BioMatNet Item: FAIR-CT96-1436 - Improvement of efficiency and reduction of application rates of preferable naturally grown biocides by complexing with gamma cyclodextrin

FAIR-CT96-1436
Improvement of efficiency and reduction of application rates of preferable naturally grown biocides by complexing with gamma cyclodextrin

Contacts
Further Information

	Type of Project	Shared Cost
	Contract No	FAIR-CT96-1436
	Total Cost	2,536,853 ECU
	EC Contribution	1,200,000 ECU
	Start Date	01/01/1997
	Duration	36 Months

Improvement of efficiency and reduction of application rates of preferable naturally grown biocides by complexation with gamma-cyclodextrin

Objectives

In accordance with the common agricultural policy concept towards new, less intensive production and application systems, which are not only environmentally friendly but are also economically viable, this project is using gamma-cyclodextrin as an auxiliary substance for biocides.

cyclodextrins (CD) are a unique group of cyclic glucose oligomers. They are biotechnologically produced from potato or maize starch. They are highly biodegradable. Up to now mainly beta-CD has been used for applications. Today however more favourable gamma-CD can be produced in necessary amounts for a reasonable price. The CD-complexation of biocides results in accelerated, enhanced biological activity. In the most cases the amount of active ingredient is significantly reduced.

Technical Approach

This project deals with:

Gamma-CD itself: the proposed application of gamma-CD to biocides includes treatment of crops and agricultural products and the registration of the active compounds. Authorities demand data on residues and the proof of toxicological safety. From all data necessary to indicate the toxicological profile of gamma-CD, reproduction toxicology and carcinogenicity studies remain to be conducted. They are an unavoidable part for the registration procedure, even these long-term toxicology studies are expected to show no risks.
The application of gamma-CD for complexation of the active ingredients scilliroside, a plant based rodenticide and pyrethrins, plant based insecticides and the application of gamma-CD for an extraction method of scilliroside from the naturally source, the red squill or sea onion Urginea maritima (L.) Baker, and an extraction method for pyrethrins from the natural sources, the flowers of Pyrethrum cinerariaefolium Trev. (chrysanthemum).

The rodenticide properties of Urginea maritima have been known for a long time. Scilliroside is the substance responsible for the toxicological effect on mice and rats. Gamma-CD complexation provides presumably rapid absorption and stability and masks the repellence of the active substance.

Gamma-CD-complexation of pyrethrins from natural sources includes and stabilises all the natural components of chrysanthemum. The aim is the protection of agricultural areas by using these gamma-CD biocide complexes against rodents and insects, expected to spread over new set aside land and agricultural products in stock.

Results to Date

The most important outcomes at present are the achieved complex formation (complexation) of the active ingredients scilliroside and pyrethrins with gamma-CD. A general model for the prediction of the complex formation behaviour of different substances and CD has also been developed. The preparation of highly pure standards and precise analytical methods for scilliroside and pyrethrins became possible. Up to now long time toxicity studies did not show any adverse effects of gamma-CD.

The bulb and flowers of red squill (Urginea maritima)

Semiempirical calculated structure of
scilliroside-gamma-CD association

Contacts

Coordinator

Diether POLHEIM / F Joh Kwizda GmbH, Agricultural Division Kwizda Agro / AUSTRIA

EC Scientific Officer

Ciarán MANGAN / European Commission - DG Research Quality of Life Programme - Unit B1.2 / BELGIUM

Participant