Speakers - Thiago André Moura Veiga

Type of the Presentation: (Short lecture)




Thiago André Moura Veiga


Department of Chemistry, Federal University of São Paulo; tveiga@unifesp.br


The development of weeds management practices is the need on control of weeds and pests, responsible for reducing the yield of food crops. The weeds compete for nutrients, water and space, being able to drain significantly the quality of crops 1. Although the pesticide industries developed a lot of synthetic herbicides to control weeds, exploring sundry of action mechanisms, the search is continuous for new herbicides more efficient, of wide spectrum, lower use rates and safe to crop and environment.

One of the strategies used to identify new models for chemicals to control weeds is about the exploration of natural products either directly as herbicides 2 or as leads for the development of new commercial products. The most isolated compounds from nature have not been evaluated for agrochemical purpose and for this reason this strategy is still very attractive. It is possible to enumerate many advantages of using natural products in programs to discovery new herbicides: reduced toxicity to non-target organisms, reduced persistence on the environment, usable in organic agriculture, low mammalian toxicity, safe for farm-workers and nearby residents, “green” technology, and non-restricted use 3.

In this sense, photosynthesis is certainly the main target for finding candidates for new herbicides. In this talk, we will emphasize the importance of natural products as electron transport chain on light reaction of photosynthesis inhibitors, at the donor and acceptor side of photosystem II. For elucidating the mechanisms of action of several natural products we have employed techniques as oximetry and fluorescence of chlorophyll a (ChL a) using chloroplasts isolated from spinach leaves as substrates on our reactions 4-6



1. Teixeira, R.R., et al (2012) Photosynthetic Inhibitors, Applied Photosynthesis. http://www.intechopen.com/books/applied-photosynthesis/photosynthetic-inhibitors

2. Copping, L.G. and Duke, S.O. Pest Management Science, 63, 524, 2007.

3. Seiber, J. N. et al. J. Agric. Food Chem. 62, 11613, 2014.

4. Ferreira, P. H. A. et al. Chem. & Biodiversity, 13, 100, 2016.

5. Carvalho, A. C. et al. Am. J. Plant Sci, 07, 1545, 2016.

6. Sampaio, O. M. et al. Pest. Biochem. Physiol., 134, 55, 2016.