Atropine, development from natural

The prototypical antimuscarinic anticholinergic drug is atropine (Fig. 19-2). Atropine is a naturally occurring substance that can be obtained from the extract of plants such as belladonna and jimsonweed. Other natural, semisynthetic, and synthetic antimuscarinic anticholinergic agents have been developed that are similar in structure or function to atropine. 

The traditional method of drag development, at least in this century, has been to develop leads by first using, and then by isolating and identifying, the active chemical constituents from natural products, some of which may have been medicinally in use since antiquity. With the advent of modem organic chemistry some of these purified compounds were used directly (e.g., morphine, cocaine, atropine, quinine), and, once their chemical structures were ascertained, they became leads for hoped-for chemical modifications to achieve improved efficacy, less toxicity, or, at least, higher potency (e.g., dihydromorphinone, homatropine, acetylsalicylic acid). 

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