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Isomeric Co(ii) paraCEST agents as pH responsive MRI probes.

ABSTRACT: A newly discovered isomer of Co(ii) (1,4,8,11-tetrakis(carbamoylmethyl)-1,4,8,11-tetraazacyclotetradecane = CCRM) produces four highly paramagnetically shifted chemical exchange saturation transfer (CEST) peaks. The 1,8-pendants of the complex are bound in a trans-arrangement to produce a Co(ii) complex of increased kinetic inertness. The isomers have a stabilized Co(ii) center (E1/2 of 540 to 550 mV versus SHE). Both the 1,8 and the 1,4-isomer are excellent pH probes in solution and in tissue homogenate by virtue of their highly paramagnetically shifted amide protons. These isomers produce both a ratiometric pH readout as well as amide proton exchange rate constants that correlate to pH.

SUBMITTER: Bond CJ

PROVIDER: S-EPMC6988567 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature

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Isomeric Co(ii) paraCEST agents as pH responsive MRI probes.

Bond Christopher J CJ Cineus Roy R Nazarenko Alexander Y AY Spernyak Joseph A JA Morrow Janet R JR

Dalton transactions (Cambridge, England : 2003) 20200101 2

A newly discovered isomer of Co(ii) (1,4,8,11-tetrakis(carbamoylmethyl)-1,4,8,11-tetraazacyclotetradecane = CCRM) produces four highly paramagnetically shifted chemical exchange saturation transfer (CEST) peaks. The 1,8-pendants of the complex are bound in a trans-arrangement to produce a Co(ii) complex of increased kinetic inertness. The isomers have a stabilized Co(ii) center (E1/2 of 540 to 550 mV versus SHE). Both the 1,8 and the 1,4-isomer are excellent pH probes in solution and in tissue h ...[more]

PMID: 31833500

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