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This article provides a method to convert landfill-designated municipal solid waste (MSW, paper-rich and food-rich) to bioproducts through integrated bioprocessing, also a way of improving the MSW ...

8-Bromoguanosine cyclic 3',5'-monophosphate, 8-bromoguanosine 5'-monophosphate, and 8-bromoguanosine served as intermediates for the chemical synthesis of a series of 8-substituted seleno cyclic nucleotides, nucleotides, and their nucleosides. Selenourea was found to be a useful reagent in synthesizing these seleno-substituted nucleoside, nucleotide, and cyclic nucleotide. A nucleic acid analyzer was used to study the hydrolysis of these cyclic nucleotides by phosphodiesterase. It was found that all of the 8-substituted selenoguanosine cyclic 3',5'-phosphates synthesized, except 8-MeSe-cGMP, were resistant to hydrolyze by phosphodiesterase. These 8-substituted seleno cyclic GMP derivatives showed some antitumor activities against murine leukemic cells (L5178Y) in vitro and in vivo.

In attempts to increase the specificity of thiol agents and protect the genetic material of the cell, which is very sensitive to radiation damage, the synthesis of a group of compounds was undertaken in which cysteamine is attached through its amino group to a series of purine and pyrimidine components of nucleic acids. The 5-position of pyrimidines and the 8-position of purines seem well suited for the attachment of groups to be introduced into nucleic acids. Attempts were also made to introduce the bis( BETA -thioethyl) amino group into suitable carrier molecules to yield doublearmed cysteamines. While attempts to isolate bis-( BETA -mercaptoethyl)amine were unsuccessful, the oxidized form of the compound, 1,2-dithia-5-azepane was prepared in good yield. Thus, the preparation of N-substituted 1,2-dithia-5azepanes appeared feasible. A number of uracilyl compounds were prepared by reaction sequences which are shown. BETA -Benzylthioethylamine, prepared by the reaction of ethyleneimine with alpha - toluenethiol, was found to react with 5-bromouracil to yield 5-L BETA - benzylthioethylamino) uracil, This compound could also be obtained by the addition of alpha -toluenethiol to 5-( BETA -chloroethylamino)uracil (onearmed uracil mustard). Debenzylation with sodium in liquid ammonia resulted in the formation of 5-( BETA -mercaptoethylamino)uracil. Attempts to isolate themore » compound were unsuccessful; however, oxidation readily yielded its disulfide form. Bis( BETA -benzylthioethyl)amine reacted with 5bromouracil to form 5-bis( BETA - benzylthtoethylamino)uracil. An alternative synthesis of the compound involved the addition of the sodium salt of benzyl mercaptan to 5-bis( BETA chloroethylamino)uracil (uracil mustard). Reduction of the bis-benzylthio compound with sodium in liquid ammonia followed by air oxidation yielded N-(5- uracilyl)-1,2-dithta5-azepane. N,N'-bis(8-adeninyl)cystamine was prepared in annlogous fashion from 8-( BETA -benzylthioethylamino)adenine, which in turn was obtained by the reaction of 8bromoadenine with BETA -benzylthioethylamine. Difficulties were encountered in isolating mercaptans as such because of the rapidity of air oxidation. (P.C.H.)« less

In view of the effectiveness of aminoethyl mercaptan (cysteamine) and of 2-aminoethylisothiouronium (AET) salts in protecting animals against ionizing radiation, efforts were made to prepare even more active analogs of the compounds. Sulfur is considered to be essential to the radioprotective action of cysteamine analogs; however, the selenium analog of cysteamine can shield mice against radiation. Since the atomic radii of sulfur and of selenium are similar, sulfur and selenium analogs may be assumed to have the same ability of fit receptor sites. The selenium analog of AET was prepared by the reaction of selenourea with 2-bromoethylamine hydrobromide. Treatment of the selenouronium salt with NaOH yielded 2-selenoethylguanidine, which was isolated as the flavianate salt. The reaction of 2-aminoethylisoselenouronium hydrobromide with boiling water resulted in the formation of 2-aminoselenazoline. Through the reaction of 2- methylaminoethyl. 2dimethylaminoethyl, and 2-diethylaminoethyl halides with selenourea the corresponding 2-alkylaminoethyl selenouronium salts were obtained. Similarly, 3-aminopropylisoselenouronium hydrobromide was synthesized.