Capillary electrophoretic separation of cationic porphyrins.

Cationic porphyrins have a wide variety of uses including those as nucleic acid binding and cleaving agents, as potential pharmacological agents, as electron donor/acceptors in intramolecular electron transfer processes and as analytical reagents. Herein, we report the separation of cationic porphyrins by capillary electrophoresis on fused silica in phosphate buffer at pH 2-5. The porphyrins studied in this work were synthesized from alkylation of the parent tetrapyridylporphyrin (TPyP) to give various pyridinium porphyrins. For example, methylation of TPyP gives a mixture of the mono-, cis-di-, trans-di-, tri- and tetramethylated porphyrins [e.g., 5,10,15,20-tetrakis(N-methyl-4-pyridiniumyl)-21H,23H-p orphyrin, TMPyP(4)]. Capillary electrophoresis on a synthetic mixture showed separation of four of these compounds. Mixtures after alkylation with iodopropionic acid and bromopropylamine were also separated. The cis-di- and trimethylated TMPyP derivatives were separated on a small preparative scale by centrifugal partition chromatography. Capillary electrophoresis was also used to separate metallo TMPyP(4) complexes including those of cobalt, copper, iron, manganese, palladium, tin, vanadium and zinc. The conformational isomers (atropisomers) of 5,10,15,20-tetrakis(N-methyl-2-pyridiniumyl)-21H,23H-p orphyrin, TMPyP(2), were also separated. Net charge, molecular mass and molecular shape all contribute to the differential retention of cationic porphyrins under capillary electrophoresis conditions. Additional factors affecting the separations, including aggregation and protonation of the porphyrins, were probed by evaluating the separation of TMPyP(4) and its butyl and octyl analogs as a function of solution conditions. Cationic porphyrins are difficult to separate using traditional chromatographic methods; capillary electrophoresis and centrifugal partition chromatography provide excellent new techniques for separation of this class of compounds.

Stacking-controlled phototransformations of the 5-fluorouracil residues in dinucleotide model compounds.

5-Fluorouracil residues can form cyclobutane-type photodimers in a direct excitation stacking-controlled process. The stacking also has an important effect on the photohydration of uracil and 5-fluorouracil in our model compounds 5RUra(CH2)35FUra, where R = H, CH3, C2H5, C3H7, F or Cl.

Azaanalogues of ebselen as antimicrobial and antiviral agents: synthesis and properties.

The different analogues of ebselen-unsubstituted benzisoselenazol-3(2H)-one (2a) 2-pyridylbenzisoselenazol-3(2H)-ones (2b-h) and 7-azabenzisoselenazol-3(2H)-ones (3a-j) were designed as new selenium-containing antiviral and antimicrobial agents and synthesized. Some of them were found in the antiviral assay in vitro to be strong inhibitors of cythopatic activity of herpes simplex virus type 1--HSV-1 (compounds 2a,b,f,h, 3a-j) and encephalomyocarditis virus--EMCV (compounds 2a,h, 3a-f,k,l). The compounds 2a,h and 3a-e,j were found to have an appreciable activity against Gram-positive bacteria (Staphylococcus aureus and Bacillus) in vitro, some of them inhibited growth of pathogenic yeasts (Candida albicans) (3a,b) and filamentous fungi (3a-e,f).

Functionalized alkyl and aryl diselenides as antimicrobial and antiviral agents: synthesis and properties.

The different dialkyl and diaryl diselenides with carbamoyl and sulfamoyl moieties 2, 3, 5 and other substituents in the ortho position of benzene ring 4, 7, 8 as well as derivatives of 1,2,4-benzoselenadiazine (6) were designed as antiviral and antimicrobial agents and synthesized. Some of them, particularly 8a and 8b, were found in the antiviral assay in vitro to be strong inhibitors of cytopathic activity encephalomyocarditis virus (EMCV). The compound 4a and 8a were found to have a broad spectrum of acivity against bacteria, yeasts and pathogenic fungi in vitro.

Novel selenoorganic compounds as modulators of oxidative stress in blood platelets.

Many selenoorganic compounds play an important role in biochemical processes and act as antioxidants, enzyme inhibitors, or drugs. The effects of five new synthesized selenoorganic compounds (2-(5-chloro-2-pyridyl)-7-azabenzisoselenazol-3(2H)-one; 2-phenyl-7-azabenzisoselenazol-3(2H)-one; 2-(pyridyl)-7-azabenzisoselenazol-3(2H)-one; 7-azabenzisoselenazol-3(2H)-one; bis(2-aminophenyl) diselenide) on oxidative changes in human blood platelets and in plasma were studied in vitro and compared with those of ebselen, a well known antioxidant. Our studies demonstrated that bis(2-aminophenyl) diselenide has distinctly protective effects against oxidative stress in blood platelets and in plasma. It might have greater biological relevance and stronger pharmacological effects than ebselen.

The structural study of internal [2+2] photodimers of the derivatives of 1,1'-trimethylene-bis-(5-fluoro) uracil.

The structure of internal [2+2] photodimers of 1,1'-trimethylene-bis-(5-fluoro) uracil derivatives has been studied. All investigated compounds have cis-syn geometry with puckered endocyclic cyclobutane ring and chair-like conformation of 1,3-diazacycloheptane ring.

[Assessment of the efficacy of drugs used in prevention of vomiting during anticancer therapy in children]. / Ocena skutecznosci leków stosowanych w zapobieganiu wymiotom w przebiegu chemioterapii przeciwnowotworowej u dzieci.

The efficiency of antiemetic drugs was investigated in 36 children with neoplasia (mainly of hematopoietic system) in the course of 83 cycles of chemotherapy. The following antiemetic drugs were investigated: Fenactil (brand of chlorpromazine), Torecan (brand of thienylpromazine maleate), Aviomarin (brand of dimenhydrinate), Decadron (brand of dexamethasone), Primperan (brand of metoclopramid), and placebo. The most efficient was dexamethasone which prevented vomiting in 54% cycles of chemotherapy and diminished their intensity in the remaining cycles. No adverse reactions were noted. Efficacy of Fenactil, Torecan, Aviomarin, and Primperan was similar to that of placebo.