Synthesis and biological activities of 5-(hydroxymethyl, azidomethyl, or aminomethyl)-2'-deoxyuridine and related 5'-substituted analogues.

The synthesis of 5-(azidomethyl)-2'-deoxyuridine (10) has been accomplished by two independent methods. The first involved tosylation of 5-(hydroxymethyl)-2'-deoxyuridine (1) to furnish a mixture of two mono- and a ditosyl nucleosides which were converted into the corresponding 5-(azidomethyl) (10), 5-(azidomethyl)-5'-azido (14), and 5-(hydroxymethyl)-5'-azido (15) derivatives of 2'-deoxyuridine. The second method was more selective and required the formation of the intermediate 5-(bromomethyl)-3',5'-di-O-acetyl-2'-deoxyuridine (8), followed by displacement of the bromo group by lithium azide and deacetylation. Catalytic hydrogenation of the azides 9, 10, 14, and 15 gave the corresponding amines 16, 2, 6, and 7, respectively. Compounds 1, 2, 10, and 16 inhibited the growth of murine Sarcoma 180 and L1210 in culture, and the activity of 2 was prevented by 2'-deoxypyrimidine nucleosides but not by purine nucleosides. The replication of herpes simplex virus type 1 (HSV-1) was strongly inhibited only by 1 and 10. Studies on the binding of the various thymidine analogues to HSV-1 encoded pyrimidine deoxyribonucleoside kinase indicate that 1 and 10 have good affinity for the enzyme.

Synthesis and biological activities of chloroethylurea, methylurea, and nitrosourea analogues of N-deacetylmethylthiocolchicine.

A series of urea and nitrosourea analogues of N-deacetylmethylthiocolchicine (1) has been synthesized, and their antineoplastic and antiviral activities were evaluated. The objective for combination of two active moieties, such as thiocolchicine and nitrosourea, into one molecule was the generation of compounds with potential improved biological and pharmacological properties. The ED50 for 2, 3, 4, and 5 was 1.6, 1.2, 3.3, and 1.8 X 10(-8) M for L1210 cells and 3.0, 2.7, 2.9, and 2.6 X 10(-8) M for S-180 cells, respectively. The synthesis and cytotoxic and antiviral properties of these compounds are discussed.

Antineoplastic agents. 1. Synthesis and antineoplastic activities of chloroethyl- and methylnitrosourea analogues of thymidine.

A new class of chloroethyl- and methylnitrosourea analogues of thymidine, 5a,b, 6, 10, and 11, has been synthesized from the corresponding amino nucleosides, 2 and 7. The 3'-chloroethyl and 3'-methyl derivatives, 10 and 11, inhibited L1210 cell growth in culture (ED50 = 1.5 and 1.0 micrometer, respectively) more effectively than 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) (ED50 = 4 micrometer) and the 5'-nitrosourea analogues. Neither the alkylating nor the carbamoylating activities of these compounds correlated with their biological activity.

Synthesis and evaluation of N-deacetyl-N-glycosylalkylthiocolchicines as antileukemic agents.

A series of N-deacetyl-N-glycosylalkylthiocolchicines (glucosyl, galactosyl, mannosyl, ribosyl, and arabinosyl) was prepared by heating N-deacetylalkylthiocolchicines with the appropriate monosaccharides in methanol. Some compounds (glucosyl-, mannosyl-, and ribosylalkylthiocolchicines) were per-O-acetylated in dry pyridine with acetic anhydride. The compounds were tested against leukemia L-1210 and P-388 systems. Preliminary results showed that the antileukemic activity of the glycosyl compounds in vitro is similar to that of the N-deacetylalkylthiocolchicines used for their preparation. However, the presence of a glycosyl moiety in the molecule gives the advantage of greater solubility in water. Of the results obtained to date in lymphoid leukemia screening in vivo, five glycosyl compounds showed promising activity levels and have now reached confirmed active status.

Alkylthiocolchicines and N-deacetyl-alkylthiocolchicines and their antileukemic activity.

A series of alkylthiocolchcines (methyl, ethyl, n-butyl, n-hexy, n-octyl, and pinanyl) was prepared from colchicine by treatment with the appropriate alkyl mercaptan and p-toluenesulfonic acid. Some of these compounds (methyl-, ethyl-, and n-butylthiocolchicines) were deacetylated in good yields with 2 N hydrochloric acid in methanol. These compounds were tested for their antileukemic activity in an in vitro assay against L-1210 (mouse leukemia). Preliminary results showed that methylthiocolchicine is more active and the other alkylthiocolchicines are much less active than colchicine. N-Deacetyl-methylthiocolchicine is as active as colchicine.

5'-Amino-5'-deoxythymidine: synthesis, specific phosphorylation by herpesvirus thymidine kinase, and stability to pH of the enzymically formed diphosphate derivative.

Radioactive 5'-amino-5'-deoxythymidine (5'-AdThd), an inhibitor of herpes simplex virus, was synthesized by direct amination of monotosylated thymidine with concentrated ammonium hydroxide. Incubation of 5'-AdThd with purified herpes simplex virus type 1-encoded pyrimidine deoxyribonucleoside kinase produced the diphosphate derivative. The monphosphate derivative of 5'-AdThd was not detected as a reaction product of this enzymatic phosphorylation. A purified mixture of nonviral thymidine kinase and thymidylate kinase derived from uninfected Vero cells was unable to phosphorylate 5'-AdThd under identical conditions. The rate of hydrolysis of 5'-AdThd diphosphate increased as the pH of the reaction mixture decreased, with a shoulder region appearing between pH 3 and 5. The rate of hydrolysis was markedly increased below pH 3. 5'-AdThd, but not the monophosphate derivative, was detected in the hydrolysis mixture. The hydrolysis of 5'-AdThd diphosphate pH 3 also yielded some thymine in addition to 5'-AdThd.