Study on Phenylalanine Substituted Serine Octamer Ions by Infrared Photodissociation Spectroscopy and Their Application in Chiral Differentiation

KeyWord:electrospray ionization£¨ESI£©  infrared photodissociation£¨IRPD£©spectroscopy  chiral differentiation  phenylalanine  serine octamer

Abstract:

      A method of infrared photodissociation£¨IRPD£©spectroscopy was developed for the determination of phenylalanine substituted L serine octamer ions.The phenylalanine substituted L serine octamer ions were generated by electrospray ionization£¨ESI£©and studied by mass spectrometry£¨MS£©coupled with infrared photodissociation£¨IRPD£©spectroscopy.Chiral preference was found existing in such cluster ions.IRPD experiments showed that the ions of £ÛL Ser7+L/D Phe1£ÝH+ and £ÛL Ser6+L/D Phe2£ÝH+ were observed in the range of 2 700-3 600 cm-1.Chiral differentiation was fulfilled by comparing their IRPD spectra or IRPD mass spectra obtained at some special wavenumbers.