Knowles, 84, studied under Robert G. Elderfield. Knowles has been retired from the Monsanto Company in St. Louis, Mo., since 1986.

He shared the $1 million prize with a Japanese colleague, Ryoji Noyori, and another American, K. Barry Sharpless.

Working independently, the three devised innovative ways to build molecules without creating a mirror-image opposite, a principle used today in making drugs from L-DOPA, a treatment f or Parkinson's, to beta blockers for heart function and the protease inhibitors for AIDS.

Their research focused on "chirality," or "handedness," which describes how organic molecules often appear in two forms, one the mirror image of the other, much as a person's two hands mirror each other.

In nature, one form often dominates, so human cells will naturally bind to one form of a molecule over the other, while the other form is ignored or may even be harmful. Handedness is what caused the thalidomide catastrophe in the late 1950s. One molecular form of thalidomide prevented nausea in pregnant women, while the other caused serious defects in the developing fetus.

During the 1960's to the 1980's, the three chemists developed catalysts for chemical reactions designed to create high concentrations of one form of a molecule while producing only tiny quantities of the undesirable mirror image. Knowles' breakthrough dates to 1968 when he was working for Monsanto. He discovered that it was possible to use transition metals to make chiral catalysts for an important type of reaction called hydrogenation. His research led quickly to an industrial process for the production of L-DOPA.

Overall, 64 individuals who have taught or studied at Columbia University have won HYIthe Nobel Prize since it was first awarded in 1901, including 21 current or former faculty members who have won the Prize for work done while at Columbia.

The 2001 Nobel prize in chemistry was announced by the Swedish Academy of Sciences on Wednesday, Oct.10.