Resiniferatoxin
If you think capsaicin is hot enough for you, you might want to think again. One of the member of a big family of daphnane diterpene is way beyond capsaicin in Scoville scale. This compound scores 16,000,000,000 Scoville Heat Unit (SHU) which is 1000 times than capsaicin itself. This chemical can be found in resin spurge ( Euphorbia resinifera ) and it is known as resiniferatoxin (RTX).