Józef Oleksyszyn

[30] Amino acid and peptide phosphonate derivatives as specific inhibitors of serine peptidases

Publisher Summary This chapter describes amino acid and peptide phosphonate derivatives as specific inhibitors of serine peptidases. Serine peptidases are excellent targets for drug design as they are essential in many important physiological processes, including coagulation, fibrinolysis, and complement activation. Amino acid and peptide organophosphate derivatives such as α-aminoalkyl phosphonate diphenyl esters comprise one class of inhibitor that is highly specific for the target serine peptidase and is quite stable in physiological media. The main advantage of the α-aminoalkyl phosphonate diphenyl ester derivatives over other types of serine peptidase inactivators is the relative ease of synthesis and use of these compounds. The α-amidoalkylation reaction to produce the phosphonate inhibitors has broad scope and many different variations in reactant structure are acceptable. The dicyclohexylcarbodiimide (DCC) method, the mixed-anhydride method, and the carbonyldiimidazole (CDI) method are all effective methods for the synthesis of these peptide inhibitors. Longer peptide phosphonates can be synthesized stepwise by extension in the N-terminal direction, starting with diphenyl α-aminoalkyl phosphonates.

Comparision of the Cytotoxic Effects of Birch Bark Extract, Betulin and Betulinic Acid Towards Human Gastric Carcinoma and Pancreatic Carcinoma Drug-sensitive and Drug-Resistant Cell Lines

Betulin and betulinic acid are naturally occurring pentacyclic triterpenes showing cytotoxicity towards a number of cancer cell lines. These compounds can be found in the bark of the many plants. In this report we have compared the cytotoxic activity of crude birch bark extract and purified betulin and betulinic acid towards human gastric carcinoma (EPG85-257) and human pancreatic carcinoma (EPP85-181) drug-sensitive and drug-resistant (daunorubicin and mitoxantrone) cell lines. Our results show significant differences in sensitivity between cell lines depending on the compound used, and suggest that both betulin and betulinic acid can be considered as a promising leads in the treatment of cancer.

Direct Synthesis of 1-Aminoalkanephosphonic and 1-Aminoalkanephosphinic Acids from Phosphorus Trichloride or Dichlorophosphines

Carbonylverbindungen (I) und Benzylurethan (II) ergeben in siedendem Eisessig mit Phosphortrichlorid nach Hydrolyse 1-Aminoalkanphosphonsauren (III) und mit Dichlorphosphanen (IV) 1-Aminoalkanphosphinsauren (V).

New phosphonic analogs of aspartic and glutamic acid by aminoalkylation of trivalent phosphorus chlorides with ethyl acetyloacetate or ethyl levulinate and benzyl carbamate

Preparation of the phosphonic analogs of α-methylaspartic (4 a–d), glutamic (7 a–b) and α-methylpyroglutamic (5 a–b) acids by aminoalkylation of trivalent phosphorus chlorides with ethyl esters of oxoalkyloacids and benzyl carbamate is described. The phosphonic analogs of pyroglutamic acid (8 a–b) was obtained by the cyclization of the corresponding esters (9 a–b). The stability of the phosphonic analogs of pyroglutamic acid in acidic and alkaline media was also studied.ZusammenfassungEs wurde die Darstellung der Phosphonanalogen der α-Methylasparaginsäure (4 a–d), Glutamin- (7 a–b) und α-Methylpyroglutaminsäure (5 a–b) in der Reaktion der trivalenten Phosphorchloride und der Oxoalkansäureethylester sowie des Benzylcarbaminats beschrieben. In der Ringschlußreaktion der Ester (9 a–b) erhält man Phosphonanaloge der Pyroglutaminsäure. Die Stabilität der Analogen der Pyroglutaminsäure wurde in sauren und alkalischen Medien geprüft.

Amidoalkylation of phosphorous acid

Abstract Amidoalkylation of phosphorous acid by the reaction of mixture of phosphorous acid and amide with carbonyl compounds in acetic anhydride, followed by hydrolysis to give 1-aminoalkanephosphonic acids, is described.

Human Neutrophil Elastase Phosphonic Inhibitors with Improved Potency of Action

Herein, we present the synthesis and the measurement of the inhibitory activity of novel peptidyl derivatives of α-aminoalkylphosphonate diaryl esters as human neutrophil elastase inhibitors. Their selectivity against other serine proteases, including porcine pancreatic elastase, chymotrypsin, and trypsin, was also demonstrated. We also describe the preparation of single peptide diastereomers. The most active and selective compound developed possessed a k(inact)/K(I) of 2353000 M(-1) s(-1), which is the most potent irreversible peptidyl inhibitor of human neutrophil elastase reported to date. The peptidyl inhibitors were demonstrated to be stable in PBS buffer and human plasma, as were their complexes with HNE.

New potent cathepsin G phosphonate inhibitors

Cathepsin G is an enzyme with dual chymotrypsin and trypsin-like specificity. As a leukocyte proteinase it is involved in the early stages of the immune response. In this work the synthesis and inhibitory activity of diaryl phosphonic-type irreversible cathepsin G inhibitors are described. Modification of the lead structure Z-Phg(P)(OPh)2 (k(obs)/I=91 M(-1)s(-1)) in phenyl ester moieties followed by incorporation of the basic functional group into the aromatic side chain yielded highly potent cathepsin G inhibitor Z-(4-guanidine)Phg(P)(OC6H4-4-S-Me)2 with the apparent second-order inhibition value at 15,600 M(-1)s(-1). Further elongation of the obtained compound by tripeptide resulted in the inhibitor Ac-Phe-Val-Thr-(4-guanidine)Phg(P)(OC6H4-4-S-Me)2 with the highest k(obs)/I value ever reported in literature (256,000 M(-1)s(-1)).

Application of specific cell permeable cathepsin G inhibitors resulted in reduced antigen processing in primary dendritic cells.

The serine protease cathepsin G (CatG) is expressed in primary antigen-presenting cells and regulates autoantigen processing in CatG pre-loaded fibroblasts. To further investigate the function of CatG in the major histocompatibility complex (MHC) class II loading compartments, a specific, cell permeable CatG-inhibitor is needed. In this study, several CatG-inhibitors were tested for their ability to penetrate the cell membrane of peripheral blood mononuclear cells (PBMC). We find that the commercially available reversible CatG-specific inhibitor I (CatG inhibitor) and the irreversible Suc-Val-Pro-Phe(P) (OPh)(2) (Suc-VPF) are both cell permeable and specifically inhibit intracellular CatG in the PBMC. Furthermore, selective inhibition of CatG resulted in reduced tetanus toxin C-fragment (TTC) and hemagglutinin (HA) processing and presentation to CD4(+) T cells. We conclude that these CatG inhibitors can be used for both antigen-processing studies and for modulation of T cell response in situ and in vivo.

Highly Sensitive Detection of Cancer Antigen 15-3 Using Novel Avian IgY Antibodies

Early detection of cancer development is crucial for successful therapy and for monitoring patient outcome. Various immunodiagnostic methods are able to detect pathological changes in the human body ahead of symptomatic manifestation of the disease. Most immunological examinations are based on the detection of specific tumor markers in body fluids. Of the various cancer-specific proteins used for breast cancer diagnostics, one of the most commonly applied is the cancer antigen 15-3 (CA 15-3). An elevation in its serum level (>25-40 U/ml) usually correlates with tumor malignancy. The CA 15-3 antigen is also used for monitoring patients after surgical treatment and for measuring therapeutic efficacy. Herein, we present the generation of polyclonal IgY antibodies isolated from egg yolks of immunized hens and their application for CA 15-3 detection. The developed sandwich ELISA assay showed a detection limit of 0.028 U/ml, thus demonstrating its potential for clinical applications.

Identification of very potent inhibitor of human aminopeptidase N (CD13).

In this Letter we describe broad comparision studies toward rat, pig, and human aminopeptidase N (CD13) orthologs using phosphinate inhibitors related in structure to hydroxamic acids. This SAR approach yielded a very potent inhibitor of human aminopeptidase N: alpha(1)-amino-3-phenylpropyl(alpha(2)-hydroxy-3-phenylpropyl)phosphinic acid with an IC(50)=60 nM.