Characterization and quantification of phenolic compounds of extra-virgin olive oils with anticancer properties by a rapid and resolutive LC-ESI-TOF MS method.

The characterization and quantification of extra-virgin olive oil (EVOO) phenolic compounds by a rapid resolution liquid chromatography (RRLC) method coupled to diode-array and time of flight mass spectrometry (TOF) detection systems was developed. The RRLC method transferred from a conventional HPLC one achieved better performance with shorter analysis times. The phenolic compounds were separated with a C18 column (150 mm x 4.6mm, 1.8 microm) using water with 0.5% acetic acid and acetonitrile as mobile phases. Good peak resolution was obtained and 19 different phenols were identified in less than 20 min providing a new level of information about the samples in shorter time. The applicability of this analytical approach was confirmed by the successful analysis of three different EVOO varieties (Picual, Hojiblanca, and Arbequina) obtained from different trademarks. Besides identification of the most important phenolic compounds and their quantification in three different ways (RRLC-UV, RRLC-MS and a new approach using the total polyphenol content obtained with Folin Ciocalteau, the relative areas and the response factors), we also described the occurrence of correlations between the phenolic composition of EVOO-derived crude phenolic extracts and their anti-proliferative abilities toward human breast cancer-derived cell lines. When compared with lignans-rich EVOO varieties, secoiridoids-rich EVOO had a significantly strong ability to alter cell viability in four different types of human breast carcinoma cells.