A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including...A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including some of the very recent developments,is reviewed with examples.Topics include merged or modified asynchronous 2Dcorrelation spectrum,two-dimensional codistribution spectroscopy(2DCDS),Pareto scaling,and null-space projection treatment of spectral dataset.展开更多
A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensi...A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.展开更多
以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可...以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可知,厚朴酚在1 365～1 455,1 600～1 720,2 000～2 181和2 275～2 465nm处有特征吸收,其中1 440nm为酚基O—H伸缩振动基频的一级倍频谱带,1 679nm为芳基C—H及与芳基相连的甲基C—H伸缩振动一级倍频谱带,2 117,2 304,2 339和2 370nm为芳基C—H伸缩振动、弯曲振动和变形振动的组合频,2 445nm为芳基相连的甲基C—H弯曲振动基频二级倍频谱带,这些波段为厚朴酚的特征归属。以藿香正气口服液复杂体系为载体,以厚朴酚光谱解析的特征波段与间隔偏最小二乘（interval partial least squares,iPLS）和组合间隔偏最小二乘（synergy interval partial least squares,SiPLS）筛选的特征波段分别建立偏最小二乘（partial least squares,PLS）定量模型,模型的决定系数R2cal和R2pre均大于0.99,校正均方根误差（root mean of square error of calibration,RMSEC）,交叉验证均方根误差（root mean of square error of cross validation,RMSECV）和预测均方根误差（root mean of square error of prediction,RMSEP）均较小。结果表明,2D-COS技术解析厚朴酚所得波段建立的定量模型与iPLS和SiPLS波段筛选的模型均相对稳定,这使定量模型的波段选择更具有解释性。该研究为中药化学成分NIR光谱解析特征波段的归属提供方法参考,同时为NIR建模波段筛选提供借鉴和指导。展开更多
采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于...采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于隐丹参酮的呋喃环双键一级倍频和组合频吸收,1696 nm为丹参酮ⅡA和隐丹参酮分子中甲基伸缩振动二级倍频,1726和1740 nm处吸收为丹参酮ⅡA和隐丹参酮环己烯亚甲基伸缩振动二级倍频,2146和2220 nm为丹参酮ⅡA和隐丹参酮苯环C-C伸缩振动与C-H伸缩振动的组合频,2300~2400 nm处一系列峰为丹参酮ⅡA和隐丹参酮甲基伸缩振动与弯曲振动组合频吸收。以丹参酮提取物为载体,以丹参酮ⅡA和隐丹参酮光谱解析特征波段及组合间隔偏最小二乘(SiPLS)筛选特征波段分别建立偏最小二乘(PLS)定量模型,模型的决定系数R^(2)均大于0.9,校正均方根误差(root mean of square error of calibration,RMSEC)和交叉验证均方根误差(RMSECV),预测均方根误差(RMSEP)均较小。结果表明,2D-COS技术解析特征波段与SiPLS波段筛选所建PLS模型均稳定。2D-COS技术使近红外定量模型更具解释性,可解析出结构差异特征吸收,同一波段可实现结构类似物的同时定量测定。展开更多
文摘A number of useful techniques associated with two-dimensional correlation spectroscopy(2DCOS)to improve its performance and utility have been developed in the last 30years.Evolution of these 2DCOS techniques,including some of the very recent developments,is reviewed with examples.Topics include merged or modified asynchronous 2Dcorrelation spectrum,two-dimensional codistribution spectroscopy(2DCDS),Pareto scaling,and null-space projection treatment of spectral dataset.
文摘A series of soy protein isolate(SPI)films plasticized by glycerol(Gly)were studied using attenuated total reflectance-Fourier transform infrared spectroscopy(ATR/FTIR).Perturbation-correlation movingwindow two-dimensional(PCMW2D)and two-dimensional correlation(2DCOS)analyses were applied to the amideⅠband and thus the hydrogen bond interaction between SPI and Gly was systematically investigated.When Gly concentrations were in the range 0~35%,the hydrogen bond amongβ-sheets was replaced by the one between SPI chain and Gly molecule,which caused these protein chains being changed toα-helix.However,the transformation ofβ-sheet toα-helix was saturated and both of them tend to change to random coil when Gly concentrations were in the range 35%~60%.
文摘以氘代氯仿为溶剂,以中药化学标准品厚朴酚为载体,采用二维相关光谱（Tow-dimensional correlation spectroscopy,2D-COS）技术,采集近红外光谱（near infrared spectroscopy,NIR）,由氘代氯仿纯溶剂与厚朴酚原始光谱的二维相关同步谱可知,厚朴酚在1 365～1 455,1 600～1 720,2 000～2 181和2 275～2 465nm处有特征吸收,其中1 440nm为酚基O—H伸缩振动基频的一级倍频谱带,1 679nm为芳基C—H及与芳基相连的甲基C—H伸缩振动一级倍频谱带,2 117,2 304,2 339和2 370nm为芳基C—H伸缩振动、弯曲振动和变形振动的组合频,2 445nm为芳基相连的甲基C—H弯曲振动基频二级倍频谱带,这些波段为厚朴酚的特征归属。以藿香正气口服液复杂体系为载体,以厚朴酚光谱解析的特征波段与间隔偏最小二乘（interval partial least squares,iPLS）和组合间隔偏最小二乘（synergy interval partial least squares,SiPLS）筛选的特征波段分别建立偏最小二乘（partial least squares,PLS）定量模型,模型的决定系数R2cal和R2pre均大于0.99,校正均方根误差（root mean of square error of calibration,RMSEC）,交叉验证均方根误差（root mean of square error of cross validation,RMSECV）和预测均方根误差（root mean of square error of prediction,RMSEP）均较小。结果表明,2D-COS技术解析厚朴酚所得波段建立的定量模型与iPLS和SiPLS波段筛选的模型均相对稳定,这使定量模型的波段选择更具有解释性。该研究为中药化学成分NIR光谱解析特征波段的归属提供方法参考,同时为NIR建模波段筛选提供借鉴和指导。
文摘采用二维相关光谱(2D-COS)技术,以氘代氯仿为溶剂,解析了丹参酮ⅡA和隐丹参酮标准品的近红外光谱(NIR)。丹参酮ⅡA和隐丹参酮二维相关切片谱在1600~1800,1900~2230和2300~2400 nm处有特征吸收,其中丹参酮ⅡA在1640和2140 nm处有不同于隐丹参酮的呋喃环双键一级倍频和组合频吸收,1696 nm为丹参酮ⅡA和隐丹参酮分子中甲基伸缩振动二级倍频,1726和1740 nm处吸收为丹参酮ⅡA和隐丹参酮环己烯亚甲基伸缩振动二级倍频,2146和2220 nm为丹参酮ⅡA和隐丹参酮苯环C-C伸缩振动与C-H伸缩振动的组合频,2300~2400 nm处一系列峰为丹参酮ⅡA和隐丹参酮甲基伸缩振动与弯曲振动组合频吸收。以丹参酮提取物为载体,以丹参酮ⅡA和隐丹参酮光谱解析特征波段及组合间隔偏最小二乘(SiPLS)筛选特征波段分别建立偏最小二乘(PLS)定量模型,模型的决定系数R^(2)均大于0.9,校正均方根误差(root mean of square error of calibration,RMSEC)和交叉验证均方根误差(RMSECV),预测均方根误差(RMSEP)均较小。结果表明,2D-COS技术解析特征波段与SiPLS波段筛选所建PLS模型均稳定。2D-COS技术使近红外定量模型更具解释性,可解析出结构差异特征吸收,同一波段可实现结构类似物的同时定量测定。
