Abstract
Small conductance Ca2+-activated K+ (SKCa) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SKCa channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SKCa channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SKCa channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([11C]9a-c and [11C]11), were prepared by N-[11C]methylation of the tertiary amine precursors (8a-c and 10) with [11C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO2 or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.
| Original language | English |
|---|---|
| Pages (from-to) | 194-202 |
| Number of pages | 9 |
| Journal | Applied Radiation and Isotopes |
| Volume | 66 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 2008 |
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Keywords
- 1-(3,4-Dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums
- Carbon-11
- Imaging
- N-methyl-laudanosine
- Positron emission tomography (PET)
- Small conductance Ca-activated K (SKCa) channels
ASJC Scopus subject areas
- Radiation
Cite this
Synthesis of carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolinium derivatives as new potential PET SKCa channel imaging agents. / Gao, Mingzhang; Wang, Min; Zheng, Qi-Huang.
In: Applied Radiation and Isotopes, Vol. 66, No. 2, 02.2008, p. 194-202.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Synthesis of carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinolinium derivatives as new potential PET SKCa channel imaging agents
AU - Gao, Mingzhang
AU - Wang, Min
AU - Zheng, Qi-Huang
PY - 2008/2
Y1 - 2008/2
N2 - Small conductance Ca2+-activated K+ (SKCa) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SKCa channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SKCa channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SKCa channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([11C]9a-c and [11C]11), were prepared by N-[11C]methylation of the tertiary amine precursors (8a-c and 10) with [11C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO2 or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.
AB - Small conductance Ca2+-activated K+ (SKCa) channels play an important role in many functions such as neuronal communication and behavioral plasticity, secretion, and cell proliferation. SKCa channel modulation is associated with various brain, heart, and cancer diseases. N-methyl-laudanosine and its structurally related derivatives, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums, are reversible and selective SKCa channel blockers. Carbon-11 labeled N-methyl-laudanosine and its tetrahydroisoquinolinium derivatives may serve as new probes for positron emission tomography (PET) to image SKCa channels in the brain, heart, and cancer. The key intermediates, substituted isoquinolines (3a-c), were synthesized using a modification of the Pomeranz-Fritsch procedure. The precursors, substituted 1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinolines (8a-c), and their corresponding reference standards, substituted 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums (9a-c), were synthesized from compounds 3a-c with 3,4-dimethoxybenzyl chloride (2) in multiple steps with moderate to excellent chemical yields. The precursor 6,7-dimethoxy-1-(3,4-dimethoxybenzyl)-2-methyl-1,2,3,4-tetrahydroisoquinoline (10) was commercially available, and the methylation of compound 10 with methyl iodide provided N-methyl-laudanosine (11). The target quaternary ammonium tracers, carbon-11 labeled 1-(3,4-dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums ([11C]9a-c and [11C]11), were prepared by N-[11C]methylation of the tertiary amine precursors (8a-c and 10) with [11C]methyl triflate and isolated by a simplified solid-phase extraction (SPE) purification using a SiO2 or cation-exchange CM Sep-Pak cartridge in 40-65% radiochemical yields.
KW - 1-(3,4-Dimethoxybenzyl)-2,2-dimethyl-1,2,3,4-tetrahydroisoquinoliniums
KW - Carbon-11
KW - Imaging
KW - N-methyl-laudanosine
KW - Positron emission tomography (PET)
KW - Small conductance Ca-activated K (SKCa) channels
UR - http://www.scopus.com/inward/record.url?scp=37149043294&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=37149043294&partnerID=8YFLogxK
U2 - 10.1016/j.apradiso.2007.08.011
DO - 10.1016/j.apradiso.2007.08.011
M3 - Article
VL - 66
SP - 194
EP - 202
JO - Applied Radiation and Isotopes
JF - Applied Radiation and Isotopes
SN - 0969-8043
IS - 2
ER -