MolDraw › 3D molecule models › Vitamin A structure
Vitamin A structure and 3D model (C20H30O)
Vitamin A (retinol) is a cyclohexene ring attached to a long chain of four conjugated all-trans C=C double bonds that ends in a CH₂OH group.
Drag to rotate · pinch or scroll to zoom. 3D coordinates: computed with RDKit (ETKDG conformer, force-field optimised).
Vitamin A at a glance
| Formula | C20H30O |
|---|---|
| Molar mass | 286.46 g/mol |
| IUPAC name | (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol |
| Atoms / bonds | 51 / 51 |
| H-bond donors / acceptors | 1 / 1 |
| logP (estimated) | 5.5 |
| SMILES | CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C |
| InChIKey | FPIPGXGPPPQFEQ-OVSJKPMPSA-N |
| PubChem | 445354 |
What the 3D model of Vitamin A shows
The model contains 51 atoms (21 heavy atoms and 30 hydrogens) joined by 51 bonds; in ball-and-stick mode every stick is one bond, and double or aromatic bonds are drawn as multiple sticks. Switch to space-filling to see the molecule as its electron cloud, scaled to van der Waals radii: this is the shape other molecules actually "feel". It can donate 1 and accept 1 hydrogen bonds, and its estimated logP of 5.5 means it is fat-loving (lipophilic). Its topological polar surface area is 20 Ų.
Shape and bond angles
| Atom(s) | Geometry / hybridisation | Angles & lengths |
|---|---|---|
| polyene chain carbons | Trigonal planar, sp²; conjugated | ≈ 120° |
| ring CH₂ and methyl carbons | Tetrahedral, sp³ | ≈ 109.5° |
| CH₂OH carbon | Tetrahedral, sp³ | ≈ 109.5° |
Is Vitamin A polar?
No, mostly non-polar. The single OH group is small compared with the 20-carbon skeleton, so retinol is a fat-soluble vitamin.
Elemental composition of C20H30O
| Element | Atoms | Mass (g/mol) | Mass % |
|---|---|---|---|
| Carbon (C) | 20 | 240.220 | 83.86% |
| Hydrogen (H) | 30 | 30.240 | 10.56% |
| Oxygen (O) | 1 | 15.999 | 5.59% |
Calculated from IUPAC standard atomic weights. Check any formula with the molar mass calculator.
Uses of Vitamin A
- Needed for vision, growth and the immune system
- Added to foods and supplements
- Retinol and related retinoids are used in skin care
Interesting facts
- The body makes retinol from beta-carotene, the orange pigment in carrots.
- In the eye, retinal (the aldehyde form) switches from 11-cis to all-trans when it absorbs light.
- Vitamin A was the first vitamin to be named with a letter.
Drawing structures for your notes? MolDraw is a free online chemical structure editor for molecules, reactions and lab diagrams.
Open MolDraw editorFrequently asked questions
What is the structure of Vitamin A?
Vitamin A (retinol) is a cyclohexene ring attached to a long chain of four conjugated all-trans C=C double bonds that ends in a CH₂OH group. Its SMILES is CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C.
Why is vitamin A fat-soluble?
It is mostly a hydrocarbon with just one OH group, so it dissolves in fats and is stored in the liver.
What is the difference between retinol and retinal?
Retinol ends in CH₂OH (an alcohol). Retinal ends in CHO (an aldehyde) and is the form used in vision.
What is the chemical formula and molar mass of Vitamin A?
Vitamin A is C20H30O with a molar mass of 286.46 g/mol. It contains 51 atoms: 20 carbon, 30 hydrogen, 1 oxygen.
What is the IUPAC name of Vitamin A?
The IUPAC name is (2E,4E,6E,8E)-3,7-dimethyl-9-(2,6,6-trimethylcyclohexen-1-yl)nona-2,4,6,8-tetraen-1-ol.
How do I draw Vitamin A?
Open the MolDraw editor, paste the SMILES CC1=C(C(CCC1)(C)C)/C=C/C(=C/C=C/C(=C/CO)/C)/C or type "Vitamin A" in name search, and the structure is drawn for you. You can then export it as PNG, SVG, MOL or CDXML.