2,6-Pyridinedicarbonitrile (1a) and 2,4-pyridinedicarbonitrile (2a) were hydrated by Rhodococcus erythropolis A4 to 6-cyanopyridine-2-carboxamide (1b; 83% yield) and 2-cyanopyridine-4-carboxamide (2b; 97% yield), respectively, after 10 min. After 118 h, the intermediates 1b or 2b were transformed into 2,6-pyridinedicarboxamide (1c; 35% yield) and 2,6-pyridinedicarboxylic acid (1d; 60% yield) or 2-cyanopyridine-4-carboxylic acid (2c; 64% yield), respectively. The nitrilase from Fusarium solani afforded cyanocarboxylic acids 1e and 2c after 118 h (yields 95 and 62%, respectively). 3,4-Pyridinedicarbonitrile (3a) and 2,3-pyrazinedicarbonitrile (4a) were inferior substrates of nitrile hydratase and nitrilase.
- MeSH
- amidy metabolismus MeSH
- aminohydrolasy metabolismus MeSH
- biotransformace MeSH
- heterocyklické sloučeniny chemie metabolismus MeSH
- houby enzymologie MeSH
- hydrolýza MeSH
- nitrily chemie metabolismus MeSH
- Rhodococcus enzymologie MeSH
- substrátová specifita MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- amidy MeSH
- aminohydrolasy MeSH
- heterocyklické sloučeniny MeSH
- nitrilase MeSH Prohlížeč
- nitrily MeSH
A new separation method based on the combination of exclusion and ion exchange chromatography in borate buffer was developed. It allows semi-preparatory and preparatory separation of isobaric N-acylhexosamines (C-2 epimers) and corresponding methyl glycosides (anomers and tautomers). Three types of polyolic gels were tested for these separations. Ion-exchange HPLC was used as a rapid and reliable method for the quantification of the respective analytes. NMR studies of the interactions of N-acetylhexosamines with borate confirmed the importance of a proper stereochemical arrangement of acetamido sugars for their interactions with borate anions.
- MeSH
- boritany chemie MeSH
- gelová chromatografie metody MeSH
- hexosaminy chemická syntéza izolace a purifikace MeSH
- molekulární sekvence - údaje MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- oligosacharidy chemická syntéza izolace a purifikace MeSH
- sacharidové sekvence MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- boritany MeSH
- hexosaminy MeSH
- N-acetylmannosamine MeSH Prohlížeč
- oligosacharidy MeSH
Carboxylic acids derived from silybin (1) and 2,3-dehydrosilybin (2) with improved water solubility were prepared by selective oxidation of parent compounds and a new inexpensive method for preparation of 2,3-dehydrosilybin from silybin was developed and optimised. The antioxidative properties of the above-mentioned compounds and of side product 3a from oxidation of compound 1 were determined by cyclic voltammetry, free radical scavenging (DPPH, superoxide) assays, and by inhibition of in vitro generated liver microsomal lipid peroxidation. Dehydrogenation at C((2))-C((3)) in flavonolignans (silybin vs 2,3-dehydrosilybin; silybinic acid vs 2,3-dehydrosilybinic acid) strongly improved antioxidative properties (analogously as in flavonoids taxifolin vs quercetin). Thus, in antioxidative properties, dehydrosilybin was superior to silybin by one order, but its water solubility is too low for application in aqueous milieu. On the other hand, 2,3-dehydrosilybinic acid is a fairly soluble derivative with antilipoperoxidation and antiradical activities better than that of silybin.
- MeSH
- antioxidancia chemie farmakologie MeSH
- jaterní mikrozomy účinky léků metabolismus MeSH
- krysa rodu Rattus MeSH
- oxidace-redukce účinky léků MeSH
- scavengery volných radikálů chemie farmakologie MeSH
- silibinin MeSH
- silymarin chemie farmakologie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- antioxidancia MeSH
- scavengery volných radikálů MeSH
- silibinin MeSH
- silymarin MeSH
Dimers of agroclavine (1) and terguride (2), as well as a series of terguride oligomers, for example trimers (5, 6), tetramer (7), hexamer (8) and functionalized tergurides for further complex clustering were synthesized. Terguride oligomers were screened for their direct cellular toxicity on lymphoma cell lines in vitro and for their immunomodulating activities, represented by the natural killer (NK) cell-mediated cytotoxicity, as the most sensitive screening marker during immune responses. Dimers linked via aromatic spacer showed a high toxicity (1 microM) to lymphoma cells, which was not detected in other derivatives. In vitro and ex vivo experiments performed on mouse spleen lymphocytes in the presence of terguride oligomers demonstrated an immunosuppressive effect of dimers with aromatic spacer (4c-d) and NK cell stimulatory effect of terguride hexamer (8) and trimer with aliphatic spacer (5c). There is a considerable evidence that indolic part of molecule contributes to immunosuppressive action of terguride, which is potentiated in dimers carrying aromatic linker. This effect can be reversed by higher oligomerization of the respective alkaloids.
- MeSH
- adjuvancia imunologická chemie farmakologie MeSH
- buňky NK účinky léků fyziologie MeSH
- dimerizace MeSH
- ergoliny chemie farmakologie MeSH
- imunosupresiva chemie farmakologie MeSH
- karbamáty chemie farmakologie MeSH
- lidé MeSH
- lisurid analogy a deriváty chemie farmakologie MeSH
- myši inbrední BALB C MeSH
- myši MeSH
- nádorové buňky kultivované MeSH
- preklinické hodnocení léčiv metody MeSH
- slezina cytologie účinky léků MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- 1-bromo-2,2-di(6-methyl-methyl-8-(diethylcarbamoylamino)-ergoline-1-yl-methyl)-3-(6-methyl-8-(diethylcarbamoylamino)-ergoline-1-yl)propane MeSH Prohlížeč
- 1,2,3,4,5,6-hexa(6-methyl-8-(diethylcarbamoylamino)-ergoline-1-yl-methyl) MeSH Prohlížeč
- adjuvancia imunologická MeSH
- agroclavine MeSH Prohlížeč
- dironyl MeSH Prohlížeč
- ergoliny MeSH
- imunosupresiva MeSH
- karbamáty MeSH
- lisurid MeSH
