Wang Yi-Bing, Chen Zhi-Cheng, Wu Wei-Hong, Kong De-Xin, Huang Rong-Shao, Liu Jun-Xian, Huang Shu-Shi
Lab of Biophysics, Guangxi Academy of Sciences, Nanning 530007, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2010 Apr;30(4):937-42.
The methods of fuzzy cluster and curve-fitting combined with FTIR were used to determine the origins of Herba Abri cantoniensis and Herba Abri mollis. The spectra of Herba Abri cantoniensis and Herba Abri mollis are similar, both with typical spectral shapes. The two spectra can be divided into 3 parts: the 1st is 3 500-2 800 cm(-1), containing stretching bands of -OH, N-H, and CH2 ; the 2nd is 1 800-800 cm(-1), containing stretching bands of ester carbonyl group and indican C-O(H), vibrational bands of C=C and benzene ring; The 3rd is 800-400 cm(-1), containing skeletal vibration and scissoring vibration of molecular. The recorded FTIR spectral data were processed by 9-point-smoothing, 1st derivative, SNV and fuzzy cluster analysis sequentially. The fuzzy cluster analysis was carried out by similarity or dissimilarity matrix, and two matrices are computed with Manhattan and Euclidean distance. The results indicated that the optimization used Manhattan and dissimilarity matrix, and 5 origins of Herba Abri cantoniensis were perfectly discriminated, but 2 origins of Herba Abri mollis were mixed and identified from the other 3 origins. So the characterized bands at 1 034 cm(-1) of the average 1-D spectra of Herba Abri cantoniensis and Herba Abri mollis were fitted combining 2nd derivative for further distinguishing their spectral characteristic. The results of curve-fitting showed that the bands of wild Herba Abri cantoniensis and the other origin ones were decomposed to 11 and 9 component bands respectively, but the bands of Shanglin and the other origins Herba Abri mollis were decomposed to 9 and 8 component bands dissimilarly, and the locations and normalized densities of these component bands were different. From this, together with the results of fuzzy cluster analysis, it is concluded that the combination of two methods may identify the origins of Herba Abri cantoniensis and Herba Abri mollis availably.
采用模糊聚类和曲线拟合结合傅里叶变换红外光谱（FTIR）的方法来确定广金钱草和耳草的产地。广金钱草和耳草的光谱相似，均具有典型的光谱形状。这两种光谱可分为3个部分：第一部分为3500 - 2800 cm⁻¹，包含 -OH、N - H和CH₂的伸缩带；第二部分为1800 - 800 cm⁻¹，包含酯羰基和靛蓝C - O(H)的伸缩带、C = C和苯环的振动带；第三部分为800 - 400 cm⁻¹，包含分子的骨架振动和剪式振动。所记录的FTIR光谱数据依次经过九点平滑、一阶导数、标准正态变量变换（SNV）和模糊聚类分析处理。模糊聚类分析通过相似性或相异性矩阵进行，两种矩阵分别采用曼哈顿距离和欧几里得距离计算。结果表明，采用曼哈顿距离和相异性矩阵进行优化时，能完美区分广金钱草的5个产地，但耳草的2个产地与其他3个产地混合在一起。因此，结合二阶导数对广金钱草和耳草平均一维光谱在1034 cm⁻¹处的特征峰进行拟合，以进一步区分它们的光谱特征。曲线拟合结果表明，野生广金钱草和其他产地的广金钱草的谱带分别分解为11个和9个成分带，但上林耳草和其他产地耳草的谱带分别分解为9个和8个不同的成分带，且这些成分带的位置和归一化密度不同。由此，结合模糊聚类分析结果得出，两种方法相结合可有效鉴别广金钱草和耳草的产地。
