Given the importance of levodopa in reducing the symptoms of PD and the apparent fragility of the production and distribution process in getting it to PwP world wide at a price they can afford, it seems reasonable to look for alternative routes to fall back on in case of emergency. The best way is to keep a reserve of your drugs. Keeping a supply of mucuna may be worth having. Growing your own fava beans (broad beans) is one way, but unless you are set up for it, it will be a matter of luck as to whether they are available at a time of need. There is a need for an alternative way of making levodopa at times of emergency.

Although not presently efficient enough to provide therapeutic concentrations of levodopa, the following possible route looks interesting:

potato + ascorbic acid = levodopa?

Wikipedia states [1]:

"tyrosinase can convert tyrosine directly to L-DOPA in the presence of a reducing agent such as ascorbic acid"

Also [2]:

"Tyrosinase is a copper-containing enzyme present in plant and animal tissues that catalyzes the production of melanin and other pigments from tyrosine by oxidation, as in the blackening of a peeled or sliced potato exposed to air."

So, potato contains both tyrosine and tyrosinase. Ascorbic acid, vitamin C, is easily available. The questions now are: is the yield of levodopa adequate? is the process safe or are dangerous substances produced alongside the levodopa?

Data from a paper by Mulder [3] shows free tyrosine levels in potatoes ranging between 1.2 and 7.1 mg per 10g of tissue. The average being about 3mg per 10g of tissue.

So, a not unreasonable 100g helping of potatoes might contain 30mg of tyrosine.

Now, not all this tyrosine will be converted in to levodopa. But, we should be getting close to therapeutic levels, perhaps 50mg, of levodopa.

Other foods may contain higher levels of tyrosine. These should be investigated.

Some of this ground was covered in a 2010 thread "l-dopa production" [4].

Before I test it on myself, I'll be grateful for any comments.

References:

[1] L-DOPA - Wikipedia

[2] Tyrosinase - Wikipedia

[3] "Mineral Nutrition in Relation to the Biochemistry and Physiology of Potatoes"
E. D. Mulder,
Plant and Soil, October 1949.
http://edepot.wur.nl/211149

[4] l-dopa production

John