Search results for "EOs"

A rapid separation of the four major deoxynucleosides and deoxyinosine by high-pressure liquid cation-exchange chromatography

1973

From the covalent linkage of drugs to novel inhibitors of ribonucleotide reductase: synthesis and biological evaluation of valproic esters of 3'-C-me…

2014

We synthesized a series of serum-stable covalently linked drugs derived from 3'-C-methyladenosine (3'-Me-Ado) and valproic acid (VPA), which are ribonucleotide reductase (RR) and histone deacetylase (HDAC) inhibitors, respectively. While the combination of free VPA and 3'-Me-Ado resulted in a clear synergistic apoptotic effect, the conjugates had lost their HDAC inhibitory effect as well as the corresponding apoptotic activity. Two of the analogs, 2',5'-bis-O-valproyl-3'-C-methyladenosine (A160) and 5'-O-valproyl-3'-C-methyladenosine (A167), showed promising cytotoxic activities against human hematological and solid cancer cell lines. A167 was less potent than A160 but had interesting featu…

An isocratic high-pressure liquid chromatographic purification method for radioactively labeled deoxyribonucleoside triphosphates.

1976

Abstract A method is described for the rapid purification of radioactively labeled deoxyribonucleoside tri­phosphates from their spontaneously emerging hydrolysis products deoxyribonucleoside diphosphate, deoxyribonucleoside monophosphate, and deoxyribonucleoside. The separations which are finished within 3 min or less are carried out on a 0.1X5 cm column filled with LiChrosorb-NH2 , using isocratic elution with 0.025 м potassium phosphate, pH 6 .8 , in a high-pressure liquid chromatograph at room temperature and a flow rate of 30 ml · h-1(flow velocity 63.7 cm·min-1).

Mandible histology in Metoposaurus krasiejowensis (Temnospondyli, Stereospondyli) from the Upper Triassic of Poland

2021

Recent studies that have systematically augmented our knowledge of dermal bones of the Late Triassic temnospondyl amphibian Metoposaurus krasiejowensis have mostly focused on shoulder girdle elements and the skull. So far, histological data on the mandible are still scant. For the present study, two mandibles have been examined, using 50 standard thin sections. Dermal bones of the mandible reveal a uniform diploë structure, with the external cortex consisting of moderately vascularised, parallel-fibred bone, as well as a distinct alternation of thick zones and thinner annuli. Dense bundles of well-mineralised Sharpey’s fibres are seen in the external cortex over the entire length of the man…

Estudio epidemiológico de las parasitosis intestinales detectadas en la población infantil de Ruanda (África Central)

2016

La presente Tesis Doctoral tiene por objetivo conocer el estado del parasitismo intestinal y su correlación con diferentes factores intrínsecos y extrínsecos en la población infantil ruandesa. Para ello, se ha estudiado un total de 674 escolares (330 niños y 344 niñas) del Colegio Nemba I (Nemba, Gakenke, Província Norte de Ruanda), con edades comprendidas entre los 6 y 18 años de edad. Se ha detectado un espectro parasitario de 17 especies (10 de protozoos y 7 de helmintos), con una prevalencia total de parasitación del 94,9% (94,5% para protozoos y 18,1% para helmintos). Las especies más prevalentes fueron: Endolimax nana (91,1%), Blastocystis hominis (89,9%) y Entamoeba coli (57,2%). Se …

Mast cells promote homeostasis by limiting endothelin-1-induced toxicity

2004

Endothelin-1 (ET-1) is a 21-amino-acid peptide, derived from vascular endothelial cells, with potent vasoconstrictor activity. ET-1 has been implicated in diverse physiological or pathological processes, including the vascular changes associated with sepsis. However, the factors that regulate ET-1-associated toxicity during bacterial infections, or in other settings, are not fully understood. Both the pathology associated with certain allergic and autoimmune disorders, and optimal host defence against bacterial and parasitic infections are mediated by mast cells. In vitro, mast cells can produce ET-1 (ref. 11), undergo ET-1-dependent and endothelin-A receptor (ET(A))-dependent activation, a…

Chiral α-P,N Ligands From a Diastereoselective Ph2PH Addition to (η6-Benzaldimine)tricarbonylchromium Complexes

1999

International audience; Chiral α-aminophosphane (α-P–C–N) ligands have been prepared by reversible addition of Ph2PH to tricarbonylchromium benzaldimine complexes (CO)3Cr[η6-o-C6H4(Y)(CH=NR)] (with Y, R = CH3, CH3 or CH2COOCH3; CH3O, CH3 or p-CH3OC6H4; Cl, C6H5), with complete diastereoselectivity. These complexes are stabilized in solution by electron-withdrawing group(s) on the imine.

Synthesis of 8-aminomorphans with high KOR affinity

2021

2-Azabicyclo[3.3.1]nonanes (morphans) with a (3,4-dichlorophenyl)acetyl group at 2-position and a pyrrolidino moiety at 8-position were designed as conformationally restricted analogs of piperidine-based KOR agonists. The synthesis started with 4-oxopiperidine-2-carboxylic acid comprising 13 reaction steps. At first the ketone 10 was transformed into diester 7 bearing a propionate side chain. Dieckmann condensation of diester 7 to afford bicyclic enolester 14 and subsequent Krapcho deethoxycarbonylation represent the key steps of the synthesis. The enantiomeric pyrrolidines (1S,5R,8R)-5a and (1R,5S,8S)-5a were separated by chiral HPLC. The eutomer (1S,5R,8R)-5a showed high KOR affinity (K-i…

Addition of dianions of carboxylic acids to imines. Influence of the acid in the outcome of the reaction

2009

The addition of different carboxylic acids dianions to N-benzylidenebenzeneamine have been studied. The outcome of the reaction depends on the acid. Saturated ones lead to β-aminoacids with good yields and syn-selectivity whereas α,β-unsaturated ones lead to α− and γ− regioisomers with a regioselectivity that depends on the steric hindrance around the reactive centre. From some of these unsaturated acids, polyunsaturated carboxylic acids can be obtained as a change in the reaction conditions lead to the in situ elimination of aniline. From o-methyl aromatic acids δ-aminoacids are isolated with uneven results. Those derived from six member arene carboxylic acids give, on standing, dihydro-2-…

Direct synthesis of C3-mono-functionalized oxindoles from N-unprotected 2-oxindole and their antileishmanial activity.

2014

A novel approach for the synthesis of unprecedented C3-mono-functionalized indolin-2-ones is reported, starting from 2-oxindole and chalcones. The reactions proceed regioselectively under mild conditions, without di- and tri-alkylated side products. The new compounds have been evaluated in vitro for their antiproliferative effects against the protozoan Leishmania infantum. Interestingly, they appear able to kill L. infantum promastigotes and amastigotes, without significant cytotoxic effects.