Composition and characterization of cordyxanthins from Cordyceps militaris fruit bodies

• The main carotenes of Cordyceps militaris fruit bodies were identified.
• Cordyceps carotenes were found novel and highly water-soluble.
• Cordyceps carotenes were significantly increased by light regulation.

Fruit bodies of Cordyceps militaris are widely used as functional food in China, Southeast Asia and North America. Cordyceps carotenoids are the important active components in the fruit bodies. However, chemical composition and property of the cordyceps carotenoids are still unknown. In this study, the novel carotenoids from C. militaris fruit bodies were separated and identified as xanthophylls and named as cordyxanthin-I (2, 3, 2′, 3′-tetradehydro-18, 16′, 17′, 18′-tetranor-ε, ε-carotene-5, 5′, 1′ -triol), cordyxanthin-II (2, 3, 2′, 3′-tetradehydro-18, 1′, 16′, 17′, 18′-pentanor-ε, ε-carotene-5, 5′, -diol), cordyxanthin-III (2, 3, 2′, 3′-tetradehydro-18, 17′, 18′-trinor-ε, ε-carotene-5, 5′, -diol) and cordyxanthin-IV (2, 3, 2′, 3′-tetradehydro-18, 18′-dinor-ε, ε-carotene-5, 5′, -diol). The four cordyxanthins proved to be highly water-soluble and could be directly quantified at 447 nm with β-carotene as a standard. Compared with traditional cultivation, the contents of the four cordyxanthins could be significantly increased by treatment of pink light (2/3 of 620–630 nm + 1/3 of 450–460 nm).