Page 87 - phytochemistry II -pharmD general

Properties

Vinblastine occurs as crystals, m.p. 211-216 °C, it is practically insoluble in
water, soluble in ethanol and chloroform. Vincristine occurs as crystals, m.p. 218-
220 °C.

Tests for identification

1.Vanillin /HCl reagent gives with:

- Vinblastine a pink color, and
- Vincristine an orange-yellow color
2.Para-dimethylaminobenzaldehyde (PDAB) reagent (Van-Urk's reagent): gives
vinca alkaloids in presence glacial acetic acid and concentrated H2SO4 a reddish-
brown color.

Uses

▪ Vinblastine is used for treatment of Hodgkin's disease and carcinoma resistant
to other therapy. Hodgkin's lymphoma, is a type of blood cancer, which is
originating from white blood cells called lymphocytes. It was named after
Thomas Hodgkin

▪ Vincristine has a cytotoxic effect. It is used in treatment of leukemia in children.
It is a type of cancer of the blood or bone marrow characterized by an
abnormal increase of immature white blood cells and results in a lack of blood
platelets).

Gelsemium alkaloids

Genus Gelsemium, “that belongs to the same family (Loganiaceae) as
Strychnos” elaborates also several alkaloids that are mostly indole derivatives.
The most important of which is the alkaloid gelsemine and its methoxy derivative
gelsemicine.

These alkaloids are characterized by the existence of an alpha carbonyl
function, (next to the nitrogen atom of the indole ring system), so, they are
considered as Oxindole derivatives.

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