degree of butyrylation and biological activity on thyroid function. Evidently other factors besides penetration, e.g., binding requirements of various enzyme systems involved in the mechanism of action of cAMP, will have to be considered to explain our results.Several groups26-27 have reported variations in the PDE isoenzyme composition of different tissues and we might speculate that there are also differences in the protein kinase system of various tissues.Comparing the effect of the various cyclic nucleotides on the thyroidal function with results previously obtained on the release of growth hormone28-29 or prolactin,30 we find some degree of tissue specificity. For example, Bt2-8HS-cAMP, which was one of the most active compounds on growth hormone release, shows only a marginal effect on thyroid function. On the other hand, 8H2N-cAMP, which is a very strong stimulator of the thyroid, is one of the least active cAMP analogues with respect to growth hormone release. This observation of relative specificity of certain cAMP derivatives could contribute to a better understanding of the mechanism of action of cAMP and lead to further study of possible therapeutic applications of cyclic nucleotides.Acknowledgment. The authors wish to thank Professor T. Postemak for stimulating discussions and helping us with his expertise in the field. They are very grateful to Nuclear Medical Systems, Inc., Newport Beach, Calif., for performing the radioimmunoassays of T4. We also wish to express our appreciation to Mrs. Helia Gergely and Mr. Robert W. Mancuso for their excellent technical assistance.
A series of thymidylate synthetase inhibitors was synthesized, some of which were potential irreversible inhibitors. 5-Formyl-2'-deoxyuridine (9) and its dithiolane derivative 11 were prepared by condensation of the bis(trimethylsilyl) derivative of 5-formyluracil dimethyl acetal and the protected chloro sugar followed by saponification of the protective groups. 5-Acetyl-2'-deoxyuridine (15) was prepared in the same way from 5-acetyluracil. Treatment of the diester of 5-allyl-2'-deoxyuridine (17 or 22) with m-chloroperbenzoic acid gave the corresponding epoxide. Dimethylamine removed the ester groups and opened the epoxide to give the amino alcohol 24. The diester of 5-chloromethyl-2'-deoxyuridine (27) treated with methanol or sodium azide gave 5-methoxymethyl- (29) and 5-azidomethyl- (31) 2'-deoxyuridines. Compound 27 also was converted to 5-iodoacetamidomethyl-2'-deoxyuridine by treatment with ammonia, chloroacetyl chloride, base saponification, and finally sodium iodide.
This article focuses on organic bromine compounds with industrial application. The organic bromine compounds are prepared and produced either by substitutive or additive bromination. Organic bromine compounds, in which the bromine atom is retained in the final molecular structure, and where its presence contributes to the properties of the desired products, are the largest segment in terms of consumed volumes. This segment includes mainly flame retardants (50%), biocides (mostly for water treatment), gasoline additives, halons, bromobutyl rubber, pharmaceuticals, and dyes. New process developments resulted in new applications in ultraviolet (UV) sunscreens, high‐performance polymers, and others.
The rates of autoxidation of crude, bleached and stripped jojoba wax were determined under conditions of accelerated oxidation (98 C). Oxidation of the raw yellow wax had a long induction period (50 hr) compared with the bleached wax (10–12 hr) or stripped wax (2 hr). These differences indicate the presence of a natural antioxidant in the crude wax. Addition of 0.02% butylated hydroxytoluene or butylated hydroxyanisole to the bleached wax restored and even improved its stability. Autoxidation of jojoba wax was also studied at room temperature. In the presence of light and air, the activity of the natural inhibitor was rapidly lost.
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