TABLE 13.2 Major types of alkaloids, their amino acid precursors, and well-known examples of each type Biosynthetic Alkaloid class Structure precursor Examples Human uses Pyrrolidine Ornithine (aspartate) Nicotine Stimulant, depressant, tranquilizer Tropane Ornithine Atropine Prevention of intestinal spasms, antidote to other poisons, dilation of pupils for examination cocaine Stimulant of the central nervous system, local anesthetic Pip perrine Lysine (or acetate) Coniine Poison (paralyzes motor neurons Pyrrolizidine Ornithine Retrorsine None Table 5-4 Quinolizidine Lupinine Restoration of heart rhythm Isoquinoline Tyrosine Codeine Analgesic (pain relief), treatment of coughs Morphi nalgesIc Indole Tryptophan Psilocybin Hallucinogen Reserpine Treatment of hypertension, treatment of psychoses Strychnine Rat poison, treatment of eye disordersTable 5-4