**2. Active compounds derived from natural sources possessing analgesic properties**

Since ancient times, many active compounds originated from natural sources have been consumed for various medical purposes including the management of pain. Opium, for example, has been used since 7000 years ago. Up to the nineteenth century, other active components derived from different natural remedies were identified, purified and utilized. Since then, analogues have been made from natural sources, and completely synthetic compounds based on natural pharmacophores have been introduced into the market [3].
