Late-Stage 18O Labeling of Primary Sulfonamides via a Degradation-Reconstruction Pathway

2020 ◽  
Author(s):  
Sean Reilly ◽  
Frank Bennett ◽  
Patrick Fier ◽  
Sumei Ren ◽  
Neil A. Strotman
Keyword(s):  
Late Stage ◽  
Parent Compound ◽  
Extreme Conditions ◽  
Isotopic Enrichment ◽  
18O Labeling ◽  
Back Exchange ◽  
Green Strategy ◽  
Labeling Approach

A late-stage <sup>18</sup>O labeling approach of sulfonamides that employs the corresponding unlabeled molecule as the starting material was developed. Upon deamination of the sulfonamide, a sulfinate intermediate was isotopically enriched using eco-friendly reagents H<sub>2</sub><sup>18</sup>O and <sup>15</sup>NH<sub>3</sub>(aq) to afford a M+5 isotopologue of the parent compound. This degradation-reconstruction approach afforded isolated yields of up to 96% for the stable isotope labeled (SIL) sulfonamides, and was compatible with multiple marketed therapeutics, including celecoxib, on a gram scale. The SIL products also exhibited no <sup>18</sup>O/<sup>16</sup>O back exchange under extreme conditions, further validating the utility of this green strategy for drug labeling for both <i>in vitro</i> and <i>in vivo</i> use. This procedure was also adapted to include pharmaceutically relevant methyl sulfones by using <sup>13</sup>CH<sub>3</sub>, affording M+5 isotopic enrichment, thereby illustrating the broad utility of this methodology.

Late-Stage 18O Labeling of Primary Sulfonamides via a Degradation-Reconstruction Pathway

2020 ◽  
Author(s):  
Sean Reilly ◽  
Frank Bennett ◽  
Patrick Fier ◽  
Sumei Ren ◽  
Neil A. Strotman
Keyword(s):  
Late Stage ◽  
Parent Compound ◽  
Extreme Conditions ◽  
Isotopic Enrichment ◽  
18O Labeling ◽  
Back Exchange ◽  
Green Strategy ◽  
Labeling Approach

A late-stage <sup>18</sup>O labeling approach of sulfonamides that employs the corresponding unlabeled molecule as the starting material was developed. Upon deamination of the sulfonamide, a sulfinate intermediate was isotopically enriched using eco-friendly reagents H<sub>2</sub><sup>18</sup>O and <sup>15</sup>NH<sub>3</sub>(aq) to afford a M+5 isotopologue of the parent compound. This degradation-reconstruction approach afforded isolated yields of up to 96% for the stable isotope labeled (SIL) sulfonamides, and was compatible with multiple marketed therapeutics, including celecoxib, on a gram scale. The SIL products also exhibited no <sup>18</sup>O/<sup>16</sup>O back exchange under extreme conditions, further validating the utility of this green strategy for drug labeling for both <i>in vitro</i> and <i>in vivo</i> use. This procedure was also adapted to include pharmaceutically relevant methyl sulfones by using <sup>13</sup>CH<sub>3</sub>, affording M+5 isotopic enrichment, thereby illustrating the broad utility of this methodology.

scholarly journals A New NonpolarN-Hydroxy Imidazoline Lead Compound with Improved Activity in a Murine Model of Late-Stage Trypanosoma brucei brucei Infection Is Not Cross-Resistant with Diamidines

2014 ◽  
Vol 59 (2) ◽  
pp. 890-904 ◽  
Author(s):  
Carlos H. Ríos Martínez ◽  
Florence Miller ◽  
Kayathiri Ganeshamoorthy ◽  
Fabienne Glacial ◽  
Marcel Kaiser ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Late Stage ◽  
Parent Compound ◽  
Central Nervous System Infection ◽  
Sleeping Sickness ◽  
Intrinsic Activity ◽  
Cross Resistance ◽  
Content Type

ABSTRACTTreatment of late-stage sleeping sickness requires drugs that can cross the blood-brain barrier (BBB) to reach the parasites located in the brain. We report here the synthesis and evaluation of four newN-hydroxy and 12 newN-alkoxy derivatives of bisimidazoline leads as potential agents for the treatment of late-stage sleeping sickness. These compounds, which have reduced basicity compared to the parent leads (i.e., are less ionized at physiological pH), were evaluatedin vitroagainstTrypanosoma brucei rhodesienseandin vivoin murine models of first- and second-stage sleeping sickness. Resistance profile, physicochemical parameters,in vitroBBB permeability, and microsomal stability also were determined. TheN-hydroxy imidazoline analogues were the most effectivein vivo, with 4-((1-hydroxy-4,5-dihydro-1H-imidazol-2-yl)amino)-N-(4-((1-hydroxy-4,5-dihydro-1H-imidazol-2-yl)amino)phenyl)benzamide (14d) showing 100% cures in the first-stage disease, while 15d, 16d, and 17d appeared to slightly improve survival. In addition, 14d showed weak activity in the chronic model of central nervous system infection in mice. No evidence of reduction of this compound with hepatic microsomes and mitochondria was foundin vitro, suggesting thatN-hydroxy imidazolines are metabolically stable and have intrinsic activity againstT. brucei. In contrast to its unsubstituted parent compound, the uptake of 14d inT. bruceiwas independent of known drug transporters (i.e.,T. bruceiAT1/P2 and HAPT), indicating a lower predisposition to cross-resistance with other diamidines and arsenical drugs. Hence, theN-hydroxy bisimidazolines (14d in particular) represent a new class of promising antitrypanosomal agents.

scholarly journals Antitrypanosomal activity of purine nucleosides can be enhanced by their conversion to O-acetylated derivatives.

1996 ◽  
Vol 40 (11) ◽  
pp. 2567-2572 ◽  
Author(s):  
J R Sufrin ◽  
D Rattendi ◽  
A J Spiess ◽  
S Lane ◽  
C J Marasco ◽  
...  
Keyword(s):  
Trypanosoma Brucei ◽  
Parent Compound ◽  
Nucleoside Analogs ◽  
Significant Activity ◽  
Structural Class ◽  
Antitrypanosomal Activity ◽  
Salvage Pathways ◽  
Purine Salvage Pathways

Fifteen purine nucleosides and their O-acetylated ester derivatives were examined for in vitro antitrypanosomal activity against the LAB 110 EATRO isolate of Trypanosoma brucei brucei and two clinical isolates of Trypanosoma brucei rhodesiense. Initial comparisons of activity were made for the LAB 110 EATRO isolate. Three nucleoside analogs exhibited no significant activity (50% inhibitory concentrations [IC50s] of > 100 microM), whether they were O acetylated or unacetylated; three nucleosides showed almost equal activity (IC50s of < 5 microM) for the parent compound and the O-acetylated derivative; nine nucleosides showed significantly improved activity (> or = 3-fold) upon O acetylation; of these nine analogs, six displayed activity at least 10-fold greater than that of their parent nucleosides. The most significant results were those for four apparently inactive compounds which, upon O acetylation, displayed IC50s of < or = 25 microM. When the series of compounds was tested against T. brucei rhodesiense isolates (KETRI 243 and KETRI 269), their antitrypanosomal effects were comparable to those observed for the EATRO 110 strain. Thus, our studies of purine nucleosides have determined that O acetylation consistently improved their in vitro antitrypanosomal activity. This observed phenomenon was independent of their cellular enzyme targets (i.e., S-adenosylmethionine, polyamine, or purine salvage pathways). On the basis of our results, the routine preparation of O-acetylated purine nucleosides for in vitro screening of antitrypanosomal activity is recommended, since O acetylation transformed several inactive nucleosides into compounds with significant activity, presumably by improving uptake characteristics. O-acetylated purine nucleosides may offer in vivo therapeutic advantages compared with their parent nucleosides, and this possibility should be considered in future evaluations of this structural class of trypanocides.

scholarly journals Bcl-2 antagonist apogossypol (NSC736630) displays single-agent activity in Bcl-2–transgenic mice and has superior efficacy with less toxicity compared with gossypol (NSC19048)

Blood ◽  
2008 ◽  
Vol 111 (6) ◽  
pp. 3211-3219 ◽  
Author(s):  
Shinichi Kitada ◽  
Christina L. Kress ◽  
Maryla Krajewska ◽  
Lee Jia ◽  
Maurizio Pellecchia ◽  
...  
Keyword(s):  
B Cells ◽  
Transgenic Mice ◽  
Parent Compound ◽  
Single Agent ◽  
Maximum Tolerated Dose ◽  
Low Grade ◽  
Altered Expression ◽  
Cell Counts

Abstract Altered expression of Bcl-2 family proteins plays central roles in apoptosis dysregulation in cancer and leukemia, promoting malignant cell expansion and contributing to chemoresistance. In this study, we compared the toxicity and efficacy in mice of natural product gossypol and its semisynthetic derivative apo-gossypol, compounds that bind and inhibit antiapoptotic Bcl-2 family proteins. Daily oral dosing studies showed that mice tolerate doses of apogossypol 2- to 4-times higher than gossypol. Hepatotoxicity and gastrointestinal toxicity represented the major adverse activities of gossypol, with apogossypol far less toxic. Efficacy was tested in transgenic mice in which Bcl-2 is overexpressed in B cells, resembling low-grade follicular lymphoma in humans. In vitro, Bcl-2–expressing B cells from transgenic mice were more sensitive to cytotoxicity induced by apogossypol than gossypol, with LD50 values of 3 to 5 μM and 7.5 to 10 μM, respectively. In vivo, using the maximum tolerated dose of gossypol for sequential daily dosing, apogossypol displayed superior activity to gossypol in terms of reducing splenomegaly and reducing B-cell counts in spleens of Bcl-2–transgenic mice. Taken together, these studies indicate that apogossypol is superior to parent compound gossypol with respect to toxicology and efficacy, suggesting that further development of this compound for cancer therapy is warranted.

scholarly journals Hematin-derived anticoagulant. Generation in vitro and in vivo.

1986 ◽  
Vol 163 (3) ◽  
pp. 724-739 ◽  
Author(s):  
R L Jones
Keyword(s):  
Aqueous Solutions ◽  
Anticoagulant Activity ◽  
Parent Compound ◽  
Iron Chelator ◽  
Ferric Citrate ◽  
Anticoagulant Effect ◽  
Single Peak

Prolongation of clotting times produced by hematin was investigated both in vitro and in vivo. Hematin-derived anticoagulant (HDA) was found to be due to a degradative product or derivative of hematin, and was generated in vitro in standing (aging) aqueous solutions of the parent compound. Generation of HDA in vitro was inhibited by antioxidants. The anticoagulant effect of HDA was inhibited by freshly prepared hematin, fresh Sn-protoporphyrin, imidazole, or the iron chelator desferrioxamine. Ferrioxamine did not inhibit HDA, and inhibition by imidazole was reversed with ferric citrate, suggesting a role for iron in the mechanism of HDA activity. HDA activity was dissociated from hematin in plasma by clotting with thrombin. HDA segregated into the clot fraction, whereas hematin remained largely in the serum fraction, suggesting that HDA may preferentially bind to fibrinogen. TLC and HPLC showed a single peak of HDA activity that was not associated with the parent compound. Evidence for HDA generation in vivo was found when rats were injected with fresh (no HDA) hematin. Prolongation of clotting times appeared after hematin appeared in the plasma, and anticoagulant activity persisted after a fall in plasma hematin concentration. Thus, there was a temporal dissociation between hematin and HDA, suggesting that a modification of hematin must occur in vivo before an anticoagulant effect is produced. Generation of HDA in vitro has implications for hematin preparation and administration. Generation of HDA in vivo suggests that similar modifications of endogenous heme or other porphyrins may occur to produce HDA under physiologic or pathophysiologic conditions.

scholarly journals Interaction of the Endocytic Scaffold Protein Pan1 with the Type I Myosins Contributes to the Late Stages of Endocytosis

2007 ◽  
Vol 18 (8) ◽  
pp. 2893-2903 ◽  
Author(s):  
Sarah L. Barker ◽  
Linda Lee ◽  
B. Daniel Pierce ◽  
Lymarie Maldonado-Báez ◽  
David G. Drubin ◽  
...  
Keyword(s):  
Late Stage ◽  
Actin Polymerization ◽  
Fluorescent Protein ◽  
Temperature Sensitive ◽  
Type I ◽  
Reading Frame ◽  
Rich Domain ◽  
C Terminus

The yeast endocytic scaffold Pan1 contains an uncharacterized proline-rich domain (PRD) at its carboxy (C)-terminus. We report that the pan1-20 temperature-sensitive allele has a disrupted PRD due to a frame-shift mutation in the open reading frame of the domain. To reveal redundantly masked functions of the PRD, synthetic genetic array screens with a pan1ΔPRD strain found genetic interactions with alleles of ACT1, LAS17 and a deletion of SLA1. Through a yeast two-hybrid screen, the Src homology 3 domains of the type I myosins, Myo3 and Myo5, were identified as binding partners for the C-terminus of Pan1. In vitro and in vivo assays validated this interaction. The relative timing of recruitment of Pan1-green fluorescent protein (GFP) and Myo3/5-red fluorescent protein (RFP) at nascent endocytic sites was revealed by two-color real-time fluorescence microscopy; the type I myosins join Pan1 at cortical patches at a late stage of internalization, preceding the inward movement of Pan1 and its disassembly. In cells lacking the Pan1 PRD, we observed an increased lifetime of Myo5-GFP at the cortex. Finally, Pan1 PRD enhanced the actin polymerization activity of Myo5–Vrp1 complexes in vitro. We propose that Pan1 and the type I myosins interactions promote an actin activity important at a late stage in endocytic internalization.

scholarly journals Amphipathic DNA Polymers Exhibit Antiherpetic Activity In Vitro and In Vivo

2008 ◽  
Vol 52 (8) ◽  
pp. 2727-2733 ◽  
Author(s):  
David I. Bernstein ◽  
Nathalie Goyette ◽  
Rhonda Cardin ◽  
Earl R. Kern ◽  
Guy Boivin ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Broad Spectrum ◽  
Parent Compound ◽  
Human Herpesvirus ◽  
Varicella Zoster ◽  
Barr Virus ◽  
Simplex Virus ◽  
Acid Stable

ABSTRACT Phosphorothioated oligonucleotides have a sequence-independent antiviral activity as amphipathic polymers (APs). The activity of these agents against herpesvirus infections in vitro and in vivo was investigated. The previously established sequence-independent, phosphorothioation-dependent antiviral activity of APs was confirmed in vitro by showing that a variety of equivalently sized homo- and heteropolymeric AP sequences were similarly active against herpes simplex virus type 1 (HSV-1) infection in vitro compared to the 40mer degenerate parent compound (REP 9), while the absence of phosphorothioation resulted in the loss of antiviral activity. In addition, REP 9 demonstrated in vitro activity against a broad spectrum of other herpesviruses: HSV-2 (50% effective concentration [EC50], 0.02 to 0.06 μM), human cytomegalovirus (EC50, 0.02 to 0.13 μM), varicella zoster virus (EC50, <0.02 μM), Epstein-Barr virus (EC50, 14.7 μM) and human herpesvirus types 6A/B (EC50, 2.9 to 10.2 μM). The murine microbicide model of genital HSV-2 was then used to evaluate in vivo activity. REP 9 (275 mg/ml) protected 75% of animals from disease and infection when provided 5 or 30 min prior to vaginal challenge. When an acid-stable analog (REP 9C) was used, 75% of mice were protected when treated with 240 mg/ml 5 min prior to infection (P < 0.001), while a lower dose (100 mg/ml) protected 100% of the mice (P < 0.001). The acid stable REP 9C formulation also provided protection at 30 min (83%, P < 0.001) and 60 min (50%, P = 0.07) against disease. These observations suggest that APs may have microbicidal activity and potential as broad-spectrum antiherpetic agents and represent a novel class of agents that should be studied further.

Stat5 and Stat3 Differentially Regulate Early and Late Stages of Primary Embryonic Erythroid Cell Maturation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3877-3877
Author(s):  
Zachary C. Murphy ◽  
Paul D. Kingsley ◽  
Kathleen E. McGrath ◽  
James Palis
Keyword(s):  
Cell Size ◽  
Late Stage ◽  
Conflicts Of Interest ◽  
Janus Kinase ◽  
Erythroid Cell ◽  
Null Mouse ◽  
Delayed Maturation ◽  
Primitive Erythropoiesis

Erythropoietin is the critical regulator of adult (definitive) red cell production, acting through its cognate receptor (EpoR) and downstream Janus kinase (Jak)2 and signal transducer and activator of transcription (Stat)5 signaling. Mutant JAK2 activation causes hyperproliferation of erythroid precursors in polycythemia vera, highlighting the importance of Jak2-STAT signaling in pathologic states in addition to normal development. EpoR-null mouse embryos die at midgestation of profound anemia and we have recently determined that EpoR signaling is also specifically required for the survival and terminal maturation of primitive erythroblasts. Unlike definitive erythropoiesis, Stat3 is significantly expressed in primitive erythroblasts but its function in erythropoiesis remains poorly understood. We find that Stat3, in addition to Stat5, is phosphorylated downstream of EpoR in primitive erythroblasts. Interestingly, phospho-Stat5 intensity decreases during primitive erythroblast maturation while phospho-Stat3 levels remain constant, resulting in an increase in relative phospho-Stat3 in late-stage primitive erythroblasts. Knockdown of Jak2 and Stat5 each results in accelerated maturation, decreased cell size, and increased apoptosis of primary primitive erythroblasts. In contrast, Stat3 knockdown results in delayed maturation and increased cell size of late-stage primary primitive erythroblasts, consistent with an increased role of phospho-Stat3 once phospho-Stat5 signal intensity has diminished. Stat3 knockdown, both in vitro and in vivo, also increased apoptosis of late-stage primitive erythroblasts. While Stat3 and Stat5 bind many apoptosis-related genes in common, Stat3 specifically binds several caspase genes and their regulators. We find that activated caspase3 levels increase in late-stage primitive erythroblasts, and that knockdown of Stat3 results in decreased levels of caspases and their regulators. In addition, caspase inhibition, like Stat3 knockdown, results in delayed maturation of late-stage primitive erythroblasts. Taken together, our data support a model where Stat3 and Stat5 differentially regulate erythroid maturation and Stat3 preferentially regulates terminal stages of primitive erythropoiesis through its activation and regulation of apoptotic machinery. Disclosures No relevant conflicts of interest to declare.

Apatinib to enhance chemosensitivity of gastric cancer to paciltaxel and 5-fluorouracil.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. e15545-e15545
Author(s):  
Xiangdong Cheng ◽  
Zhiyuan Xu ◽  
Jiahui Chen ◽  
Chunli Zhang ◽  
Jianfa Yu ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Late Stage ◽  
Zebrafish Embryo ◽  
Xenograft Model ◽  
Cytotoxic Agents ◽  
Pathological Examination ◽  
Conversion Surgery ◽  
Synergistic Interactions

e15545 Background: Patients (pts) with late-stage gastric cancer (GC) have a poor prognosis. Targeted agent combined with chemotherapy is expected to yield clinical benefits. Apatinib, a novel tyrosine kinase inhibitor targeting VEGFR-2, improves outcomes in patients with metastatic GC as a third line of treatment. Hence, we aimed to assess the efficacy and safety of apatinib plus chemotherapy in vivo and in vitro. Methods: The MGC803 cell viability was assessed by CCK-8 assay, and the interactions between apatinib and conventional cytotoxic agents revealed by combined index (CI) values were calculated using Calcusyn 2.0 software. We also used a zebrafish embryo xenograft model to validate the synergistic interactions. Furthermore, 4 pts with late-stage GC were enrolled to receive paclitaxel (PTX)/S1 chemotherapy plus apatinib in conversion surgery. Apatinib was administered 500 mg once a day continuously, PTX 130 mg/m2 was given on day 1, and S-1 was administered at 80 mg/m2for 14 consecutive days, followed by 7 days of rest. Treatment was administered for 3-5 cycles, but the last cycle did not include apatinib. Results: Apatinib showed synergistic interactions with both PTX and 5-Fu in vivo (CIs < 1). The zebrafish embryo xenograft model also demonstrated that addition of 0.25 µg/mL apatinib significantly enhanced the tumor growth inhibition effects of 25 (38.39% vs. 11.77%, P < 0.001) and 50 ng/fish (43.58% vs. 17.88%, P < 0.05) 5-Fu, as well as those of 0.75 ng/fish (53.62% vs. 35.22%, P < 0.001) and 1.5 ng/fish (59.71% vs.46.73%, P < 0.01) PTX. Apatinib plus S1/paclitaxel chemotherapy was well tolerable before surgery. Objective response to preoperative SPA treatment was achieved in all pts. No posteroperative bleeding event or wound-healing complication was observed. No postoperative mortality occurred and morbidity was encountered. Pathological examination showed that all pts had grade Ib pathological response. Conclusions: The experimental data suggested that apatinib improves the efficacy of PTX and 5-Fu both in vitro and in vivo. Clinical evidence showed that combination of PTX/S1 chemotherapy with apatinib has promising efficacy and acceptable safety profile in late-stage GC, especially in the conversion surgery.

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