In this research work, we report the synthesis of macrocyclic diamides from the reaction of diesters and aliphatic diamines in the presence of caesium carbonate. It has been demonstrated that among the carbonate of alkali metals (Li2CO3, Na2CO3, K2CO3 and CS2CO3), CS2CO3 appear to be the best catalyst for macrocyclization. Diesters with different substitution patterns on the aromatic ring react...

essential oils (eos) extracted from aerial parts of aster indamellus grierson, calamintha umbrosa benth. and erigeron annuus (l.) pres.were analyzed by gc, gc/ms. the major acetylenic constituent (cis-lachnophyllum ester) of e. annuus was isolated and characterized by 1h and 13c-nmr spectra. their toxicity and repellent effect against lipaphiserysimi was tested. oils of e. annuus and c. umbrosa...

Phthalates are plasticisers added to a wide variety of products, resulting in measurable exposure of humans. They are suspected to disrupt the thyroid axis as epidemiological studies suggest an influence on the peripheral thyroid hormone concentration. The mechanism is still unknown as only few in vitro studies within this area exist. The aim of the present study was to investigate the influenc...

A selection of cyclic and acyclic acetylenic scaffolds bearing two tetrathiafulvalene (TTF) units was prepared by different metal-catalyzed coupling reactions. The bridge separating the two TTF units was systematically changed from linearly conjugated ethyne, butadiyne and tetraethynylethene (trans-substituted) units to a cross-conjugated tetraethynylethene unit, placed in either acyclic or cyc...

Biosynthesis of prostaglandins could be stopped by several acetylenic acids. They interfered with the oxygenase activity of the sheep vesicular gland enzymic system in two distinct patterns: an instantaneous, concentration-dependent effect and a time-dependent, destructive effect. Constants for both effects are reported. No measurable oxygen consumption tias observed with the acetylenic analogs...

The irritant and tumor-promoting constituents of latex of Euphorbia tirucalli L. originating from South Africa were isolated. They were identified as irritant ingenane and tigliane type diterpene esters derived from unsaturated aliphatic acids and acetic acid and the polyfunctional diterpene parent alcohols 4-deoxyphorbol, phorbol and ingenol, respectively. The irritant and tumor-promoting este...

Freshly isolated human leukemia cells have been shown in the past to display varying in vitro responses to phorbol diesters, depending on their cell type. Specific receptors for the phorbol diesters have been demonstrated on numerous different cells. This study was designed to characterize the receptors for phorbol diesters on leukemia cells freshly isolated from patients with different kinds o...

Reaction of dialkyl acetylenedicarboxylates 1a-c andpyrrole derivatives 2a-e in the presence of triphenylphosphite (TPP) was investigated and the effect of the pyrrole substitution was established. Diastereoselectivity is observed with pyrroles, 2a,b, yieldingphosphonate ester derivatives 3a-f and 4,and their relative configuration is determined by 1H/13C and 31</...

Terminal acetylenic fatty acid mechanism-based inhibitors (Ortiz de Montellano, P. R., and Reich, N. O. (1984) J. Biol. Chem. 259, 4136-4141) were used as probes in determining the substrate specificity of rabbit lung cytochrome P-450 isozymes of pregnant animals in both microsomes and reconstituted systems. Lung microsomal and reconstituted P-450 form 5-catalyzed lauric acid omega- and (omega-...