Fragmentation of the main triterpene acids of apple by LC‐APCI‐MSⁿ

Abstract

In this paper, we investigated the fragmentation of the main triterpene acids of apple using an liquid chromatography atmospheric pressure chemical ionization mass spectrometry (LC-APCI-MS ) approach and high-resolution mass spectrometry (HR-MS) (Q-TOF). Triterpenes were isolated using semipreparative high-performance liquid chromatography, and chemical structures were elucidated by HR-MS and nuclear magnetic resonance spectroscopy. Finally, compounds were used to study MS behavior in ion trap. Isolated triterpenes present similar structures, bearing carboxyl group linked to C-17 and different substitutions. We observed significant changes in MS spectra, which were useful for further compound identification. The observed fragments allowed the discrimination of different derivatives, namely, pomaceic, annurcoic, euscaphic, pomolic, corosolic, maslinic, betulinic, oleanolic, and ursolic acids. The proposed method allows a rapid identification of triterpene acids, and it could be useful for the analysis of these compounds in apple fruits and in other natural sources.

Triterpene Acid and Phenolics from Ancient Apples of Friuli Venezia Giulia as Nutraceutical Ingredients: LC-MS Study and In Vitro Activities

“…In a previous paper we reported an LC-APCI method was developed and used to characterize apple triterpene acids. [34] As a continuation of that work, here we present the fragmentation pattern of the main triterpenes detected in FVG ancient apples. Typical collision-induced dissociation spectra are reported in supplementary figures showing the different behavior of structurally related derivatives.…”

Hepatoprotective Effects of Standardized Extracts from an Ancient Italian Apple Variety (Mela Rosa dei Monti Sibillini) against Carbon Tetrachloride (CCl4)-Induced Hepatotoxicity in Rats

“…A previously published method was used for quantification of triterpene acids [34]. Briefly, an Agilent Eclipse XDB C-18 (3.0 × 150 mm, 3.5 µm) was used as stationary phase.…”

“…Methanol (A) and H 2 O with 0.05 % formic acid (B) were the mobile phases. The analysis revealed the presence of annurcoic acid [34]; the latter was quantified using the calibration curve of the purified compound considering the ion species at m/z 485 in the range 5-50 µg/mL. The calibration curve was as follows, y = 12549x + 136925; r 2 = 0.9962.…”

Comparison of ESI‐MS/MS and APCI‐MS methods for the quantification of folic acid analogs in C. elegans

“…Using collision‐induced dissociation (CID), the ions, which entered the mass spectrometer can collide with an inert gas, typically nitrogen, to obtain product ion spectra, and is commonly combined with ESI (ESI‐CID or ESI‐MS/MS). Atmospheric pressure chemical ionization (APCI) is an alternative to ESI, which produces a corona discharge whereby atmospheric gases, such as O 2 and N 2 , are ionized and further react with analyte molecules . Notably, the use of different ion activation modes as well as different ionization sources is a powerful tool to elucidate metabolite and drug structures in complex chemical mixtures .…”

“…Atmospheric pressure chemical ionization (APCI) is an alternative to ESI, which produces a corona discharge whereby atmospheric gases, such as O 2 and N 2 , are ionized and further react with analyte molecules. 21 Notably, the use of different ion activation modes as well as different ionization sources is a powerful tool to elucidate metabolite and drug structures in complex chemical mixtures. 22 Understanding the fragmentation behavior and the product ions of FA under different MS conditions can help elucidate the structure of FA analogs 23 , as well as facilitate identification of new candidate molecules.…”