Yams ( dioscorea species ) Flashcards
many great species produce steroidal glycosides known as
sapogenins, consisting of a steroid like terpenoid with a sugar side chain
the prevailing view of chemists in early 20th century was that the removal of the side chain…
though potentially desirable for the efficient production of steroidal compounds from plant material, was not possible
russell marker
1939
- a chemist at penn state university
- devised a straightforward method for removing the side chain, converting sapogenins from rhizomes of wild sarsaparilla
- his method was very promising, but sapogenin concentration sin wild sarsaparilla rhizomes were low.
sarsaparilla
smilax glauca
-an understory vine native to eastern north america, to the steroidal hormone progesterone.
progesterone
is converted easily to testosterone, oestrogen, and other steroidal hormones
marker studied the biochemical literature and found that two plant related families
liliaceae (lilies) and dioscoreaceae (yams), include species known to produce appreciable amounts of sapogenins
yams species (genus dioscorea)
occur in mexico (both native and introduce cultivated plants), and that some of these produce very large sapogenin-rich tubers
- marker traveled to mexico in 1941-42 , returning with a single large tuber (about 20kg) smuggled across the border.
- the tuber proved to contain large amounts of the sapogenin diosgenin, yielding a considerable quantity of progesterone
marker initially attempted to work with major pharmaceutical companies to develop?
inexpensive, plant derived steroidal hormones.
-he tried to talk to both parke-davis and merk but neither was interested in partnership
marker withdrew from academia and traveled to veracruz (mexico)
where he purchased 10 tons of cabeza de negro (d. mexicana) yam tubers.
-these were sliced dried in the sun, ground to a powder and converted to 3 kg of progesterone
progesterone was selling for
US $80 per gram at the time ( $1000 in todays dollars);
in 1944
he founded syntex corporation in mexico city with two business partners, but left the company a year later in a bitter dispute over profits to found botanica-mex.
syntex hired biochemist george rosenkranz to develop a
strong research program
in 1951
the company developed an efficient method to produce cortisone and the progesterone mimic norethindrone (or northisterone) which became the active principle in the wordls first birth control pill
1960
syntex and its competitors were producing over half of the steroidal hormones sold in North america
in 1973
yam tubers were used to produce 550 tons of diosgenin; by this time another important steroid precursor was stigmasterol from soybeans, 180 tons of which were produced in the same year.
