2-Acetyl-5,6,7,8-tetrahydronaphthalene (1) was allowed to react with different aromatic aldehydes to produce the cyanopyridones 2a and 2b, which were treated with phosphorous pentasulfide to afford the corresponding thioxopyridine derivatives 3a and 3b, respectively. The reaction of 3a and 3b with ethyl bromoacetate afforded the ester derivatives 4a and 4b, while their condensation with hydrazi...

To further characterize the active site of human placental oestradiol17/3-dehydrogenase (EC 1.1.1.62), we have synthesized 4-bromoacetamidoestrone methyl ether. Starting with estrone, synthetic steps involved nitration, isolation of the I-nitro derivative with subsequent methylation, selective reduction of the nitro group, and coupling of the resulting 4-amino group with bromoacetic acid. The a...

1,25-Dihydroxyvitamin D₃ [1,25(OH)₂D₃] has shown strong promise as an antiproliferative agent in several malignancies, yet its therapeutic use has been limited by its toxicity leading to search for analogues with antitumor property and low toxicity. In this study, we evaluated the in vitro and in vivo properties of 1,25-dihydroxyvitamin D₃-3-bromoacetate [1,25(OH)₂D₃-3-BE], an alkylating deriva...

The preparation of two types of imidazole derivatives bearing a hydrazide group was achieved by treatment of the corresponding esters with NH2NH2·H2O in MeOH at room temperature. In the case of 4-(ethoxycarbonyl)-1H-imidazole 3-oxides 3, hydrazides of type 1 were formed with retention of the N-oxide structure (Scheme 1). Interestingly, due to a strong H-bonding, no deoxygenation of the N-O func...

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] has shown strong promise as an antiproliferative agent in several malignancies, yet its therapeutic use has been limited by its toxicity leading to search for analogues with antitumor property and low toxicity. In this study, we evaluated the in vitro and in vivo properties of 1,25-dihydroxyvitamin D3-3-bromoacetate [1,25(OH)2D3-3-BE], an alkylating deriva...

Human thioredoxin reductase (TR) contains selenocysteine (Secys) in a redox center [cysteine (Cys)497,Secys-498] near the C-terminus. The essential role of Secys in TR isolated from HeLa cells was demonstrated by the alkylation studies. Reaction of native NADPH reduced enzyme with bromoacetate at pH 6.5 inhibited enzyme activity 99%. Of the incorporated carboxymethyl (CM) group, 1.1 per subunit...

The 25-hydroxyvitamin D3 (25-OH-D3) is a nontoxic and low-affinity vitamin D receptor (VDR)-binding metabolic precursor of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. We hypothesized that covalent attachment of a 25-OH-D3 analog to the hormone-binding pocket of VDR might convert the latter into transcriptionally active holo-form, making 25-OH-D3 biologically active. Furthermore, it might be possibl...

Environmental pollutants containing halogenated organic compounds e.g. haloacid, can cause a plethora of health problems. The structural and functional analyses of the gene responsible of their degradation are an important aspect for environmental studies and are important to human well-being. It has been shown that some haloacids are toxic and mutagenic. Microorganisms capable of degrading the...

The copulatory act in Acanthocephala requires a complicated set of responses on the part of the male worm. The muscles associated with these responses include a set of bursal protrusor muscles plus a large bursal depressor muscle which participates in the eversion of the bursa. The anterior and posterior bursal accessory muscles are associated with the bursal depressor muscle and are described ...