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Fmoc Solid-phase Synthesis of Novel Casomorphin and Study on Its Property

Author: FuYouWei
Tutor: WuLei
School: Tianjin University of Commerce
Course: Fermentation Engineering
Keywords: Casomorphins Fmoc solid -phase synthesis Liquid chromatography and mass spectrometry Analgesic Anti-fatigue
CLC: R96
Type: Master's thesis
Year: 2010
Downloads: 52
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Abstract

Opioid peptides (Opioid peptide) is a neuro- immune peptides , can be divided into endogenous opioid peptides and exogenous opioid peptides , works on the central nervous system and peripheral organs . From the number of exogenous opioid peptides found , a large part derived from casein . They exist in an inactive state in the casein by enzymatic will , when hydrolyzed casein precursor . Alpha-S1-casein from the casein in the present study to be synthesized casomorphin 144-158 sequence , and its sequence YFYPELFRQFYQLDA, molecular weight: 2252.48 . Shorter casomorphin sequence , using Fmoc solid -phase synthesis method can be easily prepared , synthetic process as follows: Wang resin as the solid phase carrier, from the C-terminal to the synthesis of N-terminal Fmoc -amino acid as the raw material , dichloro methane (DCM) as the reaction solvent , the O - benzo nitrogen yl - N , N , N'N' - tetramethyl urea tetrafluoroborate ester / 1 - hydroxybenzotriazole three triazole (HOBt) / N, N- diisopropylethylamine (DIEA) of the condensation system, stepwise solid phase synthesis . Cleavage reaction is carried out after the completion of the synthesis , the reagent is trifluoroacetic acid / water / thioanisole / carbol ( TFA/H2O/thioanisole/Phenol ) the system ( 85: 5: 5: 5 ) ; cutting time 2h ??; cutting temperature of 24 ℃. The obtained filtrate was washed with anhydrous ether to precipitate and freeze-dried , obtained a the casomorphin white crude product , yield 57.7% . The crude product by Sephadex G-15 were isolated and purified the two peaks , has been tested and found , the first peak is active , then the first peak by high performance liquid chromatography - mass spectrometry , molecular weight determination . From chromatographic analysis chart shows that the purity of 43% . Synthetic peptides of molecular weight of 2253.4 , basically consistent with the the casomorphin the theoretical value . In order to detect whether synthetic casomorphin having biological activity, using the hot plate method and acetic acid writhing test in the experiment were detected its analgesic activity . The results show that the casomorphin not only synthetic analgesic activity also has a peripheral analgesic activity . Mice burden swimming experiment also proved that the peptide has a role in anti-fatigue . Spss software t test analysis , synthesis casomorphin obtained by hydrolysis casomorphin pain threshold in mice have significantly improved both the significant level of p = 0.05 , analgesic and anti-fatigue effect no significant differences they have analgesic and anti- fatigue , and the effect is no significant difference .

Fmoc Solid-phase Synthesis of Novel Casomorphin and Study on Its Property

Abstract

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