Page 78 - phytochemistry general program

General structure of the polypeptide alkaloids
(Showing the three amino acids part structures a, b and c)
(Linked together and to the lysergic moiety by three amide linkages)

Amino acid (a) = α-hydroxyalanine or α-hydroxyvaline
Amino acid (b) = Proline

Amino acid (c) = Valine or Leucine or Phenylalanine
Ergotamine

R1 = H, R2 =CH3, R3 = Benzyl

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