Chemistry of medicinal plants: Classification and Examples II Free Study material II Economic Botany Notes

                            

Chemistry of plant derived medicines

1.Sreoids: 

Steroids are chemically similar but biologically different depending upon type of plant. 

STRUCTURE: Structurally the cyclic nucleus is made up of three six membered rings and one five membered ring and one five membered ring called as steroid backbone and a long side chain called as sterols. 

EXAMPLES: Ergestrol-from Claviceps purpurea fungus, Spinasterol from cabbage and spinach, Sitosterol from corn, barley, cotton seeds and embryo of wheat.

Steroidal glycosides are the one which are produced by addition of sugar molecule to steroid backbone. Example-Digitoxigenin a cardiac glucoside obtained from leaves of Digitalis purpura.

2. Alkaloids: 

Alkaloids are the organic nitrogen bases. They show property of amines and used as defence against herbivores.

Alkaloids can be obtained from Solanaceae: Hyoscyamine, scopolamine and Atropine