Molecular identification and quality analysis of Rhei Rhizoma based on chloroplast matK gene and UPLC / 药学学报

ABSTRACT

Rhei Rhizoma is commonly used as a traditional Chinese medicine with multiple botanical origins. Different botanical sources may have different pharmacological activities. The germplasm resources of commercial Rhei Rhizoma were determined based on the chloroplast gene matK, and the anthraquinone and free anthraquinone content was determined by UPLC to analyze quality of commercial Rhei Rhizoma. Eighty-nine commercial Rhei Rhizoma samples were collected from 40 cities in 27 provinces. DNA was extracted and the matK gene was amplified by PCR. Results indicated that the collected samples were from the same botanical origin, Rheum palmatum, and 8 genotypes were identified, including Rp1, Rp2, Rp3, Rp4, Rp5, Rp6, Rp10 and Rp12. Rp4 and Rp6, cultivated in Gansu, Sichuan and Yunnan provinces were the main circulating genotypes, representing 40.45% and 37.08% of the total samples, respectively. Phylogenetic tree analysis showed that the eight genotypes were mainly divided into two branches, of which the main genotypes Rp4 and Rp6 were in one branch. Genetic distance analysis indicated that the genetic separation of the eight genotypes was between 0.001 and 0.010. UPLC analysis indicated that 93.26% of the samples met the Pharmacopoeia standards. There were significant differences in the content of total anthraquinone and free anthraquinone among the samples, in which the difference in free anthraquinone was 1.01% and the difference in total anthraquinone content was 3.79%, indicating that the quality of commercial Rhei Rhizoma samples varies considerably. There was no significant difference in the content of total anthraquinone and free anthraquinone in commercial Rhei Rhizoma among different collection provinces and genotypes. This study will help guide the circulation of Rhei Rhizoma in the market and provides valuable insights for molecular identification and quality analysis of other traditional Chinese medicines.