C-Sodium Acetate

Synthetic chemical approaches to the preparation of carbon-14 labeled materials iavolve a number of basic building blocks prepared from barium [ CJ-carbonate (2). These are carbon [ C]-dioxide [ CJ-acetjlene [U— C]-ben2ene, where U = uniformly labeled [1- and 2- C]-sodium acetate, [ C]-methyl iodide, [ C]-methanol, sodium [ C]-cyanide, and [ CJ-urea. Many compHcated radiotracers are synthesized from these materials. Some examples are [l- C]-8,ll,14-eicosatrienoic acid [3435-80-1] inoxn. [ CJ-carbon dioxide, [ting-U— C]-phenyhsothiocyanate [77590-93-3] ftom [ " CJ-acetjlene, [7- " C]-norepinephrine [18155-53-8] from [l- " C]-acetic acid, [4- " C]-cholesterol [1976-77-8] from [ " CJ-methyl iodide, [l- " C]-glucose [4005-41-8] from sodium [ " C]-cyanide, and [2- " C]-uracil [626-07-3] [27017-27-2] from [ " C]-urea. All syntheses of the basic radioactive building blocks have been described (4). 

The esterification reaction may be carried out with a number of different anhydrides but the literature indicates that acetic anhydride is preferred. The reaction is catalysed by amines and the soluble salts of the alkali metals. The presence of free acid has an adverse effect on the esterification reaction, the presence of hydrogen ions causing depolymerisation by an unzipping mechanism. Reaction temperatures may be in the range of 130-200°C. Sodium acetate is a particularly effective catalyst. Esterification at 139°C, the boiling point of acetic anhydride, in the presence of 0.01% sodium acetate (based on the anhydride) is substantially complete within 5 minutes. In the absence of such a catalyst the percentage esterification is of the order of only 35% after 15 minutes. 

C04-0082. What are the major species present in aqueous soiutions of each of the foiiowing (a) potassium hydrogenphosphate (b) acetic acid (c) sodium acetate (d) ammonia and (e) ammonium chioride... 

The last one (6.2 g, 18.4 mmol) was converted into 3,4-dihydro-4-hydroxy-2-(2-methoxy)ethyl-2H-thieno[3,2-e]-l,2-thiazine-6-sulfonamide 1,1-dioxide (4.87 g, 77%) m.p. 187°C by using the reaction with n-butyl lithium in anhydrous THF at -40°C for 40 min, and then bubbling sulfur dioxide gas for 20 min after which time the mixture was warmed to room temperature. After 30 min at room temperature the mixture was concentrated the residue was dissolved in water, cooled (0°C), sodium acetate trihydrate was added followed by hydroxylamine-O-sulfonic acid. The reaction mixture was stirred at room temperature for 18 h after which time was basified with solid sodium bicarbonate and extracted with ethyl acetate. 

After the base-modification reaction cold (0°C) sodium acetate and three volumes of cold (0°C) ethanol are added to dilute and chill the reaction mixture and precipitate the DNA. A five-minute spin (12,000 g) quantitatively pellets the DNA leaving most of the excess dimethylsulphate or hydrazine in the supernatant. A second precipitation followed by an ethanol wash removes the last traces of reagents and sodium acetate. 

Scheme 8, Reagents i, chloroform, NaOH (50%), tetra-n-butylammonium chloride ii, methanol, sodium carbonate iii, toluene, reflux iv, LiAlH4, AICI3, tetrahydrofuran v, H2, 10% Pd/C, sodium acetate, ethanol.

In order to check Geissmann s proposal by experimentally Whiting et al. (36, 83) injected [1- C] and [2- C] sodium acetate and malonate, [1- CJ- and [3-Nc]-phenylalanine, and sodium H-ferulate into the roots of Curcuma tonga. After a few days of incubation... 

Aminolevulinic acid (ALA), labelled with at C(i,. C(2), C, C(4, and Cjj, has been synthesized " from C-labelled KCN, glycine, Meldrum s acid or bromoacetate, prepared in turn from C-sodium acetate or C-acetic acid (equations 26 and 27). It was used for direct observation of the enzymatic transformation of ALA to porphobilinogen (PBG) by C-high-field FT-NMR spectroscopy without chemical degradation of the intermediate and the compounds. 

To determine the eaHky phosphates, a sample of 100 c.c. urine is rendered alkaline with NH HO and set aside for 12 hours the precipitate is then collected upon a filter, washed with ammoniacal water, brought into a beaker, dissolved in a small quantity of acetic add the solution diluted to 50 c.c. with H,0, treated with 5 c.c. sodium acetate solution, and the amount of determined as above. 

To determine the total phosphates in a urine 50 c.c. are placed in a beaker, 5 c.c. sodium acetate solution are added the mixture is heated on the water-bath, and the uranium solution delivered from a burette, until a drop, removed from the beaker and brought in contact with a drop of ferrocyanid solution, produces a brown tinge. The burette reading, multiplied by 0.005, gives the amount of P Os in 50 c.c. urine and this, multiplied by the amount of urine passed in 24 hours, gives the daily elimination. 

Detection kinetics of C02 after [ C]-sodium acetate injection to the animal at t = zero. 

Echinulin is a triisoprenylated cyclic dipeptide isolated from Aspergillus amstelodami and Aspergillus echinulatus (Fig. 12) [52]. Birch et al. established that the biosynthetic precursors to echinulin are L-tryptophan, L-alanine, and mevalonic acid [53] by feeding radioactive precursors to Aspergillus amsteloda-mu In these experiments it was found that [1- C] sodium acetate, dl-[1- C]-alanine,DL-[l- C]-tryptophan, [2- C]-mevalonic acid lactone, and [1- C]-glycine were incorporated into echinulin with incorporation rates of 4.25 %, 0.12 %, 1.36%, 0.74%, and 0.84%, respectively (Scheme 31). 

De novo synthesis of total fatty acids and fatty acids in PG from [1-i C]acetate in isolated chloroplasts. Intact chloroplasts were isolated from expanding leaves and purified using a Percoll step gradient as described previously (Mudd and Dezacks, 1979). Incubations were carried out in the presence of 175 uM (2-i C] sodium acetate, 33 mM Tricine-KOH, pH 7.9, 330 mM sorbitol, 2 mM MgCl2, 0.2 mM K2HPO4,0.5 mM DTT, 5 mM NaHCOa, 2 mM ATP,... 

Store a small aliquot at 4°C, the remainder at -20°C. rNTP solution, containing 5 mM of each of the four rNTPs (ATP, GTP, CTP, UTP) made from 100 mM stocks (Promega, Fisher PR-E6000), store in 500-pl aliquots at -20°C. Sodium acetate (0.3 m)... 

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