Submitted to: National Organization for the Professional Advancement of Black Chemists and Chemical Engineers
Publication Type: Abstract Only
Publication Acceptance Date: 9/6/2012
Publication Date: 9/24/2012
Citation: Harry O Kuru, R.E. 2012. The untold story of the common Milkweed (Asclepias syriaca): A new industrial crop [abstract]. National Organization for the Professional Advancement of Black Chemists and Chemical Engineers.
Technical Abstract: The common milkweed (Asclepias syriaca L.) is a perennial shrub that is native to the Americas from coast to coast, but particularly abundant east of the Mississippi River and from Southern Canada to Mexico. The plant has been given many nonglamorous names by frustrated farmers including “The Wheat Farmer’s Nightmare”. The leaves of the plant are the veritable food source for the monarch butterfly larvae which store the secondary metabolites of this plant, mainly cardenolides, for protection of the adult monarch butterfly from avian predation. Milkweed seed is adapted for wind dispersal by a fine tuft of hollow, silky fiber (floss). Use of milkweed floss as a floatation device in World War II earned the plant the status of “War Strategic Material,” however, the modest industrial use of the fiber today is as a hypoallergenic filler in high-end pillows, comforters, and jacket liners. To expand utilization of the crop, we have explored different uses of its seed resource. The Milkweed seed contains 25-35% oil by wt. This oil is highly unsaturated (92%) and we have found it to be essentially cardenolide-free on analysis. We, therefore, epoxidized the olefinic bonds of the triglycerides creating a platform intermediate to the polyhydroxy triglycerides which have excellent moisturizing properties. We have also converted both the oxiranes and polyhydroxy triglycerides into novel UV-absorbing estolides by direct esterification with trans-4-hydroxy-3-methoxycinnamic acid. Additional applications for these platform intermediates and seed meal will be discussed.