By Mana Sassanpour, 1/26/2011
After reading a book that mentioned the health benefits of ginkgo (leaf pictured right), I decided to see if there were any green chemistry related topics that involved this ancient and revered tree. The journal, Green Chemistry, has an article about a more efficient means of extracting the useful components of ginkgo (Qingyong Lang and Chien M. Wai Green Chem., 2003, 5, 415-420). The researchers developed a greener method of pressurized water extraction which is a “a more effective, selective, economical and environmentally benign technique.”
However, the article did not make clear WHY they were bothering to finding greener ways to extract these compounds – what does ginkgo do? I could pay £34 GBP ($52.50) to find out why, but I thought doing my own investigation would be more fun and less costly.
My research took me in several directions, including the Encyclopedia of Medicinal Plants by Andrew Chevallier, Rebecca’s Natural Food Store in Charlottesville, VA, and to a friend, John Soong, who knows a little something about everything.
First, some history: the ginkgo tree dates back about 200 million years to the time of the dinosaurs. Second, my friend John Soong explained that he had grown up eating ginkgo nuts in a rice porridge called congee (left). According to him, the philosophy behind eating ginkgo in Chinese cuisine is that “because the ginkgo tree has survived and lived for so long, if we eat it we will have the same longevity.”
There may be some science behind this belief: the active ingredients in ginkgo are purported to work together to produce a positive effect on the human body. The key ingredients are flavonoids, ginkgolide, and bilobalides. The Encyclopedia claims that ginkgo “improves circulation of blood to the head” which in turn leads to improved memory and is given to people with dementia. Ginkgo is also good for asthma and as an anti-inflammatory. Therefore it is not surprising that ginkgo has been noted as one of the bestselling medicines in Germany.
After my literature search, I drove to Rebecca’s Natural Food Store where one of the employees gave me an impromptu “Ginkgo 101” course. She explained that ginkgo is also a blood thinner and can help reduce the possibility of a stroke. In addition, she said it is “good for capillaries and oxygen uptake especially for those who always have cold hands and feet.” Hmmm: maybe I should start taking ginkgo?
Of course we are not qualified to make judgments or give advice on the medicinal value of ginkgo, but it seems like ginkgo is a very interesting plant. With such a wide array of potential health applications and valuable compounds, it makes sense to find more sustainable and cost effective methods of extraction.
1. Pressurized water extraction (PWE) of terpene trilactones from Ginkgo biloba leaves. Qingyong Lang and Chien M. Wai. Green Chem., 2003, 5, 415-420. DOI: 10.1039/B300496C
2. Encyclopedia of Medicinal Plants. By Andrew Chevallier – DK Pub. (1996) – Hardback – 336 pages – ISBN 0789410672