A cassette for performing a plurality of synthesis processes of preparing a radiopharmaceutical in series in a synthesizer, includes: at least one manifold provided with a plurality of valves connectable to and operable by the synthesizer; an anion-exchanger comprising an anionic exchange material; an eluent container comprising an eluent; and a recondition container comprising a reconditioning agent.

Disclosed is a method for purifying sucralose, sequentially including: adding sucralose to ultrapure water, heating the resulting mixture for dissolution to obtain a dissolved solution, filtering the dissolved solution to obtain a filtrate, and then extracting the filtrate with an extraction solvent to remove non-polar impurities; subjecting the extracted recrystallization solution to concentration by evaporation to obtain a concentrated recrystallization solution with a preset concentration, and leaving the concentrated recrystallization solution to stand at a preset temperature for a preset time to produce a sucralose crystal nucleus in the concentrated recrystallization solution; subjecting the concentrated recrystallization solution containing the sucralose crystal nucleus to programmed cooling to obtain a recrystallization solution with a large amount of a sucralose crystal; and centrifuging the recrystallization solution with a large amount of a sucralose crystal to obtain a solid, and subjecting the solid to water-washing and drying to obtain a sucralose crystal.

Disclosed is a method for purifying sucralose, sequentially including: adding sucralose to ultrapure water, heating the resulting mixture for dissolution to obtain a dissolved solution, filtering the dissolved solution to obtain a filtrate, and then extracting the filtrate with an extraction solvent to remove non-polar impurities; subjecting the extracted recrystallization solution to concentration by evaporation to obtain a concentrated recrystallization solution with a preset concentration, and leaving the concentrated recrystallization solution to stand at a preset temperature for a preset time to produce a sucralose crystal nucleus in the concentrated recrystallization solution; subjecting the concentrated recrystallization solution containing the sucralose crystal nucleus to programmed cooling to obtain a recrystallization solution with a large amount of a sucralose crystal; and centrifuging the recrystallization solution with a large amount of a sucralose crystal to obtain a solid, and subjecting the solid to water-washing and drying to obtain a sucralose crystal.

Disclosed herein are compounds having a structure according to Formula I and optionally Formula IV.

##STR00001##

The compounds may be radiolabeled compounds useful for diagnosis and/or imaging fungal infections. In such embodiments, at least one substituent is a radionuclide, such as .sup.18F. Also disclosed are precursor compounds according to Formula I and/or IV that are useful for making the radiolabeled compounds. In such embodiments, the precursor compound comprises at least one leaving group suitable for introducing a radionuclide, such as .sup.18F, at a desired position.

Also disclosed are methods for making and using the compounds, including embodiments of a method for imaging and/or diagnosing a fungal infection in a subject.

Disclosed herein are compounds having a structure according to Formula I and optionally Formula IV.

##STR00001##

The compounds may be radiolabeled compounds useful for diagnosis and/or imaging fungal infections. In such embodiments, at least one substituent is a radionuclide, such as .sup.18F. Also disclosed are precursor compounds according to Formula I and/or IV that are useful for making the radiolabeled compounds. In such embodiments, the precursor compound comprises at least one leaving group suitable for introducing a radionuclide, such as .sup.18F, at a desired position.

Also disclosed are methods for making and using the compounds, including embodiments of a method for imaging and/or diagnosing a fungal infection in a subject.

A method for synthesizing sucrose-6-ester includes: (a) in the presence of a polar aprotic solvent, contacting an organic phosphine compound represented by formula I with sucrose and an organic tin compound; (b) removing water to obtain a reaction liquid containing a tin-sucrose adduct; and (c) contacting the reaction liquid containing the tin-sucrose adduct with an acid anhydride compound to prepare a sucrose-6-ester. In formula I, R.sup.1, R.sup.2, and R.sup.3 each are a linear or branched alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms; moreover, the R.sup.1, R.sup.2, and R.sup.3 are identical groups, partially identical groups, or different groups from each other. According to the method, the reaction conversion rate and selectivity are greatly improved; moreover, it is easy to realize industrial application.

A method for synthesizing sucrose-6-ester includes: (a) in the presence of a polar aprotic solvent, contacting an organic phosphine compound represented by formula I with sucrose and an organic tin compound; (b) removing water to obtain a reaction liquid containing a tin-sucrose adduct; and (c) contacting the reaction liquid containing the tin-sucrose adduct with an acid anhydride compound to prepare a sucrose-6-ester. In formula I, R.sup.1, R.sup.2, and R.sup.3 each are a linear or branched alkyl having 1 to 20 carbon atoms, a cycloalkyl having 3 to 10 carbon atoms, or an aryl having 6 to 10 carbon atoms; moreover, the R.sup.1, R.sup.2, and R.sup.3 are identical groups, partially identical groups, or different groups from each other. According to the method, the reaction conversion rate and selectivity are greatly improved; moreover, it is easy to realize industrial application.

Disclosed is a method for purifying sucralose, including: removing a solvent from a sucralose reaction solution to obtain a concentrated crude sucralose solution; under stirring, adding ethyl acetate into the concentrated crude sucralose solution, heating to a preset temperature, and holding at the preset temperature for a first preset time to obtain a crude product slurry with a certain amount of a sucralose crystal; and subjecting the crude product slurry to gradient cooling to an endpoint temperature, holding at the endpoint temperature for a second preset time, and filtering to obtain a sucralose crystal.

Disclosed is a method for purifying sucralose, including: removing a solvent from a sucralose reaction solution to obtain a concentrated crude sucralose solution; under stirring, adding ethyl acetate into the concentrated crude sucralose solution, heating to a preset temperature, and holding at the preset temperature for a first preset time to obtain a crude product slurry with a certain amount of a sucralose crystal; and subjecting the crude product slurry to gradient cooling to an endpoint temperature, holding at the endpoint temperature for a second preset time, and filtering to obtain a sucralose crystal.

The present invention, in some aspects, provides methods, reagents, compositions, and kits for the radiolabeling of proteins, for example, of proteins useful for positron emission tomography (PET) or single-photon emission computed tomography (SPECT) (e.g., for diagnostic and therapeutic applications), using sortase-mediated transpeptidation reactions. Some aspects of this invention provide methods for the conjugation of an agent, for example, a radioactive agent or molecule to diagnostic or therapeutic peptides or proteins. Compositions comprising sortagged, radiolabeled proteins as well as reagents for generating radiolabeled proteins are also provided. Kits comprising reagents useful for the generation of radiolabeled proteins are provided, as are precursor proteins that comprise a sortase recognition motif.