poison ivy

Summer is around the corner, so in addition to the usual annoyances, mosquitos, ticks, visiting relatives (worse because insect sprays don't work very well), there is always the delightful possibility of brushing up against the always-hideous poison ivy. Poison ivy is some nasty -ass stuff. But if you read this nasty-ass article to the end at least you will no longer need to scratch your head about why you're scratching the rest of you. It's all about chemistry and toxicity.

Experienced medicinal chemists (1) will usually develop an ability called "eyeball toxicity" - the ability to look at the chemical structure of a molecule and make a pretty good guess about whether the molecule will be toxic. But this only works in one direction. It is not difficult to look...