Figure 1. General structure of the<unk> s produced in grasses infected by fungi of the Epichloë/Neotyphodium complex (epichloae endophytes); R' and R denote variable substituents that can include methyl, formyl, and acetyl groups giving rise to different<unk>  species. A<unk>  is a member of the 1-aminopyrrolizidines (often referred to as<unk> s), which are bioactive natural products with several distinct biological and chemical features. The<unk> s are insecticidal and insect-deterrent compounds that are produced in grasses infected by endophytic fungal symbionts of the genus Epichloë (anamorph species: Neotyphodium).<unk> s increase resistance of endophyte-infected grasses to insect herbivores, and may also protect the infected plants from environmental stresses such as drought and spatial competition. They are<unk> s, organic compounds containing basic nitrogen atoms. The basic chemical structure of the<unk> s comprises a saturated pyrrolizidine ring, a primary amine at the C-1 carbon, and an internal ether bridge—a hallmark feature of the<unk> s, which is uncommon in organic compounds—joining two distant ring (C-2 and C-7) carbons (see Fig. 1). Different substituents at the C-1 amine, such as methyl, formyl, and acetyl groups, yield<unk>  species that have variable bioactivity against insects. Besides endophyte–grass symbionts,<unk> s have also been identified in some other plant species; namely, Adenocarpus species (family Fabaceae) and Argyreia mollis (family Convolvulaceae).
Loline alkaloid
Alkylphenol
Biogenic amine
Polychlorinated naphthalene
Polycyclic aromatic hydrocarbon
Organobromine compound
Alcohols 
Organophosphate