Deadly Carcinogen Unraveled

May 4, 2010
3-D chemical structure of an aflatoxin molecule. Image: Wikimedia Commons

( -- Using the bright X-ray beam of the Stanford Synchrotron Radiation Lightsource, researchers have unveiled the mystery behind one of the deadliest toxins that causes liver cancer.

Aflatoxins are common contaminants of foods such as nuts and grains, which make up staple diets in many developing countries. These toxins are produced by mold and other fungi during food production, and are considered by the U.S. Food and Drug Administration to be an unavoidable food contaminant. Aflatoxin molecules are characterized by the presence of multiple aromatic rings. Chronic ingestion of one type of aflatoxin leads to liver tumors that are a major cause of death in Asia, Africa, and Central America.

This toxin wreaks havoc on an important gene that prevents cancer. Without the protective effect of this gene, aflatoxin further compromises immunity, interferes with body metabolism, and causes severe malnutrition. It is urgently important to find inexpensive strategies that help protect the world population from aflatoxin food contamination.

A group led by researcher Sheryl Tsai of the University of California at Irvine, in collaboration with the Townsend lab of The Johns Hopkins University, trained SSRL's X-ray beam on a crystallized enzyme in the polyketide synthase family, which is a component of the multi-step process of toxin synthesis. The researchers were able to determine the three-dimensional structures of a region responsible for producing a precursor of the toxin.

When analyzed in light of the biochemical data, these structures revealed for the first time how the region folds an incoming linear carbon chain called a polyketide to form two aflatoxin rings in an amazing feat of origami.

The researchers propose that understanding how is made will lead to ways in which people can reduce prevalence of the and drastically reduce terminal illness in developing countries.

Explore further: Fungus fight: Researchers battle against dangerous corn toxin

More information:

Related Stories

Fungus fight: Researchers battle against dangerous corn toxin

April 8, 2008

The spiraling use of corn for food and fuel is creating heightened concerns about contamination of this staple crop with deadly aflatoxin. Produced by certain fungi that grow on corn, this contaminant is a known human carcinogen ...

Hardy New Corn Lines Released

October 16, 2009

( -- Six new inbred maize lines with resistance to aflatoxin contamination have now been registered in the United States by the Agricultural Research Service (ARS). ARS plant pathologist Robert Brown and colleague ...

Trigger of deadly food toxin discovered

October 21, 2009

( -- A toxin produced by mold on nuts and grains can cause liver cancer if consumed in large quantities. UC Irvine researchers for the first time have discovered what triggers the toxin to form, which could lead ...

Chlorophylls effective against aflatoxin

December 29, 2009

A new study has found that chlorophyll and its derivative chlorophyllin are effective in limiting the absorption of aflatoxin in humans. Aflatoxin is produced by a fungus that is a contaminant of grains including corn, peanuts ...

Recommended for you

Scientists create revolutionary material to clean oil spills

November 30, 2015

Deakin University scientists have manufactured a revolutionary material that can clean up oil spills, which could save the earth from potential future disasters such as any repeat of the 2010 Gulf Coast BP disaster that wreaked ...

A new form of real gold, almost as light as air

November 25, 2015

Researchers at ETH Zurich have created a new type of foam made of real gold. It is the lightest form ever produced of the precious metal: a thousand times lighter than its conventional form and yet it is nearly impossible ...


Adjust slider to filter visible comments by rank

Display comments: newest first

not rated yet May 04, 2010
All of the nuts and grains we ingest contain this Aflatoxin?
not rated yet May 05, 2010
refer: masterqmr
Yes, ALL processed nuts contain this aflatoxin though in varying degrees.
The best way to protect yourself (and still enjoy nuts) is to only eat nuts that still have their original God-designed shells and or outer coverings around them, i.e. eat the nuts raw. Watch out for nuts that have obvious signs of mold or that you suspect got wet or damaged. For nuts removed from shells but not their skins, watch out for damaged ones where the flesh is exposed - cut it off. Wash the nuts in their skins before eating.
Just 2B cynical: "Evolution" is not going to help protect anyone in this case.
not rated yet May 05, 2010
All of the nuts and grains we ingest contain this Aflatoxin?

It seems that way, whether processed or not. Unless you eat large large quantities most every day it seems to not be a problem and of course raw or not, watch out for nuts that just don't look quite right.
not rated yet May 10, 2010
So, God gets credit for shells, but not for toxins, molds or cancer...that makes sense, sure it does. Not.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.