不同产区天麻近红外光谱多变量选择及二维相关光谱识别研究

Study on identification of different producing areas of Gastrodia elata using multivariable selection and two-dimensional correlation spectroscopy of near infrared spectroscopy

不同产区天麻药材的功效和质量具有较大差异,产区鉴别有助于药材的科学合理利用。采用近红外光谱结合方差光谱、主成分分析、间隔偏最小二乘、遗传算法对云南省外、省内(除昭通)及昭通天麻特征光谱进行提取,分别建立了i PLS-DA和GA-SVM模式识别模型,并对模式识别模型的适配性进行验证。结果显示,建立的i PLS-DA模型的预测正确率为96. 15%,R2,RMSECV,RMSEP分别为0. 893,0. 224,0. 321; GA-SVM的预测正确率为100%,RMSECV为0. 719 4,i PLS-DA和GA-SVM方法均能较好识别不同产区天麻样品。进一步将i PLS和GA提取的特征光谱进行二维相关光谱分析。结果表明,省外和省内天麻差异性光谱主要位于多糖类、芳香烃类、酰胺类和淀粉等物质的C-H,C-N,O-H,N-H键的伸缩、弯曲及倍频吸收区;省外与昭通天麻差异性光谱主要分布在植物蛋白、芳香烃类、多糖类及醇类物质的C-H,O-H,N-H键的伸缩、弯曲及倍频吸收区;省内与昭通天麻差异光谱主要集中于木质素、芳香烃类、醇类、多糖类及脂肪族类物质的CHO,N-H,C-H,O-H,HOH伸缩、弯曲、变形及倍频吸收区。应用近红外光谱结合多变量选择及二维相关光谱,可有效识别不同产区天麻及探析天麻组分的差异特征,对天麻的合理开发与高效利用奠定基础依据。

The efficacy and quality of Gastrodia elata from different producing areas are significant difference. The identification of producing area is helpful for the scientific and reasonable usage of medicinal material. Application near infrared spectroscopy (NIR) together with variance spectra, principal component analysis ( PCA), interval partial least squares (iPLS) and genetic algorithm ( GA), the characteristic spectra of G. elata from inside and outside of Yunnan province (except Zhaotong) and Zhaotong were extracted, and the pattern recognition models of iPLS-DA and GA-SVM were built, and the suitability of the models were also validated. The results showed that the prediction accuracy of iPLS-DA model was 96. 15%, the values of R^2, RMSECV and RMSEP were 0. 893, 0. 224 and 0. 321, respectively. The prediction accuracy of GA-SVM model was 100% and RMSECV was 0. 719 4. Both methods could identify G. elata from different producing area preferably. Further, two-dimensional spectroscopy analysis was conducted for the characteristic spectra extracted by iPLS and GA. The results showed that the differential spectra of G. elata from outside and inside Yunnan were mainly located in the absorption areas of the stretch , bending and double frequency of C-H , C-N, 0-H and N?H bonds of polysaccharides ,aromatic hydrocarbon, amides and starch. The differential spectra of G. elata from outside Yunnan and Zhaotong were mainly located in the absorption areas of the stretch, bending and double frequency of C-H,O-H and N-H bonds of vegetable protein, aromatic hydrocarbon, polysaccharides, and alcohols. The differential spectra of G. elata from inside Yunnan and Zhaotong were mainly located in the absorption areas of the stretch, bending, transformation and double frequency of CHO, N-H, C-H, O-H and HOH bonds of lignin, aromatic hydrocarbon, alcohols, polysaccharides and aliphatics. Effective recognition of different producing areas and exploration the difference of component of G. elata could be conducted through NIR combined with multivariable selection and two-dimensional spectroscopy, which provided the basis for the reasonable development and efficient utilization of G. elata.