The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities

Three Malaysian species of Neolitsea, N. kedahense Gamble, N. coccinea B. C. Stone, and N. zeylanica (Nees) Merr. have been investigated. The aims of this study were to analyse the chemical composition of the essential oils, isolate and identify the pure compounds, and screen the antibacterial, α-gl...

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Main Author:	Jani, Nor Akmalazura
Format:	Thesis
Language:	English
Published:	2017
Subjects:	Q Science (General)
Online Access:	http://eprints.utm.my/id/eprint/79161/1/NorAkmalazuraJaniPFS2017.pdf
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spelling	my-utm-ep.791612018-10-04T03:28:17Z The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities 2017 Jani, Nor Akmalazura Q Science (General) Three Malaysian species of Neolitsea, N. kedahense Gamble, N. coccinea B. C. Stone, and N. zeylanica (Nees) Merr. have been investigated. The aims of this study were to analyse the chemical composition of the essential oils, isolate and identify the pure compounds, and screen the antibacterial, α-glucosidase inhibitory and antioxidant activities. The essential oils were extracted by hydrodistillation and analysed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The pure compounds were isolated by sequential maceration followed by fractionation and purification using several chromatographic techniques. The structures of the pure compounds were elucidated by spectroscopic methods. δ-Cadinene (17.4%) was the main compound of the stem oil of N. kedahense, while β-caryophyllene (18.9%) and bicyclogermacrene (18.6%) were the major compounds of the leaf oil. The main compounds in the stem and leaf oils of N. coccinea were δ-cadinene (21.2%) and selin-11-en-4-α-ol (26.8%), respectively. The bark and the heartwood oils of N. zeylanica were found to be rich in α-cadinol (15.7%) and τ-cadinol (21.4%), respectively, while its leaf oil was dominated by β-caryophyllene (38.4%). Twenty nine compounds, comprising of twelve sesquiterpenoids, six triterpenes, six flavonoids and five alkaloids were isolated from three Neolitsea species. Two new sesquiterpenoids, kedahensane and coccinine, together with another three new alkaloids, kedahensines A-C, were successfully identified. Kedahensane, kedahensines A and B, taraxerone, taraxerol, pseudoneoliacine, daibucarboline A and linderaggrine A were obtained from the stem extract of N. kedahense. Purification of the stem and leaf extracts of N. coccinea afforded coccinine, kedahensine C, linderane, linderalactone, pseudoneolinderane, linderanlide C, linderanine A, epicatechin, (-)-taxifolin, astilbin, L-quercitrin and afzelin. Isolation of compounds from the bark and leaf extracts of N. zeylanica yielded zeylanidine, zeylanine, lupenone, epifriedelanol, lupeol, 29-norlupan-3,20-dione, genkwanin, zeylaninone, acutotrinol, afzelin, astilbin and L-quercitrin. The leaf oil of N. coccinea demonstrated moderate antibacterial activity against Bacillus subtilis with MIC value of 250 μg/mL. The stem oil of N. kedahense (IC50 16.76 μg/mL), linderalactone (IC50 12.72 μM) and linderanlide C (IC50 12.10 μM) showed the strongest activity against α-glucosidase enzyme. The ethyl acetate extract of the stem of N. coccinea showed the highest total phenolic content at 501.42 mg GAE/g and also displayed good DPPH radical scavenging activity (IC50 21.11 μg/mL). The presence of the new compounds in N. kedahense and N. coccinea could be used as chemotaxonomic markers for classification of the Neolitsea species. 2017 Thesis http://eprints.utm.my/id/eprint/79161/ http://eprints.utm.my/id/eprint/79161/1/NorAkmalazuraJaniPFS2017.pdf application/pdf en public phd doctoral Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	Q Science (General)
spellingShingle	Q Science (General) Jani, Nor Akmalazura The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
description	Three Malaysian species of Neolitsea, N. kedahense Gamble, N. coccinea B. C. Stone, and N. zeylanica (Nees) Merr. have been investigated. The aims of this study were to analyse the chemical composition of the essential oils, isolate and identify the pure compounds, and screen the antibacterial, α-glucosidase inhibitory and antioxidant activities. The essential oils were extracted by hydrodistillation and analysed by capillary gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The pure compounds were isolated by sequential maceration followed by fractionation and purification using several chromatographic techniques. The structures of the pure compounds were elucidated by spectroscopic methods. δ-Cadinene (17.4%) was the main compound of the stem oil of N. kedahense, while β-caryophyllene (18.9%) and bicyclogermacrene (18.6%) were the major compounds of the leaf oil. The main compounds in the stem and leaf oils of N. coccinea were δ-cadinene (21.2%) and selin-11-en-4-α-ol (26.8%), respectively. The bark and the heartwood oils of N. zeylanica were found to be rich in α-cadinol (15.7%) and τ-cadinol (21.4%), respectively, while its leaf oil was dominated by β-caryophyllene (38.4%). Twenty nine compounds, comprising of twelve sesquiterpenoids, six triterpenes, six flavonoids and five alkaloids were isolated from three Neolitsea species. Two new sesquiterpenoids, kedahensane and coccinine, together with another three new alkaloids, kedahensines A-C, were successfully identified. Kedahensane, kedahensines A and B, taraxerone, taraxerol, pseudoneoliacine, daibucarboline A and linderaggrine A were obtained from the stem extract of N. kedahense. Purification of the stem and leaf extracts of N. coccinea afforded coccinine, kedahensine C, linderane, linderalactone, pseudoneolinderane, linderanlide C, linderanine A, epicatechin, (-)-taxifolin, astilbin, L-quercitrin and afzelin. Isolation of compounds from the bark and leaf extracts of N. zeylanica yielded zeylanidine, zeylanine, lupenone, epifriedelanol, lupeol, 29-norlupan-3,20-dione, genkwanin, zeylaninone, acutotrinol, afzelin, astilbin and L-quercitrin. The leaf oil of N. coccinea demonstrated moderate antibacterial activity against Bacillus subtilis with MIC value of 250 μg/mL. The stem oil of N. kedahense (IC50 16.76 μg/mL), linderalactone (IC50 12.72 μM) and linderanlide C (IC50 12.10 μM) showed the strongest activity against α-glucosidase enzyme. The ethyl acetate extract of the stem of N. coccinea showed the highest total phenolic content at 501.42 mg GAE/g and also displayed good DPPH radical scavenging activity (IC50 21.11 μg/mL). The presence of the new compounds in N. kedahense and N. coccinea could be used as chemotaxonomic markers for classification of the Neolitsea species.
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Jani, Nor Akmalazura
author_facet	Jani, Nor Akmalazura
author_sort	Jani, Nor Akmalazura
title	The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
title_short	The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
title_full	The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
title_fullStr	The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
title_full_unstemmed	The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities
title_sort	essential oils and isolated constituents of neolitsea kedahense, neolitsea coccinea and neolitsea zeylanica and their bioactivities
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2017
url	http://eprints.utm.my/id/eprint/79161/1/NorAkmalazuraJaniPFS2017.pdf
_version_	1747818161029251072

The essential oils and isolated constituents of Neolitsea kedahense, Neolitsea coccinea and Neolitsea zeylanica and their bioactivities

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