Flavanoid anxiolytics like Apigenin

[Auxin]

Originally posted by John_Barleycorn:

...but I do want to talk about flavanoids with you. What do you know about the distribution of natural anxiolytics like apigenin? Obviously, it's in chamomile, but I was wondering what else. I took it into my head a while back to make up some tea out of common daisies, but it didn't seem to do much. Of course, there is the water solubility aspect to be considered, as always. Any thoughts?

Apigenin?

Lets see, Its full name is 4',5,7-Trihydroxyflavone.

I know its anxiolytic at 10mg/kg and sedative at 30-100mg/kg and has many other effects (you'll be preventing cancer, radiation poisoning, and all kinds of stuff. Just dont overdo it.) ( check the phytochemistry database HERE )

Its in many plants, but I dont have quantitative data on any of them.

I do know that before the chemical manufacturers started making it from scratch they prepared it by boiling apiin with aqueous acid (not sulfuric or nitric odviously), and purifying the apigenin out of the resulting aqueous acid/sugar/apiin mix.

They extracted the apiin from Celery (plant contains 2,000 ppm, one kilo of celery has enough apiin (2g) to produce 0.957g apigenin assuming 100% yield at every step) and it was also extracted from Parsley seed.

Apiin is soluble in hot water, hot alcohol, sodium carbonate solutions, ammonium hydroxide solutions, and dilute sodium hydroxide solutions (dissolved in the weak bases it makes a yellow solution and dissolved in sodium hydroxide it makes a pale yellow solution). You precipitate it from basic solution by making it neutral to moderatly acidic and cooling.

Apigenin itself is almost insoluble in water, moderatly soluble in hot alcohol, and its soluble in dilute sodium (or potassium) hydroxide solution with intense yellow color being produced.

Hmmm, a legal anti-tumor anxiolytic from celery. I never thought of that! Celery is cheap and the chemistry is simple, might be worth a try.

I couldnt find any quantitative data for apigenin in chamomile, but I do know it has apigenin as well as various apigenin glycosides including apiin. So if you try extracting it from chamomile do the process for extracting and converting apiin to apigenin and you'll end up with the original free apigenin and the apigenin liberated from the apigenin glycosides.

And if you do try purified apigenin as an anxiolytic dont forget to post your results

As far as other flavanoids go, most are soluble in dilute sodium hydroxide generally forming a yellow solution.

HESPERIDIN is also a anxiolytic flavanoid. Theres lots in lemon pericarp (68,800 ppm), orange pericarp (63,500 ppm), hyssop plant (50,000-60,000 ppm)

Its also analgesic, antiinflamatory, antiviral, antioxidant, antiulcer, and a few bad things too.

You have to be careful when purifying hesperidin because it is a glycoside. It should be precipitated from dilute alkali solutions by bringing it to pH 6-7, NOT TOO MUCH LOWER. 0.02g dissolves in 100ml hot water, 0.5g dissolves in 100ml alcohol, freely soluble in dilute alkalies. There are two US patents on its extraction, they are US patent numbers 2421061 and 2442110.

Note- flavanoid extracts from citrus will also contain naringin, which could water down or alter the effects of hesperidin.

[This message has been edited by Auxin (edited 29 November 2002).]

[Auxin]

My idea of hesperidin extraction from orange peel.

This process is for 1000 grams of grated orange peel.

Combine 8 grams Ca(OH)2 (hydrated lime) or 6g CaO (lime) with 1.5 liters water and stir repeatedly (limewater serves to coagulate slime and neutralize fruit acid).

Add 1000 grams grated orange peel and stir well. Let sit overnight.

Adjust pH to 10.5-11.5 with ammonia solution or additional Ca(OH)2 (as much as 10-15 g). If mixture is too thick an additional 0.5 liters of water may be added.

Let stand for 24-48 hrs stiring about every 6 hrs.

Drain off liquid and press mush to retreive remaining liquid.

Filter liquid repeatedly until clear.

Acidify liquid to pH 4-6 (pH 7 is ok, just slower) with distiled white vinegar or hydrochloric acid.

[if pH is 4.5-5 (best) heat to 50 C and keep it there for 15-60 min and remove from heat (speeds things up, better yield, cleaner mix)]

Let stand at room temp for 24 hrs.

Filter out crystals, rinse them with water, dry at room temp (20-30 C)

[Optional putification (essential if you used grapefruit peel instead of orange peel {not reccomended})

Dissolve crystals in minimum amount of dilute (around 1%) ammonia solution.

Filter it if there is any crud.

With distiled white vinegar bring to pH 9.0-8.5.

Let stand at least 24 hrs. Crystalization will be slow.

Filter out crystals, rinse with water, dry at room temp.]

The same basic process can be used to extract apiin from celery, just ignore any steps in brackets and reduce the original quantity of lime by about 50%.

[Auxin]

Chrysin (5,7-dihydroxyflavone) has produced anxiolytic effects in rats at 1mg/kg without occurance of sedation or muscle relaxation.

It also helps prevent cancer.

Am I just talking to myself here?

Oh well, something for the archives at least.

[John_Barleycorn]

Originally posted by Auxin:

Am I just talking to myself here?

Nope, count me as interested, for one. I'm still contemplating your extraction suggestions, and might just give them a go. Although it would be slightly superfluous to try this if apigenin was cheap and available, and that is something I haven't investigated.

[Auxin]

I dont think you'll want to buy apigenin, Sigma (one of the major chemical suppliers) charges $140.10 USD for 100mg of 95% pure apigenin. Its probably cheapest by far to make your own.

[theobromos]

A simple 100% alcohol extract of limeflowers (Tilia) was amazingly sedative when smoked.