Phytotoxic cyclic peptides

Fungi and bacteria produce various phytotoxic cyclic peptides using nonribosomal peptide synthetase (NRPS).308 Similar to modular organization of PKS, NRPS consists of several modules containing condensation (C), adenylation (A), and thiolation (T) domains. 

The use of biologically derived chemicals as herbicides has met with limited success. Despite this, biotechnology offers potential for the exploration of naturally occurring compounds as herbicides, which may serve as impetus for new synthetic and structure/function approaches in herbicide developement (1). In this regard we have implemented a program to study biologically active peptides from plants and fungi. Specifically, we focused on phytotoxic cyclic... 

We focus here on an approach in which synthetic fragments of a naturally occurring cyclic peptide such as tentoxin can be studied as a model for conformationally rigid peptide phytotoxins and for their potential by selective herbicidal activity. Our initial studies include the following steps 1) Screen synthetic intermediates for phytotoxicity in plants sensitive to tentoxin. 

Synthetic peptide analogs derived from the phytotoxin tentoxin, have been examined for their phytotoxicity and herbicidal potential to a variety of plants and agronomically significant weeds. Structurally modified analogs included both cyclic and acyclic derivatives. 

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