Background: Thousands of plants and animals possess pharmacological properties and there is an increased interest in using these materials for therapy and health maintenance. Efficacies of the application is critically dependent on the use of genuine materials. For time to time, life-threatening poisoning is found because toxic adulterant or substitute is administered. DNA barcoding provides a definitive means of authentication and for conducting molecular systematics studies. Owing to the reduced cost in DNA authentication, the volume of the DNA barcodes produced for medicinal materials is on the rise and necessitates the development of an integrated DNA database.Description: We have developed an integrated DNA barcode multimedia information platform- Medicinal Materials DNA Barcode Database (MMDBD) for data retrieval and similarity search. MMDBD contains over 1000 species of medicinal materials listed in the Chinese Pharmacopoeia and American Herbal Pharmacopoeia. MMDBD also contains useful information of the medicinal material, including resources, adulterant information, medical parts, photographs, primers used for obtaining the barcodes and key references. MMDBD can be accessed athttp://www.cuhk.edu.hk/icm/mmdbd.htm.Conclusions: This work provides a centralized medicinal materials DNA barcode database and bioinformatics tools for data storage, analysis and exchange for promoting the identification of medicinal materials. MMDBD has the largest collection of DNA barcodes of medicinal materials and is a useful resource for researchers in conservation, systematic study, forensic and herbal industry.

Plants of the genus Aconitum L. are commonly used in Asia for medicinal purposes. Although they are widely cultivated and marketed, there has been uncertainty about the efficacy of different species, and therefore accurate identification is crucial. To determine the genetic variation among these medicinal plants, the proposed DNA barcode psbA-trnH intergenic spacer of 134 individuals from 19 taxa of Aconitum were sequenced. Among the two most commonly used medicinal Aconitum species, A. carmichaeli and A. kusnezoffii, sequence inversions were observed. The studied samples were clustered into ten groups according to the sequence alignment and most of the tested Aconitum species could be differentiated by the psbA-trnH intergenic spacer.

Species identification of living organisms by standard DNA sequences has been well-accepted. Consortium for the Barcode of Life (CBOL) recommends chloroplast regions rbcL and matK as the DNA barcodes for the land plants. This study aims to evaluate the feasibility and limitations of rbcL, matK, and 5 other commonly used regions as the DNA barcodes for the medicinal Gentiana and their adulterants, Gentiana. rhodantha and Podophyllum hexandrum.