Qualitative identification of lonicerae japonicae flos in traditional chinese medicine using metabarcoding combined with specific mini-barcodes

Background Lonicerae japonicae flos, also known as Jinyinhua (JYH), is an important component of traditional Chinese patent medicine (TCPM) products. However, the potential for adulteration and substitution with low-quality materials highlights the need for a reliable and sensitive approach to identify the species composition of TCPM products for consumer safety. Methods and results We used universal ITS2 primers to amplify TCPMs containing JYH. However, the results were inconclusive, as only one operational taxonomic unit (OTU) was identified as Lonicera sp. , which could not be identified at the species level. To confirm the species identification of Lonicera sp. in TCPM, we developed a short mini-barcode primer based on the psbA-trnH region, which, in combination with DNA metabarcoding technology, allowed for qualitative and quantitative analysis of artificially mixed samples. We applied the mini-barcode to distinguish TCPMs containing JYH and demonstrated its relatively accurate quantitative ability in identifying two Lonicera species. Conclusions Our study presents a method for qualitative and quantitative identification of JYH, providing a promising application of DNA metabarcoding technology in the quality control of TCPM products.