Award details

To identify antipest agents for the development of pest control especially against resistant organisms

Reference	BBS/E/C/00051562
Principal Investigator / Supervisor	Dr Bhupinder Pall Singh Khambay
Co-Investigators / Co-Supervisors
Institution	Rothamsted Research
Department	Rothamsted Research Department
Funding type	Research
Value (£)	149,559
Status	Completed
Type	Institute Project
Start date	01/04/1997
End date	31/03/1999
Duration	24 months

Abstract

This project is aimed at identifying and assessing natural bioactive molecules for control of pests, especially in agricultural. Bioactive molecule are sought from three distinct areas: A network of collaborators from all over the world is being established to obtain plant extracts which are tested for pesticidal activity (RO 0515234). In appropiate cases, chemotaxonomy studies are conducted in collaboration with the Jodrell Laboratory at Kew and analogues are synthesised to establish structure-activity relationships (RO 051532). Some invertebrate mycopathogens, eg Metarhizium, are known to produce toxins which may play a crucial role during pathogenesis and provide a good source for novel and possibly selective crop protection agents. However, these toxins (eg the destruxins) are mostly peptidic in nature and consequently their use as practical pest control agents is limited by poor persistence and cuticle penetration, and cost of synthesis. These issues are investigated in RO 051535. This project involves and builds on the extensive background and experience in PU 210. Some insects produce toxins that deter predators. These too provide a good source of lead structures, however, their structures are often amino acid based and require similar considerations to those mentioned above. Even less is known about the mode of action of this small number of reported compounds and as such they provide a challenge in both chemical and biological evaluation. (Also see RO 051535). 5 All three projects require an interdisciplinary approach. Extensive efforts are directed towards efficient isolation, characterisation and synthesis of active constituents. 1. Bioactive molecules will be isolated and characterised using bioassay- directed (RO051534) chromatographic fractionation and spectroscopic techniques. In appropriate cases, SAR programmes will be initiated and external funding sought for this purpose. A dosage transfer problem recognised for a highly active natural product we isolated recently, highlights the dependence of biological efficacy on physical properties. Formulation technology and/or structural varitation will be exploited to modify transfer behaviour. 2. Work on insect mycopathogens was initiated in late 1995. Initial effort will be concentrated on detection, isolation and biological evaluation of toxins. Influence of culture conditions and diversity in fungal species will be evaluated in collaboration with PU's 208 and 209. Synthesis destruxin analogues will continue. 3. A known dipeptide toxin, originally isolated from the defence glands of the colorado beetle, will be synthesised and methods to assess biological activity will be developed. In a collaborative project (PU 236) a programme to isolate and characterise toxins from 7-spot and 2-spot ladybirds (Coccinella septeupunctata and Adalia bipunctata respectively) will be initiated. 1. Initiate collaboration with South African and Cuban institutes. 2. Identify pesticidal compounds from plants, especially Calceolaria andina, and microbial metabolities. 3. Continue to in vestigate reasons for the poor in-vivo insecticidal activity of naphthoquinones. 4. Evaluate fungicidal activity of the natural naphthoquinones, and some synthetic analogues (alrea in both in-vivo and in-vitro assays. 5. Separate additional quantities of efrapeptins to enable a fuller evaluation of their insecticidal activity. 6. Co mplete the synthesis and prelimanary bioassay evaluation of the Colorado beetle dipeptide. 7. Complete the synthesis and prelimanary bioassay evaluation of the an adenine based ami NK374200. 8. Evaluate the insecticidal activity of the active component isolated from the total extract of Adalia bipunctata (two spotted ladybird) in PU 236 (BBRSC/ROPA award). 9. Identify nematocidal compounds culture of nematophgous fungi. 10. Identify insecticidal component(s) from termites, Schedorh Berman colleagues.

Summary

unavailable

Committee	Closed Committee - Animal Sciences (AS)
Research Topics	X – not assigned to a current Research Topic
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

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