The Mystery Molecule Page: 2006

DECEMBER

In the new film “Casino Royale”, James Bond found this molecule stirred into his martini and it left him shaken. Can you guess what it is?

 

Digoxin
Actually, the incredible point-of-care device in his car’s glove compartment detects “digitalis”, the general term for cardiac glycosides derived from the foxglove plant (including digoxin, digitoxin and deslanoside). These have minor differences in either the steroid structure (in red) or the triple-sugar group attached (in green). Bond’s cardiac toxicity was quickly reversed by a defibrillator and an injection of antibody to digoxin, both also found in that handy glove compartment.

NOVEMBER

Researchers tells us that a glass filled with this molecule may help counteract the caloric effects of your Thanksgiving feast. Can you guess what it is?

 

Resveratrol

Not only did this new drug reverse the effects of obesity in mice but another independent study last month also showed that it could increase their endurance as well. It appears to influence a series of mitochondrial enzymes that prolong a cell’s life. The glass would have to be quite huge, however, as the doses of resveratrol associated with the observed effects exceeded the amounts found in red wine to a large degree.

OCTOBER

Dr. Alan Wu described how this molecule caused serotonin syndrome at the Northern CA AACC meeting last month. Can you guess what it is?

 

Meperidine
Serotonin syndrome (altered mental status, autonomic instability and neuromuscular abnormalities) can occur if a patient already receiving a drug that increases serotonin levels in the brain (such as some anti-depressants) is given another. Meperidine (an opioid analgesic) given to such a patient by an emergency physician for pain produced the syndrome in the “Clinical Chemistry CSI” case described by Dr. Wu.

 

SEPTEMBER

Floyd Landis probably wishes there had been more of this molecule in his urine specimen last month. Can you guess what it is?

 

 

 

Epitestosterone

This steroid has no biological function but it is synthesized along with testosterone. The drug testing at the Tour de France looked at the ratio of testosterone to epitestosterone. A high ratio (such as was found in Mr. Landis’s urine) indicates probable exogenous administration of testosterone.

 

AUGUST 

A molecule cloned from these fish found in the Arctic Ocean may keep your ice cream creamy on hot August days. Can you guess what it is?

 

 

 

Ice-Structuring Protein

Manufacturers fo low-fat ice cream need to use alternative ingredients to mimic the creamy texture of “real” ice cream. The FDA recently approved the use of a protein found in these fish (the ocean pout, an eel-like fish that lives in the Arctic Ocean) that prevents ice crystals from growing. Ice cream makers will be using a recombinant version so, don’t worry, the ice cream won’t taste “fishy”. Hope you all had a “cool” summer!

 

 

JULY 

This molecule was studied in the 1960s by Dr. Joseph Schildkraut, a psychiatrist who died last month, and his results helped us to understand the chemistry of mental illness. Can you guess what it is?

Norepinephrine
Although we primarily think of this catecholamine as a messenger at peripheral nerve endings, it (and epinephrine) also functions as a neurotransmitter in the central nervous system. Dr. Schildkraut’s studies of norepinephrine in patients before and after treatment with anti-depressants in the 1960s help spur intense investigation into the biochemical basis of depression.

JUNE 

This molecule reacts with iron and changes color. Can you guess what it is? 


 

Ferrozine
Serum iron assays require a decrease in pH (to release ferric iron atoms from transferrin, the transport protein) and reduction of the ferric iron to ferrous iron. Each of the reduced iron atoms are then capable of being complexed by three ferrozine molecules. These complexes have a high absorbance at 562 nm. 

 

MAY 

This molecule was at the center of one of the cases heard by the Supreme Court this year. Can you guess what it is?

Homocysteine
Well-known as a marker of cardiac disease, elevated levels of homocysteine (a sulfur-containing amino acid formed during methionine metabolism) may also be associated with vitamin B12 deficiency. This later association has been patented and the patent challenge was heard by the Supreme Court in March; look for their decision soon.

APRIL

This molecule is commonly measured in the clinical laboratory and will be the subject of our local meeting this month. Can you guess what it is?

TSH (Thyrotropin)
The alpha chain (pink to the left) is the same for all of the pituitary glycoprotein hormones but the beta chain (green to the right) confers specificity for the TSH receptor on the surface of thyroid epithelial cells. Dr. Carole Spencer discussed the implications of the proposed new reference range for TSH at our April local meeting.

MARCH

A recent study indicates that calcium supplements may not allow many women to avoid using this molecule (or a related one) when they get older. Can you guess what it is?

Bisphosphonate
This is the basic structure of the class of drugs called bisphosphonates (synthetic analogues of pyrophosphate). They inhibit bone resorption, possibly by poisoning osteoclasts (the cells that remove calcium as they dissolve the bone matrix). Some bisphosphonates are used to treat osteoporosis, a condition which recent results of the Women’s Health Initiative indicate may not be avoided by taking calcium supplements.

FEBRUARY

Dr. John Sherwin, AACC’s new president, recently spoke at our local meeting and discussed new approaches to neonatal screening using tandem MS, including a new way to measure this molecule. Can you guess what it is?

Phenylalanine
Newborn screening began with the detection of elevated levels of phenyalanine in the disorder phenylketonuria (PKU) because enzymatic conversion to tyrosine is blocked. Patients must avoid phenylalanine in their diet. The use of tandem MS (as opposed to the traditional chemical method) allows simultaneous measurement of tyrosine (and determination of the ratio of the two amino acids).

 

JANUARY

This molecule is currently at the center of a worldwide obsession and may be produced illegally by many countries. Can you guess what it is?

Oseltamivir (Tamiflu ®)
Neuraminidase helps newly formed influenza viruses release themselves from the infected host cell. Neuraminidase inhibitors such as oseltamivir prevent this from happening (and lessen the severity of the infection). Newer drugs such as oseltamivir have less viral resistance than older neuraminidase inhibitors and have been targeted as important resources in the event of a pandemic. The original molecule image lacked the double-bound in the central ring; thanks to Dr. Z. Herman for pointing this out!

 

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