碩士 / 國立屏東科技大學 / 食品科學系 / 91 / Cyanobacterium is algae of the most original and ancient and it contains phycobilin, a blue-green pigment. Synechococcus sp. is a member of cyanobacterium family. The objective of the study was focus on antioxidant activity, antioxidant compounds and mutagenic test of methanolic and water extracts from Synechococcus sp. The internal structures, cyanophycin granules, thylacoid and nucleoplasm, of Synechococcus sp. were observed by transmission electron microscope. Five common assays, thiocyanate method, reducing power, α,α-diphenyl-b-picrylhydrazyl (DPPH) radical, hydroxyl radical and superoxide radical scavenging activity, were employed for antioxidative properties investigation of Synechococcus sp. The results indicated that methanolic fraction extracted from Synechococus sp. with concentration of 1.0 mg/ml by sonicator, showed high DPPH scavenging activity, up to 74.5%, and is similar to that of β-tocopherol (0.4 mg/ml) after 30 minutes reaction, while little effect was exhibited in water extract. One of fourth reducing power of methanolic extract was detected compared to β-tocopherol (0.2 mg/ml), and it was much better than that of water extract. The water extract by sonicator held the highest hydroxyl radical scavenging activity, reached to 14.2%, but it was much less than that of β-tocopherol. However, the extracts from Synechococcus sp. enhanced the formation of superoxide anion. In respect to analysis of antioxidant compounds, the contents of total phenols, β-carotene, total chlorophyll, and phycocyanin in Synechococcus sp. were 42.11 mg/g, 0.35 mg/g, 19.1 ppm and 114.24 mg/g, respectively. Unexpectedly, no detectable ascorbic acid was found in the current sample. The extracts were subjected to Ames test using Salmonella typhimurium TA98 was testing strain, and no toxicity of the extracts were observed up to a dose of 5 mg/plate. Except methanolic extract by funnel shaker, the mutagencity in S. typhimurium TA98 was detected at 5 mg/plate of water extract by funnel shaker, water extract by sonicator and methanolic extract by sonicator.
| Identifer | oai:union.ndltd.org:TW/091NPUST253033 |
| Date | January 2003 |
| Creators | 吳玉菁 |
| Contributors | 廖遠東 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 106 |
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