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Biotech Science

Better Living Through Chiral Chemistry 68

Posted by timothy from the sinister-approach dept.
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."
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Better Living Through Chiral Chemistry More

Better Living Through Chiral Chemistry

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  • Why don't you drink Aquafina instead of Mt. Dew??? (Score:2, Funny)

    by Anonymous Coward
    you Gnu hippies
    • 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.
  • 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.


    • > 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.

      Fortunately, this one merely makes the water in your toilet spiral down the wrong way when you flush it.

    • Saccharin. What else? Please refrain from linking http://www.monsanto-is-evil.com/ and their ilk. Please no "my friend can't stand diet coke - he says he's allergic." Hard facts please.
      • MY wifes vision gets blurry and her blood suger is kept at an elevated (above 200) state if she drinks diet soda that uses nutrasweet. These effects last for a day or so after she stops using the products.

        Regular sugar dosent do that to her, and neither does saccharin or splenda.
    • You should consider the way these substances are tested. If you would test a artificial sweetener in an animal experiment, you would probably use a dose larger than the dose you expect in humans.

      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

  • The one time patents would be a Good Thing... (Score:3, Insightful)

    by RobertB-DC ( 622190 ) * on Monday October 27, 2003 @08:31PM (#7323963) Homepage Journal
    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.
    • Wrigley and Kraft have patents of their own.

      No kidding man. IIRC Wrigley has also received a patent for using chewing gum as a drug delivery system for Viagra which is a perfect example of how ridiculous our patent office has gotten. Is there anyone reading this who would like to have a patent in their name just to list on their resume but thought you didn't have any clever enough ideas? Well your prayers have been answered. The Rad shall provide. Just patent sprinkling Viagra on cupcakes as a drug delive

    • 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.

  • Whoa (Score:4, Funny)

    by xenocide2 ( 231786 ) on Monday October 27, 2003 @08:33PM (#7323977) Homepage
    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.

  • Serendipity and poor laboratory technique (Score:3, Interesting)

    by drox ( 18559 ) on Monday October 27, 2003 @08:41PM (#7324054)
    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.

  • non-nutritive "food" (Score:5, Funny)

    by dpilot ( 134227 ) on Monday October 27, 2003 @08:49PM (#7324137) Homepage Journal
    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)

  • Stereochemistry - handedness overly simplistic (Score:5, Insightful)

    by Zeio ( 325157 ) on Monday October 27, 2003 @08:58PM (#7324220)
    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.
    • "Now, as to the practicality of stereogenics and its use in zero calorie metabolism: this is probably less difficult than separating U238 and U235"

      Well duh. I can seperate sweets from no sweets using my tongue. You ain't gettin' me to put U-whatsit and U-whatsit plus 3 on my tongue.

      Nuh-uh. No way!

      How much was that again? Oh, well, what's face cancer compared to $7/hr! Bring on the uranium!

      Moral of the story - you can get any labor done for the right price. The right price is however low y
      • On the other hand, uranium is a highly toxic heavy metal. Put enough of it on your tongue and you'll be in a very bad way, like the people who did the same with lead, mercury, cadmium....

        The radiological properties of uranium are, as I understand it, vanishingly unimportant compared to the chemical toxicity.

        • The radiological properties of uranium are, as I understand it, vanishingly unimportant compared to the chemical toxicity.

          Both the chemical toxicity and radiological properties of uranium are significant. Radiation from uranium is primarily alpha radiation and therefore generally won't penetrate the skin far enough to cause problems (though skin cancer would seem to be a possibility - I'm not sure if anyone's done a study). Ingested and particularly inhaled uranium is a different story and the alpha radi

    • Why Separate? (Score:1)

      by Anonymous Coward
      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.

      • Re:Why Separate? (Score:1)

        by Anonymous Coward
        I'm curious on reading any material on stereo specific synthesis using "regular" chemistry (e.g., can be done with just reagents, heat and some basic equipment.)

        You have any links?
      • Reactions do exist, but may not be cost-effective in mass production quantities.
    • This is a pretty good comment, but I'd like to add that the reason why a certain enantiomer of a sugar would not convey calories is because it would fail to react with digestive enzymes. However, any chemical that is altered to remove specificity for these enzymes is also likely to cease its specificity for the taste receptors that register "sweet". While I believe that taste receptors might be a little bit more lenient, I would bet that this would be one of the problems. The extreme difficulty/cost of sepe
      • Taste and scent receptors are more lenient. They are not the typical "one receptor, one ligand" forms that you see everywhere else. They are designed to react to a wide array of similar molecules as opposed to having a high affinity for one molecule, and virtually none for anything else. "Sweet" receptors can react to any sugar, even disaccharides. For example, two enantiomers of glucose are much more similar chemically and biochemically than are glucose and fructose. Both fructose and glucose have the same

    • Re:Stereochemistry - handedness overly simplistic (Score:4, Informative)

      by MillionthMonkey ( 240664 ) on Tuesday October 28, 2003 @06:12AM (#7326858)
      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.

      It isn't as neat as that.

      In general N chiral carbons means 2^N possible configurations. Half of these are mirror images (enantiomers) of each other. That means there are 2^(N-1) distinct epimers. These are distinct chemicals in their own right. They don't just taste different and rotate light backwards. They have different melting points, solubilities, IR spectra, etc.

      So glucose, with its 4 chiral carbons, is a member of a family of eight related epimers. Any two of the 8 will differ from each other in that between 1 to 3 (1 to N-1) carbons have flipped chirality, making them diastereomers of each other- some carbons are flipped, some aren't. And each has a D and an L form.

      The 8 epimers of glucose (including glucose itself) have names: allose, altrose, glucose, mannose, gulose, idose, galactose, and talose. Collectively they are referred to as aldohexoses. As far as I know, most are digestible and taste more or less sweet. Gulose is nonfermentable. Galactose is less sweet than glucose but certainly has calories since it's a component of lactose. Finding information on what the rare ones taste like is difficult. They don't appear in many cookbooks and the people who work with them don't seem to be terribly interested in telling us what they taste like.

    • 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.[...]
      Are you really sure that you don't confuse d and l with Emil Fischer's D- and L- notation?
  • You can't patent sugar! that's just fucked up!
  • Wired magazine:

    The NutraSweet Web site's FAQ is devoted to answering charges that aspartame causes brain tumors, epileptic seizures, even weight gain. Such public suspicion could give all-natural tagatose a huge marketing edge

    The NutraSweet Web site's FAQ:

    American Cancer Society
    The [ACS] clearly states that aspartame does not cause cancer. In fact, aspartame (due to the nature in which it is metabolized) never reaches the organs of the body.

    Does aspartame cause cancer or tumor formation?
    Long-term

    • Aspartame never reaches the organs? Well I guess we don't have to worry about it causing cancer then, since all cancers happen in the organs.

      Right?

      And you mean isomer, not isotope.

      OTOH, you do have a point. After all, the thalidomide disaster was caused by optical isomers, that's never a good thing to associate with.
      • Aspartame never reaches the organs? Well I guess we don't have to worry about it causing cancer then, since all cancers happen in the organs.

        Yeah, especially since the stomach, intestines, skin (lips, cheeks) are not organs. :P

        So, if they don't know what an organ is, do we trust their scientific methodology? ( I don't believe aspartame is particularly harmful but I don't believe them saying so ).
    • I think I'll take NutraSweet over an ambidextrous sugar isotope invented by someone that flew radioactive sugar to Mars.

      RTFA; all he did to 'invent' it was to get a package in the mail. He figured out an economical process to synthesize it from whey, but nature invented the sugar.
  • 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 sweete
    • Dude, they already made low-cal fats. Ever hear of Olestra?
    • I'm looking forward to low-cal fat now. But I fear it will be a while.

      Up and until this post, I was going to ignore that transchiral food additives have been on the market for almost a decade. However, in light of this almost-observant post, I remind you that Olestra has been teaching us for quite some time.

      Sugar in my foeces probably won't be nearly as bad as oil, thankfully. What we need is an oil that degrades in our stomach to two other things that a) don't get ingested and b) don't leave me feelin

    • This is great -- I would probably be 15 pounds lighter if Mtn Dew were low-cal.

      Or if, you know, you, like, didn't drink so much Mountain Dew.

      If your intake of soda is high enough that artificially sweetened ones would make a large difference in your caloric intake, you're drinking too much fscking soda.

      Hell, why bother with artifical sweetners and fats? Just make like the Romans and vomit it back up again! (Though not in a "vomitorium" [straightdope.com].)

  • 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.
    • 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 thousan
      • The plan is to sell it, after all--not add it to the municipal water supply.

        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,

  • Celebrity deathmatch: Murphy vs Darwin (Score:4, Funny)

    by Alsee ( 515537 ) on Tuesday October 28, 2003 @04:06AM (#7326598) Homepage
    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.

    -
  • The article states:

    Finally, he decided to try L-tagatose, a rare left-handed sugar. When the maker accidentally sent him D-tagatose, he tested it. It was nearly as sweet as sugar, with similar baking and browning properties. By coincidence, D-tagatose is structurally similar to L-fructose, making it enough like a left-handed sugar that the small intestine absorbs only 20 to 25 percent of it. Translation: low-calorie.

    As it turns out, the perfect sugar Levin was searching for wasn't left-handed at all. But

  • 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
  • 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
    • ..."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

  • Here's something I posted on my site [quadium.net] recently:

    The November 2003 issue of Wired [wired.com] has an article about artificial sweeteners, tagatose [caloriecontrol.org] in particular. I was strongly disappointed to find that the article only mentioned stevia [steviacanada.com] once, in passing, and that it was not included in their chart of sweeteners. I would expect Wired [wired.com], of all publications, to want to be all over something so subversive [stevia.net].

    I'm even more disappointed to see no mention of it in this Slashdot discussion.

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