The synthesis and characterization of a series of peptide dendronswith glycin（Gly） and glutamate（Glu） as building blocks were described.The dendrons were prepared with convergent method by protection,deprotection and DCC coupling reactions.With the characterization of elemental analysis,（）1H-NMR,（）13C-NMR,FTIR,EI-MS and MAILD-TOF MS,the designed molecular structure was proved.It could be predicted that the obtained compounds will exhibit unique properties and potential applications in the fields of biology,medicine and so on.Further studies on the properties of these compounds are in progress.
An azyl group of ethylene diamine was protected by N-tert-butoxycarbonyl.The remaining azyl group then successively reacted with methyl acrylate, ethylene diamine and methyl acrylate again to afford the compound Boc-NH 2-(B-COOCH 3) 4 3 (AB-4).The ester groups and the Boc-end group of 3 were transferred to carboxylate 4 and azyl group 5 via hydrolyzation and deprotection respectively.The fan-shape dendron molecules with 16 exterior groups 6 were obtained by condensation of 4 and 5 in the presence of DCC.The dumbbell-like dendrimer molecules 7 could expediently prepared by coupling the dendrons with two functional groups of hexanedioyl chloride.The paper describes the synthesis procedures,reports the characterization results of FTIR、 1H-NMR、 13C-NMR and MALDI-TOF.Comparing with the PAMAM dendrimers from the divergent method, the synthesized compounds possess accurate structures and few defections.
In the present paper,FT-mid-IR fiber optics spectroscopy was used to determine the thyroid tumor.A modified WQF-500 FTIR spectrometer with MCT detector and mid-IR fiber optics ATR accessory was used in this work.Percutaneous examination of the skin overlying the thyroid tumor was performed on five patients,in vivo detection and in vitro measurement of six patients in operation room was also carried out.The experimental data indicate that malignant and benign thyroid tumor could be distinguished from the spectra of percutaneous examination,the in vivo measurement and freshly resected thyroid tissues.The relative intensity and peak position of the IR bands in the region of 1 700-1 500 cm-1（amide Ⅰ and amide Ⅱ）,1 480-1 400 cm-1,and 1 320-1 200 cm-1 are reliable spectral marker or indexes for tumor detection.These results demonstrate that FT-mid-IR fiber optics spectroscopy exhibits prospect to develop a novel non-invasive method for thyroid tumor detection.
