Liquidambar styraciflua: a renewable source of shikimic acid

An isolation procedure is presented that yields 2.4–3.7% w/w pure shikimic acid from the seeds of Liquidambar styraciflua (Sweetgum). Shikimic acid, the starting material in the commercial synthesis of the antiviral agent oseltamivir and an important intermediate in the biosynthesis of aromatic amino acids in plants, was found by HPLC to be abundant in the granular, aborted seeds (6.5% w/w) while present only in small amounts in the developed, fertile seeds (0.14% w/w). This extraction technique makes L. styraciflua, which is found in 40 states of the continental US, a potential renewable source of this important natural product.