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Title:	Phytochemical And Bioactivity Studies On Etlingera Brevilabrum, E. Sayapensis And E. Velutina (Zingiberaceae)
Authors:	Behnam Mahdavi (P51328)
Supervisor:	Laily Bin Din, Professor Dato
Keywords:	Phytochemical Studies On Etlingera Brevilabrum Bioactivity Studies On Etlingera Brevilabrum Etlingera Brevilabrum E. Sayapensis E. Velutina Zingiberaceae Phytochemicals
Issue Date:	30-Oct-2013
Description:	A phytochemical study was conducted on three plants of Zingiberaceae namely Etlingera brevilabrum, E. sayapensis and E. velutina. These plants have many uses as food and especially in traditional medicine among people from various ethnic groups in Sarawak and Sabah. There is no report of any kind so far in the literature regarding their secondary metabolites and biological activity. Several different parts of the plants were collected from Sabah. Isolation of the plant secondary metabolites involved extraction, fractionation and purification using various chromatographic means. Structures of the compounds were determined by spectroscopic data analysis and by comparing with the literature data. A total of four pure compounds were isolated from the plants extracts: β-sitosterol and stigmasterol from E. brevilabrum leaves; stigmasterol from E. brevilabrum stem; stigmasterol, α-tocopherol and rutin from E. sayapensis fruits. The presence of the rutin in the Etlingera genus was discovered for the first time. Volatile oils from different parts of the three plants were obtained by hydrodistillation using a Clevenger-type apparatus, and analysed by GC-FID and GC-MS. For the dried parts of E. brevilabrum, eucalyptol and β-pinene were the major compounds in the rhizome oil; limonene and β-pinene in the stem oil; and β-pinene and α-thujene in the leaf oil. On the other hand for the fresh parts, the main components of the rhizome oil were perilla aldehyde and bornyl acetate; the base oil, β-pinene and p-cymen-7-ol; the stem oil, δ-3-carene and α-thujene; and the leaf oil, α-thujene and p-cymen-7-ol. Essential oils from the fresh parts of E. sayapensis were marked by linalool formate and eugenol in the rhizome oil; α-terpineol and linalool formate in the stem oil; carvone and cis-carveol in the leaf oil; and linalool formate and α-terpineol in the fruit oil. The oils from fresh parts of E. velutina were characterized by the occurrence of α-cubebene and 2-undecanone in the rhizome oil; allo-aromadendrene and α-cubebene in the stem oil; and 2-undecanone and α-pinene in the leaf oil. The fresh and dried leaves of E. brevilabrum were pyrolyzed and burned in a fluidized-bed reactor under respective atmospheric nitrogen and air at different temperatures. Chemical composition of the smoke liquids was analysed using GC-MS, and it was found that they were dominated by phenols and carboxylic acids. This kind of study on the liquids from condensed smokes of any medicinal plants was the first ever being carried out. The antioxidant and antimicrobial activity of the different extracts, essential oils and smoke liquids were measured and evaluated. Among the extracts and essential oils, those obtained from the E. sayapensis fruits showed the highest values for total phenolic content, radical scavenging activity, β-carotene bleaching, and ferrous ion chelating. They were also found to be most active in antimicrobial tests using disc diffusion and minimum inhibitory concentration (MIC) assays against different Gram-positive and Gram-negative bacteria and fungi. The leaf of E. brevilabrum smoke liquids showed higher antioxidant activity than the positive control BHT. In the antimicrobial assays, the smoke liquids prevented the growth of 14 out of 18 tested microorganisms.,PhD
Pages:	266
Call Number:	QK865 .M334 2012
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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