Retinol, active vitamin A

RetinolVitaminA

 

 

Various names relate to molecular side groups.

  • retinol, the active form of Vitamin A
  • retinal
  • provitamin A carotenoids
    • beta-carotene

---

The word carotene - carot:carrot, -ene:chemistry 'double bonded carbon'

---

The Carotene Group

Only carotenes are the precursor, or provitamin-A in animals (herbivores and omnivores).

Enzymes in the gut convert carotenes into retinol, the active form.

All have the beta-ionone ring

  • alpha-carotene,
  • beta-carotene,
  • gamma-carotene
  • xanthophyll beta-cryptoxanthin

---

Vitamin-A-Ester

Vitamin-A-1 (Retinol)

Vitamin-A-Aldehyde

Vitamin-A-Saure (Retinsaure)