碩士 / 國立臺灣海洋大學 / 食品科學系 / 95 / Abstract
Cobia skin was hydrolyzed by protamex (PX), Prozyme 6 (P6) and Protease N (PN) for 2 or 5 h. The inhibitory effects of cobia skin hydrolysates against angiotensin I converting enzyme (ACE) and antihypertensive effect were investigated. The highest value of peptide content (400mg/g) of hydrolysates was prepared by PN hydrolysis for 5 h (PN5). PN5 hydrolysate showed the lowest IC50 on ACE being 0.728 mg powder/mL, and PX5 hydrolysate (IC50=0.820 mg powder/mL) was slightly higher than PN5 hydrolysate. The IC50 of PX5 hydrolysate decreased to 0.750 mg powder/mL and PN5 hydrolysate increased to 0.806 mg powder/mL after gastrointestinal digestion. The PX5 hydrolysate after gastrointestinal digestion was fractionated by size exclusion chromatography on a Sephadex G-25. A fraction of the PX5 had molecular weight about 630~450 Da (PX5-E) showed the highest inhibitory efficiency ratio (IER) being 1553 %/mg/mL, and its IC50 was 0.020 mg peptide/mL. This fraction was further analyzed by HPLC (C18 column). The peak (PX5-E-E8) of most active peptide had a highest IER value being 3335%/mg/mL. The amino acid sequences of peak E6, E7, E8 and E9 are Trp-Ala-Ala, Ala-Trp-Trp, Ile-Trp-Trp and Trp-Leu. The IC50 on ACE of these peptides are 118.5, 9.4, 0.51 and 26.8 μM.
The cobia skin hydrolysate (PX5) (210 mg peptide/rat) was oral administered to spontaneous hypertensive rat (SHR). The systolic blood pressure (SBP) of the SHR significantly reduced by 21.9 mm Hg after oral administration for 4 h. Furthermore, the SBP showed significantly different between PX5 and control group after oral administered for 8 h.
| Identifer | oai:union.ndltd.org:TW/095NTOU5253058 |
| Date | January 2007 |
| Creators | Chun-An Chen, 陳俊安 |
| Contributors | Jenn-Shou Tsai, Doctor, 蔡震壽 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 103 |
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