Akuammicine-obtained from the plant substance of Catharanthus roseus

B. Akuammicine

Biological Source It is obtained from the plant substance of Catharanthus roseus (L.) G. Don (Apocyanaceae) (Periwinkle, Madagascar or Cape Periwinkle, Old Maid); and also from the seeds of Picralima klaineana, Pierre, belonging to the natural order (Apocyanaceae).

Chemical Structure

2, 16, 19-20-Tetradehydrocuran-17-oic acid methyl ster; (C₂₀H₂₂N₂O₂).

Characteristic Features

1. It is obtained as plates from a mixture of ethanol and water having mp 182°C.

2. Its physical parameters are: [α]¹⁶_D – 745° (C = 0.994 in ethanol); pK_a 7.45; and uv_max (ethanol): 227, 330 and 330 nm (log ε 4.09, 4.07, 4.24).

Identification Tests It forms the following derivatives:

1. Akuaminicine Hydrochloride Dihydrate (C₂₀H₂₂N₂O₂.HCl.2H₂O): It is obtained as leaflets from ethanol or water having mp 171°C; and has [α]²¹_D – 610° (C = 1.430 in ethanol).

2. Akuaminicine Perchlorate Monohydrate (C₂₀H₂₂N₂O₂.HClO₄.H₂O): It is obtained as needles from a mixture of ethanol and water having mp 134-136°C.

3. Akuammicine Hydroiodide Monohydrate (C₂₀H₂₂N₂O₂.HI,H₂O): It is obtained as square plates from water having mp 128°C.

4. Akuammicine Methiodide: It is obtained as crystals from water with mp 252°C.

5. Akuammicine Nitrate: It is obtained as needles from hot water having mp 182.5°C.

Uses The drug exhibits a slight digitalis-like reaction; and is, therefore, believed to act as a heart poison.