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Better Living Through Chiral Chemistry
Atario writes "A long time ago, I remember reading in some science magazine that someone had the bright idea of using enantiomers (the two forms of asymmetrical molecules, like left- and right-handed versions of the same one) to make zero-calorie sugar -- turns out, in general, that sugars are all asymmetrical, and everything generates and uses only one of the two chiralities (handednesses) for each one. If we consume a mirrored version of, say, sucrose, we might get all of the sweet but none of the calories. Sweet-tooths rejoice! But nothing ever came of it. Now, however, Wired has an interesting article that explains what the holdup has been and indicates the logjam may break soon, but, as it turns out, in a non-synthetic, albeit nonzero-calorie, way."
you Gnu hippies
Seems like every time they come out with a new 0-cal sweetener, that is safer then the last, it turns out to have some unforseen side effect that makes it worse then the last.
"Anything is possible with enough programmers, time and pizza." (Substitute caffeine for time as needed.)
For once, a patent would appear to be supporting innovation. An individual with an idea sees the potential, files a patent, and goes on a quest to commercialize the product. There could be no better case study of how patent law is supposed to encourage innovation.
But alas, it's not to be. From the article:
The patent on tagatose as an additive expires in 2006, the two patents on production methods a few years later. [Inventor Gilbert] Levin hopes to see his sugar substitute flood the market before then.
Meanwhile, the current silliness at the patent office will help ensure that Levin will join the legions of brilliant inventors with "died nearly destitute" included somewhere in their epitaphs. Instead of an individual getting his due from an actual original thought, big corporations are set to reap millions from ridiculous "business method" patents. Again, from the article:
Kellogg's obtained a patent in 2002 to use tagatose in "improved sucrose-free, noncarcinogenic, reduced-calorie, insulin-independent" sweet cereals. Wrigley and Kraft have patents of their own.
It's situations like this that make me glad to be a wage slave, with all my original ideas signed over to my own^h^h^hemployer.
Stressed? Me? Of course not. Stress is what a rubber band feels before it breaks, silly.
For Levin, it was a third tour at Hopkins; he received a bachelor's in 1947 and a master's in sanitary engineering a year later.
And I always thought that a janitor was an entry level position.
I Browse at +4 Flamebait
Open Source Sysadmin
I was impressed by the role serendipity has played in the discovery of sweeteners. But
In 1937, a University of Illinois grad student discovered another sweetener when he set his cigarette on a lab bench during an experiment - testing a would-be antifever drug - and then took a drag off the cyclamate-coated end.
might be taking things a bit too far. Smoking in the laboratory? My how times have changed!
Still, the cyclamates are now banned (in the US anyway), while you can still buy cigarettes in any quik-E-mart. You just can't smoke them in the laboratory! Or in most public buildings.
Two years of Newtrition investment and research had produced CHOW(TM). CHOW(TM) contained spun, plaited, and woven protein molecules, capped and coded, carefully designed to be ignored by even the most ravenous digestive tract enzymes; no-cal sweeteners; mineral oils replacing vegetable oils; fibrous materials, colorings, and flavorings. The end result was a foodstuff almost indistinguishable from any other except for two things. Firstly, the price, which was slightly hgher, and secondly the nutritional content, which was roughly equivalent to that of a Sony Walkman. It didn't matter how much you ate, you lost weight.*
* And hair. And skin tone. And, if you ate enought of it long enough, vital signs.
From Good Omens, by Terry Pratchett and Neil Gaiman. (pg 110 in my copy)
The living have better things to do than to continue hating the dead.
Some compounds are listed as d- and l- refer to the highest-numbered asymmetric stereogenic centers. They also do not indicate the sign of rotation of plane-polarized light.
Most interesting organic compounds have multiple stereogenic centers. One of the main reasons plants are used to obtain starting materials for various modern drugs, ergot infested rye (indole substrate), poppies, indica sativa all provide starting points that make it so that creating synthetic materials based on these plant extracts as starting reagents is far easier due to the fact plant enzymes can place each stereogenic center in the right conformation and in wet chemistry this is exceedingly difficult. Mentioning some of the starting plants for illicit drugs is no mistake; they are notoriously sensitive to chiral conformation, and provide some of the most interesting sterochemical research subject matter. Also, due to the draconian laws surrounding federally controlled substances and their precursors, it isn't easy to study these things, despite being hugely important.
To say that stereochemistry is limited to 2-handedness is a ridiculous oversimplification of reality. If I'm not mistaken, C6-H12-O6 "glucose"; has D-glucose has 4 chiral carbon atoms (2^4 = 16 possible stereoisomers) - I believe only one of which is able to provide calories.
Various notations for stereochemistry exist, and one must factor out canonical conformations and take into account the bending of the various stereogenic centers in 3d-space, leading to notations that include "boat" and "chair."
Now, as to the practicality of stereogenics and its use in zero calorie metabolism: this is probably less difficult than separating U238 and U235, but one could probably get an enzyme of modify bacteria to plunk out zero-cal conformations, but in large scale synthetic operations, getting picky with chirality could be problematic / costly. Things are ridiculously hard to separate, and you need to use special techniques such as using tartrate salts and other expensive and slow ways of picking out the various conformations of chiral compounds.
Legalize the constitution. Think for yourself question authority.
You can't patent sugar! that's just fucked up!
I am one of many. My idea is not unique, nor do I expect my voice alone to sway you. I speak in a chorus of opinion.
Why separate when you can manufacture a chiral molecule in only one stereo-isomer? There's plenty of named reactions out there to facilitate a stereospecific synthesis, especially a relatively simple one like glucose/sucrose.
The radiological properties of uranium are, as I understand it, vanishingly unimportant compared to the chemical toxicity.
Time is Nature's way of keeping everything from happening at once... the bitch.
The NutraSweet Web site's FAQ:
I think I'll take NutraSweet over an ambidextrous sugar isotope invented by someone that flew radioactive sugar to Mars.
This is great -- I would probably be 15 pounds lighter if Mtn Dew were low-cal.
I'm looking forward to low-cal fat now. But I fear it will be a while. Whereas substitute sugar just has to be sweet (creative cooks have found ways around the missing browning/cooking characteristics), fat has to have texture and volume characteristics in addition to the flavor requirements. That adds hard-to-meet requirements to any potential solution.
With sugar, you can substitute it with some chemical that is 600X sweeter than sugar, so you hardly need any of it for it to do its job. With the volume requirement of fat, you can't just get away with a tiny amount of some chemical 600 times more "fatty". So you look for something that has the same volume and texture, but that doesn't make you get fat.
One way to do this is to use something that seems like fat, but that your body can't digest. Unfortunately, if your body doesn't digest it, it still has to go somewhere. If the fat substitute is completely undigestable, it will stay in your intestines all the way through -- and the consumer will have a nice case of the runs when it gets to the other end.
If you go for something that can be absorbed by the intestines, but somehow not be metabolized by the body, you're asking for a lot of trouble. Once it is in the bloodstream, how does it get out? It has to be something that can either safely pass through the kidneys, or something that the liver can route through the gall bladder (in which case, you're back to problem #1).
One approach might be something that is water-based but has oil-like properties until it hits the stomach acid, at which point it breaks down so that the water can be absorbed. I'm no chemist, but that seems to be asking a lot.
Here's hoping there is a chemist out there who isn't as easily discouraged as I am...
Time flies like an arrow. Fruit flies like a banana.
Most of this is correct, except that cellulose is actually a polymer made up of glucose. More specifically, cellulose is beta(1,4)-linked glucose. This online lecture has a picture of cellulose both as a linear chain and as how linear chains can form a more complex sheets (not pictured: the sheets can then stack). We can't use cellulose because we don't have cellulase, a series of enzymes that can hydrolyze the chain. It's been a while, but I think it pops off glucose pairs, not monomers but I could be mistaken.
Was anyone else put off by the comment that they might market this substitute as a fertility aid (due to a study showing it increased fertility in rats)? Somehow I think there are a lot more women in the world who don't want to get pregnant than women trying to get pregnant.
An individual with an idea sees the potential, files a patent, and goes on a quest to commercialize the product. There could be no better case study of how patent law is supposed to encourage innovation.
Good thing the idea was patented...otherwise we might have had more than one company working on this for the last twenty years.
Was anyone else put off by the comment that they might market this substitute as a fertility aid (due to a study showing it increased fertility in rats)? Somehow I think there are a lot more women in the world who don't want to get pregnant than women trying to get pregnant.
I hope you've never had to deal with the pain of wanting a child and not being able to have one. I've known more people of that ilk than those who wished the other way after having them. Many of these folks have paid tens of thousands of dollars for any number of treatments, surgical procedures, counseling, etc. to try to have kids. Do you think they'd balk at switching to a lo-cal sweetener that might increase their fertility by five percent?
The key word here is market. Someone developing a fertility aid doesn't care if five billion people don't want more kids. It's the hundreds of millions that do who will make it worthwhile. The plan is to sell it, after all--not add it to the municipal water supply.
Yes, in a free market people vote with their money, but remember that the voting options aren't Yes and No, but Yes and Abstain.
In 1879, chemists Ira Remsen and Constantine Fahlberg synthesized a derivative of coal tar called orthobenzoyl sulfimide. One day, Fahlberg spilled the substance on his hand, which later that evening he touched to his mouth. It tasted sweet. He filed for a patent and called the substance saccharin. In 1937, a University of Illinois grad student discovered another sweetener when he set his cigarette on a lab bench during an experiment - testing a would-be antifever drug - and then took a drag off the cyclamate-coated end. In 1965, a chemist named Jim Schlatter was working on a compound to treat gastric ulcers. He licked his finger to grab a sheet of paper and tasted aspartame for the first time. Then there was the 1976 discovery of sucralose by a King's College student working with chemically altered sugars. The student - not a native English speaker - mistook his professor's instruction to "test" the material and tasted a mouthful.
Thus conclusively proving that Murphy's law defeats Darwin's law.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Lars T.
To the guy who modded me down from perfect to terrible Karma - Apple haters still suck
Those who want children but are unable to have them should adopt.
Another poster was correct in pointing out that sugars have multiple chiral centres. Glucose has four, which means that there are 2^4 = 16 stereoisomers of glucose.
Prof. Fischer won the Nobel prize in 1902 for determining the correct isomer. In doing this work he invented a way of drawing these monosaccharides as a linear chain (all sugars do spend some time linear and some cyclic - it is an equilibrium) and the stereochemistry of the carbon atom furthest away from the aldehyde group determines the D or L designation.
H-C=O
|
H-C-OH
|
HO-C-H
|
H-C-OH
|
H-C-OH*
|
CH2-OH
So the ascii art above represents d-glucose because the OH group with an asterisk points to the right.
The idea is of using the opposing sugar works in theory becase we don't have the enzymes to digest them (no energy value) but we are able to recognise them (taste sweet).
This is very common practice, since it would take too many animals to do a proper test at the expected dose. To determine a 1/million fatality, you would need millions of lab rats if you'd test at the human dose.
So, if you would test at 100 times the expected dose in humans, this would be a proper experiment for an artificial sweetener.
However, if we would do the same experiment with ordinary sugar, you would get very strange results. If you would look at the risks of consuming 100 grams of sugar a day in a human, the experiment would involve daily consumption of 10 kilograms of sugar a day. Needless to say, the mortality in the subjects of such experiment would be 100% within a week or so (probably sooner).
But when testing at the normal dose, I would not be surprised if you'd find that a group on sweetener would have a better life expectancy than a group on 'real' sugar.
A one-in-a-million chance on cancer would, in my opinion, be better than a one-in-ten chance of contracting obesitas, diabetes and/or cardiovascular problems.
When looking at the total risk, it would be wise to ban sugar and favour sweeters right here, right now. Luckily, people can choose for themselves, but I think they should be informed better.
This is going to shock you, but you don't actually need to consume sweetened (or fatty) products! It's true! You see, you have a part of your body, scientifically called "the brain", which allows you to make "choices" in your diet.
Saying you can't help yourself from eating a sweet treat is like saying you can't help but rape someone because of the way they were dressed (yes, I know this is extreme, but that's sometimes necessary for making a point). In both cases, you have a response that your brain can process and chose to take action on. No one controls your body, but you. You have free will, so use it.
When I hear people say they can't stop eating because something "tastes so good", I see a person out of control, and likely a danger to themselves and possibly others. After all, if they can't control their behavior with something as simple as a bit of candy, how can they be expected to behave appropriately in any other area of their lives?
Can You Say Linux? I Knew That You Could.
I think that's the point. Making this a mass-market diet coke additive is metaphorically "adding it to the water supply". And he's right, there are a lot more women that are trying not to get pregnant that those that are having trouble getting pregnant. Look at how many women are on birth control rather than fertility drugs. I fully understand the problems people have when trying to have a child when they can't. But those people, when compared to the general populace, are rare. Even if there are tens of millions of them, compared to 6 billion they are still rare.
There is a reason for everything. Sometimes that reason just sucks.
What about stevia
..."Lightly Sarcastic" division.
No one is saying they can't not eat something. They just want to. Anything wrong with that? If science can provide a way to do so with no (or less) negative side-effects, where's the harm?
Saying "never mind technological advances, concentrate on getting along with the way things are" results in stagnation. If it weren't for human vices such as laziness and gluttony, we'd still be walking from cave to cave every morning to assemble our spear-hunting parties for the day.
Why do you drive a car, or ride a bike, or take a train, or use a computer or a telephone? To avoid all the tedium of the alternatives -- a.k.a. laziness.
Why do you buy food at the grocery store instead of growing and/or hunting your own? To avoid all the hard labor and time consumption of farming and ranching -- a.k.a. laziness -- and because you'd never be able to make enough of the foods you like -- a.k.a. gluttony -- and because hunting can be dangerous -- a.k.a. cowardice.
Why do you seek a better job or business than the one you have? Because you want more money -- a.k.a. greed.
The list goes on. Human weaknesses drive human progress.
"A great democracy must be progressive or it will soon cease to be a great democracy." --Theodore Roosevelt
Here's something I posted on my site recently:
I'm even more disappointed to see no mention of it in this Slashdot discussion.
TO BUY A NEW CAR WOULD MAKE YOU SEXUALLY ATTRACTIVE.
you Gnu hippies
Your position is inconsistent. Microsoft Hippies drink Aquafina.
GNU hippes drink straight from the tap, some straight from the river.
Apple hippes drink either Fiji or filtered tap water, depending, on how they came to the platform.
Unixware hippies, of course, are suing the rest of us for drinking water.
My God, it's Full of Source!
OUTSIDE_IP=$(dig +short my.ip @outsideip.net)