RESUMO
Ultra high performance liquid chromatography tandem linear ion trap orbitrap mass spectrometry (UHPLC-LTQ-orbitrap-MS) was applied to analyze and identify flavonoids and phenylethanoid glycosides in the Tibetan herb Lagotis brevituba Maxim. A method of data-dependent scan coupling with dynamic exclusion was developed for analyzing flavonoids and phenylethanoid glycosides under positive and negative ion mode of electrospray ionization (ESI). The compounds of Lagotis brevituba Maxim. were systematically identified through exact molecular mass, fragmentation patterns, retention time and reported references. A total of 167 compounds were detected, of which 84 were flavonoids and 83 were phenylethanoid glycosides, which greatly enriched the number and types of flavonoids and phenylethanol glycosides in Lagotis genus medicinal plants. Baohuoside Ⅰ, 4 disaccharide O-glycoside flavonoids (composed of deoxyhexose and glucuronic acid), 9 C-glycoside flavonoids, 15 tetrasaccharide phenylethanoid glycosides and 5 phenylethanoid glycosides with substituents on the β-position of the phenylethyl group were identified in Lagotis genus medicinal plants for the first time. This study provides scientific support for elucidating the material basis and improving the quality control of Lagotis brevituba Maxim.
RESUMO
Objective: To establish HPLC fingerprints of Lagotis integra and Lagotis brevituba which were contained in National Drug Standard and compared to Lagotis ramalana, Lagotis alutacea and Lagotis brachystachya by the established method. Methods: The similarity of HPLC fingerprints of L. integra and L. brevituba was low, so the HPLC fingerprint methods were established for both. The HPLC analysis was performed on Waters X-Bridge C18 (250 mm × 4.6 mm, 5 μm), using acetonitrile and 0.2% formic acid solution as the mobile phase at a flow rate of 1.0 mL/min, the detection wave-length was 328 nm and column temperature was 35 ℃ (L. integra) and 25 ℃ (L. brevituba). Results: There were 14 common peaks in the fingerprint of L. integra, and plantamajoside, hemiphroside B, 10-O-trans-p-methoxycinnamoyl-catalpol and 10-O-[(E)-3,4-dimethoxycinna moyl]-catalpol were standardized. There were 13 common peaks in the fingerprint of L. brevituba, and echinacoside, plantamajoside and acteoside were standardized. The similarity of HPLC fingerprint was more than 0.9 between L. integra and L. alutacea, but the others had low similarity with them. The similarity of HPLC fingerprint was more than 0.9 between L. brevituba from different batches and L. ramalana, while the others had low similarity with them. Conclusion: The established method could effectively identify L. brevituba, L. integra and L. alutacea were advised to be recorded in Medical Standards of the Ministry of Health. Lagotis ramalana could be used as a new base for "Honglian" (origin: Lagotis brevituba).
