Analysis of X-ray Diffraction Pattern on Pogostemon cablin and Agastache rugosa

Key words: 
• Pogostemon cablin /
• Agastache rugosa /
• X-ray

Abstract: Four cultivars of Pogostemon cablin,and Agastache rugosa were collected as samples to establish their X-ray powder diffraction fingerprint patterns for analysis.The analysis showed that the 2θ cosine values of 4 cultivars of P.cablin were similar（more than 0.6） while the 2θ cosine values of A.rugosa was 0.325,indicating a big difference between P.cablin and A.rugosa in the 2θ cosine value.It is suggested that the 2θ cosine value of 0.6 be used as the reference standard to distinguish between P.cablin and A.rugosa.P.cablin and A.rugosa were different in the intensity of characteristic peaks,and the 5 samples were divided into 3 categories.P.cablin ’Paixiang’ had a sharp,higher diffraction peak intensity at 7.5 nm and was listed in Category I;P.cablin ’Zhanxiang’,’Zhaoxiang’ and ’Nanxiang’ were grouped into Category Ⅱ because of a sharp,higher diffraction peak intensity at 4.0 nm;A.rugosa was listed in Category Ⅲ.X-ray powder diffraction fingerprint pattern can be used for identification and analysis of P.cablin,and the results of similarity calculation can be used for quality evaluation.This provides a new scientific method for effective identification of P.cablin and A.rugosa.