title: Thioesters for the in vitro evaluation of agents to image brain cholinesterases.
abstract: Cholinesterases are associated with pathology characteristic of conditions such as Alzheimer's disease and are therefore, considered targets for neuroimaging. Ester derivatives of N-methylpiperidinol are promising potential imaging agents; however, methodology is lacking for evaluating these compounds in vitro. Here, we report the synthesis and evaluation of a series of N-methylpiperidinyl thioesters, possessing comparable properties to their corresponding esters, which can be directly evaluated for cholinesterase kinetics and histochemical distribution in human brain tissue. N-methylpiperidinyl esters and thioesters were synthesized and they demonstrated comparable cholinesterase kinetics. Furthermore, thioesters were capable, using histochemical method, to visualize cholinesterase activity in human brain tissue. N-methylpiperidinyl thioesters can be rapidly evaluated for cholinesterase kinetics and visualization of enzyme distribution in brain tissue which may facilitate development of cholinesterase imaging agents for application to conditions such as Alzheimer's disease.
authors.affiliation: Department of Anatomy & Neurobiology and the Neuroscience Institute, Dalhousie University, Halifax, Nova Scotia, Canada, B3H 4R2.
authors.forename: Ian R
authors.initials: IR
authors.lastname: Macdonald
authors.forename: Courtney T
authors.initials: CT
authors.lastname: Jollymore
authors.forename: G Andrew
authors.initials: GA
authors.lastname: Reid
authors.forename: Ian R
authors.initials: IR
authors.lastname: Pottie
authors.forename: Earl
authors.initials: E
authors.lastname: Martin
authors.forename: Sultan
authors.initials: S
authors.lastname: Darvesh
mesh_terms: D000369:Aged, 80 and over; D001921:Brain / Q000201:enzymology*; D060326:Chemistry Techniques, Synthetic; D002802:Cholinesterases / Q000032:analysis* / Q000378:metabolism; D004952:Esters / Q000737:chemistry*; D005260:Female; D006801:Humans; D006868:Hydrolysis; D007700:Kinetics; D015394:Molecular Structure; D059906:Neuroimaging / Q000379:methods*
chemical_list: D004952:Esters; D002802:Cholinesterases