Piperine from pepper

Piperine is the chemical responsible for the smell and spiciness of pepper. It's an amide, which can be hydrolysed to piperic acid and piperidine – my intended use for piperine. In the mouth, piperine activates heat and pain receptors which cause the burning sensation you get from eating pepper. This is similar to capsaicin's role in chillies and allicin's role in garlic.

I tried extracting some piperine from black pepper.

I started with 100g of black peppercorns. Using a food processor, I grinded it all into a fine powder.
I added the powder to a 1000ml conical flask. 150ml of ethanol was added. I heated the mixture on a hotplate until the ethanol started to boil, then quickly took it off the heat. This was repeated 2 times, and the mixture filtered. I poured the brown/yellow filtrate into a beaker and set it aside.
I then got the residue pepper and added 100ml of ethanol (to make sure I had extracted all the piperine). The heating process was repeated and the mixture was filtered.

I added the filtrate to the product from the first extraction. This gave 250ml of ethanolic pepper extract. I distilled off 150ml of the ethanol (this can be used for future runs) and was left with about 100ml of liquid. I then prepared a solution of 5g sodium hydroxide in 40ml ethanol and added this to the liquid. A dirty brown precipitate was observed (consisting of various peptides and resins). The precipitate was filtered off and discarded. I collected the filtrate then slowly added water to it from a dropper. A pale yellow precipitate of piperine formed. I kept adding water until the piperine stopped precipitating, then filtered off the piperine product. It can be recrystallized from acetone but I didn't bother doing this. I didn't weigh it or calculate the yield because I was unable to dry it completely.


 









left = starting black pepper and right = crude moist piperine