Discovery of sarolaner: A novel, orally administered, broad-spectrum, isoxazoline ectoparasiticide for dogs.

The novel isoxazoline ectoparasiticide, sarolaner, was identified during a lead optimization program for an orally-active compound with efficacy against fleas and ticks on dogs. The aim of the discovery program was to identify a novel isoxazoline specifically for use in companion animals, beginning with de novo synthesis in the Zoetis research laboratories. The sarolaner molecule has unique structural features important for its potency and pharmacokinetic (PK) properties, including spiroazetidine and sulfone moieties.

Design and synthesis of sarolaner, a novel, once-a-month, oral isoxazoline for the control of fleas and ticks on dogs.

Over the last decade, the isoxazoline motif has become the intense focus of crop protection and animal health companies in their search for novel pesticides and ectoparasiticides. Herein we report the discovery of sarolaner, a proprietary, optimized-for-animal health use isoxazoline, for once-a-month oral treatment of flea and tick infestation on dogs.

The discovery of isoxazoline oxime ethers as a new class of ectoparasiticides for the control of Haematobia irritans (horn fly) in cattle.

Haematobia irritans (horn fly) infestation in cattle is responsible for over a billion dollars a year in global economic loss due to decreased milk production and lower feed conversion. There is significant need for new insecticidal agents since current treatments such as organophosphates and pyrethroids suffer from field resistance. Isoxazoline oxime ethers represent a new class of γ-aminobutyric acid (GABA) receptor channel blockers which show good activity (LD(90) = 1.

Synthesis of a cyclic peptide containing norlanthionine: effect of the thioether bridge on peptide conformation.

Two diastereomeric analogues of ring C of nisin incorporating a novel norlanthionine residue have been synthesized via a triply orthogonal protecting group strategy. A full structural study was carried out by NMR, which elucidated the conformational properties of the two peptides and enabled the identity of each diastereoisomer to be proposed.

Synthesis of orthogonally protected lanthionines.

Synthetic approaches to the lantibiotics, a family of thioether-bridged antimicrobial peptides, require flexible synthetic routes to a variety of orthogonally protected derivatives of lanthionine 1. The most direct approaches to lanthionine involve the reaction of cysteine with an alanyl beta-cation equivalent. Several possibilities exist for the alanyl beta-cation equivalent, including direct activation of serine under Mitsunobu conditions: however, the low reactivity of sulfur nucleophiles in the Mitsunobu reaction has previously precluded its use in the synthesis of the lantibiotics.