The Alchemist Newsletter: June 8, 2010

An old marine alkaloid may find new use in metastatic pancreatic cancer, bitter blockers could be just the thing for nasty-tasting Brussels sprouts, and lotus seed skins offer hope for a food waste product. Also in this week's Alchemist, screening crops for cyanide, gas reactions in crystal lattices, and an award for cellular insights.

back to top

New use for old drug

Manzamine A, an alkaloid isolated from a marine sponge, could find new use in treating pancreatic cancer that has spread to other parts of the body, metastasized, according to a study in the journal Investigational New Drugs. Pancreatic cancer is the fourth biggest cancer killer in the US and is highly susceptible to metastasis. It is also resistant to many conventional drugs that usually trigger cell death, apoptosis, to defeat cancer. As such, researchers are keen to find small molecules that could restore sensitivity to apoptosis or reduce metastasis. Researchers at Florida Atlantic University have turned to a natural product, manzamine A, and demonstrated activity in blocking tumor cell invasion. Moreover, they found it also restores susceptibility to apoptosis in the laboratory and so may lead to a new adjuvant treatment for existing cancer therapies.

A novel activity from an old compound: Manzamine A reduces the metastatic potential of AsPC-1 pancreatic cancer cells and sensitizes them to TRAIL-induced apoptosis

back to top

Bitter blockers

Artificial sweeteners are common enough, but bitter blockers are only recently emerging from the laboratory. Salt, sodium chloride is now known to enhance the taste of food by inhibiting various bitterness receptors (of which there are dozens) on the tongue. Monosodium glutamate has a similar action, endowing food with "umami" (deliciousness). Linguagen patented adenosine monophosphate (AMP) as a bitter blocker in 2003 and received regulatory approval a year later. Now, Givaudan Flavors Corporation of Cincinnati reports in the journal Current Biology a compound codenamed GIV3727 that defeats 400 million years of evolutionary protection against ingesting noxious or toxic foods to switch off the tongue's bitter receptors. Major food manufacturers are investigating how to incorporate bitter blockers into products that might otherwise taste off-putting.

Edible Synthetic Blocks Bitter Taste

back to top

Lotus eaters

Lotus seed skins, discarded in vast numbers across Asia, contain high levels of antioxidant flavonols and so have potential as a nutraceutical source.

The epicarp of lotus seeds is a big waste product from the use of lotus in cuisine across Asia. Now, researchers at the Huazhong Agricultural University, Wuhan, have discovered that the epicarp, or husk, of Nelumbo nucifera Gaertn. (FSENN) contains high levels of antioxidant flavonols. The epicarp could thus be converted from waste to nutraceutical source in a single step. The researchers have identified six glycosylated flavonols in a fraction from an extract of FSENN and one aglycone flavonol. They also determined flavonol aglycones, myricetin, quercetin, kaempferol and isorhamnetin in the fractions, which then also demonstrated potent antioxidant activity in standard tests.

Flavonols of lotus (Nelumbo nucifera, Gaertn.) seed epicarp and their antioxidant potential

back to top

Cyanide crop screening

A fast and efficient way to look for less toxic forms of common African crop plants, such as cassava, is being developed by European scientists. Some plants naturally release hydrogen cyanide when damaged so finding a way to quickly screen novel strains of crop plants that might produce less toxin is important in the search for ways to cope with food security in sub-Saharan Africa and tropical regions. Many food crops, such as cassava, also release cyanide and so require complicated preparation and cooking before they are rendered edible. Now, researchers at the John Innes Centre in Norwich, UK, working with colleagues in Denmark, have developed a high-throughput screening method that can identify strains of the model legume, Lotus japonicas that are deficient in the biochemical apparatus of cyanogenesis. The finding could point to ways to engineer or breed novel strains of crop plants that are less cyanogenic.

New screen for safer food crops

back to top

Crystal gas

US researchers have developed crystals of an iridium complex containing bonded dinitrogen that can undergo a reaction as other gases, such as hydrogen or ammonia diffuse through the lattice. The materials have great potential as novel reaction systems. For instance, they can catalyze ethene hydrogenation selectively even in the presence of larger molecules such as propene as these cannot enter the crystalline lattice. While these novel materials may have utility in the laboratory, designing customized versions of the crystals for industrial applications will remain a significant challenge.

Reactions in a crystal

back to top

Cellular work wins award

Chemical biologist Carolyn Bertozzi has found ways to manipulate processes within living cells and to engineer their surfaces and secreted proteins. For this pioneering research, which is internationally renowned and widely applicable in biotechnology and the pharmaceutical industry, she has been awarded the prestigious 2010 $500,000 Lemelson-MIT Prize. Bertozzi will receive the prize and present her accomplishments to the public at MIT during the Lemelson-MIT Program's fourth-annual EurekaFest, a multi-day celebration of the inventive spirit, in mid-June.

Chemical biologist and entrepreneur Carolyn Bertozzi awarded $500,000 Lemelson-MIT Prize

back to top