Structures and Analysis of Carotenoid Molecules

Area of Science:

• Plant biochemistry
• Analytical chemistry

Background:

• Carotenoids exhibit diverse structures derived from the C40 skeleton, including acyclic, monocyclic, and dicyclic forms.
• Xanthophylls can be hydroxylated or epoxidized, and carotenols may be esterified with fatty acids.
• E-Z isomerization further expands the structural diversity of plant carotenoids.

Purpose of the Study:

• To review the structural diversity of plant carotenoids.
• To discuss analytical methods for carotenoid quantification.
• To highlight the importance of accurate carotenoid analysis in plant research and breeding.

Main Methods:

• Visible absorption spectrometry and near-infrared reflectance spectroscopy for initial screening.
• Reverse-phase High-Performance Liquid Chromatography (HPLC) with a photodiode array detector as a preferred technique.
• Ultra-High-Performance Liquid Chromatography (UHPLC), HPLC-Mass Spectrometry (HPLC-MS), and Nuclear Magnetic Resonance (NMR) for advanced analysis and identification.

Main Results:

• A wide array of carotenoid structures exist in plant tissues due to modifications of the C40 skeleton.
• Quantitative analysis of individual carotenoids is essential, despite inherent difficulties.
• Knowledge of error sources has improved the reliability of carotenoid compositional data.

Conclusions:

• Accurate quantitative analysis of diverse plant carotenoids is critical for scientific advancement.
• Advanced analytical techniques like UHPLC and HPLC-MS are increasingly important for carotenoid research.
• Reliable data on carotenoid composition supports plant breeding and biochemical studies.