Direct analysis of Stevia leaves for diterpene glycosides by desorption electrospray ionization mass spectrometry

Abstract

The analysis of Stevia leaves has been demonstrated without any sample preparation using desorption electrospray ionization (DESI) mass spectrometry. Direct rapid analysis was achieved using minimal amounts of sample ( approximately 0.15 cm x 0.15 cm leaf fragment). Characteristic constituents of the Stevia plant are observed in both the positive and negative ion modes including a series of diterpene 'sweet' glycosides. The presence of the glycosides was confirmed via tandem mass spectrometry analysis using collision-induced dissociation and further supported by exact mass measurements using an LTQ-Orbitrap. The analysis of both untreated and hexane-extracted dry leaves proved that DESI can be successfully used to analyze untreated leaf fragments as identical profiles were obtained from both types of samples. Characterization and semi-quantitative determination of the glycosides was achieved based on the glycoside profile within the full mass spectrum. In addition, the presence of characteristic glycosides in an all-natural commercial Stevia dietary supplement was confirmed. This study provides an example of the application of DESI to direct screening of plant materials, in this case diterpene glycosides.

Use of Associated Chromatographic Techniques in Bio-Monitored Isolation of Bioactive Monoterpenoid Indole Alkaloids from Aspidosperma ramiflorum

“…The development of the TLC solvent system for Aspidosperma ramiflorum alkaloids at the beginning of this article clearly shows that TLC and PTLC as a routine and classical method appreciated in alkaloid separation techniques, can still be optimized with introduction of new methodologies as desorption electrospray ionization (DESI) which can permit coupled TLC with mass spectrometry (Jackson et al, 2009). This is not necessarily true for alkaloid determination by GC, because decomposition can occur due to the high temperatures applied and however widespread application of this technique is limited by volatility of more polar alkaloids.…”

Chocolate Milk Sweetened With Stevia: Acceptance by Children

“…Bertoni a herbaceous perennial plant native to subtropical and tropical rainforests of South America is an all-natural zero-calorie sweetener [15] used in a wide variety of food and beverages [16]. Stevia seems well-positioned to become a major high-potency sweetener [17] for the growing natural food market, especially given its lack of undesirable taste characteristics [18].…”

Effect of different drying methods on the composition of steviol glycosides in Stevia rebaudiana Bertoni leaves

“…In generally cultivated varieties of Stevia rebaudiana Bertoni, the main steviol glycosides found in the leaves are stevioside, rebaudioside A, and rebaudioside C; other glycosides, including dulcoside A, stevolbioside, rubusoside, rebaudioside B, D, E, and F, are present in smaller amounts (Goyal et al, 2010;Jackson et al, 2009;Wöelwer-Rieck et al, 2010).…”

“…In recent years, the food industry has focused its interest on the use of natural sweeteners, and Stevia rebaudiana Bertoni has been highlighted as it contains steviol glycosides that are 200-300 times sweeter than sugar (Goyal et al, 2010;Jackson et al, 2009). Steviol glycosides have no calories and are generally recognized as safe (GRAS) by the Food and Drug Administration in the United States of America (FDA, 2008).…”