ABSTRACT
Taking Lonicerae Japonicae Flos as an example, the method of "expert consensus of different regions" was used to screen the representative samples and evaluate their commodity grades. The correlation analysis, hierarchical cluster analysis and partial least squares discriminant analysis(PLS-DA) of "commodity grade-appearance characteristic-component content" were carried out to reveal the scientificity of traditional commodity grade of Chinese medicinal material. By referring to the existing literature and the grade investigation from the sample collection regions, 78 "initial grade" samples were screened out from 118 collected samples. Authoritative experts from four regions(n=4) including Linyi(Shangdong province), Bozhou(Anhui province), Anguo(Hebei province) and Beijing were organized to evaluate their commodity grades, separately. Based on the grade consistency rate(R_i≥70%), 69 "local grade" samples were screened out from the "initial grade" samples. Based on the average grade consistency rate ■ "authoritative grade" samples were screened out from the "local grade" samples, including15 first-grade samples, 9 second-grade samples, 11 third-grade samples and 17 fourth-grade samples. For these "authoritative grade" samples, the main appea-rance characteristics were quantified and the contents of 13 components were determined by ultra performance liquid chromatography(UPLC). Furthermore, the total contents of 6 phenolic acids, 4 flavonoids and 3 iridoids were calculated, respectively. The results of correlation analysis showed that 4 appearance characteristics indices were correlated with the commodity grades: color, rate of yellow bars(including blooming flowers), rate of black heads(including black bars), and rate of stems and leaves(including bud debris). Five component content indices were correlated with the commodity grades: chlorogenic acid, isochlorogenic acid C, sweroside, loganin and the total contents of six phenolic acids. Furthermore, chlorogenic acid, loganin and the total contents of six phenolic acids showed significantly negative correlation with the main appearance characteristics, indicating that the appearance characteristics of Lonicerae Japonicae Flos can reflect its internal quality, and these 3 indices can be used as quality markers(Q-markers). The results of hierarchical cluster analysis showed that the samples of four grades were classified into four categories, and the samples with the same grades and the same categories accounted for 80.8% of the total samples, while the samples with the different grades were obviously classified into different categories. The results of PLS-DA analysis showed that the samples of different grades showed obvious intragroup aggregation and intergroup dispersion. The above results indicated that it was feasible to evaluate the traditional commodity grade of Lonicerae Japonicae Flos by the method of "expert consensus of different regions". For the evaluation of traditional commodity grade of Chinese medicinal material, the samples should be representative, expert conclusions should have enough consensuses, and grade determination should be authoritative. As the crystallization of clinical experience, traditional commodity grade can scientifically reflect the internal quality of Chinese medicinal material.