Chemical Exploration on the Botanical Origin of Tong-guan-teng and Analysis of Its Major Constituents
The botanical origin of the traditional Chinese medicine Tong-guan-teng was investigated using ultra-high-performance liquid chromatography coupled with charged aerosol detection (UHPLC-CAD) to establish a semi-quantitative fingerprinting method for quality control. Reference material, 12 batches of commercial Tong-guan-teng, and vine samples of two putative origin species, Marsdenia tenacissima and M. cavaleriei, were analyzed on an ACQUITY BEH C18 column (100 mm × 2.1 mm, 1.7 μm) with 0.1% formic acid aqueous solution–acetonitrile gradient elution at 0.5 mL/min and 2 μL injection volume. Similarity evaluation was performed using the Similarity Evaluation System for Chromatographic Fingerprint of Traditional Chinese Medicine (2012 edition). The method demonstrated satisfactory precision, stability, and repeatability. Similarity between the reference and commercial batches ranged from 0.927 to 0.988. The reference fingerprint differed significantly from M. tenacissima stems but showed high consistency with M. cavaleriei stems (similarity > 0.85), with comparable major component contents. The relative contents of eight major components followed the order: tenacissoside A > marsdenoside H > marsdenoside K > tenacissoside B > tenacissoside H > tenacissoside D > tenacissoside I > tenacissoside E. Besides the pharmacopoeial marker tenacissoside H, tenacissoside A, marsdenoside H, marsdenoside K, and tenacissoside B were abundant and are proposed as potential quality markers. These chemical findings support revising the botanical origin of Tong-guan-teng in the Chinese Pharmacopoeia (2025 edition) from M. tenacissima to M. cavaleriei, providing a scientific basis for origin identification and quality standard improvement.