New Synthetic Hormone Stimulates Plant Growth

A research team led by Elias J. Corey, Emery Professor of Organic Chemistry, succeded in its 17-year struggle to synthesize the plant hormone gibberellic acid, the journal of the American Chemical society reported in its December 6 issue.

Natural gibberellin governs the growth and reproductive activity of plants, stimulating cells to divide and expand. Farmers cultivate a certain type of fungus to produce large quantities of the chemical. The use the extract to spur agricultural production and produce oversized fruits and vegetables.

Twenty-six teams of organic chemists have labored to synthesize the molecule since 1962, when an X-ray diffraction by William N. Lipscomb Jr., Lawrence professor of Chemistry, culminated efforts to determine the structure of gibberellin.

Dr. Rick Danheiser of the Massachusetts Institute of Technology, then a doctoral candidate at Harvard, joined Corey in 1973 and worked with a team of 40 post-doctoral fellows and graduate students. They sought to reproduce a sequence of chemical reactions in the laboratory using a plan Corey had generated in 1962 and modified over the years.

Their discovery, completed in August of 1978, "should allow chemists to construct slightly altered compounds, derivatives" of gibberellin, which permit the preparation of other synthetic molecules, Danheiser said yesterday.

"The major achievement isn't so much in the synthesis of gibberellin as in the aggregate of ingenious techniques that are developed in the course of the synthesis," Dudley R. Herschbach, chairman of the Chemistry Department, said yesterday.

Experts believe that continued synthesis of plant hormones my someday enable man to control completely the frequency and size of crop production.

Corey, famous for his achievements in synthesizing important human and animal hormones, attracted scientists from all over the world to work with him in the preparation of artificial gibberellin.