Assertion: carotenoid | /r/HasAspect | no vitamin a activity
Facets:
Source sentences:
text: All other carotenoids, including lycopene, have no beta-ring and thus no vitamin A activity (although they may have antioxidant activity and thus biological activity in other ways).
text: As only several carotenoids have vitamin A activity,
text: Carotenoids that do not contain the β-ionone moiety cannot be converted to retinol, and thus have no vitamin A activity.
text: All other carotenoids, including lycopene, have no beta-ring and thus no vitamin A activity (although they may have antioxidant activity and thus biological activity in other ways).
text: Carotenoids that contain unsubstituted beta-ionone rings (including beta-carotene, alpha-carotene, beta-cryptoxanthin, and gamma-carotene) have vitamin A activity (meaning that they can be converted to retinol).