Synthesis and binding properties of calix[4]arene diamide dicarboxylic acids

2000 ◽  
Vol 24 (12) ◽  
pp. 967-972 ◽  
Author(s):  
Françoise Arnaud-Neu ◽  
Silvia Barboso ◽  
Alessandro Casnati ◽  
Alessandra Pinalli ◽  
Marie-Jose´ Schwing-Weill ◽  
...  
Biochemistry ◽  
1993 ◽  
Vol 32 (1) ◽  
pp. 215-223 ◽  
Author(s):  
Richard T. Jones ◽  
Charlotte G. Head ◽  
Thomas S. Fujita ◽  
Daniel T. B. Shih ◽  
Jolanta Wodzinska ◽  
...  

Author(s):  
Martin Poenie ◽  
Akwasi Minta ◽  
Charles Vorndran

The use of fura-2 as an intracellular calcium indicator is complicated by problems of rapid dye leakage and intracellular compartmentalization which is due to a probenecid sensitive anion transporter. In addition there is increasing evidence for localized microdomains of high calcium signals which may not be faithfully reported by fura-2.We have developed a new family of fura-2 analogs aimed at addressing some of these problems. These new indicators are based on a modified bapta which can be readily derivatized to produce fura-2 analogs with a variety of new properties. The modifications do not affect the chromophore and have little impact on the spectral and metal binding properties of the indicator. One of these new derivatives known as FPE3 is a zwitterionic analog of fura-2 that can be loaded into cells as an acetoxymethyl ester and whose retention in cells is much improved. The improved retention of FPE3 is important for both cuvettebased measurements of cell suspensions and for calcium imaging.


1998 ◽  
Vol 36 (5) ◽  
pp. 291-298 ◽  
Author(s):  
DE LUCCA ◽  
BLAND ◽  
JACKS ◽  
GRIMM ◽  
WALSH

Planta Medica ◽  
2008 ◽  
Vol 74 (03) ◽  
Author(s):  
VLM Madgula ◽  
B Avula ◽  
X Fu ◽  
XC Li ◽  
TJ Smillie ◽  
...  

2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.


2019 ◽  
Author(s):  
Mohammad Mosharraf Hossain ◽  
Joshua Atkinson ◽  
Scott Hartley

Dissipative (nonequilibrium) assembly powered by chemical fuels has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single transient covalent bond. Here, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycle is assembled efficiently as a consequence of both fuel-dependent and -independent mechanisms: it undergoes slower decomposition, building up as the fuel recycles the components, and is a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.


Author(s):  
N. N. Loy ◽  
S. N. Gulina

The effect of presowing seed treatment on various concentrations of dicarboxylic (organic) acids on the sowing characteristics of spring barley has been studied. Seeds were treated with organic acids obtained by exposing cuttings to the radiation with a dose of 100 kGy and consequent hydrolysis, in concentrations: 1•10-7 %; 1•10-9; 1•10-11; 1•10-13 and 1•10-15 % on a laboratory rotary machine RVO-64 for one day before laying for germination. Distilled water was used for the control case. The rate of application of the working solution calculated as 10 liters / ton of seeds. Seeds were germinated in filter paper rolls in accordance with GOST 12038-84 requirements. The temperature was maintained at +24 ° C in the thermostat where the glasses with rolls were placed. For determination of germinative power and laboratory germination the sprouted seeds were evaluated after three and seven days, respectively. In laboratory experiments it was established that the treatment of barley seeds of varieties Zazersky 85, Nur and Vladimir with organic acids (OK) in different concentrations had both a stimulating and a negative effect. On the Zazersky 85 variety, in variants with acid concentrations of 1•10-9 and 1•10-11, an increase in germination energy (EP) by 2-4% and a significant decrease (by 3-4%) of laboratory germination (LV) of barley seeds were noted. On the Nur variety, the increase in EP was observed at 4% (concentration 1•10-11), LV and seed growth force (CPC) by 2-7% at a concentration of 1•10-7 and in the dose range 1•10-11 - 1•10-14 compared to the control values. On the grade of Vladimir, an increase in EP, LV, and CPC was found to increase by 1-6% at concentrations OK 1•10-7 and 1•10-13. It was shown that the treatment of seeds with acids led to an increase in the length of the germ in all studied varieties (by 3-9%) and dry biomass of 7-day-old seedlings - by 3-6%. Consequently, the treatment of seeds with a mixture of dicarboxylic acids has a stimulating effect on the sowing quality of spring barley.


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