Synthesis and Properties of "Hormonogene" and "Inhibitorogene" Type Oxytocin Analogs

1992 ◽  
Vol 57 (6) ◽  
pp. 1345-1351 ◽  
Author(s):  
B. C. Pal ◽  
Jiřina Slaninová ◽  
Tomislav Barth ◽  
Jerzy Trojnar ◽  
Michal Lebl
Keyword(s):  
Amino Acid ◽  
Inhibitory Action ◽  
Time Course ◽  
Solid Phase ◽  
Prolonged Time ◽  
Prolonged Effect ◽  
In Vivo Tests

Nα-Glycyl, diglycyl and triglycyl [2-D and [2-L-p-ethylphenylalanine]oxytocin analogs were synthesized by the solid phase technology utilizing racemic p-ethylphenylalanine. Analogs containing this amino acid of D-configuration were shown to be weak uterotonic antagonists both in vitro and in vivo tests; the compound containing triglycyl residue in position 1 was shown to have prolonged time course of inhibitory action. Analogs containing the L-amino acid were shown to be inhibitors of uterotonic activity of oxytocin in vitro, but uterotonic agonists with prolonged effect in vivo.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

Estimating the bioavailability of trace metals/metalloids and persistent organic substances in terrestrial environments: challenges and need for multidisciplinary approaches

2014 ◽  
Vol 86 (7) ◽  
pp. 1085-1095 ◽  
Author(s):  
Petr S. Fedotov
Keyword(s):  
Trace Metals ◽  
Organic Contaminants ◽  
Method Development ◽  
Solid Phase ◽  
Critical Evaluation ◽  
Polynuclear Aromatic Hydrocarbons ◽  
Mild Conditions ◽  
In Vivo Tests

AbstractDefinitions and terms related to bioavailability and bioaccessibility of trace metals/metalloids and organic contaminants in soil are briefly discussed and critically evaluated. Main distinguishing features of estimating the bioavailability by biological (in vivo) methods are characterized. Assessment of bioaccessibility using biomimetric (in vitro) methods and existing correlations with in vivo tests are summarized. The most promising biomimetric methods can be as follows: CaCl2 extraction for the assessment of metals biouptake into plants; solid-phase micro extraction, supercritical fluid extraction (SFE) under mild conditions as well as Tenax and hydroxypropyl-beta-cyclodextrin (HPCD) extractions for the estimation of biouptake of persistent organic compounds (e.g., polynuclear aromatic hydrocarbons and polychlorinated biphenyls) by soil-dwelling organisms (mainly earthworms); SFE under mild conditions, HPCD and Tenax extraction for the prediction of biodegradability (microbial degradation) of organic contaminants. However, method development should be extended to further classes of substances. In addition, multidisciplinary approaches are needed for (i) standardization and round-robin studies of the most promising biomimetric methods and protocols so that the data obtained in different laboratories can be compared; (ii) further assessment and critical evaluation of correlations between in vitro and in vivo tests; application of chemometric techniques for handling sets of data obtained both by biomimetric and biological methods is of particular importance in order to evaluate new criteria for risk assessment.

scholarly journals Prospecção de Aureobasidium pullulans, Isolado do Bioma Caatinga, no Biocontrole de Colletotrichum truncatum em Sementes de Soja

2020 ◽  
Vol 24 (4) ◽  
pp. 365-369
Author(s):  
Wictor Hugo Amorim Nogueira Paranaguá Carvalho ◽  
Helane França Silva ◽  
Alice Maria Gonçalves Santos ◽  
Elaine Martins Costa
Keyword(s):  
Biological Control ◽  
Glycine Max ◽  
Aureobasidium Pullulans ◽  
Inhibitory Action ◽  
Preventive Treatment ◽  
Colletotrichum Truncatum ◽  
In Vivo Tests ◽  
Glycine Max L

O fungo Colletotrichum truncatum (Schwein.) Andrus & W.D. Moore é um importante fitopatógeno em várias culturas de interesse econômico, inclusive na soja (Glycine max (L.) Merril), causando a doença conhecida como antracnose. Apesar do controle químico ser o método de controle mais usado pelos produtores rurais, o controle biológico se apresenta como uma alternativa sustentável para o manejo desta doença. Esta pesquisa avaliou o potencial do fungo Aureobasidium pullulans (de Bary & Lowenthal) G. Arnaud, originário do bioma Caatinga, no controle de C. truncatum. Foi avaliado o efeito inibitório sobre o crescimento micelial do patógeno a partir de compostos voláteis (in vitro), além de testes in vivo. Foram analisadas as variáveis germinação, índice de velocidade de germinação (IVG), massa seca e sanidade das sementes. Nos ensaios in vitro, os compostos voláteis produzidos pelo antagonista não apresentaram ação inibitória expressiva a C. truncatum. Nos testes in vivo, foi observada a ação inibitória de A. pullulans a C. truncatum em sementes de soja, por meio dos tratamentos preventivo e curativo. O tratamento preventivo proporcionou maior efetividade em relação ao tratamento curativo, evidenciando média superior de IVG (41,84) e menor incidência do patógeno (16,00%).  Desse modo, verificam-se as perspectivas do uso de A. pullulans no biocontrole de C. truncatum, especialmente, quando se realiza o tratamento preventivo. Este é o primeiro relato de A. pullulans sobre C. truncatum.   Palavras-chave: Antagonismo Microbiano. Controle Biológico. Fungos. Fitopatógeno.   Abstract The fungus Colletotrichum truncatum (Schwein.) Andrus & W.D. Moore is an important phytopathogen in several crops of economic interest, including soybean (Glycine max (L.) Merril), causing a disease known as anthracnose. Although chemical control is the most used control method by farmers, biological control presents itself as a sustainable alternative for the management of this disease. This study evaluated the potential of Aureobasidium pullulans (de Bary & Lowenthal) G. Arnaud, originating from Caatinga biome vegetation, in the control of C. truncatum. The inhibitory effect on the mycelial growth of the pathogen was evaluated from volatile compounds produced by the antagonist (in vitro) in addition to the in vivo tests. The following variables were analyzed, germination, germination speed index (GSI), dry mass and seed health. In the in vitro assays the volatile compounds produced by the antagonist presented no significant inhibitory action against C. truncatum. In in vivo tests, an inhibitory action of A. pullulans and C. truncatum was observed in soybean seeds, through preventive and curative treatments. The preventive treatment provided greater effectiveness in relation to the curative treatment, showing higher average of GSI (41.84) and lower incidence of the pathogen (16.00%). Thus, the perspectives of the use of A. pullulans in the biocontrol of C. truncatum are verified, especially when the preventive treatment is carried out. This is the first report of A. pullulans on C. truncatum.   Keywords: Microbial Antagonism. Biological Control. Fungi. Phytopathogen.

scholarly journals Biosynthesis of Rat serum albumin

1971 ◽  
Vol 123 (4) ◽  
pp. 649-655 ◽  
Author(s):  
J. D. Judah ◽  
Marion R. Nicholls
Keyword(s):  
Amino Acid ◽  
Serum Albumin ◽  
Time Course ◽  
Time Lag ◽  
Rat Serum ◽  
Albumin Content ◽  
Double Label ◽  
Rat Serum Albumin

1. The labelling of intracellular and extracellular serum albumin was studied in liver slices and in whole rats by using new methods for the purification of the protein. 2. The results suggest that a polypeptide precursor is formed that is converted relatively slowly into serum albumin. 3. The effect of liver cell K+has been examined by a double-label method and it is shown that K+accelerates the rate of conversion of ‘precursor’ into albumin. The rate of transit of albumin across the cell membrane appears to be unrelated to the concentration of K+within the cell. 4. The time-course of incorporation of radioactive amino acid into albumin follows a sigmoidal mode. There is a pronounced time-lag before label starts to appear in intracellular albumin, and a further time-lag before it appears in extracellular albumin. 5. In slices the sum of intra- and extra-cellular label rises steadily from 30min after the start of labelling with a pulse of labelled leucine or valine and continues to rise for at least another 60min. This occurs whether labelling is stopped by addition of excess of carrier amino acid or with cycloheximide (100μm) or both. 6. The intracellular albumin content remains constant whether slices are maintained with low or normal intracellular K+concentrations. 7. Specific radioactivities of intracellular albumin (and fractions thereof) and of extracellular albumin were determined in vitro and in vivo. The results show that the intracellular albumin cannot be a precursor of extracellular albumin, unless a very small compartment is turning over much more rapidly than the bulk of the liver albumin or even of the microsomal albumin.

Comparison of High Purity Factor IX Concentrates and a Prothrombin Complex Concentrate in a Canine Model of Thrombogenicity

1991 ◽  
Vol 66 (05) ◽  
pp. 609-613 ◽  
Author(s):  
I R MacGregor ◽  
J M Ferguson ◽  
L F McLaughlin ◽  
T Burnouf ◽  
C V Prowse
Keyword(s):  
High Purity ◽  
Time Course ◽  
Prothrombin Complex Concentrate ◽  
Degradation Products ◽  
Canine Model ◽  
Factor Ix ◽  
In Vitro Tests ◽  
Albumin Infusion

SummaryA non-stasis canine model of thrombogenicity has been used to evaluate batches of high purity factor IX concentrates from 4 manufacturers and a conventional prothrombin complex concentrate (PCC). Platelets, activated partial thromboplastin time (APTT), fibrinogen, fibrin(ogen) degradation products and fibrinopeptide A (FPA) were monitored before and after infusion of concentrate. Changes in FPA were found to be the most sensitive and reproducible indicator of thrombogenicity after infusion of batches of the PCC at doses of between 60 and 180 IU/kg, with a dose related delayed increase in FPA occurring. Total FPA generated after 100-120 IU/kg of 3 batches of PCC over the 3 h time course was 9-12 times that generated after albumin infusion. In contrast the amounts of FPA generated after 200 IU/kg of the 4 high purity factor IX products were in all cases similar to albumin infusion. It was noted that some batches of high purity concentrates had short NAPTTs indicating that current in vitro tests for potential thrombogenicity may be misleading in predicting the effects of these concentrates in vivo.

68Ga-labeled HBED-CC Variant of uPAR Targeting Peptide AE105 Compared with 68Ga-NODAGA-AE105

2019 ◽  
Vol 18 (9) ◽  
pp. 1289-1294 ◽  
Author(s):  
Kusum Vats ◽  
Rohit Sharma ◽  
Haladhar D. Sarma ◽  
Drishty Satpati ◽  
Ashutosh Dash
Keyword(s):  
Solid Phase ◽  
Evaluation Studies ◽  
Radiochemical Yield ◽  
In Vivo Evaluation ◽  
Peptide Conjugates ◽  
Biodistribution Studies ◽  
Target Organs ◽  
U87mg Tumor

Aims: The urokinase Plasminogen Activator Receptors (uPAR) over-expressed on tumor cells and their invasive microenvironment are clinically significant molecular targets for cancer research. uPARexpressing cancerous lesions can be suitably identified and their progression can be monitored with radiolabeled uPAR targeted imaging probes. Hence this study aimed at preparing and evaluating two 68Ga-labeled AE105 peptide conjugates, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 as uPAR PET-probes. Method: The peptide conjugates, HBED-CC-AE105-NH2 and NODAGA-AE105-NH2 were manually synthesized by standard Fmoc solid phase strategy and subsequently radiolabeled with 68Ga eluted from a commercial 68Ge/68Ga generator. In vitro cell studies for the two radiotracers were performed with uPAR positive U87MG cells. Biodistribution studies were carried out in mouse xenografts with the subcutaneously induced U87MG tumor. Results: The two radiotracers, 68Ga-NODAGA-AE105 and 68Ga-HBED-CC-AE105 that were prepared in >95% radiochemical yield and >96% radiochemical purity, exhibited excellent in vitro stability. In vivo evaluation studies revealed higher uptake of 68Ga-HBED-CC-AE105 in U87MG tumor as compared to 68Ga-NODAGAAE105; however, increased lipophilicity of 68Ga-HBED-CC-AE105 resulted in slower clearance from blood and other non-target organs. The uPAR specificity of the two radiotracers was ascertained by significant (p<0.05) reduction in the tumor uptake with a co-injected blocking dose of unlabeled AE-105 peptide. Conclusion: Amongst the two radiotracers studied, the neutral 68Ga-NODAGA-AE105 with more hydrophilic chelator exhibited faster clearance from non-target organs. The conjugation of HBED-CC chelator (less hydrophilic) resulted in negatively charged 68Ga-HBED-CC-AE105 which was observed to have high retention in blood that decreased target to non-target ratios.

The 1- and 2-Naphthylalanine Analogs of Oxytocin and Vasopressin

1995 ◽  
Vol 60 (12) ◽  
pp. 2170-2177 ◽  
Author(s):  
Zdenko Procházka ◽  
Jiřina Slaninová
Keyword(s):  
Amino Acids ◽  
Solid Phase ◽  
Pressor Test

Solid phase technique on p-methylbenzhydrylamine resin was used for the synthesis of four analogs of oxytocin and four analogs of vasopressin with the non-coded amino acids L- or D- and 1- or 2-naphthylalanine and D-homoarginine. [L-1-Nal2]oxytocin, [D-1-Nal2]oxytocin, [L-2-Nal2]oxytocin, [D-2-Nal2]oxytocin, [L-1-Nal2, D-Har8]vasopressin, [D-1-Nal2, D-Har8]vasopressin, [L-2-Nal2, D-Har8]vasopressin and [D-2-Nal2, D-Har8]vasopressin were synthesized. All eight analogs were found to be uterotonic inhibitors in vitro and in vivo. Analogs with 2-naphthylalanine are stronger inhibitors, particularly in the vasopressin series than the analogs with 1-naphthylalanine. Analogs with 1-naphthylalanine have no activity in the pressor test, analogs with 2-naphthylalanine are weak pressor inhibitors.

Synthesis of Fragments of the Vasoactive Intestinal Peptide (VIP) and Analysis of Their Residual Biological Activities

1995 ◽  
Vol 60 (7) ◽  
pp. 1229-1235 ◽  
Author(s):  
Ivana Zoulíková ◽  
Ivan Svoboda ◽  
Jiří Velek ◽  
Václav Kašička ◽  
Jiřina Slaninová ◽  
...  
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Residual Activity ◽  
Detailed Examination ◽  
Amino Acid Residues ◽  
Linear Peptide ◽  
Zone Electrophoresis ◽  
Capillary Zone

The vasoactive intestinal (poly)peptide (VIP) is a linear peptide containing 28 amino acid residues, whose primary structure indicates a low metabolic stability. The following VIP fragments, as potential metabolites, and their analogues were prepared by synthesis on a solid: [His(Dnp)1]VIP(1-10), VIP(11-14), [D-Arg12]VIP(11-14), [Lys(Pac)15,21,Arg20]VIP(15-22), and VIP(23-28). After purification, the peptides were characterized by amino acid analysis, mass spectrometry, RP HPLC, and capillary zone electrophoresis. In some tests, detailed examination of the biological activity of the substances in vivo and in vitro gave evidence of a low, residual activity of some fragments, viz. a depressoric activity in vivo for [His(Dnp)1]VIP(1-10) and a stimulating activity for the release of α-amylase in vitro and in vivo for [Lys(Pac)15,21,Arg20]VIP(15-22) and VIP(23-28).

Studies on the mechanism of acute inhibition of thyroglobulin hydrolysis by iodine

1985 ◽  
Vol 108 (4) ◽  
pp. 511-517 ◽  
Author(s):  
Nandalal Bagchi ◽  
Birdie Shivers ◽  
Thomas R. Brown
Keyword(s):  
Time Course ◽  
Period 2 ◽  
Iodotyrosine Deiodinase ◽  
Rate Of Hydrolysis ◽  
Underlying Mechanisms ◽  
Excess Iodide ◽  
Sites Of Action ◽  
Hydrolysis Of

Abstract. Iodine in excess is known to acutely inhibit thyroidal secretion. In the present study we have characterized the time course of the iodine effect in vitro and investigated the underlying mechanisms. Labelled thyroid glands were cultured in vitro in medium containing mononitrotyrosine, an inhibitor of iodotyrosine deiodinase. The rate of hydrolysis of labelled thyroglobulin was measured as the proportion of labelled iodotyrosines and iodothyronines recovered at the end of culture and was used as an index of thyroidal secretion. Thyrotrophin (TSH) administered in vivo acutely stimulated the rate of thyroglobulin hydrolysis. Addition of Nal to the culture medium acutely inhibited both basal and TSH-stimulated thyroglobulin hydrolysis. The effect of iodide was demonstrable after 2 h, maximal after 6 h and was not reversible upon removal of iodide. Iodide abolished the dibutyryl cAMP induced stimulation of thyroglobulin hydrolysis. Iodide required organic binding of iodine for its effect but new protein or RNA synthesis was not necessary. The inhibitory effects of iodide and lysosomotrophic agents such as NH4C1 and chloroquin on thyroglobulin hydrolysis were additive suggesting different sites of action. Iodide added in vitro altered the distribution of label in prelabelled thyroglobulin in a way that suggested increased coupling in the thyroglobulin molecule. These data indicate that 1) the iodide effect occurs progressively over a 6 h period, 2) continued presence of iodide is not necessary once the inhibition is established, 3) iodide exerts its action primarily at a post cAMP, prelysosomal site and 4) the effect requires organic binding of iodine, but not new RNA or protein synthesis. Our data are consistent with the hypothesis that excess iodide acutely inhibits thyroglobulin hydrolysis by increasing the resistance of thyroglobulin to proteolytic degradation through increased iodination and coupling.

scholarly journals 68Ga, 44Sc and 177Lu-labeled AAZTA5-PSMA-617: synthesis, radiolabeling, stability and cell binding compared to DOTA-PSMA-617 analogues

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Jean-Philippe Sinnes ◽  
Ulrike Bauder-Wüst ◽  
Martin Schäfer ◽  
Euy Sung Moon ◽  
Klaus Kopka ◽  
...  
Keyword(s):  
Human Serum ◽  
Room Temperature ◽  
Solid Phase ◽  
Negative Influence ◽  
Binding Motif ◽  
Lncap Cells ◽  
Cell Binding ◽  
Binding Characteristics

Abstract Background The AAZTA chelator and in particular its bifunctional derivative AAZTA5 was recently investigated to demonstrate unique capabilities to complex diagnostic and therapeutic trivalent radiometals under mild conditions. This study presents a comparison of 68Ga, 44Sc and 177Lu-labeled AAZTA5-PSMA-617 with DOTA-PSMA-617 analogues. We evaluated the radiolabeling characteristics, in vitro stability of the radiolabeled compounds and evaluated their binding affinity and internalization behavior on LNCaP tumor cells in direct comparison to the radiolabeled DOTA-conjugated PSMA-617 analogs. Results AAZTA5 was synthesized in a five-step synthesis and coupled to the PSMA-617 backbone on solid phase. Radiochemical evaluation of AAZTA5-PSMA-617 with 68Ga, 44Sc and 177Lu achieved quantitative radiolabeling of > 99% after less than 5 min at room temperature. Stabilities against human serum, PBS buffer and EDTA and DTPA solutions were analyzed. While there was a small degradation of the 68Ga complex over 2 h in human serum, PBS and EDTA/DTPA, the 44Sc and 177Lu complexes were stable at 2 h and remained stable over 8 h and 1 day. For all three compounds, i.e. [natGa]Ga-AAZTA5-PSMA-617, [natSc]Sc-AAZTA5-PSMA-617 and [natLu]Lu-AAZTA5-PSMA-617, in vitro studies on PSMA-positive LNCaP cells were performed in direct comparison to radiolabeled DOTA-PSMA-617 yielding the corresponding inhibition constants (Ki). Ki values were in the range of 8–31 nM values which correspond with those of [natGa]Ga-DOTA-PSMA-617, [natSc]Sc-DOTA-PSMA-617 and [natLu]Lu-DOTA-PSMA-617, i.e. 5–7 nM, respectively. Internalization studies demonstrated cellular membrane to internalization ratios for the radiolabeled 68Ga, 44Sc and 177Lu-AAZTA5-PSMA-617 tracers (13–20%IA/106 cells) in the same range as the ones of the three radiolabeled DOTA-PSMA-617 tracers (17–20%IA/106 cells) in the same assay. Conclusions The AAZTA5-PSMA-617 structure proved fast and quantitative radiolabeling with all three radiometal complexes at room temperature, excellent stability with 44Sc, very high stability with 177Lu and medium stability with 68Ga in human serum, PBS and EDTA/DTPA solutions. All three AAZTA5-PSMA-617 tracers showed binding affinities and internalization ratios in LNCaP cells comparable with that of radiolabeled DOTA-PSMA-617 analogues. Therefore, the exchange of the chelator DOTA with AAZTA5 within the PSMA-617 binding motif has no negative influence on in vitro LNCaP cell binding characteristics. In combination with the faster and milder radiolabeling features, AAZTA5-PSMA-617 thus demonstrates promising potential for in vivo application for theranostics of prostate cancer.

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