Page 64 - Color Atlas of Biochemistry

Lipids 55

A. Steroid building blocks B. 3D structure
Angular 21 22 24 27
methyl groups
18 20 23 25
Gonane 12
19 11 13 17 26
C D 16
14 15 Methyl-branched side
1 9 chain with 8 carbons
2 A 10 B 8
3 5 7
4
HO
6
Cholesterol
Double bond
Cholestane Hydroxyl group in ring B: ∆ 5
at C-3 adopts
β conformation

CH
H and CH in cis position β con- 3 R
3
formation,
β con- axial
CH 3 formation, H
equatorial CH 3
H
H
HO Cholestanol
H H and CH in
3
1. α con- H transposition 2.
formation,
axial

3.
Chair

Boat

Envelope

Ring conformations
Cholesterol (Van der Waals model)

C. Thin-layer chromatography

Thin- Chromato- Front Cholesterol
layer graphy tank esters
plate with
silica gel Triacyl-
surface a glycerols
R = b Free fatty acids
f
a
Cholesterol
b
Running
solvent: 1,3- Diacyl-
Hexane/ 1,2- glycerols
Diethylether/ Monoacyl-
Sample: Formic acid glycerols
lipid 80 : 80 : 2
mixture (v/v/v) Start Phospholipids
1. Load 2. Develop 3. Make visible

Koolman, Color Atlas of Biochemistry, 2nd edition © 2005 Thieme
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