How to measure levodopa and dopamine content?
 

Aunt Bean is looking for a chemist to measure the levodopa content of her fava beans. I would like to measure the dopamine content of banana skins.

The only reference to a DIY solution to this problem that I can find is in a blog by Ken Allan
http://home.cogeco.ca/~allan/beans.html
He describes how to use the colour of a solution to measure the levodopa of the fava beans that he grows.

Now the last chemistry lesson I took was 42 years ago, so my ideas on the subject probably aren't worth a bean, especially one of Aunt Bean's fava beans, but here goes!

Could you use a levodopa/carbidopa (Sinemet) pill as a reference, separating the two by using their different solubilities in water and ethanol?

Could you do a simplified voltammetric analysis: measure the current through a solution at different voltages?

I'd be grateful to anyone who came up with a "kitchen sink" method.

John

i'd contact the chemistry dept of your local university and ask for advice, or even wander over there, poke your head into labs and try to find a grad student who might help, they're interested in oddball stuff.

check out their histories first if possible, might be someone involved in pd, etc.
food science might be another dept.

regardless, you need to measure a known levodopa source to verify your home grown technique if you try to devise one, researchers try to find a pure qty of a substance to act as a control, if they get that right, you know you're procedure s accurrate, but even then you have to repeat it many times.

i can understand why it would be useful to measure fava bean tincture, even generic sinemet batches to see how consistant they are but can't quite understand banana skins, lots of herbicides/pesticides used on bananas and if the world reaches a point where we can't depend on getting sinemet we likely won't be getting bananas.

Possibility?
 

I knoww this is off the wall, but would it be possible to take a liter of distilled water, add a standard quantity of fava, mucuna, etc and then use a standard aquarium aerator pump to push air through the solution for a given time. Since ldopa turns very black when oxidized it would seem that a simple gradient diagram viewed through a stanrdized volume of the solution would have some value if everything else was "locked down".

I didn't know l-dopa turned black...I always have had to work with the beans and plants VERY quickly to not have them turn black after being picked. Yes , Ken Allan was the one who "kitchen tested" my fava tincture...sent it all the way to Canada. Isn't it ridiculous not to be able to find a chemistry person to work with here??? By the way, does anyone know if Ken Allan is ok? I haven't heard from him since about May and am concerned. He was a long-distance Mentor for tips on growing the beans in the first place over the computer.

magnetized l dopa
 

yes..my fava pod (no beans) juice turns black with time (a few days in the fridge) however I use a "Green Power" juicer that has magnets which help to prevent oxidation - I do like making ice cubes as it stays freshly green that way - curious thing is that even black the juice is effectiive- just doesn't taste great - maybe we should be magnetizing our water?

quality vs quantity
 

Rick, Jim, olsen,simoo,johnt,ron, laura,bob,peg, and all

Aren't we looking for nutrients that maximize our levadopa uptake?? - more levadopa may not be better- (the bbb factor )

i.e. doesn't aunt beans tincture only contains a mg or two of levadopa ?if my memory serves...(please correct me AB if this is incorrect)

lately I've been wondering if agonists (even herbs such as rhodiiola) satuurate the receptor beds really quickly - contrary to pharma doctrine.........

I've just raised a thread "Do lentils contain levodopa?" which contains this reference:

"Determination of levodopa by capillary zone electrophoresis using an acidic phosphate buffer and its application in the analysis of beans."

Zhang, Zhai and Hu write:

"A simple capillary zone electrophoresis method has been developed for the quantification of levodopa in broad bean and lentil."

http://openagricola.nal.usda.gov/Record/IND43708486

Unfortunately, I can't get through the pay wall to get to the details of their methods. But it led me to look at electrophoresis.

If I understand it correctly (and there's a good chance that I don't, I am not a chemist and I have never been a member of the chemist party) this involves:
- filling a container with gel, potato starch will do,
- putting electrodes at both ends of the container, ensuring that the electric field is equal across the width of the container;
- fitting a battery
- dripping a baseline solution of levodopa in the container
- next to it put a solution of the substance under test.
- the electrical current causes the molecules to move, the distance travelled being, in part, a function of the mass of the molecule
- wait some time and there should be streaks at a number of places, one for each molecule in the substance;
- comparing position shows whether levodopa is present, determining the intensity of the streak shows concentration.

I bet the devil is in the detail. Do we have any chemists who could comment on whether we could get this to work in the "kitchen sink"?

I see these benefits:
- it helps those using levodopa containing foods to judge how much to take;
- it allows people to breed plants that contain more levodopa;
- it allows us to judge the consistency of levodopa containing drugs.
- it allows us to separate all the molecules, pointing to other useful substances.

John

Taking just 10 minutes and using just normal kitchen equipment, measuring the approximate concentration of levodopa turns out to be very easy. Meatyard [1] and MacDonald have identified the following process:

1. Put your test substance to soak in water. Levodopa, if present, will dissolve.
2. Put a mashed up banana to soak in water. Dopa oxidase will dissolve.
3. Mix the two solutions. If levodopa is present, the dopa oxidase will react with it to give dopachrome, which is orange/red.

The degree of orange/redness is the proxy measure of the concentration. The colour change is easy to see by eye. To measure it accurately would require a colorimeter. (If this measurement proves useful, I'll be happy to build an on-line colorimeter using a webcam - it probably wouldn't be very accurate, but better than you could do by eye.)

My guess is that this test is not 100% specific. There are likely to be false positives: solutions not containing levodopa which also turn red when mixed with dopa oxidase.

My own tesing of the idea is limited to:
- Sinemet which is shown to contain levodopa (though in the worse case the test could be being confused by the carbidopa which is also present);
- water which is shown not to contain levodopa;
- white vinegar ditto
- pea pods ditto

I would be grateful if people run this test on "interesting" substances, such as fava beans.

Reference

[1] Google dopa oxidase meatyard, which gets a document
BarryMeatyardDopaoxidaseforASE2.docx

John

Ken Allan and an ETSU student (I knew that moved away) both tested my initial tincture against sinemet ...results were 2 drops tincture had approx 1 mg L-dopa. Ken Allan used kitchen testing/ ETSU expensive equipment and both got the same...pretty cool. I have since made tinctures of different plant parts (both dried and not dried that I would like tested) When I have a minute, I will look up Ken Allan's proceedure for the kitchen experient test and share it.

Kitchen test for levodopa
 

Hi All,

I've come to this thread rather late in the game but thought it worth posting the results of our kitchen test. My husband and I decided to test 3 substances for levodopa:

1. Our control - Sinemet 25/100 (carbidopa-levodopa prescribed for me but I'm not currently taking any);
2. Our homemade sprouted fava bean tincture made from fava beans sprouted for four days then ground in a coffee grinder and soaked in Everclear for two weeks;
3. Organic Mucuna Pruriens powder ordered from Indigo Herbs, UK.

We made an enzyme solution from mashed banana and water and left it to settle.
We then dissolved one crushed Sinemet in 6 ml of water.
We also dissolved one tsp of Mucuna powder in 1/2 cup water.
Our tincture was already a clear alcohol liquid so we left it as is.

After allowing about 10 minutes for each substance to settle, we put 3 ml of each in three test tubes and added another 3 ml of the banana liquid to each test tube.

The mucuna powder immediately started turning an orangy red and continued over the next 5-6 minutes to deepen in color.

The Sinemet did not change color at all.

Our tincture did not change color at all.

We were confused that the Sinemet did not turn orange as we knew it had 100 mg of levodopa in it. Maybe the 25 mg of carbidopa protects it from the dopa oxidase enzymes in the banana liquid?

We also weren't sure if the alcohol in the tincture might also prevent the dopa oxidase from causing a reaction since alcohol is a preservative and might be capable of neutralizing the enzyme?

The mucuna powder turned pretty dark so a color meter would help determine how much levodopa was detected in that.

Next we plan on testing fava leaves and tops crushed in water -- and sprouted fava beans, crushed in water (to eliminate the alcohol variable).

Thanks for the reference to this experiment, John. I found a lab in CA that will test for levodopa for $250 a sample. Bananas are much less expensive!

Joanne