Planta Med 2016; 82 - OA43
DOI: 10.1055/s-0036-1578613

Is DNA Barcoding Using Universal Barcodes A Useful Test For Botanical Raw Materials, Extracts And Products?

H Wohlmuth 1, 2, 3, D Leach 1, 4, K McGrath 5, L Gordon 5, P Mouatt 3, J De Voss 2
  • 1Integria Healthcare, Gallans Rd, Ballina NSW 2478, Australia
  • 2University of Queensland, St Lucia QLD 4072, Australia
  • 3Southern Cross University, Lismore NSW 2480, Australia
  • 4National Institute of Complementary Medicine, Western Sydney University, Campbelltown, NSW 2560, Australia
  • 5Australian Genome Research Facility, St Lucia, QLD 4072, Australia

The application of DNA barcoding to botanicals has attracted much attention recently, in part because this type of test has been used as the basis for high-profile regulatory actions.

We examined the potential utility of DNA barcoding using universal barcodes (matK, rbcL, trnH-psbA and ITS2) as a routine test for botanical raw materials, extracts and finished products, following the same batches of raw materials through extraction to finished product. Samples included 17 authentic dried raw materials, 17 hydroethanolic extracts, 7 tablets containing some of these extracts in dried form, and 15 herbarium specimens. Samples were chemically profiled by LC-MS with identification of marker compounds to validate phytochemical integrity. DNA was extracted with the NucleoSpin® 96 Plant II kit and each genetic target amplified by PCR, and Sanger sequenced. Results were compared to sequences in GenBank using BLAST.

Neither the extracts nor tablets containing the dried extracts yielded amplifiable DNA following extraction, and attempts to directly PCR amplify from the extracts were not successful. For dried plant materials, the rate of successful amplification and sequencing varied for the four targets but was low overall (highest for rbcL and trnH-psbA at 25%). Identification of species using the generated sequences was achieved for 29% (rbcL), 24% (trnH-psbA) and 6% (matK).

Our results indicate that DNA barcoding using universal barcode sequences, which are relatively long, is not suitable for routine authentication of botanical raw materials, extracts or finished products, likely due to DNA degradation. The use of shorter, species-specific sequences may yield better results.