Objective To explore the botanical origin of traditional Chinese medicine Tong-guan-teng and establish a semi-quantitative analysis method, and provide a scientific basis for the quality control and criterion improvement of the medicinal material. Methods Reference sample of Tong-guan-teng, market-available materials, and vine samples of two possible origin plants (Marsdenia tenacissima and M. cavaleriei) were collected. Ultra-high-performance liquid chromatography coupled with charged aerosol detector (UHPLC-CAD) was employed, and an ACQUITY BEH C₁₈column (100 mm×2.1 mm, 1.7 μm) was used. The mobile phase consisted of 0.1% formic acid aqueous solution and acetonitrile, at a flow rate of 0.5 mL/min, with an injection volume of 2 μL. The similarity of sample chromatograms was analyzed by the “Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine (2012 edition)”. Based on the chromatographic peak areas of eight main components in the UHPLC-CAD fingerprint, semi-quantitative analysis of relative contents and total relative contents among batches was carried out. Results The established fingerprint was validated by methodology, with demonstrated satisfactory precision, stability and repeatability, which met the requirements of traditional Chinese medicine fingerprint analysis. The similarity of fingerprints among the reference sample and 12 batches of commercial Tong-guan-teng samples ranged from 0.927 to 0.988. Significant differences were observed between the reference fingerprint of Tong-guan-teng and those of M. tenacissima stems, while a high degree of consistency was achieved with M. cavaleriei stems (similarity > 0.85) and the total contents of major components were relatively consistent. The relative contents of the eight major components followed the order: tenacissoside A > marsdenoside H > marsdenoside K > tenacissoside B > tenacissoside H > tenacissoside D > tenacissoside I > tenacissoside E. Conclusion In addition to tenacissoside H (the index component specified in the 2025 edition of the Chinese Pharmacopoeia), tenacissoside A, marsdenoside H, marsdenoside K and tenacissoside B have relatively high contents, which can serve as potential quality markers and provide a theoretical basis for the botanical origin identification of the traditional Chinese medicine Tong-guan-teng from the perspective of chemical composition.

Tong-guan-teng  /  UHPLC-CAD  /  fingerprint  /  Masdenia tenacissima(Roxb.) Wight et Arn.  /  Masdenia cavaleriei Lé  /  veillé  /  similarity evaluation