Vinca AlkaloidsIntroduction

Vinca Alkaloids Introduction 

Vinca alkaloids are a class of organic compounds containing carbon, hydrogen, nitrogen, and oxygen that are often derived from plants called alkaloids. Although the name represents alkali some do not exhibit alkaline properties. Many alkaloids with poisonous characteristics have physiological effects too which makes them useful as medicines. The oldest group of plant alkaloids groups that are used to treat cancer are the vinca alkaloids. 

Mechanism of action

The main mechanisms of alkaloid cytotoxicity are due to their interactions with tubulin and disruption of microtubule function, particularly of microtubules comprising the mitotic spindle apparatus, directly causing metaphase arrest. However, they can exert many other biochemical activities that may or may not be related to their effects on microtubules. The vinca alkaloids connect to binding sites on tubulin that are separate from those of the taxanes, colchicine, podophyllotoxin alkaloids, and guanosine-5’-triphosphate. Binding occurs rapidly and can reverse too. Current evidence maintains the existence of two vinca alkaloid binding sites per molecule of the tubulin dimer. We can see near to 16-17 high-affinity binding sites in each microtubule that are located at the ends of each microtubule. The binding of vinca alkaloids to these sites disrupts microtubule assembly, but one of the most important effects of low drug concentrations is to decrease the rate of both elongation and shortening at the assembly end of microtubules, which is a "Kinetic Cap" that can generate and suppress function.

Nitrogen and mustard

Introduction

Nitrogen mustards (NMs) are cytotoxic organic compounds with the bis(2-chloroethyl) amino (ClC2H4)2NR) functional group. Although originally produced as chemical warfare agents, they were the first chemotherapeutic agents for the treatment of cancer. Nitrogen mustards are nonspecific DNA alkylating agents.

Name 

Nitrogen mustard is not related to the mustard plant or its pungent essence, but allyl isothiocyanate of the plant name.