The synthesis and some pharmacological properties of [2-L-DOPA]-oxytocin

1976 ◽  
Vol 54 (5) ◽  
pp. 507-511 ◽  
Author(s):  
B. M. Ferrier ◽  
L. A. Branda
Keyword(s):  
Liquid Ammonia ◽  
Protecting Groups ◽  
Synthetic Analogue ◽  
Pharmacological Properties ◽  
Partition Chromatography ◽  
Alkaline Ph ◽  
Milk Ejection ◽  
Short Term ◽  
Naturally Occurring ◽  
Exclusion Chromatography

The first reported synthetic analogue of a naturally occurring peptide with a residue of L-3,4-dihydroxyphenylalanine (L-DOPA) was prepared by coupling N-carbobenzoxy-S-benzylcysteinyl-L-DOPA azide with isoleucylglutaminylasparaginyl-S-benzylcysteinylprolylleu-cylglycinamide. The protecting groups were removed from the resultant nonapeptide derivative by sodium in liquid ammonia and the peptide analogue was formed by short term oxidation of the dithiol-containing compound. It was isolated by sequential partition chromatography and exclusion chromatography on Sephadex G-25. It was unstable at neutral or alkaline pH. [2-L-DOPA]-oxytocin was found to possess a minimum milk-ejection-like activity of 54 ± 9 U/mg and uterotonic activity of 26 ± 4 U/mg. These potencies are approximately 12% and 5% of the corresponding potencies of oxytocin.

Synthesis and some pharmacological properties of [7-glycine, 8-ornithine]vasopressin and two of its analogues

1980 ◽  
Vol 45 (10) ◽  
pp. 2865-2871 ◽  
Author(s):  
Michal Lebl ◽  
Tomislav Barth ◽  
Jana Škopková ◽  
Karel Jošt
Keyword(s):  
Liquid Ammonia ◽  
Oxidative Cyclization ◽  
Protecting Groups ◽  
Pharmacological Properties ◽  
Lysine Vasopressin ◽  
Fragment Condensation ◽  
Depressor Effect ◽  
Protected Peptides

Protected peptides were prepared by fragment condensation according to the scheme 6 + 3 or 9 + 3, which, after the removal of the protecting groups by sodium in liquid ammonia and oxidative cyclization, afforded [7-glycine,8-ornithine]vasopressin, [7-glycine,8-ornithine]deaminovasopressin, and Nα-glycyl-glycyl-glycyl[7-glycine,8-ornithine]vasopressin. All the analogues had very low intrinsic vasopressin-like activities; the analogue with hormonogen nature had a depressor effect and inhibited the pressor action of lysine-vasopressin.

scholarly journals Synthesis, Modification and Biological Activity of Diosgenyl β-d-Glycosaminosides: An Overview

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5433
Author(s):  
Daria Grzywacz ◽  
Beata Liberek ◽  
Henryk Myszka
Keyword(s):  
Biological Activity ◽  
Biological Activities ◽  
Protecting Groups ◽  
Pharmacological Properties ◽  
Amino Group ◽  
Reaction Conditions ◽  
Naturally Occurring ◽  
Anti Cancer ◽  
Wide Group ◽  
Derivatives Of

Saponins are a structurally diverse class of natural glycosides that possess a broad spectrum of biological activities. They are composed of hydrophilic carbohydrate moiety and hydrophobic triterpenoid or steroid aglycon. Naturally occurring diosgenyl glycosides are the most abundant steroid saponins, and many of them exhibit various pharmacological properties. Herein, we present an overview of semisynthetic saponins syntheses–diosgenyl β-d-glycosaminosides (d-gluco and d-galacto). These glycosides possess a 2-amino group, which creates great possibilities for further modifications. A wide group of glycosyl donors, different N-protecting groups and various reaction conditions used for their synthesis are presented. In addition, this paper demonstrates the possibilities of chemical modifications of diosgenyl β-d-glycosaminosides, associated with functionalisation of the amino group. These provide N-acyl, N-alkyl, N,N-dialkyl, N-cinnamoyl, 2-ureido and 2-thiosemicarbazonyl derivatives of diosgenyl β-d-glycosaminosides, for which the results of biological activity tests (antifungal, antibacterial, anti-cancer and hemolytic) are presented.

An Empirical Analysis of the Obtrusiveness of and Participants' Compliance with the Electronically Activated Recorder (EAR)

2007 ◽  
Vol 23 (4) ◽  
pp. 248-257 ◽  
Author(s):  
Matthias R. Mehl ◽  
Shannon E. Holleran
Keyword(s):  
Empirical Analysis ◽  
Sampling Method ◽  
Daily Life ◽  
Assessment Method ◽  
Data Confidentiality ◽  
Short Term ◽  
Naturally Occurring ◽  
Two Samples ◽  
Audio Recorder ◽  
Term Monitoring

Abstract. In this article, the authors provide an empirical analysis of the obtrusiveness of and participants' compliance with a relatively new psychological ambulatory assessment method, called the electronically activated recorder or EAR. The EAR is a modified portable audio-recorder that periodically records snippets of ambient sounds from participants' daily environments. In tracking moment-to-moment ambient sounds, the EAR yields an acoustic log of a person's day as it unfolds. As a naturalistic observation sampling method, it provides an observer's account of daily life and is optimized for the assessment of audible aspects of participants' naturally-occurring social behaviors and interactions. Measures of self-reported and behaviorally-assessed EAR obtrusiveness and compliance were analyzed in two samples. After an initial 2-h period of relative obtrusiveness, participants habituated to wearing the EAR and perceived it as fairly unobtrusive both in a short-term (2 days, N = 96) and a longer-term (10-11 days, N = 11) monitoring. Compliance with the method was high both during the short-term and longer-term monitoring. Somewhat reduced compliance was identified over the weekend; this effect appears to be specific to student populations. Important privacy and data confidentiality considerations around the EAR method are discussed.

scholarly journals Hemisynthesis and Biological Evaluation of Cinnamylated, Benzylated, and Prenylated Dihydrochalcones from a Common Bio-Sourced Precursor

Antibiotics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 620
Author(s):  
Anne Ardaillou ◽  
Jérôme Alsarraf ◽  
Jean Legault ◽  
François Simard ◽  
André Pichette
Keyword(s):  
Biological Activities ◽  
Biological Evaluation ◽  
Pharmacological Properties ◽  
Cytotoxic Potential ◽  
Naturally Occurring

Several families of naturally occurring C-alkylated dihydrochalcones display a broad range of biological activities, including antimicrobial and cytotoxic properties, depending on their alkylation sidechain. The catalytic Friedel–Crafts alkylation of the readily available aglycon moiety of neohesperidin dihydrochalcone was performed using cinnamyl, benzyl, and isoprenyl alcohols. This procedure provided a straightforward access to a series of derivatives that were structurally related to natural balsacones, uvaretin, and erioschalcones, respectively. The antibacterial and cytotoxic potential of these novel analogs was evaluated in vitro and highlighted some relations between the structure and the pharmacological properties of alkylated dihydrochalcones.

scholarly journals Botulinum Toxin: An Update on Pharmacology and Newer Products in Development

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 58
Author(s):  
Supriyo Choudhury ◽  
Mark R. Baker ◽  
Suparna Chatterjee ◽  
Hrishikesh Kumar
Keyword(s):  
Botulinum Toxin ◽  
Clinical Use ◽  
First Line ◽  
High Demand ◽  
Short Term ◽  
Medical Specialties ◽  
Naturally Occurring ◽  
Pharmacokinetic Properties ◽  
Clinical Benefits ◽  
First Line Treatment

Since its introduction as a treatment for strabismus, botulinum toxin (BoNT) has had a phenomenal journey and is now recommended as first-line treatment for focal dystonia, despite short-term clinical benefits and the risks of adverse effects. To cater for the high demand across various medical specialties, at least six US Food and Drug Administration (FDA)-approved formulations of BoNT are currently available for diverse labelled indications. The toxo-pharmacological properties of these formulations are not uniform and thus should not be used interchangeably. Synthetic BoNTs and BoNTs from non-clostridial sources are not far from clinical use. Moreover, the study of mutations in naturally occurring toxins has led to modulation in the toxo-pharmacokinetic properties of BoNTs, including the duration and potency. We present an overview of the toxo-pharmacology of conventional and novel BoNT preparations, including those awaiting imminent translation from the laboratory to the clinic.

scholarly journals Regulation of rat magnocellular neurosecretory system by D-aspartate: evidence for biological role(s) of a naturally occurring free D-amino acid in mammals

2000 ◽  
Vol 167 (2) ◽  
pp. 247-252 ◽  
Author(s):  
H Wang ◽  
H Wolosker ◽  
J Pevsner ◽  
SH Snyder ◽  
DJ Selkoe
Keyword(s):  
Gene Expression ◽  
Amino Acids ◽  
Amino Acid ◽  
Physiological Function ◽  
Neurosecretory System ◽  
Milk Ejection ◽  
Magnocellular Neurons ◽  
Rat Hypothalamus ◽  
Naturally Occurring

Little evidence is available for the physiological function of D-amino acids in species other than bacteria. Here we demonstrate that naturally occurring freed -aspartate (D-Asp) is present in all magnocellular neurons of rat hypothalamus. The levels of this naturally occurring D-amino acid were elevated during lactation and returned to normal thereafter in the magnocellular neurosecretory system, which produces oxytocin, a hormone responsible for milk ejection during lactation. Intraperitoneal injections of D-Asp reproducibly increased oxytocin gene expression and decreased the concentration of circulating oxytocin in vivo. Similar changes were observed in the vasopressin system. These results provide evidence for the role(s) of naturally occurring free D-Asp in mammalian physiology. The findings argue against the conventional concept that only L-stereoisomers of amino acids are functional in higher species.

scholarly journals Natural Cyclic Peptides as an Attractive Modality for Therapeutics: A Mini Review

Molecules ◽  
2018 ◽  
Vol 23 (8) ◽  
pp. 2080 ◽  
Author(s):  
Muna Abdalla ◽  
Lyndy McGaw
Keyword(s):  
Drug Discovery ◽  
Cyclic Peptides ◽  
Cyclic Peptide ◽  
Pharmacological Properties ◽  
Biological Processes ◽  
Peptide Antibiotics ◽  
Natural Sources ◽  
Biological Targets ◽  
Naturally Occurring ◽  
Wide Range

Peptides are important biomolecules which facilitate the understanding of complex biological processes, which in turn could be serendipitous biological targets for future drugs. They are classified as a unique therapeutic niche and will play an important role as fascinating agents in the pharmaceutical landscape. Until now, more than 40 cyclic peptide drugs are currently in the market, and approximately one new cyclopeptide drug enters the market annually on average. Interestingly, the majority of clinically approved cyclic peptides are derived from natural sources, such as peptide antibiotics and human peptide hormones. In this report, the importance of cyclic peptides is discussed, and their role in drug discovery as interesting therapeutic biomolecules will be highlighted. Recently isolated naturally occurring cyclic peptides from microorganisms, sponges, and other sources with a wide range of pharmacological properties are reviewed herein.

scholarly journals Double the Chemistry, Double the Fun: Structural Diversity and Biological Activity of Marine-Derived Diketopiperazine Dimers

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 551 ◽  
Author(s):  
Nelson G. M. Gomes ◽  
Renato B. Pereira ◽  
Paula B. Andrade ◽  
Patrícia Valentão
Keyword(s):  
Wide Spectrum ◽  
Structural Diversity ◽  
Pharmacological Properties ◽  
Binding Ability ◽  
Recognition Sites ◽  
Naturally Occurring ◽  
Bioactive Properties ◽  
Models Of Disease ◽  
First Time ◽  
Biosynthetic Machinery

While several marine natural products bearing the 2,5-diketopiperazine ring have been reported to date, the unique chemistry of dimeric frameworks appears to remain neglected. Frequently reported from marine-derived strains of fungi, many naturally occurring diketopiperazine dimers have been shown to display a wide spectrum of pharmacological properties, particularly within the field of cancer and antimicrobial therapy. While their structures illustrate the unmatched power of marine biosynthetic machinery, often exhibiting unsymmetrical connections with rare linkage frameworks, enhanced binding ability to a variety of pharmacologically relevant receptors has been also witnessed. The existence of a bifunctional linker to anchor two substrates, resulting in a higher concentration of pharmacophores in proximity to recognition sites of several receptors involved in human diseases, portrays this group of metabolites as privileged lead structures for advanced pre-clinical and clinical studies. Despite the structural novelty of various marine diketopiperazine dimers and their relevant bioactive properties in several models of disease, to our knowledge, this attractive subclass of compounds is reviewed here for the first time.

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