Carotenoids with a 5,6-dihydro-5,6-dihydroxy-β-end group, from yellow sweet potato “Benimasari”, Ipomoea batatas Lam

Four carotenoids, named ipomoeaxanthins A (1), B (2), C1 (3) and C2 (4), were isolated from the flesh of yellow sweet potato “Benimasari”, Ipomoea batatas.