Androgen receptor (AR) contributes to the progression of glioblastoma (GBM), which is consistent with the sex difference in GBM, which has a higher incidence in males than in females. Therefore, targeting AR is a potential therapeutic approach for GBM treatment. However, AR mutation commonly occurs in GBM, which makes conventional AR antagonists less effective. AR degraders abolish AR at the protein level regardless of the mutation status of AR, which makes it a better strategy in GBM. Compound A is an analog of the cyclooxygenase-2 (COX-2) inhibitor Nimesulide. Mechanistically, compound A targets HSP27, disrupts the HSP27-AR complex, and thereby promotes AR degradation in GBM cells at 1 μM, leading to inhibition of AR-overexpressing GBM cell growth with IC50s around 0.2 μM. In a GBM patient-derived cell line, DI318, compound A (1 μΜ) also significantly decreases AR protein levels. The compound significantly inhibits GBM xenograft growth at 20 mg/kg and does not cause toxicity in mice up to 200 mg/kg. Pharmacokinetic studies reveal that compound A has a half-life (t 1/2) of 3.11 h and a BBB penetration of 52%, which is even higher than the standard chemotherapy Temozolomide. These results suggest that the AR degrader has great potential as a novel GBM treatment.

Background: Triple-negative breast cancer (TNBC) tumors lack expression of estrogen receptor (ER), progesterone receptor (PR), and HER2, limiting the availability of targeted therapeutic options. As a result, TNBC is characterized by a high propensity for metastasis, rapid recurrence, and poor overall prognosis. Despite significant research efforts, the molecular mechanisms that drive TNBC progression and metastasis remain incompletely understood. Y box binding protein 1 (YB1) is a multifunctional DNA/RNA-binding protein that regulates transcription, translation, and mRNA stability. Aberrant activation of YB1 has been implicated in multiple oncogenic processes, including proliferation, survival, invasion, metastasis, and therapy resistance in several cancer types, including TNBC. Our investigations have revealed a central role for YB1 in regulating key hallmarks of cancer that drive TNBC tumor progression and metastatic dissemination. Methods: Cell viability and drug sensitivity in TNBC cell lines were assessed using the MTT assay to determine IC50 values for pharmacologic inhibitors. Western blotting and quantitative RT PCR were used to quantify protein and mRNA expression levels in TNBC cell lines and tumor samples. Oncogenic phenotypes were evaluated using 2D colony formation assays, 3D tumorsphere growth assays, limiting dilution, and transwell migration assays to assess proliferative, stem-like, and migratory capacities. Cell cycle progression was analyzed using flow cytometry based assays. In vivo therapeutic efficacy was evaluated using preclinical xenograft and patient-derived xenograft (PDX) mouse models of TNBC to assess tumor growth and metastatic progression following treatment. Results: Our studies demonstrate that the small-molecule inhibitor SU056, which specifically targets YB1 for degradation, significantly suppresses the oncogenic behavior of TNBC cell lines and tumors. Pharmacologic inhibition of YB1 reduced TNBC cell proliferation, clonogenic growth, tumorsphere formation, stemness and migratory capacity. Importantly, combined treatment with SU056 and the CDK4/6 inhibitor Palbociclib enhanced the inhibitory effect on TNBC cell growth and tumor progression compared with either agent alone. Mechanistically, both genetic and pharmacologic targeting of YB1 suppressed TNBC tumor growth and metastatic potential through modulation of the Cyclin D/CDK4/6/Rb signaling axis, leading to inhibition of cell cycle progression and induction of G1 arrest. Conclusion: Collectively, these findings identify SU056/CDK4/6i combination as a potential therapeutic option for the treatment of Rb+ TNBC.

Glioblastoma (GBM, isocitrate dehydrogenase wild-type) is the most common primary malignant brain tumor in adults and is associated with a severely low survival rate. Treatments offer mere palliation and are ineffective, due, in part, to a lack of understanding of the intricate mechanisms underlying the disease, including the contribution of the tumor microenvironment (TME). Current GBM models continue to face challenges as they lack the critical components and properties required. To address this limitation, we developed innovative and practical three-dimensional (3D) GBM models with structural and mechanical biomimicry and tunability. These models allowed for more accurate emulation of the extracellular matrix (ECM) and vasculature characteristics of the native GBM TME. Additionally, 3D bioprinting was utilized to integrate these complexities, employing a hydrogel composite to mimic the native environment that is known to contribute to tumor cell growth. First, we examined the changes in physical properties that resulted from adjoining hydrogels at diverse concentrations using Fourier-Transform Infrared Spectroscopy (FTIR), compression testing, scanning electron microscopy (SEM), rheological analysis, and degradation analysis. Subsequently, we refined and optimized the embedded bioprinting processes. The resulting 3D GBM models were structurally reliable and reproducible, featuring integrated inner channels and possessing tunable properties to emulate the characteristics of the GBM ECM. Biocompatibility testing was performed via live/dead and AlamarBlue analyses using GBM cells (both commercial cell lines and patient-derived cell lines) encapsulated in the constructs, along with immunohistochemistry staining to understand how ECM properties altered the functions of GBM cells. The observed behavior of GBM cells indicated greater functionality in softer matrices, while the incorporation of hyaluronic acid (HA) into the gelatin methacryloyl (gelMA) matrix enhanced its biomimicry of the native GBM TME. The findings underscore the critical role of TME components, particularly ECM properties, in influencing GBM survival, proliferation, and molecular expression, laying the groundwork for further mechanistic studies. Additionally, the outcomes validate the potential of leveraging 3D bioprinting for GBM modeling, providing a fully controllable environment to explore specific pathways and therapeutic targets that are challenging to study in conventional model systems.

Effective and safe treatments for neglected tropical diseases caused by parasites, such as Chagas disease and sleeping sickness, remain lacking, posing a significant challenge for researchers worldwide. The rational design of dimeric compounds inspired solely by the pharmacophoric core of benznidazole (2-nitroimidazole) has proven to be a promising strategy for antiparasitic development. Thus, in the present work, it was increased the linker between the active units (2-nitroimidazole) to improve the interaction with TcNTR, facilitating the bioactivation of the longest dimers. Biological assays confirmed this, demonstrating that all compounds were active against replicative intracellular amastigotes of Trypanosoma cruzi (Tulahuen C2C4-LacZ). Notably, longer-chain dimers exhibited remarkable potency (IC50 < 1.0 μM). These compounds also showed significant activity against T. b. brucei and demonstrated very low cytotoxicity in mammalian cells, highlighting their selectivity, especially among the longer-chain dimers. These findings support the development of dimeric 2-nitroimidazole derivatives as selective agents against trypanosomes.

Dysregulated spine morphology is a common feature in the pathology of many neurodevelopmental and neuropsychiatric disorders. Overabundant immature dendritic spines in the hippocampus are causally related to cognitive deficits of Fragile X syndrome (FXS), the most common form of heritable intellectual disability. Recent findings from us and others indicate autophagy plays important roles in synaptic stability and morphology, and autophagy is downregulated in FXS neurons. However, the mechanism remains unclear. In this study, we identified that activated autophagy degrades the eukaryotic initiation factor 4G1 (eIF4G1) and postsynaptic density protein-95 (PSD-95) in hippocampal neurons of Fmr1 KO mice and FXS neurons from patients, which subsequently corrected the dysregulated postsynaptic organization and actin assembly, the critical processes determining synaptic maturation and density. Centrally activating autophagy in hippocampus degrades eIF4G1 and PSD-95, restores actin dynamics, and improves cognition of Fmr1 KO mice. In human neurons derived from patients diagnosed with both FXS and intellectual disability, activating autophagy corrected the aberrant actin assembly. Thus, our findings revealed a previously unappreciated mechanism through which autophagy affects actin assembly and synaptic organization, suggesting a critical role of autophagy in regulating structural synaptic plasticity in healthy and diseased conditions.

Human African Trypanosomiasis (HAT), or sleeping sickness, is a life-threatening disease endemic to sub-Saharan Africa, caused by the protozoan parasite Trypanosoma brucei. The disease progresses from hemolymphatic to neurological stages, often leading to death if untreated. Current treatments are limited by severe side effects and the necessity for parenteral administration, underscoring the urgent need for safe, effective, and orally bioavailable therapies. Previous studies have identified tubulin inhibitors with promising in vitro activity against T. brucei; however, their clinical application is hindered by poor oral bioavailability. This study aims to optimize these inhibitors to enhance their oral efficacy and therapeutic potential. A series of 30 novel tubulin inhibitor analogs were synthesized using combinatorial chemistry techniques, focusing on reducing molecular weight and hydrophobicity to improve solubility and oral bioavailability. The anti-trypanosomal activity of these compounds was evaluated in vitro using T. brucei brucei cultures, while cytotoxicity assays were conducted on human kidney (HEK293) and mouse macrophage (RAW264.7) cell lines to assess selectivity. Compounds demonstrating low micromolar inhibitory concentrations (IC50) against T. brucei and minimal cytotoxicity to mammalian cells. Structure-activity relationship (SAR) analyses and molecular docking studies were performed to elucidate binding affinities to the trypanosome tubulin homolog. The most promising compound, referred to as compound 7, was selected for in vivo evaluation. In vivo efficacy was assessed using an acute mouse infection model. Mice were intraperitoneally injected with 1×106 T. brucei cells to induce infection. Compound 7 was administered orally for three consecutive days at dosages up to 50 mg/kg/day. Daily diagnostic microscopic examinations of tail blood samples were conducted to monitor parasitemia levels. Body weights of the mice were measured before and after the treatment period to evaluate the compound*s impact. Several synthesized analogs exhibited potent in vitro anti-trypanosomal activity, with IC50 values in the low micromolar range, effectively inhibiting T. brucei proliferation without significant cytotoxic effects on mammalian cells. SAR analysis revealed that reducing aromatic moieties and molecular weight correlated with enhanced activity and selectivity. Molecular docking studies indicated a strong correlation between binding energies to trypanosome tubulin and observed anti-parasitic activity. Compound 7, in particular, demonstrated a favorable binding profile and was advanced to in vivo studies. In the acute mouse infection model, the control group exhibited a steady rise in parasitemia, peaking at an average of 40 million parasites/mL in the blood by day 5. In contrast, mice treated with compound 7 experienced a significant reduction in parasite numbers, averaging 10 million parasites/mL on day 5. These findings strongly suggest a potential protective effect of compound 7. The optimization of tubulin inhibitors has led to the identification of compound 7, which exhibits potent oral activity against T. brucei in vitro and in vivo. This compound represents a promising development of orally administered therapies for HAT, addressing the limitations of current treatment regimens. Evaluating the pharmacokinetics, and efficacy of compound 7 in clinical settings is essential to determine its potential as a more accessible and effective treatment option for populations affected by HAT.

The modification of the 7-position in the estradiol structure has drawn significant attention from pharmacologists. In this paper, we synthesize various amine derivatives of estradiol, functionalized with a side chain at the 7-position. The anti-tumor activities of target compounds were evaluated using MTT assay. As the side chain is alkyl amides or halogen atoms substituted alkyl amine, the compounds exhibit excellent activity, with short chains being more active than long chains. Additionally, we studied the antitumor mechanism of the 7-substituted estradiol amide compounds. Compounds 9o can effectively inhibit the proliferation and migration of MCF-7 cells and induce early apoptosis in breast cancer tumors under certain concentration conditions.

Abstract Metastatic breast cancer (BC) is the 2nd leading cause of death in women in the US, annually accounting for more than 43,000 deaths and 281,000 new cases of invasive BC. Amongst genetically distinct BC subtypes, those classified as being “triple-negative” (TNBC) are especially devastating due to their highly metastatic behavior, their propensity to recur rapidly, and their low response to standard-of-care therapies. In fact, the acquisition of chemoresistant phenotypes represents the main cause of disease recurrence, metastasis, and death in TNBC patients. Currently, the molecular mechanisms that regulate TNBC progression and metastasis remain unknown, as does the way these metastatic tumors acquire resistance to standard-of-care therapies. We recently established YB1 as a novel driver of these deadly TNBC activities, doing so by stimulating the cancer stem cell phenotype, and by disrupting normal cell cycle progression, therefore promoting therapy resistance and metastasis of TNBC tumors. YB1 is a multifunctional protein that acts as a transcription factor of cancer stem cell genes Nanog, Oct and Sox. Moreover, aberrant activation of YB1 contributes to the metastatic progression of several cancers, including TNBC. Our investigations revealed a major role of YB1 in the regulation of several hallmarks of cancer that drive TNBC tumors progression and metastasis, both in vitro and in preclinical mouse models of TNBC tumors. In extending these discoveries, we now show that aberrant YB1 expression activates oncogenic signaling leading to the dysregulation of cell cycle progression through the regulation of the Cyclin D/CDK4/6 complex signaling and the RB pathway. We also report the identification of a novel small molecule inhibitor, SU056, that specifically targets YB1 and inhibits its oncogenic activity in TNBC cell lines. We further show that the SU056-mediated inhibition of YB1, either as monotherapy or in combination with the CDK4/6 inhibitors, has a significant impact on inhibiting TNBC tumor progression and metastasis. In fact, the SU056-CDK4/6 inhibitors combination showed a synergistic effect when compared to monotherapy, at the same time reducing the toxicity associated with CDK4/6 inhibitors. Mechanistically, our studies revealed that genetic or pharmacologic targeting of YB1 inhibits TNBC tumor progression and metastasis through the regulation cyclin D-CDK4/6-RB pathway and blockade of cell cycle progression. Together, our data support the notion that targeting YB1 represents a potential therapeutic option for the treatment of TNBC, which could be enhanced when combined with standard of care treatment modalities. Citation Format: Wei Wang, Lamyae El Khalki, Neelum Yousaf Zai, Justin Szpendyk, Akram Alkrekshi, Bin Su, Khalid Sossey-Alaoui. YB1 is a novel therapeutic for the treatment of triple negative breast cancer tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5728.

In previous studies, we developed anti-trypanosome tubulin inhibitors with promising in vitro selectivity and activity against Human African Trypanosomiasis (HAT). However, for such agents, oral activity is crucial. This study focused on further optimizing these compounds to enhance their ligand efficiency, aiming to reduce bulkiness and hydrophobicity, which should improve solubility and, consequently, oral bioavailability. Using Trypanosoma brucei brucei cells as the parasite model and human normal kidney cells and mouse macrophage cells as the host model, we evaluated 30 new analogs synthesized through combinatorial chemistry. These analogs have fewer aromatic moieties and lower molecular weights than their predecessors. Several new analogs demonstrated IC50s in the low micromolar range, effectively inhibiting trypanosome cell growth without harming mammalian cells at the same concentration. We conducted a detailed structure-activity relationship (SAR) analysis and a docking study to assess the compounds' binding affinity to trypanosome tubulin homolog. The results revealed a correlation between binding energy and anti-Trypanosoma activity. Importantly, compound 7 displayed significant oral activity, effectively inhibiting trypanosome cell proliferation in mice.

Glioblastoma (GBM) is the most common malignant brain tumor with poor prognosis under the current standard treatment. It is critical to develop new approaches to selectively battle the disease. GBM sex differences suggest that an androgen receptor (AR) is a potential therapeutic target to treat AR-overexpressed GBM. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein that stabilizes AR. Inhibition of HSP27 leads to AR degradation, indicating that HSP27 inhibitors could suppress AR activity in GBM. We have identified a lead HSP27 inhibitor that could induce AR degradation. Lead optimization resulted with two new derivatives (compounds 4 and 26) showing potent anti-GBM activity and improved drug distribution in comparison to the lead compound. Compounds 4 and 6 exhibit IC(50)s of 35 and 23 nM, respectively, to inhibit cell proliferation and also show significant activity to decrease the tumor growth in vivo.

Inhalation is a convenient way to deliver drugs to the respiratory tract in the treatment of respiratory diseases. For dry powder inhalers (DPI's), the principle of operation is to use the patient-generated inspiratory flow as energy source for emptying of the dose system and the delivery of fine drug particles into the respiratory tract. Resistance to airflow of the inhaler device is a major determinant for the inspiratory flow profile through the dry powder inhaler that can be generated by the patient. Therefore, resistance to airflow is one of the design parameters for DPI's, that could be used to control the inspiratory flow profile, and is one of the parameters to optimise particle deposition in the airways. In this study the effect of resistance to airflow on different parameters of the inspiratory flow curves as generated by healthy subjects, asthmatics and COPD patients was determined. As a result of increased resistance to airflow, the peak inspiratory flow (PIF), the flow increase rate (FIR) and the inhaled volume to reach PIF is decreased. On the other hand, the total inhalation time as well as the 80% dwell time is increased. In general, tuning of the resistance to airflow in the design of a dry powder inhaler may improve the drug deposition in the respiratory tract.

Human African trypanosomiasis (HAT) remains a health threat to sub-Saharan Africa. The current treatments suffer from drug resistance and life-threatening side effects, making drug discovery for HAT still important. A high-throughput screening of the library of pharmaceutically active compounds identified prazosin, an α-adrenoceptor antagonist, that showed selective activity toward Trypanosoma brucei brucei. Furthermore, a series of prazosin analogues were examined, and overall, the new analogues had improved activity and selectivity. To elucidate the binding partner, a biotin-conjugated probe was synthesized, and a protein pulldown assay combined with a proteomic analysis identified the flagellum attachment zone 1 (FAZ1) filament as an interacting partner. Additionally, prazosin treatment resulted in dysfunction of the flagellum of trypanosome cells, which is indicative of a FAZ1 irregularity. We also examined the drug distribution by utilizing immunofluorescence with a designed fluorescent analogue that showed partial colocalization with FAZ1. With the activity of the prazosin analogues, a structure-activity relationship (SAR) was summarized for future lead optimization. Our findings provide a new group of FAZ1 inhibitors as novel antitrypanosomal agents.

Human African trypanosomiasis is caused by a protozoan parasite Trypanosoma brucei majorly infecting people living in sub-Saharan Africa. Current limited available treatments suffer from drug resistance, severe adverse effects, low efficacy, and costly administrative procedures in African countries with limited medical resources. Therefore, there is always a perpetual demand for advanced drug development and invention of new strategies to combat the disease. Previous work in our lab generated a library of sulfonamide analogs as selective tubulin inhibitors, based on the structural difference between mammalian and trypanosome tubulin proteins. Further lead derivatization was performed in the current study and generated 25 potential drug candidates to improve the drug efficacy and uptake by selectively targeting the parasite's P2 membrane transporter protein with imidamide moiety. One of the newly synthesized analogs, compound 25 with a di-imidamide moiety, has shown greater potency with an IC50 of 1 nM to selectively inhibit the growth of trypanosome cells without affecting the viability of mammalian cells. Western blot analyses reveal that the compound suppressed tubulin polymerization in T. brucei cells. A detailed structure-activity relationship (SAR) was summarized that will be used to guide future lead optimization.

Resistance to endocrine therapies remains an impediment for the treatment of estrogen receptor (ER) positive breast cancer. ER down regulator Fulvestrant has showed great activity to overcome the endocrine resistance. However, Fulvestrant has poor bioavailability due to the hydrophobicity. Identification of novel ER down regulator is still important. Compounds 172 and 183 are two steroidal compounds with androgen scaffold but significantly down regulated ER in multiple breast cancer cell lines. RT-PCR results indicated that both compounds did not affect ER gene expression. Proteasome inhibitor MG132 could attenuate ER down regulation effect of the compounds, suggesting that the ER down regulation was via ubiquitin-proteasomal pathway. Furthermore, compounds 172 and 183 could downregulate ER in endocrine resistant breast cancer cell model long term estrogen deprivation (LTED) MCF-7 cells. Hydrophobicity of compounds 172 and 183 were determined and showed improved solubility compared to Fulvestrant. All these results suggested that compounds 172 and 183 could be potential lead compounds for drug development for the treatment of endocrine resistance breast cancer.

Previously compound I showed great anti-glioblastoma activity without toxicity in a mouse xenograft study. In this study, a sensitive and rapid high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method was developed and validated to investigate the pharmacokinetics and brain distribution of compound I in mice. The protein precipitation method was applied to extract the compound from mouse plasma and brain homogenates, and it was then separated using a Kinetex C 18 column with a mobile phase consisting of acetonitrile–0.1% formic acid water (50:50, v/v). The analytes were detected with multiple reaction monitoring for the quantitative response of the compounds. The inter- and intra-day precisions were <8.29 and 3.85%, respectively, and the accuracy range was within ±7.33%. The method was successfully applied to evaluate the pharmacokinetics of compound I in mouse plasma and brain tissue. The peak concentration in plasma was achieved within 1 h. The apparent elimination half-life was 4.06 h. The peak concentration of compound I in brain tissue was 0.88 μg/g. The results indicated that compound I was rapidly distributed and could cross the blood–brain barrier. The pharmacokinetic profile summarized provides valuable information for the further investigation of compound I as a potential anti-glioblastoma agent.

Androgen receptor (AR) contributes to the progression of glioblastoma (GBM), and antiandrogen agents have the potential to be used for the treatment of GBM. However, AR mutation commonly happens in GBM, which makes the antiandrogen agents less effective. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein to stabilize ARs. Inhibition of HSP27 results in AR degradation regardless of the mutation status of ARs, which makes HSP27 a good target to abolish ARs in GBM. Compound I is a HSP27 inhibitor that significantly induces AR degradation in GBM cells via the proteasomal pathway, and it selectively inhibits AR-overexpressed GBM cell growth with IC50 values around 5 nM. The compound also significantly inhibits in vivo GBM xenograft at 20 mg/kg and does not cause toxicity to mice up to 80 mg/kg. These results suggest that targeting HSP27 to induce AR degradation in GBM is a promising and novel treatment.

Previously compound 12 showed great anti-trypanosome activity without toxicity in an in vivo study. In the current study, a sensitive and rapid high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method was developed and validated to investigate its pharmacokinetics in mouse plasma. A protein precipitation method was applied to extract the compound, and it was then separated using a Kinetex C18 column with mobile phase consisting of acetonitrile-0.1% formic acid water (50:50, v/v) at a flow rate of 300 μl/min. The analytes were detected with the multiple reaction monitoring in negative electrospray ionization source for quantitative response of the compounds. Compound 12 was detected at m/z 477.0 → 367.2, while the internal standard compound 14 was detected at m/z 499.2 → 268.2. Inter- and intra-day precision was <5.22 and 2.79% respectively, while the accuracy range was within ±9.65%. The method was successfully applied to evaluate the pharmacokinetics of compound 12 in mouse plasma with two formulations (20% Cremophor EL or sesame oil) and drug administration routes (oral and intraperitoneal injection). We observed a better drug serum concentration with the Cremophor formulation, and the two different drug administration routes did not show significant differences from the drug distribution.

EphA2 receptor kinase could become a novel target for anti-glioblastoma treatment. Doxazosin previously identified acts like the endogenous ligand of EphA2 and induces cell apoptosis. Through lead structure modification a derivative of Doxazosin possessing unique dimeric structure showed an improvement in the activity. In the current study, we expanded the dimeric scaffold by lead optimization to explore the chemical space of the conjoining moieties and a slight variation to the core structure. 27 new derivatives were synthesized and examined with EphA2 overexpressed and wild type glioblastoma cell lines for cell proliferation and EphA2 activation. Three new compounds 3d, 3e, and 7bg showed potent and selective activities against the growth of EphA2 overexpressed glioblastoma cells. Dimer 3d modification replaces the long alkyl chain with a short polyethylene glycol chain. Dimer 7bg has a relatively longer polyethylene glycol chain in comparison to compound 3d and the length is more similar to the lead compound. Whereas dimer 3e has a rigid aromatic linker exploring the chemical space. The diversity of the linkers in the active suggest additional hydrogen binding sites has a positive correlation to the activity. All three dimers showed selective activity in EphA2 overexpressed cells, indicating the activity is correlated to the EphA2 targeting effect.

Previously synthesized tubulin inhibitors showed promising in vitro selectivity and activity against Human African Trypanosomiasis. Current aim is to improve the ligand efficiency and reduce overall hydrophobicity of the compounds, by lead optimization. Via combinatorial chemistry, 60 new analogs were synthesized. For biological assay Trypanosoma brucei brucei Lister 427 cell line were used as the parasite model and for the host model human embryonic kidney cell line HEK-293 and mouse macrophage cell line RAW 264.7 were used to test efficacy. Of the newly synthesized compounds 5, 39, 40, and 57 exhibited IC(50)s below 5 mu M inhibiting the growth of trypanosome cells and not harming the mammalian cells at equipotent concentration. Comparably, the newly synthesized compounds have a reduced amount of aromatic moieties resulting in a decrease in molecular weight. Due to importance of tubulin polymerization during protozoan life cycle its activity was assessed by western blot analyses. Our results indicated that compound 5 had a profound effect on tubulin function. A detailed structure activity relationship (SAR) was summarized that will be used to guide future lead optimization.

Compound 27 {1, 12-bis[4-(4-amino-6,7-dimethoxyquinazolin-2-yl)piperazin-1-yl]dodecane-1,12-dione} is a novel small molecule agonist of EphA2 receptor tyrosine kinase. It showed much improved activity for the activation of EphA2 receptor compared with the parental compound doxazosin. To support further pharmacological and toxicological studies of the compound, a method using liquid chromatography and electrospray ionization tandem mass spectrometry (LC-MS/MS) has been developed for the quantification of this compound. Liquid-liquid extraction was used to extract the compound from mouse plasma and brain tissue homogenate. Reverse-phase chromatography with gradient elution was performed to separate compound 27 from the endogenous molecules in the matrix, followed by MS detection using positive ion multiple reaction monitoring mode. Multiple reaction monitoring transitions m/z 387.3 → 290.1 and m/z 384.1 → 247.1 were selected for monitoring compound 27 and internal standard prazosin, respectively. The linear calibration range was 2-200 ng/mL with the intra- and inter-day precision and accuracy within the acceptable range. This method was successfully applied to the quantitative analysis of compound 27 in mouse plasma and brain tissue with different drug administration routes.