18 Steroids 12 CH3 1 11 H 2 15 B 4 6 Polycyclic,usually all trans. Common structural features: >=O or-OH at C3 >Side chain at C17 >Double bond from C5 to either C4 or C6 => Chapter 25 15Chapter 25 15 Steroids • Polycyclic, usually all trans. • Common structural features: ➢=O or -OH at C3 ➢Side chain at C17 ➢Double bond from C5 to either C4 or C6. => CH3 H H A B C D CH3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19