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Title:	Chemical constituents of two etlingera species with bioactivities of their essential oils and extracts
Authors:	Abdo Ali Mohammed Yahya. (P48790)
Supervisor:	Wan Yaacob Wan Ahmad, Associated Prof.
Keywords:	Essences and essential oils.
Issue Date:	29-Dec-2011
Description:	Essential oils of fresh parts of Etlingera sphaerocephala var. grandiflora and E. triogyalis (Zingiberaceae) were hydrodistilled and analysed by capillary GC and GCMS using HP-5 column. Seventeen compounds were identified from E. sphaerocephala var. grandiflora oils with rhizome gave 10 components, stem 4, leaf 14 and whole plant 13. Monoterpenes dominated these oils with 1,8-cineole was the main compound in all the parts of rhizomes (52.8%), stem (58.1%), leaves (36.7%) and whole plant (42.9%). Etlingera triogyalis oils contained 27 compounds with 12 in rhizomes; 11, stem; 12, leaves; 21, fresh flowers; 14, flower buds; and 16, whole plant. Monoterpenes dominated the leaf and whole plant oils of which β-pinene was the major component with respective 46.1 and 28.8%. Non-terpenes dominated the remaining four oils with the major compound being anethole in the rhizome (54.7%), stem (48.2%), fresh flowers (66.5%) and flower buds (62.2%). Etlingera sphaerocephala var. grandiflora oils were also analysed using GCxGC-TOFMS and 70 components gave good matches. They comprise 42 compounds of the rhizomes; 32, stem; 40, leaves; and 36, whole plant. These oils were dominated by monoterpenes with the major compounds being 1,8-cineole in the rhizomes (16.8%) and stem (17.4%), α-phellandrene (12.3%) leaves and β-pinene (12.2%) whole plant. Chromatographic isolation on E. sphaerocephala var. grandiflora extracts produced β-sitosterol, stigmasterol and paeonol of the rhizomes and stem. Their structures were determined by spectroscopic data analysis and by comparing the data with those of the literature. Antioxidant test on the oils by 1,1-diphenyl-2-picrylhydrazyl showed that all the oils, except those of E. sphaerocephala var. grandiflora rhizome (18.9% inhibition) and stem (21.6%), were stronger antioxidants (28.6-38.7%) than Trolox (27.3%). β-Carotene bleaching (BCB) in linoleic acid showed that all the oils were weaker antioxidants than butylated hydroxytouluene (99.5% inhibition). However, leaf oils of E. sphaerocephala var. grandiflora (88.9%) and E. triogyalis (76.1%) gave fairly good inhibitions. For the extracts, the ranking of ascorbic acid equivalent antioxidant capacity (AEAC), ferrous ion chelating (FIC) ability and total phenolic content (TPC) of E. sphaerocephala var. grandiflora extracts was: leaves > stem > rhizomes. In BCB test, the order was: leaves > rhizomes > stem. In the E. triogyalis, leaf extract had the highest AEAC, FIC ability and TPC followed by stem, fresh flowers, flower buds and rhizomes. This order was different in the BCB activity whereby it was: fresh flowers > fresh buds > leaves > stem > rhizomes. Antibacterial tests using disc-diffusion and micro-dilution methods showed that both oils and extracts of the two Etlingera species exhibited stronger inhibition against Grampositive of Bacillus subtilis and Staphylococcus aureus than Gram-negative of Escherichia coli and Pseudomonas aeruginosa.,Master
Pages:	187
Call Number:	QD416.A23 2011
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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