New Prospects for an All-Around Spice

People use anise to add a hint of licorice to everything from holiday springerle cookies to robust bottles of ouzo and raki. Now Agricultural Research Service (ARS) postdoctoral scientist Nurhayat Tabanca and plant pathologist David Wedge have found that anise (Pimpinella sp.) is more than just another jar in the spice rack.

Teaming up with colleagues in Mississippi and Turkey, they isolated 22 compounds in Pimpinella's essential oils and found high levels of organic mixtures called phenylpropanoids. Phenylpropanoids are found in a wide variety of plants, and some are thought to have health-boosting benefits.

However, the chemical structure and biological activity of the Pimpinella phenylpropanoids are unique. Some phenylpropanoid compounds the team found have only been found in Pimpinella, and four of the compounds they isolated had never before been identified in any plant.

The compounds were evaluated for their activities against the plant fungus Colletotrichum, which causes anthracnose diseases worldwide. One unique compound was especially effective against strawberry anthracnose and strawberry soft rot and leaf blight. In addition, Pimpinella isaurica essential oils were more effective in controlling aphids than isolated Pimpinella phenylpropanoids.

These compounds were also tested for their activity against various major and minor microbes. A few showed some effectiveness against Plasmodium falciparum, the parasite that causes malaria in humans, and Mycobacterium intracellulare, a bacterium which can cause illness in immunocompromised patients.

Some phenylpropanoids exhibited anti-inflammatory activities. Pimpinella essential oils also showed estrogenic effects in a yeast model and were considered to have phytoestrogen properties.

These results suggest that Pimpinella essential oils may be a source of potent compounds that could be used in developing powerful new pharmaceuticals and agrochemical agents.

Tabanca and Wedge work at the ARS Natural Products Utilization Research Laboratory in Oxford, Miss. Other researchers who contributed to this research include K. Husnu Can Baser and Nese Kirimer with Anadolu University in Eskisehir, Turkey; Erdal Bedir with Ege University in Izmir, Turkey; Ikhlas Khan and Shabana Khan from the University of Mississippi; and Blair Sampson, who works at the ARS Thad Cochran Southern Horticultural Laboratory in Poplarville, Miss.

ARS is the U.S. Department of Agriculture's chief scientific research agency.