This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: ζ-Carotene, a key intermediate in lycopene biosynthesis, is widely found in plants and photosynthetic microorganisms, but its isomer-specific properties remain poorly understood due to isolation and purification challenges. Researchers have now developed a purification strategy to obtain high-purity geometric isomers and systematically characterized, for the first time, their isomer-specific spectral properties, photoisomerization behavior, UV-shielding capacity, antioxidant activity and skin-related biological activities—highlighting ζ-carotene's promise as a natural ingredient for skin health and photoprotection. ζ-Carotene is a naturally occurring carotenoid found in edible plants and photosynthetic microorganisms, where it functions as a key intermediate in lycopene biosynthesis.
Previous studies have suggested that ζ-carotene-containing materials may help alleviate oxidative stress and inflammatory responses and may contribute to the maintenance of skin health. These findings have increased interest in ζ-carotene as a potential ingredient in ingestible and topical skincare products. However, despite its biological relevance and potential applications, the intrinsic physicochemical properties and biological activities of ζ-carotene remain poorly understood.
This knowledge gap is largely attributable to its relatively low abundance in natural sources and the difficulty of obtaining highly purified ζ-carotene, particularly as individual geometric isomers. To address this knowledge gap, a team of researchers from Japan, led by associate professor Masaki Honda from Meijo University, successfully separated and purified four major geometric isomers of ζ-carotene: all-E-, 9Z, 9Z,9′Z, and 9Z,13Z,9′Z. The purified isomers were used to analyze their structural, spectroscopic, antioxidant and biological properties.
Kento Nakamura from Harima Chemicals, Japan, collaborated on the research team. Their research is published in the Journal of Agricultural and Food Chemistry. "The separation, purification, and functional assessment of carotenoid geometric isomers have long piqued the interest of our research team.
Although carotenoids like lycopene and astaxanthin have been shown to exhibit isomer-dependent features, nothing was known about the properties of specific ζ-carotene isomers. To investigate their potential as novel functional ingredients, we worked on extracting highly purified ζ-carotene isomers and elucidated their distinct physicochemical and biological characteristics," Honda and Nakamura explained. The team used normal-phase chromatography to separate the four ζ-carotene isomers, which were subsequently isolated, purified and structurally characterized by nuclear magnetic resonance analysis.
They then investigated the stability of these compounds when exposed to light, revealing a unique photoisomerization pattern. Exposure to white LED light rapidly shifted all isomers toward a steady chemical mixture dominated by the 9Z isomer, demonstrating a distinctive response to light. While prolonged illumination caused gradual degradation, the carotenoids remained comparatively stable during storage in the dark at 30°C (86°F).
Extract — continue reading at the source.
