#phytochemicals

Tea Chem 101: L-Theanine! What is it, why is it good for you, and how heckin delish is it? 🍵🧬

When it comes to satisfying your sweet tooth without compromising on health, exploring the world of healthy Korean desserts is a delightful journey. Let’s explore the five guilt-free treats that not only please your taste buds but also contribute to your overall well-being. 1. Bingsu (Shaved Ice Dessert) Bingsu, a popular Korean shaved ice dessert, goes beyond its refreshing taste. Packed with…

Hey there, friends! I’m a bit scattered this week, but I’m probably gonna go buy some plants! I’ll make sure to post fun facts about whatever plants I buy.

Tl;dr: chrysanthemums are great insect repellents and break chemistry rules.

Fun fact, chrysanthemums produce compounds called pyrethrins, which are so effective at repelling pests that they’re used commercially as insecticides! Pyrethrins are relatively nontoxic to vertebrates, but in insects they bind to Na+ conducting nerves and hold them “open”, causing fatal excitotoxicity. I had to use a pyrethrin aerosol “flea bomb” to deal with a flea infestation this summer, it was surprisingly effective. Pyrethrins alone are relatively mild but environmentally safe insecticides,  but their synthetic derivatives such as permethrin (in the broad class pyrethroids) are much more potent but dangerous. For example, permethrin is safe for humans and dogs, but extremely toxic to cats and many other mammals (who can’t metabolize it), and unlike pyrethrins it builds up in the environment.  The toxicity in cats, but not dogs and humans, is from the same enzyme that metabolizes acetaminophen/paracetamol; cats lack UDP glucuronyl transferase, which neutralizes many toxic chemicals by binding them to an acid derivative of glucose. However, pyrethroids are STILL much safer than many industrial pesticides, and an area of ongoing research.

Part of what makes pyrethrins notable, other than replacing organophosphates (like parathion) and organochlorides (like DDT) as an insecticide, is their chemical structure. They contain a cyclopropane ring, a three-carbon ring that is HIGHLY unstable due to angle strain. Carbon prefers to form (single) bonds at about 109.5° degree angles, and the further the angle is from 109.5° the more unstable the compound is. Cyclopropane forms a triangle of carbon-carbon bonds, meaning the angles are 60°; this is INCREDIBLY reactive/unstable, and rarely found in nature. Even in a laboratory, dangerous reagents (like diazomethane, mentioned in the last post) are required to create cyclopropane-based chemicals. But, by the miracle of nature, chrysanthemum plants have an enzyme that smoothly creates this crazy ring in the pyrethrin precursor chrysanthemic acid, (Another of the few examples of cyclopropane in nature is in Archaean membrane lipids, which are designed to tolerate harsh conditions. Archeaea are just about the only other living things I know of that do this, so how cool does that make chrysanthemums?!)

I’ll post about organophosphate insecticides at some point as well, as they’re historically/biologically much more important-- and MUCH more dangerous. And if the slew of posts on nitrogen allotropes didn’t get this across already, I’m a fan of unnecessarily dangerous chemicals.