Synthesis of the sulfonamido derivatives of arabinonucleosides

1985 ◽  
Vol 50 (2) ◽  
pp. 383-392 ◽  
Author(s):  
Ladislav Novotný ◽  
Hubert Hřebabecký ◽  
Jiří Beránek
Keyword(s):  
Sodium Salt ◽  
Cyclization Reaction ◽  
Leukemia Cells ◽  
Inhibition Activity ◽  
Chloro Derivatives ◽  
L 1210 Leukemia ◽  
Kinetics Of ◽  
Derivatives Of

Reaction of the sodium salt of 4-aminobenzenesulfonamide with cyclocytidine I and cyclouridine II led to the 2-sulfonamido derivatives V and VI while the reaction with the 5'-chloro derivatives of anhydronucleosides III and IV afforded compounds VIII and IX containing nitrogen bridge between the carbon atoms in position 2 and 5'. Kinetics of the model cyclization reaction of 5'-chloroarabinosylisocytosine (XI) was followed and the structure of prepared compounds was confirmed. Inhibition activity against L 1210 leukemia cells in the experiments in vitro was exhibited by compounds V (1.4 . 10-5 mol l-1) and VIII (3.3 . 10-6 mol l-1).

scholarly journals Synthesis, Antitumor Activity, and Docking Analysis of New Pyrido[3’,2’:4,5]furo(thieno)[3,2-d]pyrimidin-8-amines

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3952 ◽  
Author(s):  
Sirakanyan ◽  
Spinelli ◽  
Geronikaki ◽  
Hakobyan ◽  
Sahakyan ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Heterocyclic Compounds ◽  
Phosphorus Oxychloride ◽  
Docking Analysis ◽  
Structure Activity ◽  
Biological Tests ◽  
Amino Derivatives ◽  
Chloro Derivatives ◽  
Derivatives Of

Continuing our research in the field of new heterocyclic compounds, herein we report on the synthesis and antitumor activity of new amino derivatives of pyrido[3’,2’:4,5](furo)thieno[3,2-d]pyrimidines as well as of two new heterocyclic systems: furo[2–e]imidazo[1,2-c]pyrimidine and furo[2,3-e]pyrimido[1,2-c]pyrimidine. Thus, by refluxing the 8-chloro derivatives of pyrido[3’,2’:4,5]thieno(furo)[3,2-d]pyrimidines with various amines, the relevant pyrido[3’,2’:4,5]thieno(furo)[3,2-d]pyrimidin-8-amines were obtained. Further, the cyclization of some amines under the action of phosphorus oxychloride led to the formation of new heterorings: imidazo[1,2-c]pyrimidine and pyrimido[1,2-c]pyrimidine. The possible antitumor activity of the newly synthesized compounds was evaluated in vitro. The biological tests evidenced that some of them showed pronounced antitumor activity. A study of the structure–activity relationships revealed that the compound activity depended mostly on the nature of the amine fragments. A docking analysis was also performed for the most active compounds.

scholarly journals BST-236, a Novel Cytarabine Prodrug, Is Safer and As Effective As Cytarabine in In Vivo Leukemia Models

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 1451-1451 ◽  
Author(s):  
Shoshi Tessler ◽  
Inbal Mishalian ◽  
Ronny Peri-Naor ◽  
Stela Gengrinovitch ◽  
Raphael Mayer ◽  
...  
Keyword(s):  
Weight Loss ◽  
Cell Death ◽  
Systemic Toxicity ◽  
In Vivo Studies ◽  
Leukemia Cells ◽  
Severe Toxicity ◽  
Unfit Patients ◽  
Kinetics Of

Abstract Introduction: Acute myeloid leukemia (AML) is associated with poor outcomes in older and medically unfit patients, largely due to the severe toxicity associated with cytarabine treatment, which precludes the administration of effective cytarabine doses. BST-236 is a prodrug of cytarabine, inactive in its prodrug form and designed to deliver cytarabine to leukemia cells with reduced systemic toxicity, thus to enable delivery of high cytarabine doses to leukemia cells with relative sparing of normal tissues. Results: BST-236 is a conjugate of cytarabine and asparagine (Figure 1). It was demonstrated that BST-236 is inactive as an intact prodrug and that its activity is exerted by release of cytarabine via non-enzymatic hydrolysis. Unlike free cytarabine, the bound cytarabine in BST-236 is not phosphorylated into its active metabolite Ara-CTP and it is protected by the asparagine residue from deamination into its inactive form Ara-U. In vitro studies demonstrate that BST-236 enters into leukemia cells, accompanied by cellular accumulation of free cytarabine, which is released from BST-236 (Figure 2). Like cytarabine, treatment with BST-236 result in induction of cell death of various leukemia cell lines via apoptosis, an activity which is dependent on the human equilibrative nucleoside transporter 1 (hENT1). The in vitro kinetics of BST-236-induced toxicity were found to be delayed compared to administration of free cytarabine, correlating with an observed delayed cellular availability of cytarabine. In vivo studies in mice and dogs demonstrate that BST-236 concentrations in the plasma are dose-proportional, with a prodrug-typical profile and only ~5% of free cytarabine present in the plasma. The maximal tolerated dose of BST-236 was found to be several-fold higher than reported for cytarabine, with mainly hematological effects and no unexpected toxicities. In vivo head-to-head studies in human leukemia mouse models with equimolar doses of cytarabine and BST-236 demonstrate similar efficacy of complete elimination of the leukemia cells in the bone marrow, spleen, and peripheral blood by both molecules (Figure 3A). However, while cytarabine treatment was associated with significant toxicity including weight loss, dramatic reduction in spleen size and number of mouse spleen cells, and delayed normal murine white blood cell recovery, equimolar BST-236 doses enabled spleen and BM recovery with minimal weight loss and no observed clinical signs (Figure 3B, 3C). Summary: in vitro and in vivo studies demonstrate that BST-236 is a prodrug of cytarabine, which enables the delivery of cytarabine to target cells, resulting in elimination of the leukemia with reduced systemic toxicity compared to free cytarabine. The data also suggest that while the mechanism of cell death induced by BST-236 and cytarabine is similar, the observed differential kinetics of the delivery of cytarabine by BST-236 and its metabolism may explain its reduced systemic toxicity. Our nonclinical findings are in line with the clinical results of the BST-236 Phase 1/2 study (ASH 2017 abstract no 893, manuscript in preparation) and suggest that BST-236 may enable delivery of high cytarabine doses to older and medically-unfit patients who currently cannot benefit from an effective cytarabine therapy. This suggestion is to be confirmed by an ongoing Phase 2b study. Disclosures Tessler: Biosight: Employment. Gengrinovitch:Biosight: Employment. Ben Yakar:Biosight: Employment. Peled:Cellect Biotherapeutics Ltd: Consultancy. Flaishon:Biosight: Employment.

The Potential Role of the Six1/Eya1 Pathway in the Establishment of Leukemia Stem Cells in MLL-ENL – Induced Leukemia

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1362-1362 ◽  
Author(s):  
Sylvia Takacova ◽  
Pavla Luzna ◽  
Viktor Stranecky ◽  
Vladimir Divoky
Keyword(s):  
Bone Marrow ◽  
Cellular Transformation ◽  
Leukemia Cells ◽  
Leukemia Stem Cells ◽  
Transcription Profile ◽  
Self Renewal ◽  
Kinetics Of

Abstract Abstract 1362 During the multistep pathogenesis of acute leukemia (AL), a pool of leukemia stem cells (LSCs) emerges that is capable of limitless self-renewal and ensuring disease maintenance. The molecular mechanism that controls the kinetics of cellular transformation and development of LSCs is largely unknown. Using our MLL-ENL-ERtm mouse model, we have previously shown (Takacova et al., Blood 2009, 114 (22): 947–947, ASH abstract) activation of the ATR/ATM-Chk1/Chk2-p53/p21 checkpoint leading to senescence at early stages of cellular transformation (myeloproliferation), thereby preventing AL development in vivo. Experimental ATM/ATR inhibition accelerated the transition to immature cell states, acquisition of LSC properties and AL development in these mice. The MLL-ENL-ERtm mouse model allows us to study the kinetics of MLL-ENL-ERtm LSC development. We raised the questions how the transformation process progresses from the pre-LSC to the LSC state, and how DNA damage response (DDR) - mediated senescence affects the transition in gene expression. Given that the threshold of DDR signaling events is rate-limiting, we determined the transcription profile of the pre- LSC–enriched cell states derived from bone marrow and spleen of the MLL-ENL-ERtm mice at the early disease stage, and we correlated this transcription profile with the level of DDR, proliferation rate and induction of senescence. Pair-wise comparisons revealed up-regulation of the Six1 transcription factor gene and its cofactor Eya1 in the MLL-ENL-ERtm pre-LSCs in association with aberrant proliferation in both tissues. The notable difference between the two tissues concerning the barrier induction was the higher threshold of DDR and senescence in the bone marrow due to cooperation with inflammatory cytokines that fine-tune the DDR level. Interestingly, the expression of Six1 and Eya1 genes was down-regulated in senescence exclusively in the bone marrow. Consistent with these in vivo data, we found Six1 expression decreased in response to inflammation/DDR-induced senescence in the MLL-ENL-ERtm bone marrow cells cultured in vitro and correlated with SA-beta-gal positivity and p16 up-regulation. Six1 mRNA level was decreased only transiently after ionizing radiation (4 Gy)-induced DDR in the same cell line. These data suggest that Six1 expression is down-regulated in response to high DDR and permanent cell-cycle arrest in the MLL-ENL-ERtm pre-LSCs. Furthermore, we identified the transcription profile of the LSC-enriched cell state after inhibition of DDR in caffeine-treated MLL-ENL-ERtm mice in vivo. Interestingly, the expression level of Six1 and Eya1 was significantly increased in the bone marrow and spleen of the MLL-ENL-ERtm AML mice compared to the early (preleukemia) stage. High expression of Six1 and Eya1 and higher cell number expressing these genes was further confirmed by immunohistochemical staining on tissue sections. The MLL-ENL-ERtm LSC-enriched spleen cells showed increased colony forming ability in vitro and leukemia-initiating potential in serial transplantation experiments compared to pre-LSCs. Moreover, we detected Six1 and Eya1 expression in the infiltrating leukemia cells in tissues of the caffeine-treated MLL-ENL-ERtm AML mice and in a subset of leukemia cells in transplanted mice. Based on these findings and correlations, we hypothesized that the Six1/Eya1 pathway might be involved in regulation of some of the aspects of LSC development as well as invasion and maintenance of leukemia in our MLL-ENL-ERtm mice. Notably, our data indicate that senescence represses a subset of the MLL-ENL-downstream transcription response and prevents full activation of self-renewal. Experiments leading to more detailed understanding of the role of the Six1/Eya1 pathway in the MLL-ENL-induced cellular transformation are ongoing. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Formulations and evaluation of Cyclodextrin complexed Ceadroxil loaded nanosponges

2017 ◽  
Vol 9 (3) ◽  
pp. 84 ◽  
Author(s):  
Pawan Dubey ◽  
Hemant Kumar Sharma ◽  
Sunil Shah ◽  
Chandra Kishore Tyagi ◽  
Amol R. Chandekar ◽  
...  
Keyword(s):  
Lactone Ring ◽  
Release Kinetics ◽  
Major Drawback ◽  
Zeta Potentials ◽  
Poorly Soluble ◽  
Dosing Intervals ◽  
And Control ◽  
Kinetics Of ◽  
Derivatives Of

<p>Cefadroxil (CFD) is a broad spectrum antibiotic that acts against an extensive variety of bacteria, including Gram-positive and Gram-negative bacteria. The major drawback of orally administered drug like cefadroxil is its shorter half life of 1.2 hrs. The goal of the study is to prolong the drug release, producing a desired blood serum level, reduction in drug toxicity and improving the patient compliance by prolonging the dosing intervals. Cyclodextrin-based nanosponges (NS) are a novel class of cross-linked derivatives of cyclodextrins. They have been used to increase the solubility of poorly soluble actives, to protect the labile groups and control the release. This study aimed at formulating complexes of CFDwith three types of β-cyclodextrin NS obtained with different cross-linking ratio (viz. 1:2, 1:4 and 1:8 on molar basis with the cross-linker) to protect the lactone ring from hydrolysis and to prolong the release kinetics of CFD. Crystalline (F<sub>1:2</sub>, F<sub>1:4</sub> and F<sub>1:8</sub>) and paracrystalline NS formulations were prepared. XRPD, DSC and FTIR studies confirmed the interactions of CFDwith NS. XRPD showed that the crystallinity of CFD decreased after loading. CFD was loaded as much as 21%, 37% and 13% w/w in F<sub>1:2 </sub>, F<sub>1:4</sub> and F<sub>1:8</sub>, respectively while the paracrystalline NS formulations gave a loading of about 10% w/w or lower. The particle sizes of the loaded NS formulations were between 450 and 600 nm with low polydispersity indices. The zeta potentials were sufficiently high (-20 to -25 mV) to obtain a stable colloidal nanosuspension. The in vitro studies indicated a slow and prolonged CFD release over a period of 24 h. The NS formulations protected the lactone ring of CFD after their incubation in physiological conditions at 37°C for 24 h with a 80% w/w of intact lactone ring when compared to only around 20% w/w of plain CFD.</p>

scholarly journals Resistance to Quinupristin-Dalfopristin Due to Mutation of L22 Ribosomal Protein in Staphylococcus aureus

2002 ◽  
Vol 46 (7) ◽  
pp. 2200-2207 ◽  
Author(s):  
Brigitte Malbruny ◽  
Annie Canu ◽  
Bülent Bozdogan ◽  
Bruno Fantin ◽  
Virginie Zarrouk ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Plasmid Dna ◽  
Ribosomal Proteins ◽  
23S Rrna ◽  
Dna Encoding ◽  
Fluorescence Kinetics ◽  
C Terminus ◽  
Kinetics Of ◽  
Derivatives Of

ABSTRACT The mechanism of resistance to the streptogramin antibiotics quinupristin and dalfopristin was studied in a Staphylococcus aureus clinical isolate selected under quinupristin-dalfopristin therapy, in four derivatives of S. aureus RN4220 selected in vitro, and in a mutant selected in a model of rabbit aortic endocarditis. For all strains the MICs of erythromycin, quinupristin, and quinupristin-dalfopristin were higher than those for the parental strains but the MICs of dalfopristin and lincomycin were similar. Portions of genes for domains II and V of 23S rRNA and the genes for ribosomal proteins L4 and L22 were amplified and sequenced. All mutants contained insertions or deletions in a protruding β hairpin that is part of the conserved C terminus of the L22 protein and that interacts with 23S rRNA. Susceptible S. aureus RN4220 was transformed with plasmid DNA encoding the L22 alteration, resulting in transformants that were erythromycin and quinupristin resistant. Synergistic ribosomal binding of streptogramins A and B, studied by analyzing the fluorescence kinetics of pristinamycin IA-ribosome complexes, was abolished in the mutant strain, providing an explanation for quinupristin-dalfopristin resistance.

scholarly journals The effects of combined antifolates on inhibition of growth of murine leukemia cells cultured in vitro.

1997 ◽  
Vol 44 (4) ◽  
pp. 743-750
Author(s):  
M Balińska ◽  
I Szablewska ◽  
D Janiszewska ◽  
K Bartuzi ◽  
K Pawełczak
Keyword(s):  
De Novo ◽  
Inhibitory Effect ◽  
Leukemia Cells ◽  
Intact Cells ◽  
Inhibition Of Growth ◽  
Prior Application ◽  
Thymidylate Synthesis ◽  
Derivatives Of ◽  
Murine Leukemia

The synergistic effect of trimetrexate (TMTX) and sulphonamide derivatives of quinazoline on the cultured 5178Y murine leukemia cells was examined. On exposure to the slightly inhibitory concentrations of TMTX (0.1 nM) in combination with 2-desamino-2-methyl-10-propargyl-5,8-dideaza-pteroyl-sulphoglyc ine (DMPDDSF) (0.02 microM) a synergistic inhibitory effect of the antifolates on cell growth was observed. These two drugs in the same combination caused also synergistic inhibition of de novo synthesis of thymidylate in intact cells as measured by tritium release from [5-(3)H]deoxyuridylate. This was accompanied by a marked reduction in intracellular concentration of 5,10-methylenetetrahydro-pteroyl-polyglutamate (5,10CH2H4PteGlu(n)) (0.2 microM) and dihydropteroyl-polyglutamate (0.12 microM). In these conditions de novo biosynthesis of purine was decreased by 50%. These observations show that growth inhibition by combined antifolates is mediated by intracellular depletion of the substrate of thymidylate synthase -- 5,10CH2H4PteGlu(n). The results obtained strongly suggest that under certain conditions inhibition of thymidylate synthesis by DMPDDSF is intensified by prior application of TMTX -- an inhibitor of dihydrofolate reductase.

In vitro Organogenesis and Alkaloid Accumulation in Datura innoxia

2006 ◽  
Vol 61 (7-8) ◽  
pp. 560-564 ◽  
Author(s):  
Rawia Zayed ◽  
Michael Wink ◽  
Hesham El-Shamy
Keyword(s):  
Tropane Alkaloids ◽  
Stem Explants ◽  
Ms Medium ◽  
Datura Innoxia ◽  
Callus Differentiation ◽  
Kinetics Of ◽  
Derivatives Of ◽  
Indole 3 Acetic Acid ◽  
Undifferentiated Callus

The kinetics of tropane alkaloids accumulation in different organs such as roots, leaves, stems, flowers and seeds of Datura innoxia was investigated by GC-MS. Twenty-six tropane alkaloids were detected. The ester derivatives of tropine (3α-tigloyloxytropine and 3-tigloyloxy- 6-hydroxytropine) are the major compounds. Undifferentiated callus were established from the stem explants of Datura innoxia using Murashige and Skoog (MS) medium supplied with 6-benzylaminopurine (BA, 1 mg l-1) and indole-3-acetic acid (IAA, 0.5 mg l-1) in combination for 6 weeks. Callus differentiation was initiated by subculture onto solid MS medium, free from hormones, for more than 10 months. Initially, shoots were formed after four weeks from subculture. Further subculturing in basal MS medium without growth regulators initiated the rooting of a shooty callus after 6 weeks. Investigation of the alkaloid content of the unorganized and organized callus revealed that callus (either green or brown) yielded only trace amounts of alkaloids. On the other hand, re-differentiated shoots contained mainly scopolamine while re-differentiated roots biosynthesized hyoscyamine as the main alkaloid.

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