Phosphorus-containing purines and pyrimidines: A new class of transition state analogs

Synthetic routes to the [1,5,2]-diazaphosphorine (“4-phosphapyrimidine”), imidazo[4,5-e][1,5,2]-diazaphosphorine (“6-phosphapurine”), and imidazo[4,5-d][1,3,2]-diazaphosphorine (“2-phosphapurine”) ring systems have been developed. Appropriately functionalized derivatives of these heterocycles are desired as possible transition state analogs of the nucleoside deaminases.     

The biomimetic cyclization of I,3-dimethyl-2-(trans-trans-7,II-dimethyl-3,7,II-dodecatrienyl)-2-cyclohexenol to give the d-homosteroid nucleus (I)

The cyclization of tetraenols 3 and 4 has been studied. The tetraenols were prepared as follows: alkylation of the lithium salt of 1-benzyloxy-3-butyne with the previously known trans-tosylates 19 and 20 gave the dienynes 21 and 22. Reduction with sodium in ammonia gave the trans,trans-trienols 25 and 26, which were used to alkylate, via the tosylates 27 and 28, the sodio salt of Hagemann's ester 7. Decarbethoxylation gave the tetraenones 29 and 30 which were converted with methyllithium to 3 and 4. Treatment of tetraenol 3 with trifluoroacetic acid in pentane at −78°C to −10°C gave tetracyclic diene 5 stereoselectively in 45% yield, along with 5% tricyclic triene 32 and a mixture of esters. The esters were reduced and eliminated, giving a mixture (25% yield based on 3) of 66% diene 5 and 34% triene 32. Tetraenol 3 was cyclized with stannic chloride in nitromethane at 22°C giving a 77% yield of a 4:1 mixture of 5 and 32. Treatment of tetraenol 4 with anhydrous formic acid followed by cleavage of the formate esters gave tetracyclic alcohol 6 (isolated in 9% yield) and a mixture of tricyclic trienes 36 and alcohols 37. Cyclization of 4 in trifluoroacetic acid led to larger amounts of tetracyclic diene 40. The structure and configuration (anti,trans,anti,trans) of the cyclization products, 5 and 6, were established by conversion of 6 into the dl ketone 38 and comparison with authentic d-38. Also d-38 was converted into authentic d-5 which was compared with the synthetic dl-5. The comparison substances were prepared as follows. Testosterone benzoate (41) was methylated at C-4, and the C-3 carbonyl group was removed by conversion to the acetate 44, followed by reductive cleavage of the allylic acetate with lithium in ethylamine. Oxidation of the C-17 alcohol gave the ketone 46, which was converted to the carbinolamine 49 by epoxidation with dimethylsulfonium methylide, followed by conversion to the hydroxyazide and reduction with lithium aluminum hydride. Nitrous acid deamination led to the d-homoketone d-38. Treatment of d-38 with methyllithium followed by dehydration led to a mixture of dienes from which d-5 was isolated.     

Optimal conditions for post-translational uptake of proteins by isolated chloroplasts. In vitro synthesis and transport of plastocyanin, ferredoxin-NADP+ oxidoreductase, and fructose-1,6-bisphosphatase

Many polypeptides translated in the cytosol enter the chloroplast where they assemble into macromolecular complexes. The transport of these polypeptides into the plastid can be examined in vitro by mixing isolated chloroplasts with pea poly(A) RNA translation products. Following optimization of both translation in the wheat germ system and the conditions during in vitro uptake, we observe the post-translational transport of over 100 polypeptides; many remain in the soluble phase of the organelle while others integrate into the thylakoid membranes. Most products transported in vitro co-migrate with in vivo products on sodium dodecyl sulfate-polyacrylamide gels. Furthermore, with the improved conditions, we demonstrate the transport of plastocyanin, ferredoxin-NADP+ oxidoreductase, and fructose-1,6-bisphosphatase into isolated plastids. While we have not been able to detect any cell-free translation product that is immunologically related to fructose-1,6-bisphosphatase, both plastocyanin and ferredoxin-NADP+ oxidoreductase are synthesized as precursors in vitro. These precursors are imported into the organelle where they are processed to the size of their mature counterparts. As determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the molecular weight of the precursor to plastocyanin is 15,000 larger than the mature product and the precursor to ferredoxin-NADP+ oxidoreductase is 8,000 larger than the mature product.     

Evidence for two adenine derivative receptors in rat ileum which are not involved in the nonadrenergic, noncholinergic response.

The receptors mediating inhibition of the rat ileum by adenosine and adenine nucleotides were studied. ATP and ADP were more potent than AMP or adeonsine. Theophylline antagonized the effects of adenosine and AMP but not those of ATP or ADP. Preparations desensitized to ATP or ADP were still inhibited by adenosine and vice versa. The nonadrenergic, noncholinergic inhibition produced by field stimulation or nicotine was not attenuated by the presence of theophylline or desensitization to ATP. These data indicate that more than one adenine derivative receptor is present in rat ileum and that ATP and adenosine are unlikely candidates for the unknown transmitter.     

Assignment of the red cell antigen, Targett (Rh40), to the Rh blood group system.

Statistical and serological evidence from a large kindred and two unrelated adults indicates that Targett (Tar) is an antigen in the Rh blood group system and that its presence is assocciated with a weak expression of the Rh antigen D. In the numerical notation the Tar antigen is designated Rh40.