N‒substituted 5‒hydroxy‒pyrrol‒2‒ones based cholecystokinin‒2 antagonists as experimental anticancer agents for the treatment of lung cancer

Background: Cholecystokinin and gastrin are endocrine growths factors for certain tumours and CCK1 R and CCK2R receptors are ideal molecular targets for novel smart chemo‒ therapeutics with a beneficial overall profile due to their anxiolytic and antidepressant properties. Lung cancers are fuelled by gastrin and therefore, selective gastrin (CCK2 R) antagonists are ideal experimental drug candidates. Objective: Synthesis and evaluation of novel CCK antagonists, most preferred CCK2 / gastrin selective for the treatment of lung cancers. Methods: A fast and efficient synthesis of hydroxy‒pyrrolones in 2 steps from renewable biomass was performed. After initial radiolabelled receptor binding studies with hot CCK8, subsequent in vitro evaluation with isolated duodenum preparations confirmed CCK antagonism. Cell based studies using the MTT assay provided a candidate for in vivo xenograft models with nude mice. Rational drug design was supported by molecular modelling experiments. Results: Potent and selective CCK antagonists were prepared as stable crystalline materials in high yields. Gastrin antagonists were in vitro active on isolated tissue preparations and inhibited breast, colon and lung cancer cell lines in vitro with IC50 to 45nM for the privileged hydroxyl‒pyrrolone lead structure in the MTT assay for human cancer cell lines. PNB‒101, a fluorinated 5‒hydroxy‒5‒aryl‒pyrrol‒2‒one, gave up to 80% inhibition of tumour growths by oral administration in athymic mice transplanted with the human lung cancer cell line H727. Conclusion: PNB‒101 is a potential chemotherapeutic agent for CCK‒gastrin related cancers and entered preclinical development

Cholecystokinin-1 receptor antagonists:5-hydroxy-5-aryl-pyrrol-2-ones as anticancer agents

A new class of 5-arylated 5-hydroxypyrrolones was derived from mucochloric acid in 2 synthetic steps and the chemical structure was confirmed additionally by X-ray analysis. Using a radiolabelled binding assay, potent CCK1 selective ligands were identified (CCK1: 12 nM) and the antagonism was confirmed by using isolated tissue preparations. A series of isobutyl derivatives displayed unsurmountable CCK antagonistic properties and in vitro excellent inhibition of proliferation was obtained in cholecystokinin related cancer cell lines in the nanomolar range. Finally, using xenograft studies in nude mice, two selected pyrrolone derivatives, X = H and X = F a fluorinated analogue (PNB-028), showed a strong inhibition of tumour growth in a chemo-resistant colon cancer-(MAC 16) and a human pancreatic cell line (MIAPACA) at 50 mg kg-1 by oral administration

A thrombin assay based upon the release of fibrinopeptide a from fibrinogen: Definition of a new thrombin unit

An assay for thrombin is presented wherein thrombin-catalyzed hydrolysis at Arg-A[alpha]-16 to release fibrinopeptide A (FPA) from fibrinogen is measured using high-performance liquid chromatography (HPLC). In this assay one thrombin unit (TU) is defined as that amount of thrombin that will release half of the FPA in one min from one ml of a solution of >90% clottable normal human fibrinogen (-1. Variability in fibrinogen samples which produce dramatic differences in clotting time assays with the same sample of thrombin, produce little or no variation in the catalytic assay for TU. The assay for TU obviates the need for maintenance of a thrombin reference standard.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24758/1/0000180.pd

Some Recent Developments in the Pharmacology of Heparin

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97239/1/j.1552-4604.1979.tb02490.x.pd

Analysis and characterization of heparin impurities

This review discusses recent developments in analytical methods available for the sensitive separation, detection and structural characterization of heparin contaminants. The adulteration of raw heparin with oversulfated chondroitin sulfate (OSCS) in 2007–2008 spawned a global crisis resulting in extensive revisions to the pharmacopeia monographs on heparin and prompting the FDA to recommend the development of additional physicochemical methods for the analysis of heparin purity. The analytical chemistry community quickly responded to this challenge, developing a wide variety of innovative approaches, several of which are reported in this special issue. This review provides an overview of methods of heparin isolation and digestion, discusses known heparin contaminants, including OSCS, and summarizes recent publications on heparin impurity analysis using sensors, near-IR, Raman, and NMR spectroscopy, as well as electrophoretic and chromatographic separations