A series of macrocyclic imides and Schiff-bases have been prepared via the cyclocondensation of pyridine-2,6-dicarbonyl dichloride (1) with L-ornithine methyl ester to give the corresponding macrocyclic bisester 2. Treatment of 2 with hydrazine hydrate gave macrocyclic bisacid hydrazide 3, which was used as starting material. Condensation of bishydrazide 3 with diacid anhydrides or aromatic ald...

Background: The advances in cytogenetic techniques during the last few years have permitted not only the study of large populations of wild and domestic animals, but also the detection of chromosome anomalies in embryos. Chromosomal abnormalities are the most common cause of embryonic and fetal mortality in mammals. Most reports of chromosome anomalies in parthenogenetic embryos describe numeri...

magnetic resonance imaging (mri) contrast agents most commonly agents used in diagnosing different diseases. several agents have been ever introduced with different peculiar characteristics. they vary in potency, adverse reaction and other specification, so it is important to select the proper agent in different situations. we conducted a systematic literature search in medline/pubmed, web of s...

The title compound, C(28)H(52)N(6) (6+)·6Cl(-)·4H(2)O, is a dinucleating 28-membered centrosymmetric hexa-azamacrocyclic complex. The macrocyclic ligand adopts a chair-like conformation, with the crystallographic inversion center located in the macrocyclic cavity. The six chloride ions and four water mol-ecules are situated symmetrically outside the macrocyclic cavity. The crystal structure is ...

Macrocyclic complexes of Mn, Co, Ni and Cu using a macrocyclic ligand derived by the condensation of Trimethoprim and diethyl phthalate have been prepared and characterized by electronic, IR and NMR spectral studies as well as magnetic moment and conductivity. On the basis of spectral studies, an octahedral geometry has been proposed for all the complexes. INTRODUCTION: The chemistry of macrocy...

Macrocyclic peptides are a promising class of compounds that can often engage challenging therapeutic targets. Display technologies, such as mRNA display, allow for the efficient discovery macrocyclic peptides. This article reviews current approaches generating peptide libraries using display and highlights some recent examples ribosomal incorporation nonproteinogenic amino acids into

Cadmium promoted diastereoselective amplification of a single member from a dynamic combinatorial library of stereoisomeric oligoimines of different sizes allows the efficient preparation of a new macrocyclic polyamine.

A domino process is described combining an ene reaction between two alkynes and a Diels-Alder cycloaddition of the vinylallene formed. The process accounts for the thermally induced cycloisomerization of macrocyclic triynes and enediynes to give fused tetracycles in a stereoselective manner.

abstract background: fertilization failure is one of the most problems in assisted reproduction technology (art). objective: the aim of this study was the evaluation of oocytes activation by addition of calcium ionophore in unfertilized oocytes in icsi cycles. materials and methods: this study was done on 15 icsi cycles (stimulated with standard long protocol). mature retrieved oocytes with nor...

Voltammetric ion-selective electrodes (ISEs) based on poly(3-octylthiophene) (POT) in connection with ultra-thin membranes formulated different selective receptors (i.e., ionophores) are proposed for detection of lead, copper and silver ions (Pb2+, Cu2+ Ag+). The working mechanism the POT-membrane electrode is interconnected charge transfer processes both sides membrane, overall process dependi...