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Considering its very short elimination half-life, the approved oxacillin dosage might not be sufficient to maintain the pharmacokinetic/pharmacodynamics (PK/PD) target of time-dependent antibiotics. This study aimed to describe the population pharmacokinetics of oxacillin and to explore the probability of PK/PD target attainment by using various dosing regimens with oxacillin in staphylococcal infections. Both total and unbound oxacillin plasma concentrations retrieved as a part of routine therapeutic drug-monitoring practice were analyzed using nonlinear mixed-effects modeling. Monte Carlo simulations were used to generate the theoretical distribution of unbound oxacillin plasma concentration–time profiles at various dosage regimens. Data from 24 patients treated with oxacillin for staphylococcal infection have been included into the analysis. The volume of distribution of oxacillin in the population was 11.2 L, while the elimination rate constant baseline of 0.73 h−1 increased by 0.3 h−1 with each 1 mL/s/1.73 m2 of the estimated glomerular filtration rate (eGFR). The median value of oxacillin binding to plasma proteins was 86%. The superiority of continuous infusion in achieving target PK/PD values was demonstrated and dosing according to eGFR was proposed. Daily oxacillin doses of 9.5 g, 11 g, or 12.5 g administered by continuous infusion have been shown to be optimal for achieving target PK/PD values in patients with moderate, mild, or normal renal function, respectively. [ABSTRACT FROM AUTHOR]

The combination of cytotoxic amino‐BODIPY dye and 2‐phenyl‐3‐hydroxy‐4(1H)‐quinolinone (3‐HQ) derivatives into one molecule gave rise to selective activity against lymphoblastic or myeloid leukemia and the simultaneous disappearance of the cytotoxicity against normal cells. Both species′ conjugation can be realized via a disulfide linker cleavable in the presence of glutathione characteristic for cancer cells. The cleavage liberating the free amino‐BODIPY dye and 3‐HQ derivative can be monitored by ratiometric fluorescence or by the OFF‐ON effect of the amino‐BODIPY dye. A similar cytotoxic activity is observed when the amino‐BODIPY dye and 3‐HQ derivative are connected through a non‐cleavable maleimide linker. The work reports the synthesis of several conjugates, the study of their cleavage inside cells, and cytotoxic screening. [ABSTRACT FROM AUTHOR]

Various bromophenylalkenes were reductively photodebrominated by using 1,3-dimethyl-2-phenyl-1H-benzo-[d]imidazoline (DMBI) and 9,10-dicyanoanthracene. With deuterated DMBI analogs (the most effective was DMBI-d11), satisfactory to excellent isotopic yields were obtained. DMBI-d11 could also be regenerated from the reaction mixtures with a recovery rate of up to 50%. The combination of the photodebromination reaction with conventional methods for bromoalkene synthesis enables sequential monodeuteration of a double bond without the necessity of a metal catalyst. [ABSTRACT FROM AUTHOR]

A synthetic three-fluorophore system with two enzymatically cleavable linkers has been developed for the simultaneous detection of two proteases in a mixture. The probe was designed to afford single excitation/triple emission ratiometric detection through a fluorescence change during the cleavage of a peptide linker. The developed assays were verified for trypsin and chymotrypsin as the model enzymes. [ABSTRACT FROM AUTHOR]

Trimethylsilanolate alkali salts are widely used in organic synthesis, mainly due to their solubility in common organic solvents. They are frequently used as nucleophiles in ester hydrolysis, both in solution and solid-phase chemistry. However, they have also been used as mild bases or as specific reagents in some chemical transformations. Reactions employing trimethylsilanolate alkali salts as the key component are typically performed under mild reaction conditions. This review summarizes the utilization of trimethylsilanolate alkali salts in various organic transformations. 1 Introduction 2 Properties of Alkali Metal Trimethylsilanolates (TMSO[M]) 3 Trimethylsilanolate Alkali Salts in Organic Synthesis 4 Conclusion [ABSTRACT FROM AUTHOR]

Herein, we report the regioselective synthesis of 5-[(2,3-dihydroxypropoxy)methyl]uracil analogues with hydroxy alkyl chains that mimic the natural C-nucleoside pseudouridine. We developed multiple disparate synthetic procedures and approaches for the preparation of a wide range of derivatives, such as amino, acyl, halogen or azido compounds. Their synthesis was based on the different reactivity of the primary and secondary hydroxy groups. The final compounds might be further considered as new building blocks for oligonucleotide synthesis. [ABSTRACT FROM AUTHOR]

Quercetin and phenylpropanoids are well known chemoprotective compounds identified in many plants. This study was aimed at determining their effects on activation of Nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response element (Nrf2-ARE) signalling pathway and expression of its important downstream effector phase II detoxification enzyme glutathione-S-transferase P1 (GSTP1) in BJ foreskin fibroblasts and skin HaCaT keratinocytes. Cell lines and their corresponding Nrf2-ARE luciferase reporter cells were treated by ginger phenylpropanoids and quercetin for 10 h and the level of Nrf2 activity was subsequently determined. Both, ginger phenylpropanoids and quercetin, significantly increased the level of Nrf2 activity. Subsequent western blot analyses of proteins showed the increased expression level of glutathione-S-transferase P1 (GSTP1) in BJ cells but not in HaCaT cells. Such phenomenon of unresponsive downstream target expression in HaCaT cells was consistent with previous studies showing a constitutive expression of their GSTP1. Thus, while both ginger phenylpropanoids and quercetin have the property of increasing the level of Nrf2 both in HaCaT and in BJ cells, their effects on its downstream signalling were mediated only in BJ cells. [ABSTRACT FROM AUTHOR]

Propargyl anthranilate, a simple and less studied molecule with several reactive sites, is widely applicable in organic synthesis. An optimized synthesis of this compound and its derivatives and the preparation of azide derivatives are described. The optimized process of the known intramolecular cyclization is described, and the unknown intermolecular cyclizations of these azido derivatives and formation of a macrocycle are discussed. [ABSTRACT FROM AUTHOR]

A new procedure for the preparation of macrocycles containing 1,2,3-triazole motifs is developed. The macrocyclic precursor is constructed by repetition of a series of steps which include cycloaddition of an azide with an alkyne, alkylation of a carboxylic acid with propargyl bromide and formation of an azide from an amino group. The order of the steps and the size of the connected fragments are determined by the desired ring size. Chromatographic purification techniques for the poorly soluble final products are also described. [ABSTRACT FROM AUTHOR]

Four new 3-hydroxy-quinolinone derivatives with promising anticancer activity could be solubilized using liposomes as vehicle to an extent that allows their in vitro and in vivo testing without use of toxic solvent(s). A screening method to identify the maximum incorporation capacity of hydrophobic drugs within liposomes was successfully applied. The compounds and lipid(s) were dissolved in methanol, and the solvent was removed by rotary evaporation. The film was resuspended with phosphate buffer (pH 7.4), and the dispersion was sonicated to reduce vesicle size. Ultracentrifugation was used to separate liposome-associated drug from free (i.e., precipitated) drug, and the amount of drug incorporated within the liposomes was quantified using high-performance liquid chromatography. All four compounds were found to be significantly incorporated within soy phosphatidylcholine (SPC) liposomes, resulting in a 200-500-fold increase in apparent solubility. Drug-to-lipid ratios in the range of 2-5 µg/mg were obtained. Interestingly, the four quinolinone derivatives have shown different association tendencies with liposomes, probably due to the physicochemical properties of the different group bonded in position 2 of the quinolinone ring. None of the alternative lipids/lipid blends tested incorporated as much drug as SPC. Photon correlation spectroscopy analyses indicated that use of ultrasounds produced an efficient reduction in liposome size. The present approach appears suitable for incorporation capacity studies of any lipophilic drug in liposomes. [ABSTRACT FROM AUTHOR]

A structure-activity relationship of some derivatives of 2-phenyisubstituted- hydroxyquinoun-4(lH)-one-7-carboxarnid(;s was systematically studied using combinatorial solid-phase synthesis and in vitro cytotoxic activity screening on representative cancer lines. The effect of subsetituent type in position 2 as well as of the carboxamide group was investigated via synthesis of generic libraries constructed with respect to polarity and bulkiness of appropriate substituents. The process of development afforded a set of compounds with, significant cytotoxic activity. Subsequently, corresponding 2-phenylsubstituted-3-hydroxyquinolin-4(l,h)-one-6-carboxamides and 2-phenylsubstitutted- 3-hydroxyquinolin 4-(lH)-one-8-carboxamides were prepared to evaluate the influence of the carboxamide group position on the resulting biological activity. [ABSTRACT FROM AUTHOR]

Solid-phase synthesis of bisheterocyclic compounds that contain purine and the 3-hydroxyquinolin-4(1H)-one skeleton connected with an aliphatic spacer of a different length/structure is described. The reaction sequence started from the primary amines immobilized on aminomethylated polystyrene resin equipped with an acid-labile linker (4-(4-formyl-3-methoxyphenoxy)butyric acid). After the arylation of amines with 2,6-dichloropurine via its C6, purine N9was alkylated and subsequently the chlorine at purine C2was substituted with aliphatic diamines. The resulting terminal amino group was used as the starting point for the synthesis of 3-hydroxyquinolin-4(1H)-one precursors based on the acylation with 3-amino-4-(methoxycarbonyl)benzoic acid followed by the saponification of the methyl ester and esterification of the resulting carboxylic acid with various haloketones. The intermediates were cleaved from the resin, and their cyclization to the target purine-hydroxyquinolinone bisheterocycles was accomplished by heating in acetic or trifluoroacetic acid. [ABSTRACT FROM AUTHOR]