3 research outputs found
New Inhibitors of Breast Cancer Resistance Protein (ABCG2) Containing a 2,4-Disubstituted Pyridopyrimidine Scaffold
Multidrug
resistance (MDR) occurring during cancer chemotherapy
is a major obstacle for effectiveness and response to therapy and
is often caused by ATP-binding cassette (ABC) efflux transporters.
Belonging to the family of ABC transporters, breast cancer resistance
protein is getting more and more in the spotlight of research. As
a strategy to overcome MDR, inhibitors of ABC transporters were synthesized,
which could be applied in combination with cytostatic drugs. For this
purpose, 2,4-disubstituted pyridopyrimidine derivatives were synthesized.
The investigations confirmed three key characteristics of good inhibitors:
a low intrinsic cytotoxicity and a high potency and selectivity toward
ABCG2. For selected compounds the interaction with ABCG2 was elucidated
and their effect on ATPase activity and conformation sensitive 5D3
antibody binding was investigated. Their ability to reverse MDR in
coadministration with the active metabolite of irinotecan and mitoxantron
was confirmed
New Inhibitors of Breast Cancer Resistance Protein (ABCG2) Containing a 2,4-Disubstituted Pyridopyrimidine Scaffold
Multidrug
resistance (MDR) occurring during cancer chemotherapy
is a major obstacle for effectiveness and response to therapy and
is often caused by ATP-binding cassette (ABC) efflux transporters.
Belonging to the family of ABC transporters, breast cancer resistance
protein is getting more and more in the spotlight of research. As
a strategy to overcome MDR, inhibitors of ABC transporters were synthesized,
which could be applied in combination with cytostatic drugs. For this
purpose, 2,4-disubstituted pyridopyrimidine derivatives were synthesized.
The investigations confirmed three key characteristics of good inhibitors:
a low intrinsic cytotoxicity and a high potency and selectivity toward
ABCG2. For selected compounds the interaction with ABCG2 was elucidated
and their effect on ATPase activity and conformation sensitive 5D3
antibody binding was investigated. Their ability to reverse MDR in
coadministration with the active metabolite of irinotecan and mitoxantron
was confirmed
Solubility of Carvedilol in Ethanol + Propylene Glycol Mixtures at Various Temperatures
Solubilities of carvedilol (CVD)
in binary mixtures of (ethanol
+ propylene glycol (PG)) at 298.2, 303.2, 308.2, and 313.2 K are reported.
The modified versions of the vanât Hoff and Gibbs equations
were used to calculate the thermodynamic properties (enthalpy (Î<i>H</i>°), entropy (Î<i>S</i>°), and
Gibbs energy (Î<i>G</i>°) standard changes of
solutions) for CVD dissolved in (ethanol (1) + PG (2)) mixtures from
the solubility data. The solubility data of CVD in (ethanol (1) +
PG (2)) at different temperatures were correlated using different
mathematical models, i.e., the JouybanâAcree model, a combination
of the JouybanâAcree model with the vanât Hoff model,
and two modified versions of the JouybanâAcree model. Solubility
data of seven drugs in (ethanol (1) + PG (2)) at different temperatures
were used to develop a quantitative structureâproperty relationship
model for predicting solubility in solvent mixtures. In addition,
enthalpyâentropy compensation using Î<i>H</i>° vs Î<i>G</i>° and Î<i>H</i>° vs <i>T</i>ÎS° which explains the mechanism
of cosolvency at different temperatures was discussed