To investigate the mechanism(s) of bisalkylation by isophosphoramide mustard (IPM), IPM-beta,beta,beta',beta'-d(4) was synthesized and the products of its reaction with thiosulfate (at pD 7.0) were analyzed by NMR. By both (1)H and (13)C NMR, the distribution of deuterium in the products was consistent with bisalkylation through sequential aziridinyl intermediates [(NCH(2)CD(2)S):(NCD(2)CH(2)S) = 53:47]. Under the given reaction conditions, label scrambling as a result of thiosulfate acting as a leaving group was ruled out through control experiments. The data gave a calculated kinetic isotope effect of 0.97 per deuterium. For the initial aziridine species formed from IPM, ab initio quantum chemical calculations gave a hybridization value of sp(2.4)(-)(2.5) for each of the C-H bonds of the reaction centers, and this correlated with the observed inverse isotope effect. Other structure and bond order data were also determined for this aziridine intermediate and related compounds.
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http://dx.doi.org/10.1021/jo980546s | DOI Listing |
Front Vet Sci
February 2024
Department of Anatomy, Physiology and Pharmacology, College of Veterinary Medicine, Auburn, AL, United States.
Introduction: Osteosarcoma (OSA) is an aggressive form of bone cancer in both dogs and humans. The treatment options for metastatic (stage III) OSA are currently limited and the prognosis is poor. Zoledronate, a second generation amino-bisphosphonate, is commonly used for palliation of cancer induced bone pain.
View Article and Find Full Text PDFOncologist
November 2021
Medical Oncology Department, Hospital Universitario 12 de Octubre, Instituto de Investigación 12 de Octubre (i+12), Universidad Complutense de Madrid (UCM), Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain.
Background: Sunitinib (SUN)-induced hypoxia within the tumor could promote the activation of the prodrug evofosfamide (EVO), locally releasing the cytotoxic DNA alkylator bromo-isophosphoramide mustard. SUNEVO, a phase II, open-label, single-arm trial, investigated the potential synergy of SUN plus EVO in advanced progressive pancreatic neuroendocrine tumors (panNETs).
Methods: Systemic treatment-naïve patients with advanced or metastatic, unresectable, grade 1/2 panNETs with a Ki67 ≤20%, received EVO 340 mg/m on days 8, 15, and 22 every 4 weeks and sunitinib 37.
Evofosfamide (Evo or TH302) is a hypoxia-activated prodrug which is reduced leading to the release of alkylating agent bromo-isophosphoramide mustard, which has shown safety and signals of efficacy in a prior phase 1 study in recurrent glioblastoma. We performed a dual center single-arm Phase II study to expand on the safety and efficacy of Evo plus bevacizumab in bevacizumab refractory glioblastoma. 33 patients with bevacizumab refractory GBM received Evo 670 mg/m in combination with Bevacizumab 10 mg/kg IV every 2 weeks.
View Article and Find Full Text PDFCancer Res Treat
April 2021
Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
Purpose: Hypoxia is widely known as one of the mechanisms of chemoresistance and as an environmental condition which triggers invasion and metastasis of cancer. Evofosfamide is a hypoxia-activated prodrug of the cytotoxin bromo-isophosphoramide mustard conjugated with 2-nitroimidazole. Biliary tract cancer (BTC) is known to contain large hypoxic area.
View Article and Find Full Text PDFJ Immunother Cancer
August 2020
Molecular Radiotherapy and Innovative Therapeutics, Unité Mixte de Recherche 1030 INSERM, Gustave Roussy, F-94805, Villejuif, France
Background: Oxazaphosphorines (cyclophosphamide (CPA), ifosfamide (IFO)) are major alkylating agents of polychemotherapy protocols but limiting their toxicity and increasing their efficacy could be of major interest. Oxazaphosphorines are prodrugs that require an activation by cytochrome P450 (CYP). CPA is mainly metabolized (>80%) to phosphoramide mustard while only 10%-50% of IFO is transformed in the alkylating entity, isophosphoramide mustard and 50%-90% of IFO release chloroacetaldehyde, a nephrotoxic and neurotoxic metabolite.
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