Non-peptide Substance Research Articles

Update on Preclinical Development and Clinical Translation of Cholecystokinin-2 Receptor Targeting Radiopharmaceuticals.

Simple SummaryPeptide analogs, derived from the natural peptide hormone gastrin, are promising candidates for improving the visualization and treatment of tumors. Gastrin specifically binds to the cholecystokinin-2 receptor, a G-protein-coupled receptor expressed on the cell surface of different tumors. This enables specific targeting of tumor cells using gastrin analogs, labeled with radioisotopes. The receptor is expressed at high incidence in medullary thyroid carcinoma, a rare form of thyroid cancer lacking effective treatments at an advanced stage. Different radiolabeled gastrin analogs as well as nonpeptidic compounds targeting CCK2R have been developed. Specific modifications have been introduced in order to safely deliver the radiation to the tumor site. In this review, recent strategies applied to improve the targeting properties are described. These developments enabled the introduction of new radiolabeled peptide analogs for imaging and therapy in cancer patients. In addition to highlighting the current clinical trials, the perspectives for future applications are given.The cholecystokinin-2 receptor (CCK2R) has been a target of interest for molecular imaging and targeted radionuclide therapy for two decades. However, so far CCK2R targeted imaging and therapy has not been introduced in clinical practice. Within this review the recent radiopharmaceutical development of CCK2R targeting compounds and the ongoing clinical trials are presented. Currently, new gastrin derivatives as well as nonpeptidic substances are being developed to improve the properties for clinical use. A team of specialists from the field of radiopharmacy and nuclear medicine reviewed the available literature and summarized their own experiences in the development and clinical testing of CCK2R targeting radiopharmaceuticals. The recent clinical trials with novel radiolabeled minigastrin analogs demonstrate the potential for both applications, imaging as well as targeted radiotherapy, and reinforce the clinical applicability within a theranostic concept. The intense efforts in optimizing CCK2R targeting radiopharmaceuticals has led to new substances for clinical use, as shown in first imaging studies in patients with advanced medullary thyroid cancer. The first clinical results suggest that the wider clinical implication of CCK2R-targeted radiopharmaceuticals is reasonable.

Effect of the Mobile Phase Compositions on the Confirmation Analysis of Some Prohibited Substances in Sport by LC–ESI–MS/MS

In this study, the influence of the different mobile phase compositions on the sensitivity and chromatographic performance of prohibited small peptides (< 2 kDa), their metabolites, and non-peptide substances (anamorelin, ibutamoren) were demonstrated using LC–electrospray ionization coupled with triple quadrupole tandem mass spectrometry (LC–ESI–MS/MS). In the mobile phase, widely used mobile phase additives, ammonium formate (AF), formic acid (FA), and dimethylsulfoxide (DMSO) were employed with different organic phase modifiers such as acetonitrile (ACN) and methanol (MeOH). To evaluate the limit of detection (LOD) and matrix effect of analytes, urine samples were prepared by solid-phase extraction (SPE), and then, their analysis was performed by LC–ESI–MS/MS. LOD values of analytes were found to be between 0.05–2 ng mL−1 except for ibutamoren, anamorelin, and leuprolide (5–9), which had LOD values of lower than 0.05 ng mL−1. The best results related to sensitivity and chromatographic performance for the analysis of the analytes were achieved using ACN-based mobile phase containing 0.1% FA, which led to less ion suppression for most analytes compared to other employed mobile phase compositions. The proposed method to use for confirmation analysis of analytes was validated with respect to selectivity, carryover, precision, the limit of identification (LOI), recovery, matrix effect, and robustness. The applicability of the method in real urine samples was demonstrated by analyzing two different excretion urine samples containing leuprolide and triptorelin.

Aprepitant and Warfarin Drug Interaction

Aprepitant is a novel, potent, selective, oral non-peptide substance P/ NK1 receptor antagonist that inhibits chemotherapy induced nausea and vomiting (CINV), Aprepitant represents a new class of anti-emetics and it’s the first to gain regulatory approval for the management of chemotherapy induced nausea and vomiting. Warfarin is an oral coumarin that inhibits vitamin K dependent clotting factors leading to its anti-coagulant effect. It is a key medicine in the prophylaxis and treatment of thromboembolic diseases and in the prevention of complications that might rise after prosthetic cardiac valve replacement. Drug- drug interaction is a major concern for health care professionals. Though not all interactions have clinical consequences; as many as 20-30% of adverse drug events results from those interactions. The NK1 receptor antagonist Aprepitant is a key medication in the management and prevention of CINV resulting from high emetogenic chemotherapeutic protocols, especially high dose Cisplatin, as it improved patients’ side effect profile regarding nausea and vomiting, which highlights the importance of its use in cancer patients. Metabolized by liver and with a high protein binding capacity one might expect drug- drug interaction between Aprepitant and other medications. Warfarin - the anticoagulant of vast drug - drug interactions - is used commonly among cancer patients, as prophylaxis or treatment of hypercoagulable state. When used with Aprepitant care should be taken as after the 3 days dosing of Aprepitant the INR levels will start to decrease resulting in sub-therapeutic ranges of INR, this interaction is the result of Aprepitant effect on CYP2C9. It is recommended to monitor INR levels for 2 weeks after the three days Aprepitant dosing, especially days 7- 10, and to adjust Warfarin dose accordingly.

Twenty-one hormones fail to inhibit the brain to blood transport system for Tyr-MIF-1 and the enkephalins in mice.

Tyr-MIF-1 (Tyr-Pro-Leu-Gly-amide) and methionine enkephalin are transported intact across the blood-brain barrier by a saturable, stereospecific system. This system has been found to be modulated by a few non-peptide substances and by certain conditions such as ageing and some stresses. We investigated the possibility that hormones structurally unrelated to Tyr-MIF-1 and the enkephalins might also be capable of modulating this transport. Twenty-one hormones were tested including steroids, proteins, glycoproteins, peptides, and thyroid hormones, in doses ranging from 0.01 pmol to 1 nmol/mouse by injecting each hormone directly into the lateral ventricle simultaneously with [125I]Tyr-MIF-1. No clear effect on transport could be established for any of the substances at the doses tested. None of these substances seemed able to act as competitive inhibitors, to share their respective transport systems with Tyr-MIF-1, or to modulate immediately the saturable transport system.

Endogenous hypometabolic-hypothermic factors and their possible application to life in the cold

Hibernation is a natural model of Tolerance of hypometabolism, hypothermia, hypoxia, bradycardia, and longterm hypophagia. Here, we review recent advances in the isolation and identification of some natural endogenous regulators from hibernating and cold-adapted animals: proteins, peptides, and nonpeptide substances. We also discuss the employment of molecular, biochemical, and physiological bases of natural hypobiosis in ecology, cryomedicine, and the cryopreservation of genetic material from rare and endangered species. We suppose that our approaches can be extensively used (i) in medicine, when there is a need to slow down or suspend life processes for a short time; (ii) for the adaptation of humans to cold; and (iii) in long-term space flights.

Metabolism, Pharmacokinetics, and Excretion of a Nonpeptidic Substance P Receptor Antagonist, Ezlopitant, in Normal Healthy Male Volunteers: Characterization of Polar Metabolites by Chemical Derivatization with Dansyl Chloride

The excretion, biotransformation, and pharmacokinetics of ezlopitant [(2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl)-(5-isopropyl-2-methoxy-benzyl)-amine], a substance P receptor antagonist, were investigated in healthy male volunteers after oral administration of a single 200-mg (approximately 93 microCi/subject) dose of [(14)C]ezlopitant. The total recovery of administered radioactive dose was 82.8 +/- 5.1, with 32.0 +/- 4.2% in the urine and 50.8 +/- 1.4% in the feces. Mean observed maximal serum concentrations for ezlopitant and total radioactivity were achieved at approximately 2 h after oral administration; thus, ezlopitant was rapidly absorbed. Ezlopitant was extensively metabolized in humans, since no unchanged drug was detected in urine and feces. The major pathway of ezlopitant in humans was the result of the oxidation of the isopropyl side chain to form the omega-hydroxy and omega-1-hydroxy (M16) metabolites. M16 and omega,omega-1-dihydroxy (1,2-dihydroxy, M12) were identified as the major circulating metabolites accounting for 64.6 and 15.4% of total circulating radioactivity, respectively. In feces, the major metabolite M14 was characterized as the propionic acid metabolite and formed by further oxidation of the omega-hydroxy metabolite. The urinary metabolites were the result of cleaved metabolites caused by oxidative dealkylation of the 2-benzhydryl-1-aza-bicyclo[2.2.2]oct-3-yl moiety. The metabolites (M1A, M1B, and M4), approximately 34% of the total radioactivity in urine, were identified as benzyl amine derivatives. These were polar metabolites that were further characterized using the reaction with dansyl chloride to derivatize the primary amines and phenol moieties to less polar analytes. The other metabolites were the result of O-demethylation, dehydrogenation of the isopropyl group, and oxidation on the quinuclidine moiety.

Molecular shape of palytoxin in aqueous solution

Palytoxin, one of the most toxic non-peptide substances, formed an associated dimer of 5 nm length in aqueous solution.

Tritiation of nonpeptide substance P antagonist CP-96,345 and its azido analogue. Synthetic and characterization details

CP-96,345 ( 1) was the first nonpeptide antagonist discovered for the SP receptor and [ 3H] CP-96,345 was required to study the mechanism of receptor action. The radioligand was prepared at high specific activity by catalytic dehalogenation of a dibrominated precursor and this same approach was also used to prepare a photoaffinity analogue.

Tribulin and Endogenous MAO-Inhibitory Regulation In Vivo

Tribulin is the name given to a family of endogenous nonpeptide substances which inhibit monoamine oxidase (MAO) and benzodiazepine binding. It is widely distributed in mammalian tissues and body fluids, and exhibit some species and tissue variations. Several components selectively inhibiting MAO A, MAO B, central and peripheral benzodiazepine binding (tribulins A, B, BZc and BZp, respectively) have been recognised. Tribulin A represents some tissue-specific metabolites of trace amines, whereas isatin is the major component of tribulin B. Tribulin content increases in brain under conditions of stress and anxiety and is reduced under sedation. Changes in tribulin content in the brain are accompanied by corresponding changes in the content of monoamines and their acidic metabolites, and also by altered susceptibility of MAO to specific mechanism-based inhibitors. This suggests that tribulin is involved in MAO inhibitory regulation in vivo.

Identification of the degradation product of ezlopitant, a non-peptidic substance p antagonist receptor, by hydrogen deuterium exchange, electrospray ionization tandem mass spectrometry (ESI/MS/MS) and nuclear magnetic resonance (NMR) spectroscopy

The degradation product of ezlopitant was isolated from low specific activity material and identified by solution phase hydrogen/deuterium (H/D) exchange and electrospray ionization tandem mass spectrometry (ESI/MS/MS) to be an isopropyl peroxide analog of ezlopitant. The structure of the degradant was further confirmed by nuclear magnetic resonance (NMR) spectroscopy utilizing complete 1H and 13C assignments. Studies were also performed to identify the factors responsible for the oxidative degradation of ezlopitant, which included salt form, storage conditions and salt formation solvent. Of all the variable studies over a 3 weeks period, only a change in the salt form prevented this oxidative degradation.

A non-peptide substance P antagonist down-regulates SP mRNA expression in human mononuclear phagocytes

Substance P (SP), a potent modulator of neuroimmunoregulation, exerts its activity by binding to the neurokinin-1 receptor (NK-1R). The SP–NK-1R interaction is important in inflammation and viral infections, including HIV infection of human immune cells. We recently demonstrated that SP modulates HIV replication and that a non-peptide SP antagonist CP-96,345 inhibits HIV replication in human monocyte-derived macrophages (MDM) by affecting the SP–NK-1R interaction. In order to examine the effect of the SP antagonist on SP mRNA expression, MDM was incubated with or without CP-96,345 in the presence or absence of HIV infection. SP mRNA expression in these cells was then determined by real-time PCR technology. The effect of CP-96,345 on chemokine gene expression was also investigated by using a cDNA array assay. CP-96,345 down-regulated SP mRNA expression and antagonized exogenous SP-enhanced SP expression at the mRNA level, suggesting that SP autocrine regulation was interrupted by CP-96,345. CP-96,345 inhibited HIV replication in MDM, associated with down-regulated SP mRNA expression in comparison to HIV infection controls. In parallel with down-regulated SP and CCR5 mRNA expression, cDNA array assays indicated that CP-96,345 treatment also inhibited IL-8 gene expression, while enhancing expression of fractalkine and monocyte chemotactic protein-3 (MCP-3). Since SP plays an important role in inflammation and viral infections, these studies may have potential applications for therapeutic intervention of inflammation and viral infection of immune cells.

B16-BL6 melanoma cells release inhibitory factor(s) of active pump activity in isolated lymph vessels.

We investigated whether supernatant cultured with melanoma cell lines B16-BL6 and K1735 or the Lewis lung carcinoma cell line (LLC) can regulate lymphatic pump activity with bioassay preparations isolated from murine iliac lymph vessels. B16-BL6 and LLC supernatants caused significant dilation of lymph microvessels with cessation of pump activity. B16-BL6 supernatant produced dose-related cessation of lymphatic pump activity. There was no significant tachyphylaxis in the supernatant-mediated inhibitory response of lymphatic pump activity. Pretreatment with 3 x 10(-5) M N(omega)-nitro-L-arginine methyl ester (L-NAME) or 10(-7) M or 10(-6) M glibenclamide and 5 x 10(-4) M 5-hydroxydecanoic acid caused significant reduction of supernatant-mediated inhibitory responses. Simultaneous treatment with 10(-3) M L-arginine and 3 x 10(-5) M L-NAME significantly lessened L-NAME-induced inhibition of the supernatant-mediated response, suggesting that endogenous nitric oxide (NO) plays important roles in supernatant-mediated inhibitory responses. Chemical treatment dialyzed substances of <1,000 molecular weight (MW), producing complete reduction of the supernatant-mediated response. In contrast, pretreatment with heating or digestion with protease had no significant effect on supernatant-mediated response. These findings suggest that B16-BL6 cells may release nonpeptide substance(s) of <1,000 MW, resulting in significant cessation of lymphatic pump activity via production and release of endogenous NO and activation of mitochondrial ATP-sensitive K(+) channels.

Substance P: a new era, a new role.

Substance P has been extensively studied and is considered the prototypic neuropeptide of the more than 50 known neuroactive molecules. The understanding of substance P has evolved beyond the original concept as the pain transmitter of the dorsal horn. Animal and genetic research, recent developments of nonpeptide substance P antagonists, and important changes in the understanding of neurotransmission have each contributed to the current understanding of substance P After 7 decades, the physiologic role of substance P is known as a modulator of nociception, involved in signaling the intensity of noxious or aversive stimuli. Genetic studies in mice and development of substance P antagonists provide more recent results that support the redefinition of the central role of substance P Evidence suggests that this neuropeptide is an integral part of central nervous system pathways involved in psychologic stress.

Cyclohexenonic Long‐chain Fatty Alcohols as Neuronal Growth Stimulators

AbstractFor Abstract see ChemInform Abstract in Full Text.

Cyclohexenonic Long-Chain Fatty Alcohols as Neuronal Growth Stimulators

Neurotrophic factors play an important role in the development and maintenance of neurons, thus providing a suitable therapeutic approach for the treatment of neurodegenerative diseases. However, their clinical use has revealed problematic because of a number of technical and biological disadvantages. Among the different strategies proposed to overcome such difficulties, the search for non-peptide substances with neurotrophic potential is giving promising results. Here we will expose major findings in this field, drawing special attention to cyclohexenonic long-chain fatty alcohols, a novel family of compounds that promote neuronal survival and neurite outgrowth.

Secretory, Endocrine and Autocrine/Paracrine Function of the Adipocyte

Obesity is a major public health problem in Western countries, and >55% of adult Americans are overweight or obese. A major contributor to the epidemic of obesity is the current environment, which is characterized by increased availability of high energy foods and decreased physical activity. Several studies also demonstrated that genetic susceptibility contributes to obesity in some populations. Obesity research has focused primarily on the role of the hypothalamus in neuroendocrine regulation of food intake. However, a growing number of studies support a potential contribution of adipose tissue, via its newly discovered secretory function, to the pathogenesis of obesity and co-morbid conditions including cardiovascular disease, diabetes and hypertension. This paper will review the role of four factors secreted by adipose tissue (leptin, agouti, angiotensin II and prostaglandins) and their functions in the regulation of energy balance and whole-body homeostasis. Several other peptide and nonpeptide substances are secreted from adipose tissue; their function and regulation have been documented extensively.

Plant protein hydrolysates: preparation of defined peptide fractions promoting growth and production in animal cells cultures.

A new approach was applied with the aim at producing plant protein hydrolysates less heterogeneous and less contaminated with nonpeptide substances than are the presently available digests. A significant reduction of nonprotein contaminants was achieved by extraction of the plant material, soy flour or wheat flour, with acetone prior to isolation of the protein. Enzymes of nonanimal origin, papain or Pronase, were used for protein hydrolysis. The components of the hydrolysates were resolved by low-pressure liquid chromatography. Separation of peptide fractions and of remaining nonpeptide contaminants was achieved using small-pore size-exclusion chromatography matrices, Sephadex G-15 or Biogel P-2. Individual peptide fractions, both from soy protein and from wheat gluten, varied substantially in their growth-promoting and production-enhancing activities when tested on a mouse hybridoma culture in protein-free medium. The highest enhancement of viable cell density in batch cultures was 180% of control, and the highest enhancement of final immunoglobulin concentration was more than 230% of control. The existence of marked differences in activity of individual peptide fractions leads to a suggestion that the hydrolysates may provide peptides exerting specific positive effects on cultured animal cells.

Stereoselective synthesis of (2 S,3 S)-3-hydroxy-2-phenylpiperidines, precursors of non-peptidic substance P antagonists

(2 S)- N-Boc-3-oxo-2-phenylpiperidine 5 and (2 S,3 S)- N-Boc-3-hydroxy-2-phenylpiperidine 6, known chiral building blocks for the synthesis of non-peptidic substance P antagonists, were prepared from erythro (2 S)- N-benzyl 2-hydroxybenzylpyrrolidine derived from ( S)- N-methoxy- N-methylpyroglutamide.

Tuberculosis I: a conceptual frame for the immunopathology of the disease

An analysis of the cellular and humoral immune responses after bacille Calmette-Guérin (BCG) vaccination and during tuberculosis treatment favors the hypothesis of an immune defence developed in four overlapping successive stages. The initial immune response is innate. The following two intermingle innate and specific responses against low molecular weight oligopeptidic and nonpeptidic antigens, as muramyldipeptide and trehalose dimycolate, and large molecular weight nonpeptidic antigens such as lipoarabinomannan. The ultimate specific response is directed aginst protein antigens as Antigen 60.BCG and primary tuberculosis (TB) infections induce cellular and humoral immune responses essentially against oligopeptidic and small and large molecular weight nonpeptidic antigens. Immune responses against non-peptidic substances contribute to the immunoprotection of the infected person who develops a primary infection. Some infected people allow the expression of the immunosuppressive activity of the pathogen. This results in the synthesis of interleukin-10 (IL-10), which suppresses the formation of interferon-γ (INF-γ) and IL-2, and of IL-6, which suppresses T-cell responses. These patients have a skewed immune response against non-peptidic antigens and present with symptoms. They will not recover unless responses directed against proteinic antigens occur, which restore INF-γ and IL-2 production. The formation of immumoglobulin-G (IgG)-type antibodies and of a cellular immunity against mycobacterial peptidic antigens is essential for a good protection against a post-primary infection.

Action of non-peptide substance P antagonist, CP 96 345, on cholera toxin and E. coli enterotoxin-induced secretion

Action of non-peptide substance P antagonist, CP 96 345, on cholera toxin and E. coli enterotoxin-induced secretion