Hey Mario, That's a very nice question. Unfortunately you are not going to find the answer to that on the internet easily. But no worries!
According to the Law of Turkey (article 2249/5) it is illegal to own a mace. Unfortunately, the law does not distinguish between the intent of self defense or any other purpose. It is illegal to own, purchase or sell mace and pepper spray without a permit.

If you acquire a permit to carry and own weapons ( can you buy a gun in Turkey ) you can visit any gun shop and ask if they have what you seek or not. my recommendation based on online reviews is a store called Icten Av Silahlari located in the Mercan, Uzun Çarşı Cd. you can see the location of it on map here.

good luck

thanks mate