A simple HPLC method for the comprehensive analysis of cis/trans (Z/E) geometrical isomers of carotenoids for nutritional studies

A comprehensive review on the colorless carotenoids phytoene and phytofluene

“…Several geometrical isomers of PTF are known to occur in red tomatoes, although their conclusive identification remains obscure [20,21]. At least 3 geometrical isomers of PT and 6 of PTF can be readily formed and detected by using conventional stereomutation procedures and routine analytical procedures [22]. Chemical and in silico evidences indicate that certain Z-isomers of both phytoene and phytofluene could be thermodynamically favoured over the respective (all-E)-isomers [23].…”

“…Typical spectra in a MeOH/MTBE-based mobile phase are shown in Fig 3. Spectroscopic data of different geometrical isomers of phytoene and phytofluene have been reported elsewhere [22].…”

“…However, ferrets are known to absorb carotenoids more efficiently. Both phytoene ((15Z)-and all-E-phytoene) and phytofluene (up to 5 isomers), along with several geometrical isomers of both b-carotene and lycopene have been reported to accumulate in the lungs of male ferrets receiving a diet supplemented with a tomato extract [22].…”

Tentative Identification of Torulene Cis/trans Geometrical Isomers Isolated from Sporidiobolus pararoseus by High-Performance Liquid Chromatography-Diode Array Detection-Mass Spectrometry and Preparation by Column Chromatography

“…APCI-MS was taken into account because carotenoids lack a site for protonation detection by ESI. 34,35 As a result, a total of 8 torulene geometrical isomers that had the protonated molecular ion [M+H] + at m/z 535, consistent with C40H54, and in common except for Peak 6 (not detected) among purified torulene, were tentatively confirmed by mass spectrometry. At the same time, Peaks 1, 5 and 7 showed similar mass spectra, producing a fragment ion at Table 3, which are the general characteristic fragments of carotenoids.…”

“…At the same time, Peaks 1, 5 and 7 showed similar mass spectra, producing a fragment ion at Table 3, which are the general characteristic fragments of carotenoids. 32,35 Absorption spectroscopy is still the major technique to identify and quantitate carotenoids. In the UV region, an absorption peak referred to as the cis peak is apparent for cis isomers, with the intensity of this peak varying with the position and number of cis double bonds.…”