地塞米松棕榈酸酯分子结构导数中红外光谱研究

Study on the Dexamethasone Palmitate Molecular Structure by Derivative Middle Infrared Spectroscopy

采用中红外(MIR)光谱开展地塞米松棕榈酸酯(DXP)的结构研究.实验发现:地塞米松棕榈酸酯分子结构的红外吸收模式主要包括:C—H伸缩振动模式(ν_(CH-DXP))、CH_(3)基团不对称伸缩振动模式(ν_(as CH3-DXP))、CH2基团不对称伸缩振动模式(ν_(as CH2-DXP))、CH_(2)基团对称伸缩振动模式(νs CH2-DXP)、C=O伸缩振动模式(νC=O-DXP)、C=C伸缩振动模式(νC=C-DXP)、CH_(2)基团变角振动模式(δ_(CH2-DXP))、CH_(3)基团对称变角振动模式(δ_(s CH3-DXP))和CH_(2)基团面内摇摆振动模式(ρCH2-DXP).地塞米松棕榈酸酯原始光谱进行不同阶数(包括:一阶、二阶、三阶及四阶)处理,其中二阶导数MIR光谱的谱图分辨能力优于其他导数MIR光谱,二阶导数MIR光谱在不同平滑点(包括:5、9、13、19、25、37、49、149个平滑点)下具有一定的差异性,其中5个平滑点的二阶导数MIR光谱提供的光谱信息最丰富,但随着平滑点的增加,二阶导数MIR光谱的谱图分辨能力进一步降低.

Mid infrared(MIR)spectroscopy are used to study the molecular structure of dexamethasone palmitate(DXP).The experiment finds that the infrared absorption mode of dexamethasone palmitate molecular structure mainly includes:C—H stretching vibration mode(ν_(CH-DXP)),CH_(3) groups asymmetric stretching vibration mode(ν_(asCH3-DXP)),CH_(2) group asymmetric stretching vibration mode(ν_(asCH2-DXP)),CH_(2) group symmetric stretching vibration mode(ν_(sCH2-DXP)),C=O group stretching vibration mode(ν_(C=O-DXP)),C=C group stretching vibration mode(ν_(C=C-DXP)),CH_(2) group bending vibration mode(δ_(CH2-DXP)),CH_(3) group symmetric bending vibration mode(δ_(sCH3-DXP))and CH_(2) group rocking vibration mode(ρ_(CH2-DXP)).The original spectrum of dexamethasone palmitate is processed at different orders(including first,second,third,and fourth orders),and the spectral resolution of the second derivative MIR spectrum is better than that of other derivative MIR spectra,The second-order derivative MIR spectra exhibits certain differences at different smoothing points(including 5 smoothing points,9 smoothing points,13 smoothing points,19 smoothing points,25 smoothing points,37 smoothing points,49 smoothing points,and 149 smoothing points).Among them,the second-order derivative MIR spectra of 5 smoothing points provides the richest spectral information,but as the number of smoothing points increases,the spectral resolution of the second-order derivative MIR spectra further decreases.