Design,Synthesis And Application Of Fluorescent Molecules Being Sensitive To Environmental Polarity

Two fluorescent molecules being sensitive to envirolnental polarity have been designed and synthesized by introducing electron donor and electron acceptor groups to rigid aromatic rings. Their fluoresecent characteristic and response to different organic solvents were investigated by steady fluorescence. A highly selective and sensitive compound for Cu²⁺ recognition was discovered and prepared. Insecticidal peptide Helicokinin-I was synthesized by solid phase peptide synthesis (SPPS) and its structural modification was also carried on.The major results are described below.1. (αS, 1S)-α-[N-(1-methyl)benzyl]-β-[(4-methoxy)benzoyl]alanine is synthesized via Friedal- Craft acylation followed by Michael addtion: the total yield was 45.9%. It is disclosed via steady fluorescence that the maxium fluorescent emission wavelength and quantum yields of the target molecule are sensitive to enviromental polarity. This is evidence that the compound might be able to be used as a potential fluorescent probe for detecting environmental polarity.2. A new route for synthesizing Aladan, an intramolecular charge transfer fluorescent amino acid has been designed and performed. It turns out that this new scheme has several prominent advantages like operational simplicity, inexpensive reagents, shorter reaction time, higher overall yield, high stereo-selectivity and easily workup.3. 6-(N, N-dimethylamino)-2-naphthoylacryl acid(Acadan) is synthesized. The fluorescent response to different ions of this compound has also been investigated. It turns out that the molecule is able to recognize copper (â…¡) selectively in H₂O/CH₃OH(V/V=5/95) solution.4. Insecticidal peptide Helicokinin-I is synthesized via solid phase peptide synthesis. Fluorescent amino acid (αS, 1S)-α- [N-(1-methyl) benzyl]-β-[(4-methoxy)benzoyl]alanine is further incorporated into Helicokinin-I to get [Alb¹] Helicokinin-I. Backbone cyclization of helicokinin I in diluted solution has also been carried on; Purification of the crude helicokinin-I by chromatography employed polyamide column was also conducted. Purer peptide is able to be obtained via this way.