These toxic molecules, produced by seaweed, damage some of the most fragile coral in the oceans. Identify the class of molecules they belong to and the unlikely sea critter that gobbles them up.

From Gloria Marino: Corals in the genus acropora are highly prone to damage from a certain toxic seaweed, chlorodesmis fastigiata, better known as turtleweed. This seaweed produces two toxic terpenes, as shown in the picture above. Terpenes can be either hydrocarbons or have ketones and aldehydes. They can also be found in cleaning products and certain topical medications. When this toxic seaweed comes in contact with the coral, the coral releases an odor that attracts goby fish. These fish eat up the seaweed and thereby reduce the damage that it would cause. After eating it, the goby become toxic and are thereby more protected against predators. In this way, gobies exhibit a symbiotic relationship with coral. Fun fact: these gobies are only 3 cm long but are responsible for protecting the main structural component of most coral reefs!

References:
Dixson, D.; Hay, M Corals Chemically Cue Mutualistic Fishes to Remove Competing Seaweeds. Science. 9 November, 2102. (Accessed November 26, 2012).

Everts, S. The Coral-Seaweed Battleground. Chemical and Engineering News. (Accessed November 26, 2012).

Kashani, J. Terpene Toxicity. Medscape Reference. (Accessed November 26, 2012).

This molecule and others like it are at the center of a recent lawsuit. Identify the molecule and discuss the merits of the lawsuit.

From Ellen Hightower: The molecule shown is glucuronolactone, which is a naturally occurring chemical that is found in connective tissues. It is often used in energy drinks as a means of detoxifying the body. Glucuronolactone has been shown to interfere with the synthesis of toxic by-products linked to heavy exercise or fatigue.

The recent lawsuit regarding glucuronolactone concerns an FDA statement that 13 deaths may have been caused by the consumption of 5-Hour Energy, a popular energy drink. 5-Hour Energy contains high amounts of caffeine, taurine, glucuronolactone, and malic acid, among other ingredients. In addition, 30 out of 90 cases regarding the effects of 5-Hour Energy have stated that the drink caused serious or life-threatening conditions, such as miscarriages or heart problems.

Sources:
CNN Health. FDA investigates deaths preliminarily linked to energy shots. (accessed Nov 22, 2012).

The Merck Index. D-Glucuronolactone. (accessed Nov 22, 2012).

Newsmax. 5-Hour Energy Cited in 13 Deaths; Caffeine in Energy Drinks Blamed. (accessed Nov 22, 2012).

The Use of Taurine and D-Glucurono-gamma-lactone As Constituents of the So-Called "Energy" Drinks. EFSA Journal [Online] 2009, 935, 1-31. (accessed Nov 22, 2012).

Wikipedia. Glucuronolactone. (accessed Nov 22, 2012).

Identify this molecule and discuss its importance to dogbane beetles and milkweed bugs.

From William Martin: While ouabain is actually lethal to many animals (including humans!) in anything but minute doses (if small enough, it can help with heart function), it is a very interesting subject when it comes to dogbane beetles and milkweed bugs. To ward off insects and other animals that may eat their leaves for lunch, plants such as milkweed (in addition to foxglove and oleander) produce heart-stopping and brain-freezing compounds called cardenolides, which are toxins. Ouabain is one of these cardenolides produced by these plants, and it is meant to act as a defense mechanism against these leaf-eating insects. In response to this, a wide variety of insects, including dogbane beetles and milkweed bugs, have evolved and developed a resistance to this poison, allowing them to continue eating these plants that produce such cardenolides. A research team found that these poison-leaf-eating insects developed a few mutations on a specific protein, which in turn blocks any ingested cardenolides (like ouabain) from binding, and therefore having any effect. Additionally, the same research team discovered that instead of inheriting this mutation from a common ancestor, diverse species of insects have evolved this poison protection mechanism in parallel.

Source: Chemical & Engineering News. Volume 90 Issue 41, p. 48. Issue date: October 8, 2012.

The most recent article of C&ENews has an article about hexabromocyclododecane. Identify the article, determine what this molecule is traditionally used for, and discuss the controversary surrounding it as well as alternatives. Don't forget to properly cite your source(s).

From Katie Brodie: A Chemical and Engineering News article from October 29, 2012 titled "Ablazed Over Furniture Fires" talks about the presence of flame retardant chemicals in furniture and their risks to health. Almost all furniture has some sort of flame retardant found usually in the polyurethane foam of the furniture's innards. One particular chemical, hexabromocyclododencane that is used as a flame retardant in furniture, is under fire (no pun intended) by the EPA for the health risks it carries. Hexabromocyclododecane comes from a class of flame-retardants known as pentabromodiphenyl ethers. Some scientists insist that brominated flame-retardants, such as hexabromocyclododecane, can act as endocrine disrupters or have neurological and other health effects. It has even been found to accumulate in the tissues and has been detected in the blood of adults and children. Children are at the most risk to have chronic health problems resulting from exposure to these fire retardants. Not only is it argued that these flame-retardants are toxic, it is also thought that are not as effective as they are advertised to be. The scientists studying their toxicity and use have a goal of removing these flame-retardants from furnitures.

Schulz, W. Ablazed Over Furniture Fires. Chemical and Engineering News. 2012.

Identify this molecule and decide whether the benefits of it are worth the risks. Make sure your sources are scientific.

Maha Hassan: N,N-diethyl-3-methylbenzamide, also known as DEET, is the most common active ingredient in insect repellents. Compared to other synthetic and botanical repellents, DEET protects considerably longer against insects. However, negative effects can occur, usually as a result from the overuse of DEET or high concentrations. Additionally, DEET does irritate mucous membranes, and at high concentrations, can dissolve plastic. With this information, DEET's benefits outweigh its risks, if used properly. A repellent with a low concentration of DEET should be used conservatively, and should be washed off from clothes and skin when it is no longer needed.

Citations Richard J. Pollack, Ph.D., Anthony E. Kiszewski, D.Sc., and Andrew Spielman, Sc.D. N. Repelling Mosquitoes. England Journal of Medicine. 2002, 347:2-3 (accessed Oct 29, 2012)

Deb, Utsab; Ahmed, Fakhruddin; Singh, Seema; Mendki, M. J.; Vijayaraghavan, R. Comparative effects of insect repellent N,N-diethylbenzamide, N,N-diethylphenylacetamide, and N,N-diethyl-3- methylbenzamide aerosols on the breathing pattern and respiratory variables in mice. Inhalation Technology 2010 pp 469-478. (accessed Oct 29, 2012)

This molecule changed the course of history. Identify it, describe it's infamy, and discuss the general features of the class of compounds it belong to.

Michael Zhang: The molecule of the week is coniine, which is found in the plant Hemlock. As many of us know, Socrates was sentenced to death for "corrupting the minds of the youth" for refusing to retract his principles and retract his claim that only wise people acknowledge their own ignorance. He basically critiqued the government and high officials and was termed the "gadfly" of Athens. The punishment was drinking a solution containing hemlock. It's a poisonous neurotoxin that causes respiratory paralysis, and belongs to a group of compounds called alkaloids, compounds that contain nitrogen. Many other alkaloids are toxic to animals. These compounds can also be synthesized into medications.

Wikipedia. Coniine. (accessed October 16, 2012) Wikipedia. Alkaloid. (accessed October 16, 2012)

This molecule has a distinctive flavor and odor. Identify it and explain why, although it's completely edible, it's not possible to eat an entire teaspoonful of it at one time.

From Sarah Tait: The molecule of the week is cinnamaldehyde. A popular game called the "cinnamon challenge" requires a person to eat an entire teaspoon of tablespoon without water. Though it sounds simple enough, it's actually impossible to do. The cinnamon powder blocks the salivary glands, preventing them from releasing any saliva into the mouth. When the salivary glands are functioning, saliva helps to lubricate food and allow it to easily pass into the esophagus and down into the stomach. Without saliva or water, the cinnamon just sits in the mouth and causes choking and coughing. Choking and coughing, in turn, can allow some cinnamon powder into the lungs. Any fine powder that coats the lungs can lead to infection and pulmonary edema. Finally, while taking the cinnamon challenge some have had such a strong coughing reaction to the cinnamon that a lung collapses. Though cinnamon itself is not bad for the body, attempting to swallow a teaspoon of cinnamon without water is not only impossible, it's dangerous.

ABC News: Medical Unit. 'Cinnamon Challenge' Sparks Health Concerns. (accessed Oct 9, 2012).

CBS News. Popular "Cinnamon Challenge" Has Potential to be Deadly. (accessed Oct 9, 2012).

Today Moms. Poison Centers Warn About Cinnamon Challenge. (accessed Oct 9, 2012).

Research the new guidelines for labeling sunscreens and comment on whether you think this new system is better for consumers. If you use web sources, make sure they are legitimate and as unbiased as possible. Click here for a guide to help you decide.

• All sunscreens must undergo new testing for effectiveness in skin protection
• Sunscreens no longer can list an SPF higher than 50 since there is no evidence that an SPF higher than 50 is any more effective. Labels now say SPF 50+.
• Sunscreens that prevent against all types of sun damage (ultraviolet A (UVA) and ultraviolet B (UVB) radiation) will be labeled “Broad Spectrum”
• Sunscreens that are not Broad Spectrum or have an SPF 2-14 will have warnings on the label.
• Waterproof sunscreens must indicate how long they remain effective (40 or 80mins).

"FDA Sheds Light on Sunscreens." U.S. Food and Drug Administration. U.S. Department of Health & Human Services, 9 Aug. 2012. Web. 30 Sept. 2012.

This molecule is often added to dog foods. Identify it and decide whether you would buy foods for your pup that contain it. Be sure to include properly formated references.

From Allie Ivener: The molecule is L-methionine.I would definitely feed my dog food with l-methionine in it. Methionine is one of the 10 essential amino acids to have in a diet and it is not produced in the body. It is added to a dog's food to enhance its diet. One study showed that a lack of methionine in a dog's diet led to severe weight loss and loss of appetite. Additionally, methionine is known to treat liver disorders, to help the liver process fats, and to improve wound healing. It also provides sulfur to help prevent disease of the skin, hair, and nails. Mainly, methionine is involved in controlling the acidity of urine. It helps to regulate the formation of ammonia and the ammonia content in urine. Based on those benefits, I would feed my dog food with this molecule in it.

Dodman, N. Methionine. (accessed 9/26/2012). Nutrition Requirements of Dogs and Cats; The National Academy of Sciences: Washington, D.C. 2006.

MP NOTE: Some studies have show negative side effects when given in too high of levels.

Dagada, R.; Advances in Aging Research: Why Methionine Restriction is an Attractive Life-Extension Strategy. Examiner, July 14, 2009; (accessed Sept 22, 2012).

Not a bad molecule to have during these hot, muggy days. Research it and let me know what it's used for.
Be sure to include properly formated references.

From Thamanna Nishath: The molecule of the week is Quinine; it comes from a plant named Cinchona succirubra (1). It is used to treat malaria (2).

1. "Quinine Bark." Rainforest-Database. N.p., n.d. Web. 19 Sept. 2012.
2. "Quinine." Quinine. U.S. National Library of Medicine, 1 Feb. 2011. Web. 19 Sept. 2012.

Watch The Icy Finger of Death and then send me via email a brief description of the chemical principle at work and at least two other common examples which make use of the principle.

From Bryan Cochran: The chemical principle behind the 'brinicle' is that adding an impurity to a substance will raise its boiling point and lower its freezing point. Salt in this case is the impurity. The super salty brine water has a lower freezing point and is much colder than the surrounding ocean water so the ocean water freezes on contact.

Another example of this is adding salt to water when boiling it for pasta. By adding the salt, the boiling temperature is raised just slightly and better cooks the pasta.

Another example of this principle can be seen in winter time when salt trucks dump salt out on the roads. The salt lowers the freezing point of the snow/water and makes it harder for ice to form on the roads.

Identify the common name for this molecule, discuss its natural origins, and identify the elict drug it's used to make.

From Ben Learner: The molecule is 5-allylbenzo[d][1,3]dioxole, also known as safrole, which is an oil extracted from sassafras plants. In plants, it functions as a natural pesticide. Safrole is also used to manufacture the drug MDMA, widely known as ecstasy. Safrole has been found to be a carcinogen in rats. [Funny that the structure looks like a rat! MP]

Citation "Safrol." Report on Carcinogens (1981). Web. 30 Nov. 2011.

From Thomas Scheevel: There are multiple routes for synthesiszing ecstasy, but one stood out as particularly easy—just required the addition of HBr followed by methylamine to safrole. By some quick checks and estimations I made, it seems like this could be used to make over a thousand tabs of ecstasy for under $200!

Reading the label of my Powerade Ion4, I came across the following ingredient: glycerol ester of rosin. Identify this Molecule of the Week and tell me what it's doing in my drink. Convince me that your source is trustworthy (and not just a paid advertisement)

From John Neseman: According to several sources, glycerol esters of resin acids of wood rosins or glycerol ester of rosin is used as an additive in beverages and chewing gum. Rosin is collected from the stumps of the longleaf pine (Pinus palustris), purified, and mixed with other ingredients to form a thickening agent called ester gum. This ester gum is usually used to stabilize food such as ice cream and chewing gum, and is not suitable for beverages. However, when it is combined with glycerol it becomes a useful stabilizer for beverages. The wood acid composition of rosin can vary a lot however the main one is abietic acid and the rest are a complex mixture of isometric ditrepenoid monocarboxylic acids with an empirical formula of C20H30O2. The main use of glycerol ester of rosin is used to help the flavoring oils mix with the carbonated water, or just normal water, in many commercial drinks. As oils do not mix well with water the addition of glycerol ester of rosin lets the flavoring oils remain in suspension when blended with water instead of remaining separated. There is not much evidence that wood rosin can be detrimental to the health of consumers. Even so, the FDA prevents a concentration of 100 parts of wood rosin per million, thus there is only a trace amount of wood rosin in a typical comercial drink.

Dr G.J.A. Speijers, GLYCEROL ESTER OF WOOD ROSIN (food and beverage grade) at RIVM; Bilthoven, Netherlands. (accessed Nov 17, 2011)

Code of Federal Regulations: Sec. 172.735 Glycerol ester of rosin. (accessed Nov 17, 2011)

JECFA; Glycerol Ester of Wood Rosin. (accessed Nov 17, 2011)

Identify the following two molecules and discuss why they're important to honey bees.

From Alex Reed: The top molecule is (E)-9-hydroxydec-2-enoic acid, also known as 9-HDA. 9-HDA is part of a "pheromone cycle" for bees, in which worker bees convert 9-ODA, sent by the queen, into 9-HDA and send 9-HDA back to the queen. 9-ODA is produced in the mandibular glands of the queen bee. These pheromones are used for communication between the queen bee and worker bees. The 9-ODA produced by the queen after the queen receives 9-HDA from the workers is involved in "caste maintenance."

The second molecule is (E)-10-hydroxydec-2-enoic acid, also known as 10-HDA. This molecule is secreted by young honeybees and maintains the freshness of the royal jelly. It is capable of fighting gram-positive bacteria, viruses, and fungus. As a result, this molecule prevents illness in the beehive by keeping the food source safe. Interestingly, 10-HDA is also valuable in medicine because of its ability to fight pathogens. It stimulates the production of antibodies and is frequently included in nutritional supplements

Kodai, T.; Nakatani, T.; Noda, N. The Absolute Configurations of Hydroxy Fatty Acids from the Royal Jelly of Honeybees (Apis mellifera). AOCS. 2010, 46, 263-270.

Royal Jelly. Guarantee 10-HAD. (accessed Nov 12, 2011). .

From Laura Baker: Alpha titanium has a hexagonal close packed (hcp) lattice structure while beta titanium has a body centered cubic (bcc) lattice structure. In the hcp lattice structure, there are three layers of atoms. In the bottom layer and top layer, six titanium atoms are arranged in a hexagon shape with one atom in the center. In the middle layer, there are three titanium atoms that are situated in the gaps. In the bcc lattice structure, the titanium atoms are at eight corners of a cube and then there is one central titanium atom. This is the high temperature form of the titanium metal. The beta phase forms when the temperature is above 883 °C. The bcc structure does not allow the atoms to pack together as closely as the hcp structure; it is more loosely packed. The packing factor of the bcc structure is .68, while the packing factor of the hcp structure is .74. This information is in agreement with the video, which says that the alpha phase is stiffer than the beta phase of titanium. Stiffness is important in bone transplant considerations because bones have to be both flexible and strong.

NDT Resource Center. Primary Metallic Crystalline Structures. (accessed Oct 23, 2011).

From Duanpeng (Roy) Ma: Nicotine is a well-known component of cigarettes, and nicotine addiction has been cited as one of the primary reasons why quitting cigarette smoking is difficult for many smokers. Many of the products that are sold as nicotine substitutes or smoking cessation aids, such as Fluoxetine Hydrochloride (also known as Prozac), and electronic cigarettes, have not been FDA approved. These products often have been known to have their own harmful side effects, and the companies that produce them often provide inaccurate information regarding the components of their product and health hazards involved in consumption.These non-FDA approved products are likely not safer for consumption than nicotine, because their adverse effects are still being researched, and they do often do not follow strict FDA regulations.

Trehy, M. L.; Ye, W.; Hadwiger, M. E.; Moore, T. W.; Allgire, J. F.; Woodruff, J. T.; Ahadi, S. S.; Black, J. C.; Westenberger, B. J. J. Liq. Chromatogr. Relat. Technol. 2011, 34, 1442-1458

Di, X.; Zhao, B.; Zhongguo Yancao Xuebao. 2011, 17, 71-77

From Laura Baker: This molecule is called Bisphenol A, or BPA. It is used in polycarbonate plastics and epoxy resins. BPA can be dangerous at high levels because it acts as an endocrine disruptor and can mimic the body's hormones. This can cause large imbalances that lead to health problems, especially in early development. Research shows that BPA might contribute to cardiovascular disease, decreases in fertility, and some cancers.

Polypropylene, Polyethylene Terephthalate (PET), and High Density Polyethylene (HDPE) are all plastics that can be used as replacements for BPA. Polypropylene is a widely spreading alternative because it can be used to create re-usable containers. HDPE is not known to leach any suspected carcinogenic or hormone disrupting chemicals. PET is safe for one time use, but refilling a PET bottle might increase the possibility of chemicals leaching into the water. The plastic alternatives are not known to pose any major health risks, but more research is needed. Two additional alternatives for BPA bottles are aluminum and stainless steel. Stainless steel would be the best alternative, since it is known to be safe and it does not require a lining, unlike aluminum. An alternative for the BPA-containing sealants of canned foods and drinks is a lining made from the oil and resin extracted from plants.

Bounce Energy. The Dangers of BPA. (accessed Oct. 2, 2011).

National Institute of Environmental Health Sciences. Bisphenol A (BPA). (accessed Oct. 2, 2011).

Oregon Environmental Council. Safer Alternatives to Bisphenol A (BPA). (accessed Oct. 2, 2011).

Live Science. Are BPA-Free Plastics Really Safe? (accessed Oct. 2, 2011).

I

From Emily Tonks: The first molecule is oxybenzone and the second is known as an avobenzone. Both compounds can be used as sunscreen. Oxybenzone is the more effective sunscreen, however, because it protects against two types of UV light, UVB and UVA II, while the avobenzone only protects against UVA I radiation. Avobenzone's region of absorbtion also includes some rays of visible light which are not malignant to the integumentary system. The oxybenzone has also been proven safe for application to the human skin, while avobenzones are only just beginning to be marketed as sunscreens, and there are some concerns about their photostability.

Roscher, N.M.; Lindemann, M.K.O.; Kong, S.B.; Cho, C.G.; Jiang, P. J. Photochem. Photobiol. A: Chem,1994, 80, 417-421.

Juan, S.R.; Santiago, N.; Francisco, M.O.; Ricardo, M.; Adaya, G.S. 3-Dialkylaminophenyl 2-Alkoxycarbonylbenzoic Compounds. European Patent Office. 2010.

From Triet Nguyen: This molecule belongs to a group of compounds called iso-alpha-acids that contribute to the bitter taste of beer, infamously known as skunking. As the beer ages, the iso-alpha-acids degrade and release a long-lasting, volatile aftertaste. This means that fresher beer is more likely to have a desirable bitter taste without the harsh aftertaste. In order to keep degradation of iso-alpha-acids low, the beer's pH level should be kept constant with its temperature as low as possible. Therefore, you should get fresh beer and store it on a cold place immediately so that it doesn't skunk.

Intelmann, D.; Haseleu, G.; Dunkel, A.; Lagemann, A.; Stephan, A.; Hofmann, T. J. Agric. Food Chem., 2011, 59 (5), pp 1939–1953.

Vitamin D promotes calcium absorption in the gut, thus helping the body maintaining calcium and phosphate concentrations. Some have also suggested that vitamin D is essential for preventing various types of cancer, high blood pressure, cardiovascular disease, and immune system abnormalities, but no real strong evidence exists.

Adults need about 600 International Units (IU) of vitamin D per day. Most of this can be obtained through exposure to the sun; three 10-15 minute sessions of full sun exposure per week is sufficient. Experts also recommend eating natural sources of vitamin D (e.g. dairy products, egg yolks, fatty fish, lean meats).

Office of Dietary Supplements, National Institutes of Health's Dietary Supplement Fact Sheet: Vitamin D. (accessed Sep 12, 2011).

Congratulations to Arslan Zahid, winner of this week's chocolate!

Nylon 6,6 is produce from the following reaction:

Congratulations to Sarah Heuer, winner of this week's chocolate!

2,4,6-trinitrotoluene, or TNT, is the yellow-colored solid with the following spectral data:

     Molecular formula: C₇H₅N₃O₆

     IR: strong peaks at 1350 and 1530 cm^-1

     ¹H-NMR: singlet @ δ ~1 ppm (3H)
                   singlet @ δ ~7 ppm (2H)

Note: The spectral data does not uniquely identify this as TNT; an alternative assignment is 3,4,5-trinitrotoluene. Do you think this particular compound is also yellow?

In early 2009, the FDA approved a new zero-calorie sweetner developed by Coca-Cola and the agribusiness giant Cargill. You may have recently seen commercials for it; it's marketed as Truvia. Truvia is composed of erythritol and a component from a small herb plant called stevia. Some research has been done on the safety of erythritol but relatively little is known about the strevia component. Identify this second component in Truvia and discuss whether you think it is safe for consumption based on current research. The research you cite must be peer-reviewed (i.e. from a scientific journal and not a website. Be careful what you believe because Coca-Cola sponsored much of the research out there.)

There are a couple of candidates for the chemical with the longest name in most shampoos: methylchloroisothiazolinone (left) and guar hydroxyproplytrimonium chloride (not pictured and much more complicated!). Methylchloroisothiazolinone is added to shampoo as a preservative and anti-bacterial/anti-fungal. It is added to other comsmetic products for these same properties. The guar compound primarily acts as a conditioner to reduce tangling.

Congratulations to Dianne Cheon, winner of this week's chocolate!

In 1973, Walter Morris published a paper containing high-resolution infrared (IR) specta of 99 fragrance and flavor compounds. Cuminaldehyde, eugenol, and carvone— components of the essential oils we'll explore later in the semester—were included. The reference is below. (Note that the title of the article is not included in the reference.)

Morris, W. W. J. Assoc. Off. Anal. Chem. 1973, 56, 1037-1064.

Congratulations to Mackenzie Long, winner of this week's chocolate!

Avobenzone is an oil soluble substance used in sunscreens. Its absorption max is at 357 nm, but is it considered a broad spectrum UV protectant because of its ability to absorb a wide range of UV light. Unfortunately, it degrades rather quickly. And, avobenzone binds with iron, causing it to stain skin and clothes. What's in your sunscreen?

Congratulations to Noaa Spiekermann, winner of this week's chocolate!

One of the Journal of the American Chemical Society articles we looked at this week in class was authored by William Jones. In a 1997 article I published with Prof. Jones, I predicted the structure of (C₅Me₅)Rh(PMe₃)(η²-C,S-C₄H₂S) using computational chemistry which he later confirmed in the laboratory. The structure of the molecule is shown on the left and the complete and accruate citation to the article is:

Blonski, C.; Myers, A.W.; Palmer, M.; Harris, S.; Jones, W.D. Organometallics. 1997, 16, 3819-3827.

Congratulations to Jonathan Torre, winner of this week's chocolate!

Fluticasone priopionate (pictured) is mixed with salmeterol xinafoate (C₂₅H₃₇NO₄) to make Advair, which is commonly prescribed for asthma.

Congratulations to Hyeon Jin Lee, the first to identify this week's mystery molecule!

Though it has many unique properties and uses, theobromine is most well known for its mild stimulant effects and the slightly bitter taste it imparts on chocolate.

Congratulations to Anne Knisely & Dylan Holt, the first to identify this week's mystery molecule!