Isolation and Purification
If the lead compound (or active principle) is present in a mixture of other compounds from a natural source, it has to be isolated and purified. The ease with which the active principle can be isolated and purified depends much on the structure, stability, and quantity of the compound. For example, Alexander Fleming recognized the antibiotic qualities of penicillin and its remarkable non-toxic nature to humans, but he disregarded it as a clinically useful drug because he was unable to purify it. He could isolate it in aqueous solution, but whenever he tried to remove the water, the drug was destroyed. It was not until the development of new experimental procedures such as freeze drying and chromatography that the successful isolation and purification of penicillin and other natural products became feasible.
Read more about this topic: Natural Product
Famous quotes containing the word isolation:
“One who shows signs of mental aberration is, inevitably, perhaps, but cruelly, shut off from familiar, thoughtless intercourse, partly excommunicated; his isolation is unwittingly proclaimed to him on every countenance by curiosity, indifference, aversion, or pity, and in so far as he is human enough to need free and equal communication and feel the lack of it, he suffers pain and loss of a kind and degree which others can only faintly imagine, and for the most part ignore.”
—Charles Horton Cooley (1864–1929)