Vindoline-obtained from the plant Catharanthus roseus (L.) G. Don (Apocynaceae)

C. Vindoline

Biological Sources It is obtained from the plant Catharanthus roseus (L.) G. Don (Apocynaceae) (Periwinkle, Madagascar or Cape Periwinkle; Old Maid). It is found to be the major alkaloid from the leaves of Vinca rosea Linn. (Apocynaceae).

Chemical Structure

(2β, 3β, 4β, 5α,12β, 19α)-4-(Acetyloxy)-6, 7-didehydro-3-hydroxy-16-methoxy-1 methylaspidospermidine-3-carboxylic acid methyl ester; (C₂₅H₃₂N₂O₆).

Isolation It is isolated from the leaves of Vinca rosea by the method suggested by Gorman et al.*

Characteristic Features

1. Vinodoline is obtained in two forms: first, as needles from a mixture of acetone and petroleum ether having mp 164-165°C; and secondly, as prisms having mp 174-175°C.

2. It has [α]²⁰_D - 18° (chloroform) and dissociation constant pKa 5.5 in 66% DMF.

3. It has uv_max (ethanol): 212, 250, 304 nm (log ε 4.49, 3.74, 3.57).

Identification Tests It gives specific derivatives as.

1. Vindoline Hydrochloride (C₂₅H₃₂N₂O₆.HCl): It is obtained as crystals from acetone having mp 161-164°C.

2. Demethoxy Vindoline (C₂₄H₃₀N₂O₅) (Vindorosine, Vindolidine): It is obtained as needles from benzene and petroleum ether having mp 167°C. It has [α]¹⁶_D -31° (Chloroform); and uv_max (methanol): 250, 302 nm (log ε 3.98, 3.52).