.my/id/eprint/41888/ https://eprints.ums.edu.my/id/eprint/41888/1/24%20PAGES.pdf text en public https://eprints.ums.edu.my/id/eprint/41888/2/FULLTEXT.pdf text en validuser dphil doctoral Universiti Malaysia Sabah Institut Biologi Tropika dan Pemuliharaan
institution	Universiti Malaysia Sabah
collection	UMS Institutional Repository
language	English English
topic	QK504-(638) Cryptogams
spellingShingle	QK504-(638) Cryptogams Takashi Kamada Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
description	Red algae genus Laurencia is known to be prolific producer of halogenated metabolites such as brominated indoles, terpenes and C15 acetogenins. Malaysian waters are rich with many species of Laurencia, but very few are documented and published. In this investigation, we have analyzed the chemical composition of L. similis, L. snackeyi, L. majuscula and L. nangii. A total of 72 secondary metabolites including 17 new compounds were isolated. Laurencia similis contained 1 new and 6 known metabolites that belongs to brominated indoles and non-halogenated aristolan type. Laurencia snackeyi contained 2 new and 15 known metabolites of snyderane, monocyclofarnesol, cuparane, cyclolaurane and chamigrene types. Laurencia majuscula produced 12 new and 14 known metabolites of chamigrene, rhodolaurane and omphalane types. Laurencia nangii contained 2 new and 20 known metabolites of acetogenins, sesquiterpenes, diterpenes and triterpenes chemical types. It also revealed the possible presence of "chemical race" in L. snackeyi with the isolation of chamigrene, cuparane and cyclolaurane type compounds. First record of Laurencia derived omphalane type halogenated secondary metabolites were isolated from populations of L. majuscula. It was also clear that L. majuscula is present in two chemical types; 1) population that produces elatol, laurencenone B and 2-chloro-3-hydroxy-α-chamigren-9-one, 2) population that produces (E)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene and (Z)-10,15-dibromo-9-hydroxy-chamigra-1,3(15),7(14)-triene. Laurencia nangii consist of two chemical races; 1) race that produces C15 acetylenes and terpenes, 2) race that produces C15 bromoallenes and terpenes. All the isolated compounds were subjected to biological activity evaluations such as antibacterial, cytotoxic and antiinflammatory activities. Potent antibacterial activities were observed in α-chamigrenes and brominated indole. Cytotoxic activities, particularly against Adult T-Cell Leukemia were seen in α-chamigrene, β-chamigrene, rhodolaurane and snyderane type compounds. While, strong anti-inflammatory activity was exhibited by aplysistatin, 5β- hydroxypalisadin B and nangiol. Hence, secondary metabolites from Laurencia have potential to be developed into a lead pharmaceutical metabolites.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Takashi Kamada
author_facet	Takashi Kamada
author_sort	Takashi Kamada
title	Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
title_short	Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
title_full	Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
title_fullStr	Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
title_full_unstemmed	Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
title_sort	laurencia chemistry : structural diversity chemotaxonomy and bioactive properties of halogenated metabolites
granting_institution	Universiti Malaysia Sabah
granting_department	Institut Biologi Tropika dan Pemuliharaan
publishDate	2013
url	https://eprints.ums.edu.my/id/eprint/41888/1/24%20PAGES.pdf https://eprints.ums.edu.my/id/eprint/41888/2/FULLTEXT.pdf
_version_	1818611438230437888

Laurencia chemistry : Structural diversity chemotaxonomy and bioactive properties of halogenated metabolites

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