Hypocholesterolemic activity of 17-alpha-methyl-5-alpha-androstane-3-beta, 17-beta-diol, a metabolite of 17-alpha-methyltestosterone

The hypocholesterolemic activities of 17alpha-methyltestosterone and its major identified fecal metabolite, 17alpha-methyl-5alpha-androstane-3,17-diol, were compared in dogs. The dose-response curves indicated that the two compounds had similar effects, although at doses below 1 mg/kg per day the diol appeared to be more active than the parent compound.     

Preparation of 9-alpha,11-xi-tritiated 17-alpha-ethynylestradiol, mestranol, estradiol-alpha-17-beta, and norethindrone

The preparation of 9alpha, 11xi-tritiated 17alpha-ethinyl estradiol, mestranol, estradiol-17beta, and norethindrone are described. Estrone-3-methyl ether was employed as starting material, and ethinylation with lithium acetylide-ethylene diamine resulted in 95% mestranol. Demethylation of mestranol with boron tribromide at 0 degrees resulted in 92% 17alpha-ethinyl estradiol. Dimethylsulfoxide was the choice of reagent for the condensation reaction which was complete at room temperature in about 4 hours. The usually less than 3% of unreacted 17-oxo product was removed by Girard separation. Demethylation of methyl ether with boran tribromide in methylene chloride resulted in an excellent yield of 17alpha-ethinyl estradiol-9alpha, 11xi-tritium. 3-methoxyestra-1,3,5-trien-17-one-9alpha, 11xi-tritium was reduced with sodium bis(2-methoxyethoxy) aluminum hydride to the 17beta-hydroxy compound and subsequent demethylation resulted in estradiol-9alpha, 11xi-tritium. The general method of Ringold et al was employed for the preparation of 17beta-hydroxy-17alpha-ethinylestr-4-en-3-one. Improvements for small scale radiosynthesis are also presented.     

Synthesis of 5 beta,17 alpha-19-norpregn-20-yne-3 beta,17-diol and of 5 beta,17 alpha-19-norpregn-20-yne-3 alpha,17-diol, human metabolites of norethindrone

A convenient synthesis of both 5 beta,17 alpha-19-norpregn-20-yne-3 beta,17-diol (1) and 5 beta,17 alpha-19-norpregn-20-yne-3 alpha,17-diol (2) in multigram quantities from estr-4-ene-3,17-dione is reported. Full characterization of these often-cited human metabolites of norethindrone is presented for the first time.     

Effects of novel 17alpha-hydroxylase/C17, 20-lyase (P450 17, CYP 17) inhibitors on androgen biosynthesis in vitro and in vivo

Aiming at the development of new drugs for the treatment of prostate cancer, the effects of steroidal compounds and one non-steroidal substance on androgen biosynthesis were evaluated in vitro and in vivo. Sa 40 [17-(5-pyrimidyl)androsta-5,16-diene-3beta-ol], its 3-acetyl derivate Sa 41 and BW 19 [3,4-dihydro-2-(4-imidazolylmethyl)-6-methoxy-1-methyl-naphthalene] are compounds from our group, which have been developed as inhibitors of CYP 17 (17alpha-hydroxylase-C17, 20-lyase, the key enzyme in androgen biosynthesis). They have been compared with CB 7598 [abiraterone: 17-(3-pyridyl)androsta-5,16-diene-3beta-ol], its 3-acetyl compound CB 7630 and ketoconazole, compounds which already have been used clinically. The most potent compound toward human CYP 17 (testicular microsomes) was Sa 40 (IC(50) value of 24 nM), followed by Sa 41, CB 7598, BW 19, CB 7630 and ketoconazole. Sa 40 shows a type II difference spectrum and a non-competitive type of inhibition (K(i) value of 16 nM). No recovery of enzyme activity was observed after preincubation of CYP 17 with Sa 40 and subsequent charcoal treatment. In Escherichia coli cells coexpressing human CYP 17 and NADPH-P450 reductase, Sa 40 was more active than CB 7598 and BW 19, whereas the acetyl compounds were not active. The latter three compounds were equally active towards rat CYP 17. Male Sprague-Dawley (SD) rats were administered daily for 14 days BW 19 and the acetyl derivatives Sa 41 and CB 7630 as prodrugs (0.1 mmol/kg intraperitoneally). The test compounds strongly reduced plasma testosterone concentration, as well as prostate and seminal vesicles weights. They showed moderate inhibitory effects on the weights of levator ani, bulbocavernosus and testes, whereas they led to an increase in adrenal and pituitary weights. The only exception was BW 19 which did not change pituitary weights. Based on its superiority on the human enzyme, it was concluded that Sa 40 in its 3beta-acetate form (Sa 41) could be a promising candidate for clinical evaluation.     

IL-17E, a novel proinflammatory ligand for the IL-17 receptor homolog IL-17Rh1

We report identification of interleukin (IL)-17E, a novel member of the IL-17 family of cytokines. IL-17E is a ligand for the recently identified protein termed EVI27/IL-17BR, which we term IL-17 receptor homolog 1 (IL-17Rh1) in light of the multiple reported ligand-receptor relationships. Murine EVI27 was identified through its location at a common site of retroviral integration in BXH2 murine myeloid leukemias. IL-17Rh1 shows highest level expression in kidney with moderate expression in multiple other organs, whereas IL-17E mRNA was detected at very low levels in several peripheral tissues. IL-17E induces activation of NF-kappaB and stimulates production of the proinflammatory chemokine IL-8.     

Radioimmunoassays for androsterone, 5alpha-androstane-3alpha, 17beta-diol and 5alpha-androstane-3beta, 17beta-diol

Androsterone (3alpha-hydroxy-5alpha-androstan-17-one), 5alpha-androstane-3alpha, 17beta-diol and 5alpha-androstane-3beta, 17beta-diol were conjugated at C-16 through sulfur to bovine and human serum albumin. Rabbits injected with these conjugates produced antibodies suitable for radioimmunoassays of these hormone metabolites. Samples were purified on Sephadex LH-20 columns. Levels of these steroids were measured in a rat blood serum pool and in ovarian tissue extract pools.     

AtCOX17, an Arabidopsis homolog of the yeast copper chaperone COX17

We have identified a new plant gene, AtCOX17, encoding a protein that shares sequence similarity to COX17, a Cu-binding protein from yeast (Saccharomyces cerevisiae) and vertebrates that mediates the delivery of Cu to the mitochondria for the assembly of a functional cytochrome oxidase complex. The newly characterized Arabidopsis protein has six Cys residues at positions corresponding to those known to coordinate Cu binding in the yeast homolog. Moreover, we show that the Arabidopsis COX17 cDNA complements a COX17 mutant of yeast restoring the respiratory deficiency associated with that mutation. These two lines of evidence indicate that the plant protein identified here is a functional equivalent of yeast COX17 and might serve as a Cu delivery protein for the plant mitochondria. COX17 was identified by investigating the hypersensitive response-like necrotic response provoked in tobacco (Nicotiana tabacum) leaves after harpin inoculation. AtCOX17 expression was activated by high concentrations of Cu, bacterial inoculation, salicylic acid treatment, and treatments that generated NO and hydrogen peroxide. All of the conditions inducing COX17 are known to inhibit mitochondrial respiration and to produce an increase of reactive oxygen species, suggesting that gene induction occurs in response to stress situations that interfere with mitochondrial function.