The preparation and characterization of products of the chemical and photochemical rearrangements of a 19-membered o,o'-azoxybenzocrown are presented. In photochemical rearrangement, besides the expected product i. e. 19-membered o-hydroxy-o,o'-azobenzocrown (19-o-OH) obtained under defined conditions with 75 % yield, also other macrocyclic products were isolated and identified, namely: 19-membered phydroxy-o,o'-azobenzocrown (19-p-OH), 21-membered o'hydroxy-o,p'-azobenzocrown (21-o'-OH) and 19-membered macrocycle containing a 5-membered ring bearing an aldehyde group (19-al). The structures of two atypical products of the photochemical rearrangement-21-o'-OH and 19-al-were determined in the solid state by X-ray analysis and in solution using NMR spectroscopy. Tautomeric equilibrium of the formed hydroxyazobenzocrowns and its change depending on acidity/ basicity of the environment and alkali and alkaline earth metal cations complexation were studied using UV-Vis spectrophotometry, spectrofluorimetry and 1 H NMR spectroscopy.
Unsymmetrical bisacridines (UAs) represent a novel class of anticancer agents previously synthesized by our group. Our recent studies have demonstrated their high antitumor potential against multiple cancer cell lines and human tumor xenografts in nude mice. At the cellular level, these compounds affected 3D cancer spheroid growth and their cellular uptake was selectively modulated by quantum dots. UAs were shown to undergo metabolic transformations in vitro and in tumor cells. However, the physicochemical properties of UAs, which could possibly affect their interactions with molecular targets, remain unknown. Therefore, we selected four highly active UAs for the assessment of physicochemical parameters under various pH conditions. We determined the compounds’ pKa dissociation constants as well as their potential to self-associate. Both parameters were determined by detailed and complex chemometric analysis of UV-Vis spectra supported by nuclear magnetic resonance (NMR) spectroscopy. The obtained results indicate that general molecular properties of UAs in aqueous media, including their protonation state, self-association ratio, and solubility, are strongly pH-dependent, particularly in the physiological pH range of 6 to 8. In conclusion, we describe the detailed physicochemical characteristics of UAs, which might contribute to their selectivity towards tumour cells as opposed to their effect on normal cells.
New unsymmetrical bisacridines (UAs) demonstrated high activity not only against a set of tumor cell lines but also against human tumor xenografts in nude mice. Representative UA compounds, named C-2028, C-2045 and C-2053, were characterized in respect to their physicochemical properties and the following studies aimed to elucidate the role of metabolic transformations in UAs action. We demonstrated with phase I and phase II enzymes in vitro and in tumors cells that: (i) metabolic products generated by cytochrome P450 (P450), flavin monooxygenase (FMO) and UDP-glucuronosyltransferase (UGT) isoenzymes in noncellular systems retained the compound’s dimeric structures, (ii) the main transformation pathway is the nitro group reduction with P450 isoenzymes and the metabolism to N-oxide derivative with FMO1, (iii), the selected UGT1 isoenzymes participated in the glucuronidation of one compound, C-2045, the hydroxy derivative. Metabolism in tumor cells, HCT-116 and HT-29, of normal and higher UGT1A10 expression, respectively, also resulted in the glucuronidation of only C-2045 and the specific distribution of all compounds between the cell medium and cell extract was demonstrated. Moreover, P4503A4 activity was inhibited by C-2045 and C-2053, whereas C-2028 affected UGT1A and UGT2B action. The above conclusions indicate the optimal strategy for the balance among antitumor therapeutic efficacy and drug resistance in the future antitumor therapy.
Unsymmetrical bisacridines (UAs) are a novel potent class of antitumor-active therapeutics. A significant route of phase II drug metabolism is conjugation with glutathione (GSH), which can be non-enzymatic and/or catalyzed by GSH-dependent enzymes. The aim of this work was to investigate the GSH-mediated metabolic pathway of a representative UA, C-2028. GSH-supplemented incubations of C-2028 with rat, but not with human, liver cytosol led to the formation of a single GSH-related metabolite. Interestingly, it was also revealed with rat liver microsomes. Its formation was NADPH-independent and was not inhibited by co-incubation with the cytochrome P450 (CYP450) inhibitor 1-aminobenzotriazole. Therefore, the direct conjugation pathway occurred without the prior CYP450-catalyzed bioactivation of the substrate. In turn, incubations of C-2028 and GSH with human recombinant glutathione S-transferase (GST) P1-1 or with heat-/ethacrynic acid-inactivated liver cytosolic enzymes resulted in the presence or lack of GSH conjugated form, respectively. These findings proved the necessary participation of GST in the initial activation of the GSH thiol group to enable a nucleophilic attack on the substrate molecule. Another C-2028-GSH S-conjugate was also formed during non-enzymatic reaction. Both GSH S-conjugates were characterized by combined liquid chromatography/tandem mass spectrometry. Mechanisms for their formation were proposed. The ability of C-2028 to GST-mediated and/or direct GSH conjugation is suspected to be clinically important. This may affect the patient's drug clearance due to GST activity, loss of GSH, or the interactions with GSH-conjugated drugs. Moreover, GST-mediated depletion of cellular GSH may increase tumor cell exposure to reactive products of UA metabolic transformations.
The aim: To assess the quality of life in women after mastectomy. Materials and methods: The study included 25 women after mastectomy. The patients were aged 31 to over 50 years and were members of a breast cancer support group at the Holy Cross Cancer Centre in Kielce. During group meetings, the patients underwent rehabilitation and worked with psychologists and social workers. Results: Most women after mastectomy who underwent breast reconstruction or wore breast prostheses reported a better quality of life. Mastectomy affects ipsilateral upper limb function and causes difficulty with activities of daily living, such as cleaning, cooking, brushing hair, bathing, and dressing. Conclusions: 1. All women who rated their health as poor experienced such negative emotions as sadness, low mood, dejection. 2. Mastectomy affects ipsilateral upper limb function. 3. Breast reconstruction after mastectomy improves patient-rated quality of life. 4. Pain in the ipsilateral upper limb is considerably more common in women with a limited range of motion. 5. All women who participated in breast cancer support group meetings found support there and the time they spent together resulted in an improved quality of life.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.