Molecularly Imprinted Polymers Doped with Carbon Nanotube with Aid of Metal-Organic Gel for Drug Delivery Systems.

PURPOSE: The incidence of breast cancer worldwide has been on the rise since the late 1970s, and it has become a common tumor that threatens women's health. Aminoglutethimide (AG) is a common treatment of breast cancer. However, current treatments require frequent dosing that results in unstable plasma concentration and low bioavailability, risking serious adverse reactions. Our goal was to develop a molecularly imprinted polymer (MIP) based delivery system to control the release of AG and demonstrate the availability of this drug delivery system (DDS), which was doped with carbon nanotube with aid of metal-organic gel. METHODS: Preparation of MIP was optimized by key factors including composition of formula, ratio of monomers and drug loading concentration. RESULTS: By using multi-walled carbon nanotubes (MWCNT) and metal-organic gels (MOGs), MIP doubled the specific surface area, pore volume tripled and the IF was 1.6 times than the reference. Compared with commercial tablets, the relative bioavailability was 143.3% and a more stable release appeared. CONCLUSIONS: The results highlight the influence of MWCNT and MOGs on MIP, which has great potential as a DDS.

Enantioseparation of racemic aminoglutethimide using asynchronous simulated moving bed chromatography.

The separation of aminoglutethimide enantiomers by the continuous multicolumn chromatographic processes were investigated experimentally and theoretically, where the columns were packed with cellulose tris 3,5-dimethylphenyl-carbamate stationary phase (brand name Chiralcel OD) and mobile phase was a mixture of n-hexane and ethanol with monoethanolamine additive. The continuous enantioseparation processes included a synchronous shifting process (SMB) and an asynchronous shifting process (VARICOL), which allowed reducing the column number (here from six-column SMB to five-column VARICOL process). Transport-dispersive model with the consideration of both intraparticle mass transfer resistance and axial dispersion was adopted to design and optimize the operation conditions for the separation of aminoglutethimide enantiomers by SMB process and VARICOL process. According to the optimized operation conditions, experiments were carried out on VARICOL-Micro unit using five-column VARICOL process with 1/1.5/1.5/1 configuration and six-column SMB process with 1/2/2/1 configuration. Products of R-aminoglutethimide (R-AG) enantiomer and S-aminoglutethimide (S-AG) enantiomer with more than 99.0% purity were obtained continuously from extract stream and raffinate stream, respectively. Furthermore, the experiemntal data obtained from five-column VARICOL process were compared with that from six-column SMB process, the feasibility and efficiency for the separation of guaifenesin enantiomers by VARICOL processes were evaluated.

Aminoglutethimide-imprinted xerogels in bulk and spherical formats, based on a multifunctional organo-alkoxysilane precursor.

The multifunctional alkoxysilane precursor, 2,6-bis(propyl-trimethoxysilylurelene)pyridine (DPS) was designed and synthesized, envisaging a multiple hydrogen-bond interaction in the molecular imprinting of the drug aminoglutethimide (AGT). Imprinted xerogels were obtained in bulk and spherical formats. The spherical format was achieved by pore-filling onto spherical mesoporous silica, as a straightforward technique to generate the spherical format. The bulk gels presented better selectivity for the template against its glutarimide (GLU) analogue (selectivity factor: bulk 13.4; spherical 4.6), and good capacity (bulk 5521µmol/L; spherical 2679µmol/L) and imprinting factor parameters (bulk 11.3; spherical 1.4). On the other hand, the microspherical format exhibited better dynamic properties associated to chromatographic efficiency (theoretical plates: bulk 6.8; spherical 75) and mass transfer, due mainly to the existence of a mesoporous network, lacking in the bulk material. The performance of the imprinted xerogels was not as remarkable as that of their acrylic counterparts, previously described. Overall it was demonstrated that the use of designed new "breeds" of organo-alkoxysilanes may be a strategy to achieve satisfactory imprints by the sol-gel processes. DPS may in principle be applied even more effectively to other templates bearing better-matching spatially compatible acceptor-donor-acceptor arrays.

Macromolecular crowding of molecular imprinting: A facile pathway to produce drug delivery devices for zero-order sustained release.

This paper reported the facile fabrication of drug delivery devices for zero-order sustained release by molecular crowding strategy of molecularly imprinting technology. Crowding-assisted molecularly imprinting polymers (MIPs) matrices were prepared by free-radical precipitation polymerization using aminoglutethimide (AG) as a model drug. The crowding effect was achieved by adding polystyrene as a macromolecular co-solute in pre-polymerization mixture. The MIP prepared under the non-MMC condition and the two corresponding non-imprinted particles were tested as controlled vehicles. The release profiles presented zero-order behaviors from two crowding-assisted polymers, the duration of approximately 18h for the crowding-assisted MIP and 10h for the crowding-assisted NIP, respectively while AG were all very rapid released from the other two controlled particles (85% occurring in the first hour). The BET surface area and pore volume of the crowding-assisted MIP were about ten times than those of the controlled MIP. The value of imprinting factor is 6.02 for the crowding-assisted MIP and 1.19 for the controlled MIP evaluated by the equilibrium adsorption experiment. Furthermore, the values of effective diffusivity (Deff) obtained from crowding-assisted MIP (10(-17)cm(2)/s) was about two orders of magnitude smaller than those from the controlled MIP, although the values of free drug diffusivity (D) were all found in the order of 10(-13)cm(2)/s. Compared with the commercial AG tablet, the MMC-assisted MIP gave a markedly high relative bioavailability of 266.3%, whereas the MMC-assisted NIP gave only 57.7%. The results indicated that the MMC condition can modulate the polymer networks approaciate to zero-order release of the drug and maintain the molecular memory pockets, even if under the poor polymerization conditions of MIPs preparation.

Hepatic effects of aminoglutethimide: a model aromatic amine.

Primary aromatic amine drugs are structural alerts in drug development because of their association with a high incidence of idiosyncratic drug reactions (IDRs). If biomarkers could be found that predict IDR risk, it would have a major impact on drug development. Previous attempts to do this through screening of hepatic gene expression profiles in rodents treated with aromatic amine drugs found limited changes. Of the drugs studied, aminoglutethimide (AMG) induced the most changes, and this led to a more comprehensive study of its effects on the liver. Brown Norway rats treated with AMG for up to 14 days showed only a transient elevation of glutamate dehydrogenase. Pathway-specific PCR arrays found few AMG-induced gene changes associated with an immune response and, of these changes, the majority were involved with innate immunity such as Tlr2, Ticam2, CD14, and C3. AMG treatment also led to significant changes in the apoptosis and mitochondrial panel of genes. It was recently found that AMG does induce significant changes in the bone marrow of rats, and agranulocytosis is a common IDR caused by AMG. In contrast, liver injury is not a common IDR associated with AMG. Therefore, the liver may be able to effectively deal with AMG reactive metabolites, and changes observed in this study may be involved in adaptation. Myeloperoxidase is also known to be able to oxidize aromatic amines to reactive metabolites, and these observations suggest that metabolism outside of the liver may be important for the mechanism of aromatic amine-induced IDRs.

[Chromatographic separation of aminoglutethimide enantiomers on cellulose tris(3,5-dimethylphenylcarbamate) chiral stationary phase].

Aminoglutethimide (AG) has been used clinically as a drug in the treatment of hormone-dependent metastatic breast cancer. It was reported that S-(-)-AG enantiomer had small activity and sometimes might cause side effects. Therefore, it was of great significance to obtain the high-purity R-(+)-AG by enantioseparation. In this work, aminoglutethimide enantiomers were separated by high performance liquid chromatography (HPLC) using an analytical column which was packed with cellulose tris(3,5-dimethylphenylcarbamate) stationary phase (Chiralcel OD-H). The solubilities of racemic AG in two different solvent compositions, n-hexane/ethanol and n-hexane/isopropanol, were measured, separately. The effects of alcohol content and monoethanolamine additive on the separation performance of racemic AG by HPLC were investigated. According to the experiments, n-hexane-ethanol (30:70, v/v) with 0.1% monoethanolamine additive was selected as the mobile phase. The separation factor, resolution, asymmetry factor, number of theoretical plates and maximum column capacity were measured and analyzed for the chromatographic separation of racemic AG at a flow-rate of 0. 6 mL/min and column temperature of 25-40 °C, with Chiralcel OD-H as stationary phase and n-hexane-ethanol (30:70, v/v) with 0. 1% monoethanolamine as mobile phase. This work provides the basic information of chromatographic separation for the batch and continuous production of aminoglutethimide enantiomers.

Recognitive nano-thin-film composite beads for the enantiomeric resolution of the metastatic breast cancer drug aminoglutethimide.

Straightforward crushing and sieving bulk polymeric R-aminoglutethimide-imprinted materials were prepared by classical free radical polymerization, whereas nano thin walled grafted imprinted materials were prepared using RAFT mediated control polymerization technique. A stoichiometric non-covalent approach based on a triply hydrogen bonding functional monomer-template 1:1 complex (K=599mol(-1)L(-1)) led to chiral selectors far outperforming previously used selectors for resolving this racemate. The recognitive materials produced here (enantioselectivity factors, α∼10) also have no match within the previously reported enantioselective imprinted polymers (α 1.2-4.5). We here demonstrate a potentially generic solution to produce good quality grafted MIPs for templates interacting by hydrogen bonding alone, relying on solvent polarity tuning, significantly extending the range of templates compatible with this format.

Molecularly imprinted microspheres for the anticancer drug aminoglutethimide: synthesis, characterization, and solid-phase extraction applications in human urine samples.

Molecularly imprinted microspheres (MIMs) for the anticancer drug aminoglutethimide (AG) were synthesized by aqueous suspension polymerization. The expected size and diameter of MIMs are controlled easily by changing one of the surfactant types, ratio of organic-to-water phase or stirring rate during polymerization. The obtained MIMs exhibit specific affinity toward AG with imprinting factor of 3.11 evaluated with a chromatographic model. The resultant MIMs were used as the SPE materials for the extraction of AG from human urine. A molecularly imprinted SPE (MISPE) method coupled with HPLC has been developed for the extraction and detection of AG in urine. Our results showed that most impurities from urine can be removed effectively after a washing step and the AG has been enriched effectively after MISPE operation with the recovery of >90% (n = 3). The developed MISPE-HPLC method could be used for enrichment and detection of AG in human urine.

Effect of aminoglutethimide on neutrophils in rats: implications for idiosyncratic drug-induced blood dyscrasias.

Aminoglutethimide (AMG) is an aromatic amine aromatase inhibitor associated with a high incidence of idiosyncratic blood dyscrasias, especially agranulocytosis. Animal models of idiosyncratic drug reactions (IDRs) represent essential tools to study these reactions; however, there is currently no valid model of idiosyncratic drug-induced agranulocytosis. Although AMG does not cause agranulocytosis in most animals or humans, drugs associated with serious IDRs generally cause a higher incidence of mild reactions that resolve despite continued treatment. Therefore, the effects of AMG on neutrophils and bone marrow in rats were studied to understand the mechanisms of more serious IDRs. An increase in peripheral blood neutrophils occurred as early as 24 h after AMG treatment with minimal changes to the total leukocyte count. Further investigation using 5-bromo-2'-deoxyuridine (BrdU) found an increased release of neutrophils from the bone marrow. Histologically, this corresponded to an increase in myeloid cells in the bone marrow, which was confirmed by differential staining with CD45 and CD71. AMG treatment stimulated an increase in colony forming unit granulocyte-macrophage and colony forming unit granulocyte ex vivo. There was also a marked increase in the number of activated neutrophils in the circulation expressing the extravasation marker CD62L. These findings indicate that AMG affects neutrophil production, release, and function. Similar effects on neutrophil kinetics in clozapine-treated rats have previously been found, and transient neutrophilia has been observed in patients taking other drugs associated with idiosyncratic agranulocytosis; therefore, the changes observed with AMG may be biomarkers to predict the risk that a drug will cause agranulocytosis.

Synthesis and aromatase inhibitory activity of some new 16E-arylidenosteroids.

A new series of 16E-arylidene androstene derivatives has been synthesized and evaluated for aromatase inhibitory activity. The impact of various aryl substituents at 16 position of the steroid skeleton on aromatase inhibitory activity has been observed. The 16E-arylidenosteroids 6, 10 and 11 exhibited significant inhibition of the aromatase enzyme. 16-(4-Pyridylmethylene)-4-androstene-3,17-dione (6, IC(50): 5.2 µM) and 16-(benzo-[1,3]dioxol-5-ylmethylene)androsta-1,4-diene-3,17-dione (11, IC(50): 6.4 µM) were found to be approximately five times more potent in comparison to aminoglutethimide.

Aminoglutethimide-induced protein free radical formation on myeloperoxidase: a potential mechanism of agranulocytosis.

Aminoglutethimide (AG) is a first-generation aromatase inhibitor used for estrogen-dependent breast cancer. Unfortunately, its use has also been associated with agranulocytosis. We have investigated the metabolism of AG by myeloperoxidase (MPO) and the formation of an MPO protein free radical. We hypothesized that AG oxidation by MPO/H2O2 would produce an AG cation radical that, in the absence of a biochemical reductant, would lead to the oxidation of MPO. We utilized a novel anti-DMPO antibody to detect DMPO (5,5-dimethyl-1-pyrroline N-oxide) covalently bound to protein, which forms only by the reaction of DMPO with a protein free radical. We found that AG metabolism by MPO/H2O2 induced the formation of DMPO-MPO, which was inhibited by MPO inhibitors and ascorbate. Glutethimide, a congener of AG that lacks the aromatic amine, did not cause DMPO-MPO formation, indicating the necessity of oxidation of the aniline moiety in AG. When analyzed by electron spin resonance spectroscopy, we detected a phenyl radical adduct, derived from AG, which may be involved in the free radical formation on MPO. Furthermore, we also found protein-DMPO adducts in MPO-containing, intact human promyelocytic leukemia cells (HL-60). MPO was affinity-purified from HL-60 cells treated with AG/H2O2 and was found to contain DMPO. These findings were also supported by the detection of protein free radicals with electron spin resonance in the cellular cytosolic lysate. The formation of an MPO protein free radical is believed to be mediated by one of two free radical drug metabolites of AG, one of which was characterized by spin trapping with 2-methyl-2-nitrosopropane. These results are the first demonstration of MPO free-radical detection by the anti-DMPO antibody that results from drug oxidation. We propose that drug-dependent free radical formation on MPO may play a role in the origin of agranulocytosis.

Effects of aromatase inhibitors on human osteoblast and osteoblast-like cells: a possible androgenic bone protective effects induced by exemestane.

Effects of aromatase inhibitors (AIs) on the human skeletal system due to systemic estrogen depletion are becoming clinically important due to their increasing use as an adjuvant therapy in postmenopausal women with breast cancer. However, possible effects of AIs on human bone cells have remained largely unknown. We therefore studied effects of AIs including the steroidal AI, exemestane (EXE), and non-steroidal AIs, Aromatase Inhibitor I (AI-I) and aminoglutethimide (AGM), on a human osteoblast. We employed a human osteoblast cell line, hFOB, which maintains relatively physiological status of estrogen and androgen pathways of human osteoblasts, i.e., expression of aromatase, androgen receptor (AR), and estrogen receptor (ER) beta. We also employed osteoblast-like cell lines, Saos-2 and MG-63 which expressed aromatase, AR, and ERalpha/beta in order to further evaluate the mechanisms of effects of AIs on osteoblasts. There was a significant increment in the number of the cells following 72 h treatment with EXE in hFOB and Saos-2 but not in MG-63, in which the level of AR mRNA was lower than that in hFOB and Saos-2. Alkaline phosphatase activity was also increased by EXE treatment in hFOB and Saos-2. Pretreatment with the AR blocker, flutamide, partially inhibited the effect of EXE. AI-I exerted no effects on osteoblast cell proliferation and AGM diminished the number of the cells. hFOB converted androstenedione into E2 and testosterone (TST). Both EXE and AI-I decreased E2 level and increased TST level. In a microarray analysis, gene profile patterns following treatment with EXE demonstrated similar patterns as with DHT but not with E2 treatment. The genes induced by EXE treatment were related to cell proliferation, differentiation which includes genes encoding cytoskeleton proteins. We also examined the expression levels of these genes using quantitative RT-PCR in hFOB and Saos-2 treated with EXE and DHT and with/without flutamide. HOXD11 gene known as bone morphogenesis factor and osteoblast growth-related genes were induced by EXE treatment as well as DHT treatment in both hFOB and Saos-2. These results indicated that the steroidal aromatase inhibitor, EXE, stimulated hFOB cell proliferation via both AR dependent and independent pathways.

HPMA copolymer-aminoglutethimide conjugates inhibit aromatase in MCF-7 cell lines.

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer-doxorubicin (Dox) has already shown clinical activity in breast cancer patients. Moreover, we have recently found that an HPMA conjugate containing a combination of both Dox and the aromatase inhibitor aminoglutethimide (AGM) shows significantly increased anti-tumour activity in vitro. To better understand the mechanism of action of HPMA copolymer-AGM conjugates several models were used here to investigate their effect on cell growth and aromatase inhibition. Cytotoxicity of HPMA copolymer conjugates containing AGM, Dox and also the combination AGM-Dox was determined by MTT assay in MCF-7 and MCF-7ca cells. Androstenedione (5 x 10(- 8) M) stimulates the growth of MCF-7ca cells. Both free AGM and polymer-bound AGM (0.2-0.4 mg/ml) were shown to block this mitogenic activity. When MCF-7ca cells were incubated [(3)H]androstenedione both AGM and HPMA copolymer-GFLG-AGM (0.2 mg/ml AGM-equiv.) showed the ability to inhibit aromatase. Although, free AGM was able to inhibit isolated human placental microsomal aromatase in a concentration dependent manner, polymer-bound AGM was not, suggesting that drug release is essential for activity of the conjugate. HPMA copolymer conjugates containing aromatase inhibitors have potential for the treatment of hormone-dependant cancers, and it would be particularly interesting to explore further as potential therapies in post-menopausal women as components of combination therapy.

Aminoglutethimide included in nanocapsules suspension: comparison of GC-MS and HPLC methods for control.

Gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) offer highly efficient and potentially sensitive separation and detection techniques. This work describes the quantification of aminoglutethimide (AG) in nanocapsules suspension with both techniques. The analysis of different lots containing known concentrations of drug (1, 2, 3 and 4 mg ml(-1)) were used to investigate the quantitative capabilities of both chromatographic techniques. Both chromatographic methods were successful and on an analytical point of view the validations of aminoglutethimide dosing were suitable in both cases. In routine, the determination of the quality of nanocapsules suspension could be preferentially evaluated by difference between total AG concentration in suspension (evaluated by direct HPLC measure of the suspension diluted in acetonitrile) and free AG concentration (evaluated by direct HPLC measure of simple dilution of the supernatant).

Stereoselective determination of pyridoglutethimide enantiomers in serum with a chiral cellulose-based high-performance liquid chromatographic column using solid phase extraction and UV detection.

A sensitive method for the separation and determination of R(+)- and S(-) enantiomers of pyridoglutehimide in serum by high performance liquid chromatography (HPLC) with UV detection was developed. The assay involves the use of a solid-phase extraction for serum sample clean-up prior to HPLC analysis using a C18 Bond-Elute column. Chromatographic resolution of the enantiomers was performed on a reversed-phase cellulose-based chiral column (Chiralcel OD-R, 250 x 4.6 mm I.D.) under isocratic conditions using a mobile phase of 25:75 v/v acetonitrile-0.3 M aqueous sodium perchlorate (pH 6.2 adjusted with perchloric acid) at a flow rate of 0.8 ml/min. Recoveries for R(+)- and S(-)-pyridoglutethimide enantiomers were in the range 86-91% at 300-900 ng/ml level. Intra-day and inter-day precision calculated as %R.S.D. were in the ranges of 2.9-3.9 and 1.5-4.7% for both enantiomers, respectively. Intra-day and inter-day accuracies calculated as percentage error were in the ranges of 1.9-3.3 and 1.5-3.9% for both enantiomers, respectively. Linear calibration curves in the concentration ranges of 100-1500 ng/ml for each enantiomer show correlation coefficient (r) of more than 0.9995. The limit of quantification (LOQ) of each enantiomer was 100 ng/ml using 1 ml of serum. The detection limit (LOD) for each enantiomer in serum using a UV detection set at 257 nm was 50 ng/ml (S/N = 2).

Identification of the aromatase inhibitor aminoglutethimide in urine by gas chromatography/mass spectrometry.

Aminoglutethimide is used therapeutically as an aromatase inhibitor in the treatment of metastatic breast cancer in post-menopausal women. For doping purposes, aminoglutethimide may be used for treatment of adverse effects of an extensive abuse of anabolic androgenic steroids (gynaecomastia) and to increase the testosterone concentration and stimulation of testosterone biosynthesis. The use of aromatase inhibitors has been prohibited for male athletes since September 1, 2001. The purpose of this study was to develop methods for the identification of the parent compound or its main metabolite and the inclusion of this information into established screening procedures in doping analysis. An excretion study was conducted using oral application of one single therapeutic dose (500 mg) of Orimeten. The analysis was performed by gas chromatography/mass spectrometry (GC/MS). Aminoglutethimide is excreted almost totally as unconjugated parent compound and is detectable by different screening procedures for up to 165 h. Most suitable for the detection of aminoglutethimide is the screening procedure for heavy volatile nitrogen-containing drugs ('Screening 2'). However, since only competition samples are analysed in that screening procedure, the additional inclusion of aminoglutethimide in the screening procedure for anabolic androgenic agents ('Screening 4') is recommended. Full mass spectra and diagnostic ions for the analysis of aminoglutethimide are presented.

Aromatase inhibitors in breast cancer: an update.

BACKGROUND: Tamoxifen has been the endocrine treatment of choice for patients with breast cancer. The development of selective aromatase inhibitors has offered an alternative management approach for patients in whom a hormonal approach is indicated. METHODS: The authors reviewed reports in which aromatase inhibitors were compared with tamoxifen for the treatment of metastatic disease, as well as information pertinent to their use as adjuvant therapy. RESULTS: Both nonsteroidal (anastrozole and letrozole) and steroidal (exemestane) aromatase inhibitors for metastatic disease appear to provide superior efficacy and a better toxicity profile in first- and second-line treatment of metastatic disease than tamoxifen. Early results from the ATAC trial suggest anastrozole is superior to tamoxifen for disease-free survival, particularly in receptor-positive patients, and in reducing the incidence of contralateral breast cancer. CONCLUSIONS: Aromatase inhibitors have important roles in optimal management of postmenopausal patients with hormone-responsive metastases in both the adjuvant and advanced-disease settings.

Enantioseparation of aminoglutethimide with cyclodextrins in capillary electrophoresis and studies of selector-selectand interactions using NMR spectroscopy and electrospray ionization mass spectrometry.

The enantiomers of aminoglutethimide [2-(p-aminophenyl)-2-ethylglutarimide, AGT] can be resolved in CE using all of three most commonly used native cyclodextrins (CD): alpha-, beta-, and gamma-CDs. The migration order of the enantiomers was opposite using beta-CD compared to alpha- and gamma-CDs as chiral selectors. In order to examine some underlying mechanisms of the chiral recognition the interaction of AGT with the chiral selectors was studied with one- and two-dimensional NMR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). The Job's and Scott's plots constructed based on the complexation-induced chemical shifts (CICS) observed in NMR spectra provided some preliminary information on the stoichiometry of the intermolecular complexes but did not seem to be absolutely reliable perhaps because the self-association of the analyte molecules and the formation of multiple type selectand-selector complexes. Therefore, an attempt was made to characterize the complexes using ESI-MS. This technique provided information on the stoichiometry and relative affinity constants of selector-selectand complexes. The information on the structure of complexes in the solution was obtained using one-dimensional rotating frame nuclear Overhauser enhancement (1D-ROESY) NMR spectroscopic studies. Significant differences were observed between the structures of the AGT complexes with beta- and gamma-CD.

Synthesis and biochemical evaluation of novel inhibitors of aromatase (AR) using an enhanced representation of the active site of AR derived from the consideration of the reaction mechanism.

A novel molecular modeling study, involving inhibitors bound to the iron of cytochrome P450 heme, is described for nonsteroidal inhibitors of aromatase (AR). Study of compounds such as aminoglutethimide (AG) suggests that it utilizes hydrogen bonding group(s) at the active site which would usually H-bond to the steroid C(17) carbonyl group. Interaction between AG's carbonyl groups and the area of the active site corresponding to the substrate C(3)==O group is not possible due to steric interaction. Possible reasons for the difference in activity of enantiomers of alternative inhibitors is also suggested, as well as the mode of action of the new AR inhibitor, Arimidex-whose inhibitory activity previously has not been rationalized. The present study proposes that it is able to use hydrogen bonding groups at the active site corresponding to the steroid C(17)==O and C(3)==O area, contradicting a previous study where it is postulated that azole-type compounds only use polar groups at the active site corresponding to the steroid D ring. Using the hypotheses of the modeling study, we designed and synthesized a number of novel (enantiomerically pure) inhibitors, which upon biochemical evaluation were found to be good inhibitors; the N-nonyl derivative of the S-enantiomer was found to possess 39% inhibition at 100 microM inhibitor concentration (using androstenedione as the substrate), under similar conditions, and AG possessed 20% inhibition.