Investigation of chemical transformations of thiophenylglycoside of muramyl dipeptide on the fumed silica surface using TPD-MS, FTIR spectroscopy and ES IT MS
- Equal contributors
1 Chuiko Institute of Surface Chemistry, The National Academy of Sciences of Ukraine, 17 Generala Naumova Str., 17, Kyiv 03164, Ukraine
2 Taurida National V.I. Vernadsky University, Akademika Vernadskogo av. 4, Simferopol 95007, Ukraine
Nanoscale Research Letters 2014, 9:234 doi:10.1186/1556-276X-9-234Published: 13 May 2014
In this study, chemical transformations of benzyl ester of О-(phenyl-2-acetamido-2,3-dideoxy-1-thio-β-D-glucopyranoside-3-yl)-D-lactoyl-L-alanyl-D-isoglutamine (SPhMDPOBn) on the fumed silica surface were examined, and the surface complex structure was characterized by temperature-programmed desorption mass spectrometry (TPD-MS), infrared spectroscopy (FTIR) and electrospray ion trap mass spectrometry (ES IT MS). Stages of pyrolysis of SPhMDPOBn in pristine state and on the silica surface have been determined. Probably, hydrogen-bonded complex forms between silanol surface groups and the C = O group of the acetamide moiety NH-(CH3)-C = O…H-O-Si≡. The thermal transformations of such hydrogen-bonded complex result in pyrolysis of SPhMDPOBn immobilized on the silica surface under TPD-MS conditions. The shifts ∆ν of amide I band (measured from 1,626 to 1,639 cm−l for SPhMDPOBn in pristine state) of 33 and 35 cm−l which occurred when SPhMDPOBn was immobilized on the silica surface may be caused by a weakening of the intramolecular hydrogen bonding of the SPhMDPOBn because the interaction with the silica surface as hydrogen bond with silanol groups is weaker than that in associates.