Application ofH NMR-based metabolomics for discrimination of different parts and development of a new processing workflow for

ABSTRACT

(CD) is one of the two authoritative source plants of Cistanches Herba, a well-known medicinal plant. Herein,H NMR spectroscopy was employed to characterize the chemical profile and to distinguish the different parts, as well as to propose a new processing workflow for CD. Signal assignment was achieved by multiple one and two dimensional NMR spectroscopic techniques in combination with available databases and authentic compounds. The upper parts of the plant were distinguished from the lower parts by combiningH NMR spectroscopic dataset with multivariate statistical analysis. A new processing method that hyphenated steaming with freeze-drying, was demonstrated to be superior to either steaming coupled with oven-drying or direct freeze-dryingholisticH NMR-based metabolomic characterization. Phenylethanoid glycosides, mainly echinacoside and acteoside, were screened out and confirmed as the chemical markers responsible for exhibiting the superiority of the new processing workflow, whereas serial primary metabolites, especially carbohydrates and tricarboxylic acid cycle metabolites, were found as the primary molecules governing the discrimination between the upper and lower parts of the plant. Collectively,H NMR spectroscopy was demonstrated as a versatile analytical tool to characterize the chemical profile and to guide the in-depth exploitation of CD by providing comprehensive qualitative and quantitative information.