(S)-Bicalutamide-d4

Synthetic Routes and Reaction Conditions

The synthesis of (S)-Bicalutamide-d4 involves several steps, starting from commercially available starting materials. The key steps include:

Deuterium Exchange Reaction: This involves the replacement of hydrogen atoms with deuterium atoms using deuterated reagents.

Coupling Reactions: These reactions form the core structure of this compound, typically involving palladium-catalyzed cross-coupling reactions.

Purification: The final product is purified using techniques such as recrystallization or chromatography to ensure high purity.

Industrial Production Methods

Industrial production of this compound follows similar synthetic routes but on a larger scale. The process is optimized for efficiency and cost-effectiveness, often involving continuous flow reactors and automated systems to ensure consistent quality and yield.

Types of Reactions

(S)-Bicalutamide-d4 undergoes various chemical reactions, including:

Oxidation: This reaction involves the addition of oxygen or the removal of hydrogen, often using oxidizing agents like potassium permanganate.

Reduction: This involves the addition of hydrogen or the removal of oxygen, typically using reducing agents such as lithium aluminum hydride.

Substitution: This reaction involves the replacement of one functional group with another, often using nucleophilic or electrophilic reagents.

Common Reagents and Conditions

Oxidation: Potassium permanganate, hydrogen peroxide.

Reduction: Lithium aluminum hydride, sodium borohydride.

Substitution: Halogenating agents, nucleophiles like amines or thiols.

Major Products

The major products formed from these reactions depend on the specific conditions and reagents used. For example, oxidation may yield hydroxylated derivatives, while reduction could produce deuterated alcohols.

Pharmacological Studies

Mechanism of Action
(S)-Bicalutamide-d4 acts as an androgen receptor antagonist, inhibiting the effects of androgens such as testosterone and dihydrotestosterone. It competes for binding at the androgen receptor sites, thereby blocking androgen-induced gene expression. This mechanism is crucial in understanding prostate cancer's growth dynamics and resistance mechanisms.

Research on Prostate Cancer
Numerous studies utilize this compound to investigate its efficacy in combination therapies for advanced prostate cancer. For instance, it has been shown to enhance the effects of luteinizing hormone-releasing hormone (LHRH) analogs, which suppress serum testosterone levels. Clinical data indicate that patients receiving this compound alongside LHRH therapy exhibit improved outcomes compared to those receiving LHRH alone .

Neurodegenerative Disease Research

Recent studies have explored the potential of this compound in treating neurodegenerative diseases like spinal and bulbar muscular atrophy (SBMA). Research indicates that this compound can enhance autophagic processes, leading to increased degradation of toxic proteins associated with neurodegeneration. In a mouse model of SBMA, administration of this compound resulted in improved motor function and extended survival rates by reducing androgen receptor toxicity .

Case Study: SBMA Model

• Objective : To assess the neuroprotective effects of this compound.
• Methodology : Mice were treated with this compound alongside trehalose, a natural disaccharide known for its protective effects on neurons.
• Results : The combination therapy led to significant improvements in motor behavior and muscle morphology, demonstrating the compound's potential as a therapeutic agent for neurodegenerative conditions .

Dermatological Applications

This compound has also been investigated for its efficacy in treating hyperandrogenism-related dermatological conditions such as hirsutism and acne. Clinical trials have shown that patients treated with bicalutamide formulations exhibit significant reductions in symptoms associated with excessive androgen levels.

Case Study: Treatment of Female Pattern Hair Loss

• Study Population : 44 women with female pattern hair loss.
• Dosage : 25-50 mg of bicalutamide daily for over six months.
• Outcomes : A mean reduction in hair loss severity was observed, with some patients maintaining or improving their condition without significant side effects .

Comparative Data Table

(S)-Bicalutamide-d4 exerts its effects by binding to androgen receptors, thereby inhibiting the action of androgens like testosterone. This inhibition prevents the growth and proliferation of androgen-dependent prostate cancer cells. The deuterium atoms in this compound may enhance its binding affinity and metabolic stability, leading to prolonged action.

Non-Deuterated Bicalutamide

Bicalutamide is a racemic mixture of (R)- and (S)-enantiomers, with the (S)-enantiomer being pharmacologically inactive. The parent compound binds to the AR ligand-binding domain (Ki = 12.5 µM; IC₅₀ = 1.2 µM), inhibiting androgen-mediated gene transcription .

Key Differences :

• This compound lacks therapeutic activity but provides analytical precision.
• Deuterated form avoids metabolic interference in assays, unlike non-deuterated bicalutamide, which may undergo sulfonation or hydroxylation .

Other Deuterated Internal Standards

Stable isotope-labeled analogs like S-1-d4 and atorvastatin-d5 are used alongside this compound in multi-residue analyses.

Key Insights :

• This compound exhibits significant matrix suppression in wastewater (up to 85%) but remains effective as an IS due to consistent co-elution with the analyte .
• Unlike S-1-d4 , which lacks documented matrix interference, this compound’s performance is well-characterized in complex matrices like influent and effluent .

Therapeutic Analogues: Enzalutamide and Derivatives

Enzalutamide, a second-generation AR antagonist, shows superior potency compared to bicalutamide.

IC₅₀ Values in Prostate Cancer Cell Lines :

Key Differences :

• Enzalutamide has a 4–5-fold lower IC₅₀ in androgen-sensitive LNCaP cells due to its irreversible AR binding .
• Bicalutamide analogs with sulfone groups (e.g., Compound 21) show moderate activity but lack clinical relevance compared to deuterated IS forms .

(S)-Bicalutamide-d4 is a deuterated analogue of bicalutamide, a well-known non-steroidal antiandrogen primarily used in the treatment of prostate cancer. This article explores the biological activity of this compound, focusing on its mechanism of action, efficacy in various cancer models, and potential therapeutic applications.

This compound functions as an androgen receptor (AR) antagonist . It binds to the AR and inhibits its activity, preventing the receptor from translocating to the nucleus where it would typically promote the expression of genes involved in cell proliferation and survival. Research indicates that this compound exhibits a similar mechanism to its parent compound, bicalutamide, by effectively blocking dihydrotestosterone (DHT) from activating the AR pathway .

Prostate Cancer

A significant body of research has focused on the efficacy of this compound in prostate cancer models. In vitro studies have demonstrated that this compound can inhibit cell growth in various prostate cancer cell lines, including LNCaP and DU-145. The half-maximal inhibitory concentration (IC50) values for these cell lines have been reported as follows:

These values indicate that this compound is effective at concentrations comparable to bicalutamide, suggesting potential for similar therapeutic applications .

Breast Cancer

Recent studies have also explored the use of bicalutamide and its analogues in treating androgen receptor-positive breast cancer. A phase II trial involving patients with estrogen receptor-negative breast cancer demonstrated that bicalutamide treatment resulted in a clinical benefit rate (CBR) of 19% among those with AR-positive tumors. Although specific data for this compound in this context is limited, its structural similarity implies potential efficacy against AR-positive breast cancers as well .

Case Studies and Clinical Trials

• Phase II Trial in Breast Cancer : A clinical trial evaluated bicalutamide's effectiveness in patients with metastatic breast cancer who were AR-positive. The study found that 12% of screened patients had AR-positive tumors, with a CBR of 19% after treatment with bicalutamide at 150 mg daily .
• Neuronal Cell Model : In studies involving spinal and bulbar muscular atrophy (SBMA), bicalutamide was shown to reduce toxic effects related to mutant AR aggregation. While specific results for this compound were not reported, these findings highlight the potential neuroprotective roles of antiandrogens in conditions associated with AR dysregulation .

Comparative Analysis with Other Compounds

To better understand the biological activity of this compound, it is essential to compare it with other antiandrogens such as enzalutamide and hydroxyflutamide:

This table illustrates that while this compound has comparable efficacy to other established antiandrogens, ongoing research may reveal additional benefits or specific applications for this compound.

Basic Research Questions

Q. How can I design experiments to assess the enantiomeric purity of (S)-Bicalutamide-d4 in preclinical studies?

• Methodological Answer : Utilize chiral chromatography coupled with mass spectrometry (LC-MS/MS) to separate and quantify enantiomers. Validate the method using reference standards of this compound and its (R)-enantiomer. Include parameters such as retention time, resolution factor (>1.5), and peak symmetry to confirm specificity . For reproducibility, perform intra- and inter-day precision tests with spiked plasma/serum matrices, adhering to ICH guidelines for analytical validation .

Q. What frameworks can guide the formulation of research questions for studying this compound’s androgen receptor binding kinetics?

• Methodological Answer : Apply the PICOT framework to structure the research question:

• P (Population): Androgen receptor-positive cell lines (e.g., LNCaP).
• I (Intervention): this compound at varying concentrations.
• C (Comparison): Non-deuterated (S)-Bicalutamide or (R)-enantiomer.
• O (Outcome): Receptor occupancy measured via radioligand binding assays.
• T (Time): Time-dependent dissociation rates (e.g., 24–72 hours).
  Refine feasibility using the FINER criteria (Feasible, Interesting, Novel, Ethical, Relevant) to ensure alignment with preclinical research ethics .

Q. How should I address discrepancies in reported IC50 values for this compound across different studies?

• Methodological Answer : Conduct a systematic review to identify variables affecting IC50 measurements, such as assay type (competitive binding vs. functional antagonism), cell line heterogeneity, or deuterium kinetic isotope effects. Perform meta-analysis using fixed- or random-effects models to quantify heterogeneity (I² statistic). Replicate key experiments under standardized conditions (e.g., uniform cell culture protocols, ligand concentrations) to resolve contradictions .

Advanced Research Questions

Q. What strategies can resolve contradictions in metabolic stability data between in vitro and in vivo models for this compound?

• Methodological Answer :

In vitro-in vivo extrapolation (IVIVE) : Compare hepatic microsomal stability (e.g., human vs. rodent) with pharmacokinetic data from animal models. Adjust for deuterium’s impact on metabolic pathways (CYP3A4 vs. non-enzymatic degradation).

Mechanistic modeling : Use physiologically based pharmacokinetic (PBPK) models to simulate deuterium’s isotope effect on clearance rates. Validate with tracer studies using deuterated vs. non-deuterated analogs .

Tissue-specific analysis : Apply imaging techniques (e.g., MALDI-MS) to assess localized drug distribution and metabolism in prostate tumors .

Q. How can I integrate multi-omics data to elucidate this compound’s off-target effects in androgen-sensitive tissues?

• Methodological Answer :

• Transcriptomics : Perform RNA-seq on treated vs. untreated tissues to identify dysregulated pathways (e.g., AR signaling, apoptosis). Use gene set enrichment analysis (GSEA) to prioritize targets.
• Proteomics : Combine SILAC (stable isotope labeling) with LC-MS/MS to quantify protein expression changes. Cross-validate with phosphoproteomic data to map kinase activity.
• Metabolomics : Analyze tissue extracts via NMR or HR-MS to detect deuterium-induced shifts in metabolic flux (e.g., lipid peroxidation, glutathione depletion).
  Triangulate findings using network pharmacology tools (e.g., Cytoscape) to identify hub nodes of off-target activity .

Q. What ethical and methodological considerations are critical when sharing patient-derived data from this compound clinical trials?

• Methodological Answer :

• De-identification : Apply GDPR-compliant anonymization techniques (e.g., k-anonymity, differential privacy) to protect patient identities. Remove indirect identifiers (e.g., rare diagnoses, precise ages) .
• Data Use Agreements (DUAs) : Restrict access to accredited researchers via controlled repositories (e.g., EGA, dbGaP). Include clauses for prohibitions on re-identification attempts.
• Consent forms : Predefine data-sharing scopes in informed consent documents, specifying allowable reuse (e.g., meta-analyses, machine learning). Update ethics approvals for secondary studies .

Q. Data Presentation and Validation

Q. How should I present conflicting enantiomer-specific efficacy data for this compound in a grant proposal?

• Methodological Answer :

• Comparative tables : Tabulate IC50, AUC, and receptor occupancy values for (S)- vs. (R)-enantiomers across studies. Highlight methodological differences (e.g., assay temperature, ligand purity).
• Sensitivity analysis : Use Monte Carlo simulations to model how variability in enantiomer ratios affects therapeutic outcomes.
• Preclinical justification : Propose head-to-head enantiomer studies in PDX (patient-derived xenograft) models to validate superiority claims .

Q. What statistical approaches are recommended for analyzing dose-response curves in this compound combination therapy studies?

• Methodological Answer :

• Synergy assessment : Apply the Chou-Talalay method (Combination Index) to distinguish additive, synergistic, or antagonistic effects. Use CompuSyn software for dose-effect matrix calculations.
• Non-linear regression : Fit data to log-logistic models (e.g., Hill equation) using tools like GraphPad Prism. Report EC50, Hill slope, and R² values.
• Bootstrap resampling : Estimate confidence intervals for EC50 to account for biological variability .