Ricin

It's a toxicology marathon this week, today we're looking at ricin. Ricin's rise to fame was catalysed by the assassination of Georgi Markov. Markov's mysterious death was discovered to be due to a pellet of ricin injected into his leg by a contraption in an umbrella. Ricin is especially deadly as it takes a comparatively long time to kill compared to the other poisons featured.

Name: Ricin

Structure: Glycoprotein

Effect on Victim: Ricin has serious effects but not ones immediately seen as life threatening. Ricin's symptoms include dizziness, a high temperature, vomiting and diarrhoea. However Ricin can cause death in just 24 hours. Ricin works by inhibiting the cell's ability to synthesis proteins from amino acids according to the mRNA received in the ribosomes. These proteins are essential and without them the body quickly dies.

Lethal Dose: The lethal dose is just 22 micrograms per kilogram if ricin is injected, however if it is taken orally the lethal dose is much higher, around 30 milligrams per kilogram.

This is a photomicrograph of the pellet found in Markov's leg. The pellet held less than 500mg of ricin, a testament to it's lethality!

Diagnosis: The symptoms are akin to a very severe, incredibly quick working septicaemia. Since much more ricin is required to kill orally than by injection any puncture wounds should arouse suspicion. Ricin can be made from castor oil, so large quantities of that is also a clue. Ricin can be identified by mass spectrometry in a sample of tissue so it can be detected in human tissue. This works by detection of selected marker peptides specific for ricin (Ricin is composed of two protein chains); T5, T7, T11, T12, and T13 from the A-chain and T3, T5, T14, T19, and T20 from the B-chain.

You may remember me warning you to steer clear of apricot kernels, due to the possibility of cyanide poisoning, well castor seeds are a very similar case. Thanks for reading, over and out!