MS-FINDER and SIRIUS for phenolic compound identification from high-resolution mass spectrometry data.

LC-HR-MS/MS is the predominant analytical technique in phenolic compound (PC) research. However, the manual interpretation of mass spectra is a heavy nontrivial time-consuming task and depends on mass spectrometry and phenolic compounds fragmentation deep knowledge. We think this manual approach should be partially translated into a practical software that allows users to perform such complicated analyses. In silico fragmentation software have been tested for small molecule identification, MS-FINDER and SIRIUS stood out at identification contests and challenges. We evaluated both software to identify PC from two data categories: 1st MS/MS spectra from 18 phenolic compound standards (PCS) and 2nd phenolic compounds from 8 food samples (FPC) (coffee, green tea, cranberry juice, grape juice, orange juice, apple juice, soy extract and parsley extract). MS-FINDER and SIRIUS were able to correctly identifymore than 90% of the PCS by LC-HR-MS/MS. The main FPC were also correctly identified by MS-FINDER (70%) and SIRIUS (38%). We highlight that these software were unable to differentiate PC isomers. This task is only possible by using additional information, such as chromatographic behavior and manual analysis of the relative intensity of fragments in the MS/MS spectra. Therefore, the combination of initial screening by using MS-FINDER and SIRIUS with manual analyses of additional information is a powerful and efficient approach for identifying phenolic compounds.

New insights into the phenolic compounds and antioxidant capacity of feijoa and cherry fruits cultivated in Brazil.

Acca sellowiana (feijoa) and Eugenia involucrata (cherry) are fruits species of Brazilian biodiversity (Myrtaceae family). In this study, a sampling process was used with three different harvesting sites. The composition of phenolic compounds of these fruits was determined by HPLC-DAD-MS/MS. Moreover, the antioxidant capacity of hydroethanolic extracts against hydrogen peroxide (H2O2), hydroxyl (OH), peroxyl (ROO-) and ABTS radicals was evaluated. Thirty and twenty-seven phenolic compounds were identified in feijoa and cherry, respectively. The major phenolic compounds found were pedunculagin isomer (5040.87, 3443.66 and 1324.95 µg·g-1) in feijoa and procyanidin (1406.54, 1888.00 and 1380.64 µg·g-1) in cherry. Hydroethanolic extract of these fruits was a potent scavenger of free radicals and excellent source of phenolic compounds. In hydroethanolic extracts of feijoa, the phenolic content increased by around 50%, while in the cherry the content was similar to that found in the fruit. For ORAC method, sample 2 of feijoa and cherry showed values of 383 and 126 µM·TE·g-1, respectively, featuring the highest antioxidant capacity. This study is the first to report the identification of castalagin, catechin and epicatechin in feijoa, and rutin in cherry. Besides, the health benefits, these fruits can contribute to biodiversity conservation.