Coby
moleculeoftheday
Posts by this author
October 9, 2006
Indole-3-butyric acid is a member of a class of hormones known as auxins, which are responsible for all sorts of plant growth regulation. You may have seen it on the shelves at a garden store, sold as "rooting hormone" - among other things, it can help a cutting of a plant set down roots more…
October 6, 2006
Lactisole is a pretty simple compound, apparently first found in roasted coffee. I doubt it tastes like much; maybe soapy at high concentrations. However, at relatively low concentrations (0.1% by weight), it has the unique ability to suppress sweet flavors.
The estimable Harold McGee says that it…
October 5, 2006
Stevioside is an intense sweetener found in stevia, an herb that's known pretty much for expressing this sort of molecule:
Stevioside, shown above, is a glycoside (that is, a glucose derivative) of a terpene. Unlike a lot of other sweeteners, stevioside is actually a sugar derivative (for others,…
October 4, 2006
Eugenol is a substance found in cloves. In addition to the distinct aroma of cloves, it's responsible for the numbness that clove oil can induce (dentists often swab your gums with it before giving you an injection of novocaine or lidocaine):
Sharp readers will notice the similarity to vanillin.…
October 3, 2006
Brass is an alloy of copper and zinc. Pennies, fortunately, have both, so you can actually use them to make some brass.
To get at the zinc (which makes up the creamy center of a penny), use a file to make some ridges in the edge of your penny. You can use electricity to oxidize the Zn metal on the…
September 29, 2006
Is a blogger and synthetic organic chemist in Barry Trost's group at Stanford. He has successfully e-panhandled his way to an iPod. He will not be blogging anymore starting in a couple days (presumably because it's dissertation time for him). This also means his blog will only be publicly…
September 29, 2006
Another member of the unusual collection of decent-smelling thiols (take a look at the previous entries on diallyl sulfide and ethyl thiolactate) is furfuryl mercaptan:
Furfuryl mercaptan smells of coffee. You'd expect it to smell awful, but it doesn't. Fragrance and flavor people talk about this…
September 28, 2006
(Oops, this should have been published on Tuesday. I didn't click publish. Sorry!)
Certain bacteria, under certain conditions, will excrete plastic.
The one above is a polybutyrate, but many are possible.
This is neat, first of all, because it's bizzare. Can you imagine being able to excrete…
September 27, 2006
Check out Khymos, a molecular gastronomy website, as I work my way through it too (thanks Jase!)
September 27, 2006
Inspired by Keith's comment on polylactic acid's tendency to deform under heat, and procrastination, I just did a quickie test of the heat-deformation characteristics of my polylactic acid bottle.
I took my PLA bottle and a cute little PET bottle I had lying around. I put some tap-hot water in the…
September 25, 2006
This weekend I came across Biota brand spring water, which is the normal expensive kind of spring water (the kind where they make a point of saying where in the earth it came from rather than obfuscating the "municipal source" text). It was pretty good - maybe even one of the better waters I've had…
September 22, 2006
Inspired by the comments yesterday, here is a compound that was used in early human genetics: phenylthiocarbamide, or PTC:
PTC is one of those molecules with the puzzling properties of tasting bitter to some, and like nothing at all to others. This page gives a good overview:
To some people the…
September 21, 2006
This is one that will be familiar to anyone who works in chemistry, but I was a bit surprised to see it the first time I went into a lab.
Certain compounds, called esters, can be prepared from an acid and an alcohol (usually a carboxylic acid). They are ubiquitous in the flavor and fragrance…
September 19, 2006
Yesterday's entry on crown ethers demonstrated a way to do reactions with a mixture of polar and nonpolar substrates. These crowns allowed for ions to be brought into the nonpolar solvent. Another approach is to just throw up your hands and mix oil and water, so to speak: reactions can occur with…
September 18, 2006
Crown ethers are an unusual series of molecules that have the ability to complex small cations, notably alkali metals such as sodium and potassium. These cyclic molecules, upon complexing a cation, can allow a salt to go into organic solvent that otherwise wouldn't. This makes reactions that are…
September 14, 2006
These are great: ferrofluids are stable suspensions of ferromagnetic particles. Typically, the liquid is something organic and nonvolatile, and the magnetic particles are iron oxides (such as Fe2O3 or Fe3O4).
Why so neat? Look here. Magnets, moved around near a ferrofluid, can create beautiful…
September 13, 2006
The lablels on bottles of chemicals with warnings always make me smile. One often-joked about example is the bottles of chemicals labeled "Flammable (US) / Highly Flammable (Europe)," which makes you feel smug if you're on my side of the pond. Another is "STENCH!". There's really no other way to…
September 12, 2006
Yesterday's mention of tyramine, and the comment, reminded me of inhibitors in general, and one in particular: harmine. Harmine belongs to a class of MAOIs known as the beta-carbolines.
MAOIs are problematic because they inhibit the metabolism of certain (toxic in the absence of gastrointestinal…
September 11, 2006
A diverse series of compounds, known as the phenethylamines, are created from the amino acid tyrosine (bold, at bottom, below). In vivo, things like adrenaline and dopamine are generated. Small amounts of tyramine are also generated. These are particularly concentrated in fermented foods like…
September 8, 2006
And I don't have the patience or energy to get it to right now. Come back Monday for something fun, hopefully I'll have it sorted by then.
September 7, 2006
There are two kinds of fatty acids: saturated and unsaturated. Saturated fatty acids have no carbon-carbon double bonds (-CH=CH-), they have only (-CH2-CH2-) single bonds. Notice that carbons only involved in single bonds have one more hydrogen than those involved in a double bond. They are "…
September 6, 2006
Longtime readers will recall this Palahniuk-inspired image from my articles on the old site about the twelve-carbon detergents Sodium Lauryl/Dodecyl Sulfate and sodium laurate/dodecanoate.
Today, I point you to Adam Engelhart's excellent (and thoroughly overdocumented) home preparation of…
September 5, 2006
The dimethoxytrityl, or DMT, ligand, is one of my favorite protecting groups in organic chemistry. Oftentimes, you need to "mask" part of a molecule to keep it from reacting during a step in a synthesis. DMT does this without breaking a sweat and gives you pretty colors to look at to boot.
Those…
August 31, 2006
Now with cyanide, it's Laetrile:
Which hydrolyzes to:
Please check out the laetrile entry on the old site. Various proponents of this bizzare cancer treatment (which liberates cyanide, of all things, upon hydrolysis) pop up occasionally. If anyone knows of any peer-reviewed studies on Laetrile, I…
August 31, 2006
Teflon, while it seems like a material in a weird class of its own, is actually just the fluorinated analogue of polyethylene - milk jugs and Saran wrap.
Fluorination, however, does funny things to molecules. Difluorine, or F2 is an absurdly reactive molecule. It has a lot of energy to give up in…
August 30, 2006
Ferrocene is another one of those weird molecules we just stumbled on. Upon reacting the anion of cyclopentadiene with an iron (II) salt, an "unusually stable" compound resulted. In inorganic chemistry, that often means stuff like stable to water or air, since much of this stuff falls apart…
August 29, 2006
I may get one up later, but there's a good chance you'll just have to wait til tomorrow for the next installment of MOTD-y goodness.
August 27, 2006
These are rare enough that I'm surprised every time I see one. It's a very simple molecule, that apparently makes its way into certain fruit flavorings: ethyl thiolactate.
As you probably have guessed by the numerous references to it, I love the flavor and fragrance field. I don't think I could…