ABSTRACT
[11C]PIB is the most used amyloid plaques-specific positron-emitting radiotracers. The radiosynthesis of this compound, carried out by methylation of its precursor with [11C]methyl triflate in 2-butanone, has been improved optimizing the initial concentration and the purification method. Two HPLC methods were compared: good radiochemical yields, specific activities, and chemical purity above 98% were achieved by using as eluant acetonitrile/citrate and formulation in 10% ethanol.
Subject(s)
Alzheimer Disease/diagnostic imaging , Amyloid beta-Peptides/metabolism , Benzothiazoles/chemical synthesis , Carbon Radioisotopes , Positron-Emission Tomography/methods , Radiopharmaceuticals/chemical synthesis , Alzheimer Disease/diagnosis , Alzheimer Disease/metabolism , Aniline Compounds , Benzothiazoles/isolation & purification , Benzothiazoles/standards , Carbon Radioisotopes/isolation & purification , Carbon Radioisotopes/standards , Humans , Quality Control , Radiopharmaceuticals/isolation & purification , Radiopharmaceuticals/standards , ThiazolesABSTRACT
Mercaptobenzothiazole (MBT) compounds are well known contact allergens. To detect rubber allergic patients we use both MBT (2% in petrolatum) and a mercapto-mix with 4 constituents of 0.5% each in our standard series. In this article the EECDRG presents data of in total 32,475 consecutive tested patients attending the respective contact dermatitis clinics from 11 centres in Europe to determine if the mix and MBT detected the same allergic patients. We found 327 patients positive to the mix or MBT, or to both. 261 were positive to the mix and 254 to MBT. MBT was negative in 73 patients who were positive to the mix. If the mix had not been in the standard series, on average 22% of patients allergic to a mercapto-compound would have been missed, for MBT this would have been on average 20%. All clinics would have missed a significant number of positive reactions if both compounds had not been tested. We conclude, that both the mercapto mix and MBT are required in the standard series.
Subject(s)
Benzothiazoles , Dermatitis, Contact/diagnosis , Skin Tests/methods , Sulfhydryl Compounds , Benzothiazoles/standards , Dermatitis, Contact/etiology , Europe , Humans , Retrospective Studies , Skin Tests/standards , Sulfhydryl Compounds/standardsABSTRACT
The (1)H and (13)C NMR resonances for forty-three 2-aryl and 2-N-arylamino benzothiazole derivatives were completely assigned using a concerted application of one- and two-dimensional experiments (DEPT, gs-COSY, gs-HMQC and gs-HMBC).