Search results for "phosphonate"

Serum levels of RANKL and OPG, and the RANKL/OPG ratio in bisphosphonate-related osteonecrosis of the jaw: Are they useful biomarkers for the advance…

2017

We determined whether serum levels of Receptor Activator for Nuclear Factor κ B Ligand (RANKL), Osteoprotegerin (OPG), and the RANKL/OPG ratio could be useful biomarkers for the severity of oral lesions in bisphosphonate-related osteonecrosis of the jaw (BRONJ). A case-control study in which Group 1 consisted of 41 patients with BRONJ due to bisphosphonates, and Group 2 consisted of 44 healthy control cases. The plasma levels of RANKL and OPG were analyzed by an ELISA assay. The OPG/RANKL ratio was also calculated. We determined if the mean serum values differed among the different stages of BRONJ. Serum levels of RANKL were lower in Group 1 than in Group 2 (p =0.01), and serum levels of OP…

Preventing bone loss during androgen deprivation therapy for prostate cancer: Early experience with neridronate

2005

Abstract Objective: Androgen-deprivation therapy (ADT) is the usual treatment for locally advanced or metastatic prostate cancer. Osteoporosis is a common complication of ADT. The aim of our study was to evaluate the efficacy of neridronate, a relatively new bisphosphonate to prevent bone loss during androgen ablation. Methods: Sixty patients with prostate cancer and osteoporosis were enrolled and randomly assigned to 2 different treatment regimes: group A (30 patients) treated with maximum androgenic blockage (MAB), and group B (30 patients) treated with bicalutamide 150mg. Each group was divided in 2 subgroups A1–A2 and B1–B2. All patients received calcium and cholecalciferol supplements …

LC-MS/MS characterisation and determination of dansyl chloride derivatised glyphosate, aminomethylphosphonic acid (AMPA), and glufosinate in foods of…

2021

Abstract Glyphosate and other polar and acidic pesticides have been particularly studied due to the concerns over widespread and intensive use. The chemical properties of these compounds necessitate use of customised methods, such as derivatisation or ion exchange chromatography. These approaches present a compatibility problem with ESI-MS due to presence of salts and non-volatile compounds. For that reason, a simple procedure has been developed for the extraction, pre-column derivatisation with dansyl chloride (5-(dimethylamino)naphthalene-1-sulfonyl chloride), and mass spectrometric detection of glyphosate, AMPA, and glufosinate after the separation on a C18 stationary phase. The dansyl d…

Structure-Guided, Single-Point Modifications in the Phosphinic Dipeptide Structure Yield Highly Potent and Selective Inhibitors of Neutral Aminopepti…

2014

Seven crystal structures of alanyl aminopeptidase from Neisseria meningitides (the etiological agent of meningitis, NmAPN) complexed with organophosphorus compounds were resolved to determine the optimal inhibitor–enzyme interactions. The enantiomeric phosphonic acid analogs of Leu and hPhe, which correspond to the P1 amino acid residues of well-processed substrates, were used to assess the impact of the absolute configuration and the stereospecific hydrogen bond network formed between the aminophosphonate polar head and the active site residues on the binding affinity. For the hPhe analog, an imperfect stereochemical complementarity could be overcome by incorporating an appropriate P1 side…

Mevalonate pathway: role of bisphosphonates and statins.

2011

Cover Picture: Design, Synthesis, and Miniemulsion Polymerization of New Phosphonate Surfmers and Application Studies of the Resulting Nanoparticles …

2012

Toward very potent, non-covalent organophosphonate inhibitors of cathepsin C and related enzymes by 2-amino-1-hydroxy-alkanephosphonates dipeptides

2013

Cathepsins play an important role in several human disorders and therefore the design and synthesis of their inhibitors attracts considerable interest in current medicinal chemistry approaches. Due to the presence of a strong sulphydryl nucleophile in the active center of the cysteine type cathepsins, most strategies to date have yielded covalent inhibitors. Here we present a series of non-covalent β-amino-α-hydroxyalkanephosphonate dipeptidic inhibitors of cathepsin C, ranking amongst the best low-molecular weight inhibitors of this enzyme. Their binding modes determined by molecular modelling indicate that the hydroxymethyl fragment of the molecule, not the phosphonate moiety, acts as a t…

Substituted phosphonic analogues of phenylglycine as inhibitors of phenylalanine ammonia lyase from potatoes.

2018

A series of phosphonic acid analogues of phenylglycine variously substituted in phenyl ring have been synthesized and evaluated for their inhibitory activity towards potato l-phenylalanine ammonia lyase. Most of the compounds appeared to act as moderate (micromolar) inhibitors of the enzyme. Analysis of their binding performed using molecular modeling have shown that they might be bound either in active site of the enzyme or in the non-physiologic site. The latter one is located in adjoining deep site nearby the to the entrance channel for substrate into active site.

Reaction of 3-Amino-1,2,4-Triazole with Diethyl Phosphite and Triethyl Orthoformate: Acid-Base Properties and Antiosteoporotic Activities of the Prod…

2017

The reaction of diethyl phosphite with triethyl orthoformate and a primary amine followed by hydrolysis is presented, and the reaction was suitable for the preparation of (aminomethylene)bisphosphonates. 3-Amino-1,2,4-triazole was chosen as an interesting substrate for this reaction because it possesses multiple groups that can serve as the amino component in the reaction-namely, the side-chain and triazole amines. This substrate readily forms 1,2,4-triazolyl-3-yl-aminomethylenebisphosphonic acid (compound 1) as a major product, along with N-ethylated bisphosphonates as side products. The in vitro antiproliferative effects of the synthesized aminomethylenebisphosphonic acids against J774E m…

Effects of zoledronic acid and dexamethasone on early phases of socket healing after tooth extraction in rats : a preliminary macroscopic and microsc…

2018

Background The exact pathogenesis of medication-related osteonecrosis of the jaw (MRONJ) is still unknown. The aim of this paper was to investigate the effects of zoledronic acid and dexamethasone on the early phases of socket healing in rats subjected to tooth extractions. Material and Methods Thirty male Sprague-Dawley rats were divided into 2 groups: pharmacologically treated group (T, n=20) and non-pharmacologically treated group (C, n=10). T group rats received 0.1 mg/Kg of zoledronic acid (ZOL) and 1 mg/Kg of dexamethasone (DEX) three times a week for 10 consecutive weeks. C group rats were infused with vehicle. After 9 weeks from the first infusion, first maxillary molars were extrac…