Coby
moleculeoftheday
Posts by this author
January 27, 2011
A US Army base in Utah was locked down for some time on Wednesday, because they discovered that they (transiently) misplaced a container of VX - a potent chemical weapon. Like they used in The Rock!
A neurotransmitter called acetylcholine (or ACh) helps your muscles contract, as well as regulating…
May 7, 2010
When you mix bromine with another molecule that has a carbon-carbon double bond, the bromine can add across the double bond.
The bromine atoms are very heavy - about 80 times as heavy as a hydrogen atom, or 7 times as heavy as a carbon atom. Bromination usually gives you a molecule that has higher…
April 29, 2010
If you take or are close to someone who takes antidepressant medication, you're probably aware that one class, the SSRIs, is particularly prone to causing sexual side effects. These effects can run the gamut from inhibition of libido, to erectile dysfunction, to a diminished or complete inability…
June 4, 2009
Wow. It's not just anticancer drugs for dogs, there are also "lifestyle" drugs. They think they're people!
Just like people obesity drugs, they're intended for short-term use, coupled with a diet and exercise plan.
I really don't understand. It's not hard to put your dog on a diet. See here if you…
June 3, 2009
A few months ago, a tyrosine kinase inhibitor anticancer drug for people, this month, one for dogs.
It is made to treat cutaneous mast cell tumors, which apparently account for about a quarter of dog cancers.
I know a lot of people drugs end up in pets, but do pet drugs ever end up crossing over…
April 22, 2009
There are a number of tobacco-associated compounds that are formed by reactions of nicotine. Cotinine is a metabolite formed from nicotine in the body - it hangs around a relatively long time, so it is a good marker for recent nicotine exposure.
Additionally, a number of nitrosamines, formed during…
April 22, 2009
Going through emails, I came across a request from ASPEX to link to a scholarship they're offering. $1,000 and "an opportunity to co-author a poster with ASPEX at Pittcon 2010." If you are an undergrad thinking of applying for this, going to Pittcon might be worth more than the $1,000. You couldn't…
April 9, 2009
Yesterday, I mentioned naphthoresorcinol as a reagent for aldehyde testing. Did you know: at one point during the Cold War, the Soviets used to put a certain aldehyde on American operatives in the USSR as a tracer?
That aldehyde, NPPD, caused a kerfuffle in the 80's. There was outrage that…
April 8, 2009
Before the advent of modern spectrometry techniques (NMR and mass spectrometry), there was a compendium of tests to suss out what sort of things were hanging off a molecule. You took your stuff, added some eye of newt, and if black (but not white) soot rose up, you knew you had an arylamine (or at…
March 18, 2009
Sulfur usually stinks. Previously, I've covered ammonium thioglycolate, mercaptoethanol, and dithiothreitol, all of which are used to break up S-S bonds in biomolecules. The S-H group is what does the job here, and where this functional group is found, stink is usually nearby. The above thiols all…
March 3, 2009
There was a nice interview on the Daily Show with former NIH director and Nobel laureate Harold Varmus. Good on Jon Stewart for having him, he got to make the kind of points you wouldn't usually on a book tour. He touches on some interesting points regarding just how science funding works in…
March 2, 2009
Awhile back, I discussed dicyclohexylcarbodiimide: a condensing agent that helps turn biological monomers (like amino acids) into polymers (like proteins). People use it a lot on peptide synthesizers for this purpose, where the peptides are made in organic solvents. A related compound, EDAC, works…
February 16, 2009
I just read the excellent Not Rocket Science for the first time. He has a nice writeup of the propranolol story that is making the rounds. Some researchers conditioned some subjects to get stressed when they saw a picture of a spider by shocking them while viewing spider pictures. Then, everyone…
December 15, 2008
Methyl anthanilate occurs naturally in grapes, along with a suite of other aroma compounds, which combine to give that complex, earthy, bright grape juice aroma.
If you use it in a prepared food at high concentration, as the lone or primary flavorant, however, you end up with the cloying, floral…
December 4, 2008
Acetonitrile is essential to a lot of chemical analysis - HPLC, or high-performance liquid chromatography, is a workhorse technique for just about anyone who wants to purify on a smallish scale, or see how pure their stuff is. This means pharmaceuticals, prepared foods, agribusiness, fine chemicals…
December 3, 2008
Levamisole is one of those drugs that was discovered quite awhile ago, when we had even less idea what target things were hitting. It's not used often in people these days. What's interesting about it is that it is occasionally found as an adulterant in cocaine (PDF) - and it popped up again…
November 26, 2008
The Royal Society of Chemistry is offering a million pounds to anyone who can bring them 100% chemical-free material.
The manufacturers of a popular "organic" fertiliser recently drew the attention of the public when it claimed in promotional materials the product contained no chemicals whatsoever…
November 17, 2008
Loratadine is an antihistamine used for treatment of allergies. Its main distinguishing characteristic is that it is nonsedating, because the molecule minimally penetrates the barrier separating the brain from the bloodstream.
November 10, 2008
Metformin is about as simple as a drug gets:
It's an antidiabetic drug that diminishes the amount of glucose generated in the liver. There aren't many oral antidiabetic drugs, and there are loads and loads of diabetics out there, so Americans use it by the bucket.
November 7, 2008
Cyprodenate is an old antidote for benzodiazepene overdose:
It is a relatively rare drug that doesn't have a single aromatic ring - steroids are the broad class of exceptions that come to mind. It looks like this is some sort of cholinergic compound, but that's just an educated guess. Doesn't look…
November 3, 2008
Limonene is a monoterpene that occurs in citrus peel, and it has a strong generic citrus smell. Many terpenes are smelly, like carvone (spearmint or caraway). Interestingly, limonene is cheap and abundant enough to use as a semi-green degreaser or solvent.
Green or not, limonene isn't totally…
October 30, 2008
Atropine can:
Dilate pupils
Speed the heart
Inhibit sweat and salivation
Serve as an "antidote" to "nerve gas"
Sounds like powerful medicine, and it is, indeed. On the other hand, it is named for Atropos, the Greek goddess responsible for deciding how people die, for a reason. This is a molecule…
October 27, 2008
Geosmin smells of earth:
You can smell vanishingly small amounts of it, too - mere nanograms of the stuff! It smells this way for a reason - countless soil bacteria busily produce it in your backyard as you read this.
The first thing I thought of when I started this entry was Demeter's Dirt…
October 9, 2008
Takin' off that TBDMS? TBAF isn't your only choice:
TEA.(HF)3 is another source of the fluoride ion. Neat TEA-HF3 is a liquid, so it's about 10 M vs typical 1 M TBAF. A little nastier than TBAF, since it's able to liberate HF.
October 8, 2008
Stick that TBDMS on Monday and helplessly flailing around, looking for a way to get your alcohol back? Have a little TBAF:
TBAF is one of the most common sources of fluoride ion for silyl deprotection. You usually get a 1M solution in THF with a little water, too. It can be a pain to get rid of…
October 6, 2008
Just like boc protects amines, TBDMS protects alcohols.
TBDMS chloride will protect alcohols. The silicon-oxygen bond is pretty strong, and the silicon-fluorine bond is even better. This provides a protecting group that's pretty robust - fluoride reagents are typically used for removing the silyl…
September 30, 2008
Last year, we were fretting about melamine contamination in foods from China. Again, this week, it's happening - melamine was put into milk by some unscrupulous vendors. The idea here is that melamine is high in nitrogen and cheap. An easy way to get an idea of how much protein is in something is…
September 24, 2008
Yesterday, I discussed ammonium nitrate, an industrial fertilizer. One problem with it is its lavish reactivity. On its own, and particularly in combination with hydrocarbons, it makes a potent explosive - it was used in the attack on Oklahoma City in the 1990's.
Apparently, adding a different…
September 23, 2008
Plants need nitrogen. You're soaking in it - the air is 78% N2 Trouble is, the kind of nitrogen plants need is reduced (i.e., has more electrons) relative to dinitrogen in the air. In the past, this meant rotating crops - peanuts, for example, promote nitrogen-reducing, or "nitrogen-fixing"…