Identification of Botanicals Based on Their Mass Spectrum Fingerprints Using Ultra-Performance Liquid Chromatography-Mass Spectrometry

Abstract

In the current scenario, herbal raw materials are identified via morphotaxonomy, microscopic pharmacognosy, or DNA barcoding. However, these methods do not reveal their chemical integrity, while plant raw materials play a crucial role in the quality of plant-based medicine. To overcome this limitation, we used a mass spectrometry-based method to identify 30 botanicals. This assay followed a standard operating procedure (SOP) from sample preparation to the reference library's mass spectrum fingerprint (MSFP) search. The MS1 score showed a similarity index between the input data and the reference mass spectrum. A more than 50% MS1 score was the critical threshold for accurately identifying botanicals based on their chemical integrity. Interestingly, the analysis of 30 different plant species yielded no false results. The results were 100% accurate and selective for tested botanical samples. However, we found that the standard deviation of analytical assays and biological replicates was ± 3.5 and ± 6.3 (MS1 score) for all analyzed samples, respectively. Intraspecies variability showed MS1 scores > 50% ± 10, whereas interspecies variability was observed with MS1 scores < 50% ± 10. The MS1 score was observed, dependent on the plant species, ranging from 53.00% (± 2.65) to 89.76% (± 4.08). In addition, the method was tested to see how seasonal and geographical changes affected search results. The MS1 score changed by less than 15%. We simultaneously created a chemical barcode (unique molecular weight sequence) for each plant species to validate search results and ensure the reliable identification of botanicals.