Cannot See the Flowers nor the Tree: Plants and the Pill.

T modern world suffers from a syndrome known as plant blindnessthe inability to perceive plants. The lack of awareness occurs in the natural environment, the home landscape, and even the scientific lab. The third article in the inaugural issue of the American Chemical Society’s ACS Central Science recognizes Carl Djerassi’s pioneering work in steroidal syntheses. However, the article belies the essential role that plant natural products played in one of the most significant technological achievements of the 20th century. The author the ACS Central Science article writes, “Scientists’ first attempts to create birth control pills focused on extracting progesterone from plants and animals. However, this approach failed to yield an effective oral medication.” There are three major flaws with these statements. First, progesterone’s insolubility in water and short half-life make it a poor candidate for oral contraceptives. Second, plants were not sources of progesterone, but rather sources of steroidal sapogenins that could be converted into progesterone and other steroids. Third, and the focus of this paper, Djerassi acknowledged the pioneering work of Russell Marker and the role plants played: “Marker ... made me focus on steroidal sapogenins [plant natural products] as starting materials for the synthesis of estrone and estradiolsteroid hormones that had not been part of his synthetic repertoire.” Marker had successfully produced progesterone from the sapogenins diosgenin and sarsasapogenin (Figure 1), but none of the known plant sources yielded sufficient quantities of sapogenins to be cost-effective for industry. The intrepid chemist then began a search for better sapogenin sources which led to a Mexican species of yam (Dioscorea mexicana). Pharmaceutical companies spurned his discoveries, so Marker moved to Mexico and started Syntex, S.A. in 1944. His involvement with Syntex was short, and, following a quarrel with his partners, he soon left the company. Syntex floundered without Marker’s expertise and lab notes, until the company hired George Rosenkranz, who recruited Carl Djerassi and other talented chemists. After joining Syntex in 1949, Djerassi synthesized both cortisone and norethisterone, a progesterone mimic, from diosgenin extracted from Dioscorea mexicana. The role of plants in supplying the starting material for subsequent modifications is unquestioned and is noted by physicians, historians, and scientists, including Djerassi