Figure 2 from: Voynikov Y, Gevrenova R, Zheleva-Dimitrova D, Balabanova V, Nikolova I, Marinov L, Benbassat I, Momekov G (2023) UHPLC-Orbitrap screening of oleraindoles in hydromethanolic extracts of Portulaca oleracea. Pharmacia 70(4): 1521-1527. https://doi.org/10.3897/pharmacia.70.e113577

Figure 2 MS2 spectra and fragmentation analysis of the three basic HCA-I conjugates in negative ionization mode. The characteristic difference of 149.048 Da, indicating a neutral loss of the 5,6-dihydroxyindole is indicated. The fragment ion corresponding to 5,6-dihydroxyindole is 148.04 m/z.