Shen Yun-xia, Zhao Yan-li, Zhang Ji, Jin Hang, Wang Yuan-zhong
Guang Pu Xue Yu Guang Pu Fen Xi. 2016 Aug;36(8):2468-73.
Multiple cropping systems are the way to cope with the shortage of traditional Chinese medicine (TCM) resources and enhance the utilization ratio of land. The aim of this study was to investigate seventy Gentiana rigescens Franch samples which were planted in slope and in multiple cropping system mixed with Juglans regia, Alnus nepalensis, Eucalyptus robusta, Alnus nepalensis, Camellia sinensis, Chaenomeles sinensis using Fourier transform infrared (FTIR) spectroscopy. The pretreatments such as baseline correction, normalization and second derivative of all the original spectra were performed with Omnic 8.0 software. Moreover, second derivative spectra of samples and gentiopicroside standard were analyzed. In addition, two spectral databases were set up based on the average spectra of every variety with Omnic 8.0 software. The first library (Lib1) which included the spectra region from 1 800 to 600 cm-1 had the algorithm of expert retrieve while the correlation retrieve and square differential retrieve were dealt with the second library (Lib2) in the full spectral range. The results indicated that it is difficult to identify the infrared spectra of samples directly because they had high similarities. There were multiple common peaks between spectra of samples and gentiopicroside standards. The absorption peaks of 1 611 and 1 076 cm-1 of gentiopicroside were the two main characteristic peaks in the second derivative spectra. The difference of peak shape of every sample in the wave number of 1 076 cm-1 was small. By comparing peak area at 1 611 cm-1, the samples planted with J. regia contained highest content of gentiopicroside while the content of this effective constituent was the lowest in the samples which were planted in the slope and in the multiple cropping systems mixed with C sinensis. The differences of effective components in the samples with different planting patterns were represented by the variances of spectral matching values. The difference of matching values of samples planted with J. regia, A. nepalensis, E. Robusta and A. nepalensis were lower than that with slope and C. Sinensis. The number of misjudgment of expert retrieval, correlation retrieve and square differential retrieve were 11, 4 and 9, respectively. The discrimination result of correlation retrieve was the best in the full spectral range and the correct recognition rate was 94.29%. Fourier transforms infrared (FTIR) spectroscopy combined with second derivative and retrieval had good ability to discriminate G. rigescens with different cropping systems. It could provide a basis for the discrimination of different planting patterns of TCM
多熟种植系统是应对中药资源短缺、提高土地利用率的途径。本研究旨在利用傅里叶变换红外光谱（FTIR）对70份种植于坡地以及与核桃、尼泊尔桤木、大叶桉、尼泊尔桤木、茶树、中华猕猴桃混种的多熟种植系统中的滇龙胆样品进行研究。使用Omnic 8.0软件对所有原始光谱进行基线校正、归一化和二阶导数等预处理。此外，对样品和龙胆苦苷标准品的二阶导数光谱进行分析。另外，使用Omnic 8.0软件基于每个品种的平均光谱建立了两个光谱数据库。第一个库（Lib1）包含1800至600 cm-1的光谱区域，采用专家检索算法，而第二个库（Lib2）在全光谱范围内进行相关检索和平方差检索。结果表明，由于样品的红外光谱相似度较高，直接识别较为困难。样品光谱与龙胆苦苷标准品光谱之间存在多个共同峰。龙胆苦苷在1611和1076 cm-1处的吸收峰是二阶导数光谱中的两个主要特征峰。每个样品在1076 cm-1波数处的峰形差异较小。通过比较1611 cm-1处的峰面积，与核桃混种的样品中龙胆苦苷含量最高，而种植于坡地以及与茶树混种的多熟种植系统中的样品中该有效成分含量最低。不同种植模式下样品中有效成分的差异通过光谱匹配值的方差来体现。与核桃、尼泊尔桤木、大叶桉和尼泊尔桤木混种的样品匹配值差异低于与坡地和茶树混种的样品。专家检索、相关检索和平方差检索的误判数分别为11、4和9。相关检索在全光谱范围内的判别结果最佳，正确识别率为94.29%。傅里叶变换红外光谱（FTIR）结合二阶导数和检索对不同种植系统的滇龙胆具有良好的判别能力。可为中药不同种植模式的鉴别提供依据
