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 functions as diverse as sweating, heart function, and pupil dilation. When everything is working correctly, ACh is a transient thing. It sends a message - for example, contract this muscle - and it is then broken down by an enzyme. It is important that, once it's done its job, ACh get broken down…
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 density than the parent molecule.
Vegetable oil - which has a density of about 0.9 grams per milliliter - can be made as dense as water (i.e., 1 gram per milliliter) by adding the right amount of bromine.
Brominated vegetable oil can give an emulsion in water that is opaque and visually pleasing…
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 to achieve orgasm. It's that last one that we take a look at today - a SSRI went on sale in Britain this week that is touted as inhibiting orgasm - on purpose!
This SSRI, dapoxetine, is marketed to treat premature ejaculation. Previously sold in a few European countries, it has just gone on the…
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 are interested in reading some dog forum chatter (including a first-person owner account) about the drug.
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 into human medicine? Anyone know anything about how the decision to go after a dog-specific drug works? Just cheaper to go after?
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 tobacco processing, are present - many formed from nicotine. Nitrosamines are pretty nasty - just about any compound of this class is regarded as a suspect carcinogen. Nitrosamines are responsible for a lot of the bad rap cured meat gets for its role in colon cancer risk. These nicotine-derived…
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 ask for a better analytical chemistry meeting to attend, and this could be a great place to find a job or grad school advisor.
Also, if you have something you'd like to see SEM'd, they'll do it for free (although you have to be OK having it out there for the world to see).
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 Americans were being "tagged," and speculation as to whether it might be dangerous. Some analytical chemists leaned back, scratched their beards, and said "sounds kind of neat." And even recently, the compound was re-examined.
Anyone have any NPPD stories?
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 least had some evidence you did). You still see them occasionally in sophomore Organic chemistry labs, but they're going by the wayside, too.
One such reagent was naphthoresorcinol:
This one will give you a red adduct with an aldehyde in acidic solution. Anyone know the pathway or care to guess??
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 have some degree of stink.
Not all thiols stink. Previously, I've covered a grapefruit thiol, a fruity thiol, and a coffee thiol.
Methanethiol is not one of the nice-smelling thiols. With a smell most often described as rotten cabbage or rotten eggs, you'd think it was useless. You'd be wrong.…
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 practice in the States, as well as the broad range of constituencies agencies like NIH have to satisfy.
Sorry, the video is from Comedy Central and, likely, US-only.
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The Daily Show With Jon StewartM - Th 11p / 10c
Harold Varmus
Daily Show Full EpisodesImportant Things With Demetri Martin…
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 in water:
EDAC works just like dicyclohexylcarbodiimide, but in water. People have used it to, for example, condense short pieces of DNA into longer ones.
I've heard it's a sensitizer (allergen) like DCC, but I'm not sure if it's quite as bad (no vapor pressure, anyway).
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 got more spider pictures (with no shocks), this time with loud noises! The fear response to these picture/noise combos was measured by observing the subjects' blinking.
On the second day of the experiment, everyone got a pill with their spider picture and loud noise. Some of them got a placebo, and…
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 aroma of grape soda.
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, and on and on. We use lots of acetonitrile.
From a recent C&E News:
Acetonitrile is a coproduct of the process used to make acrylonitrile, a building block for acrylic fibers and acrylonitrile-butadiene-styrene (ABS) resins. An acrylonitrile plant yields 2 to 4 L of acetonitrile for every 100…
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 recently.
It is truly bizzare what people use to cut drugs. I once heard of a chemistry professor who told his class about how he walked into a head shop and saw a big sack of mannitol behind the counter (which is used as a cutting or bulking agent for street drugs as well). He marvelled that he had just…
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.
The product's manufacturer makes the fantastic claim to be "100% chemical free" in its advertising and on its packaging. The back of the packaging lists its chemical-free ingredients, which include phosphorus pentoxide and potassium oxide.
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.
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.