Organická chemie se dále zabývá chemickou stukturou molekul, jejich reakcemi a reakčními mechanismy. Skripta Chemie pro biology II navíc zohledňují další kritéria, jako je výskyt konkrétních látek v přírodě, jejich vzájemné vztahy a zejména vztah těchto látek k regulaci a vývoji rostlinných a živočišných systémů. Nakladatelská anotace. Kráceno

• MeSH
• organická chemie MeSH

• Konspekt
• Organická chemie
• Učební osnovy. Vyučovací předměty. Učebnice
• NLK Obory
• chemie, klinická chemie
• NLK Publikační typ
• učebnice vysokých škol

Silene latifolia serves as a model species to study dioecy, the evolution of sex chromosomes, dosage compensation and sex-determination systems in plants. Currently, no protocol for genetic transformation is available for this species, mainly because S. latifolia is considered recalcitrant to in vitro regeneration and infection with Agrobacterium tumefaciens. Using cytokinins and their synthetic derivatives, we markedly improved the efficiency of regeneration. Several agrobacterial strains were tested for their ability to deliver DNA into S. latifolia tissues leading to transient and stable expression of the GUS reporter. The use of Agrobacterium rhizogenes strains resulted in the highest transformation efficiency (up to 4.7% of stable transformants) in hairy root cultures. Phenotypic and genotypic analyses of the T1 generation suggested that the majority of transformation events contain a small number of independent T-DNA insertions and the transgenes are transmitted to the progeny in a Mendelian pattern of inheritance. In short, we report an efficient and reproducible protocol for leaf disc transformation and subsequent plant regeneration in S. latifolia, based on the unique combination of infection with A. rhizogenes and plant regeneration from hairy root cultures using synthetic cytokinins. A protocol for the transient transformation of S.latifolia protoplasts was also developed and applied to demonstrate the possibility of targeted mutagenesis of the sex linked gene SlAP3 by TALENs and CRISPR/Cas9.

• MeSH
• Agrobacterium genetika   MeSH
• chromozomy rostlin genetika   MeSH
• CRISPR-Cas systémy MeSH
• DNA bakterií genetika   MeSH
• exprese genu MeSH
• genetické techniky MeSH
• geneticky modifikované rostliny MeSH
• modely genetické MeSH
• molekulární evoluce MeSH
• regenerace genetika   MeSH
• reportérové geny MeSH
• Silene genetika   mikrobiologie   fyziologie   MeSH
• TALENs MeSH
• transformace genetická * MeSH
• Publikační typ
• časopisecké články MeSH

UV záření (UVA a UVB), které je složkou slunečního světla dopadajícího na zemský povrch, má vysokou energii. Díky této skutečnosti může přímo reagovat s biomolekulami (DNA, lipidy nebo proteiny), případně vyvolávat tvorbu reaktivních forem kyslíku (ROS), které mohou tyto biomolekuly poškozovat, což se projeví nevratnými změnami kůže vedoucími k jejímu předčasnému stárnutí, v horším případě ke karcinogenezi. Ve snaze potlačit nežádoucí účinky slunečního záření se využívají různé přístupy ochrany kůže. Kromě anorganických a organických UV filtrů jsou zkoumány přirozeně se vyskytující nízkomolekulární látky rostlinné povahy, které mohou eliminovat nežádoucí účinky slunečního záření. Rostlinné hormony cytokininy, zejména kinetin (Kin), který je N6-substituovaným derivátem adeninu, jsou známy pro svou schopnost zpomalovat přirozené stárnutí buněk, to znamená, že vykazují tzv. antisenescenční vlastnosti. Nedávno bylo prokázáno, že některé cytokininy a jejich deriváty mají ochranné vlastnosti vůči UVA i UVB záření. Jejich využití při zpomalení předčasného stárnutí kůže působením slunečního záření je předmětem intenzivního studia.

UV radiation (UVA and UVB), is an integral part of the sunlight reaching the earth's surface containing high energy photons. Owning to the high energy, the photons they can directly interact with biomolecules like DNA, lipids, and proteins and/or generate reactive oxygen species (ROS) causing oxidative damage and irreversible changes in the skin. The changes can lead to premature skin ageing (photoageing) and even skin cancer. Adequate protection of the skin is hence of paramount importance. Exogenous protection approaches that are being developed include organic and inorganic sunscreens as well as various naturally occurring low molecular weight compounds of plant-origin. The plant hormones, cytokinins, especially kinetin (Kin), which is a N6-substituted adenine derivative, are known for their antisenescence and antioxidant effects. Some cytokinins and their derivatives, in addition, have been shown to have photoprotective properties against UVA and UVB radiation. Their application in the prevention of photoageing is being intensively studied.

• MeSH
• cytokininy * terapeutické užití   MeSH
• lidé MeSH
• přípravky chránící proti slunci MeSH
• sluneční záření * škodlivé účinky   MeSH
• stárnutí kůže MeSH
• Check Tag
• lidé MeSH

Eleven 6-furfurylaminopurine (kinetin, Kin) derivatives were synthesized to obtain biologically active compounds. The prepared compounds were characterized using 1H NMR, mass spectrometry combined with HPLC purity determination and elemental C, H, N analyses. The biological activity of new derivatives was tested on plant cells and tissues in cytokinin bioassays, such as tobacco callus, detached wheat leaf chlorophyll retention bioassay and Amaranthus bioassay. The selected compounds were subsequently tested on normal human dermal fibroblasts (NHDF) and keratinocyte cell lines (HaCaT) to exclude possible phototoxic effects and, on the other hand, to reveal possible UVA and UVB photoprotective activity. The protective antioxidant activity of the prepared cytokinin derivatives was further studied and compared to previously prepared antisenescent compound 6-furfurylamino-9-(tetrahydrofuran-2-yl)purine (Kin-THF) using induced oxidative stress (OS) on nematode Caenorhabditis elegans damaged by 5-hydroxy-1,4-naphthoquinone (juglone), a generator of reactive oxygen species. The observed biological activity was interpreted in relation to the structure of the prepared derivatives. The most potent oxidative stress protection of all the prepared compounds was shown by 6-(thiophen-2-ylmethylamino)-9-(tetrahydrofuran-2-yl)purine (6) and 2-chloro-6-furfurylamino-9-(tetrahydrofuran-2-yl)purine (9) derivatives and the results were comparable to Kin-THF. Compounds 6 and 9 were able to significantly protect human skin cells against UV radiation in vitro. Both the derivatives 6 and 9 showed higher protective activity in comparison to previously known structurally similar compounds Kin and Kin-THF. The obtained results are surprising due to the fact that the prepared compounds showed to be inactive in the ORAC assay which proved that the compounds did not act as direct antioxidants as they were unable to directly scavenge oxygen radicals.

• MeSH
• cytokininy chemická syntéza   chemie   farmakologie   MeSH
• kůže účinky léků   MeSH
• lidé MeSH
• molekulární struktura MeSH
• ochranné látky chemická syntéza   chemie   farmakologie   MeSH
• oxidační stres účinky léků   MeSH
• ultrafialové záření * MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Isoprenoid cytokinins play a number of crucial roles in the regulation of plant growth and development. To study cytokinin receptor properties in plants, we designed and prepared fluorescent derivatives of 6-[(3-methylbut-2-en-1-yl)amino]purine (N6-isopentenyladenine, iP) with several fluorescent labels attached to the C2 or N9 atom of the purine moiety via a 2- or 6-carbon linker. The fluorescent labels included dansyl (DS), fluorescein (FC), 7-nitrobenzofurazan (NBD), rhodamine B (RhoB), coumarin (Cou), 7-(diethylamino)coumarin (DEAC) and cyanine 5 dye (Cy5). All prepared compounds were screened for affinity for the Arabidopsis thaliana cytokinin receptor (CRE1/AHK4). Although the attachment of the fluorescent labels to iP via the linkers mostly disrupted binding to the receptor, several fluorescent derivatives interacted well. For this reason, three derivatives, two rhodamine B and one 4-chloro-7-nitrobenzofurazan labeled iP were tested for their interaction with CRE1/AHK4 and Zea mays cytokinin receptors in detail. We further showed that the three derivatives were able to activate transcription of cytokinin response regulator ARR5 in Arabidopsis seedlings. The activity of fluorescently labeled cytokinins was compared with corresponding 6-dimethylaminopurine fluorescently labeled negative controls. Selected rhodamine B C2-labeled compounds 17, 18 and 4-chloro-7-nitrobenzofurazan N9-labeled compound 28 and their respective negative controls (19, 20 and 29, respectively) were used for in planta staining experiments in Arabidopsis thaliana cell suspension culture using live cell confocal microscopy.

• MeSH
• 4-chlor-7-nitrobenzofurazan farmakologie   MeSH
• adenin analogy a deriváty   chemie   MeSH
• Arabidopsis metabolismus   MeSH
• barvicí látky chemie   MeSH
• cytokininy chemie   farmakologie   MeSH
• fluorescenční barviva chemie   MeSH
• isopentenyladenosin chemická syntéza   chemie   farmakologie   MeSH
• karbocyaniny chemie   MeSH
• konfokální mikroskopie MeSH
• kukuřice setá metabolismus   MeSH
• molekulární struktura MeSH
• proteiny huseníčku metabolismus   MeSH
• puriny chemie   MeSH
• receptory cytokinové antagonisté a inhibitory   chemie   MeSH
• regulace genové exprese u rostlin MeSH
• regulátory růstu rostlin metabolismus   MeSH
• rhodaminy chemie   MeSH
• semenáček metabolismus   MeSH
• terpeny metabolismus   MeSH
• vývoj rostlin MeSH
• Publikační typ
• časopisecké články MeSH

Clonal propagation plays a critical integral role in the growth and success of a global multi-billion dollar horticulture industry through a constant supply of healthy stock plants. The supply chain depends on continuously improving the micropropagation process, thus, understanding the physiology of in vitro plants remains a core component. We evaluated the influence of exogenously applied cytokinins (CKs, N6-benzyladenine = BA, isopentenyladenine = iP, meta-topolin = mT, 6-(3-hydroxybenzylamino)-9-(tetrahydropyran-2-yl)purine = mTTHP) in Murashige and Skoog (MS)-supplemented media on organogenic response and accumulation of endogenous CK and indole-3-acetic acid (IAA) metabolites. The highest shoot proliferation (30 shoots/explant) was obtained with 20 μM mT treatment. However, the best quality regenerants were produced in 10 μM mT treatment. Rooting of Amelanchier alnifolia in vitro plantlets was observed at the lowest CK concentrations, with the highest root proliferation (3 roots/explant) in 1 μM mTTHP regenerants. Similar to the organogenic response, high levels of endogenous bioactive CK metabolites (free bases, ribosides, and nucleotides) were detected in mT and mTTHP-derived regenerants. The level of O-glucosides was also comparatively high in these cultures. All CK-treated plants had high levels of endogenous free IAA compared to the control. This may suggest an influence of CKs on biosynthesis of IAA.

• MeSH
• cytokininy farmakologie   MeSH
• ovoce růst a vývoj   MeSH
• Rosaceae růst a vývoj   MeSH
• Publikační typ
• časopisecké články MeSH

In an attempt to improve specific biological functions of cytokinins routinely used in plant micropropagation, 33 6-benzylamino-9-tetrahydropyran-2-ylpurine (THPP) and 9-tetrahydrofuran-2-ylpurine (THFP) derivatives, with variously positioned hydroxy and methoxy functional groups on the benzyl ring, were prepared. The new derivatives were prepared by condensation of 6-chloropurine with 3,4-dihydro-2H-pyran or 2,3-dihydrofuran and then by the condensation of these intermediates with the corresponding benzylamines. The prepared compounds were characterized by elemental analyses, TLC, HPLC, melting point determinations, CI+ MS and (1)H NMR spectroscopy. The cytokinin activity of all the prepared derivatives was assessed in three classical cytokinin bioassays (tobacco callus, wheat leaf senescence and Amaranthus bioassay). The derivatives 6-(3-hydroxybenzylamino)-9-tetrahydropyran-2-ylpurine (3) and 6-(3-hydroxybenzylamino)-9-tetrahydrofuran-2-ylpurine (23) were selected, because of the high affinity of their parent compound meta-topolin (mT, 6-(3-hydroxybenzylamino)purine) to cytokinin receptors, as model compounds for studying their perception by the receptors CRE1/AHK4 and AHK3 in a bacterial assay. Both receptors perceived these two derivatives less well than they perceived the parent compound. Subsequently, the susceptibility of several new derivatives to enzyme degradation by cytokinin oxidase/dehydrogenase was studied. Substitution of tetrahydropyran-2-yl (THP) at the N(9) position decreased the turnover rates of all new derivatives to some extent. To provide a practical perspective, the cytotoxicity of the prepared compounds against human diploid fibroblasts (BJ) and the human cancer cell lines K-562 and MCF-7 was also assayed in vitro. The prepared compounds showed none or marginal cytotoxicity compared to the corresponding N(9)-ribosides. Finally, the pH stability of the two model compounds was assessed in acidic and neutral water solutions (pH 3-7) by high-performance liquid chromatography (HPLC).

• MeSH
• cytokininy chemie   metabolismus   MeSH
• fibroblasty účinky léků   MeSH
• financování organizované MeSH
• furany chemická syntéza   chemie   toxicita   MeSH
• kinetika MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• puriny chemická syntéza   chemie   toxicita   MeSH
• pyrany chemická syntéza   chemie   toxicita   MeSH
• stabilita léku MeSH
• Check Tag
• lidé MeSH

A series of square-planar Pd(II) complexes of the composition cis-[Pd(L(n))(2)Cl(2)] {L(1)=2-chloro-6-benzylamino-9-isopropylpurine (1), L(2)=2-chloro-6-[(4-methoxybenzyl)amino]-9-isopropylpurine (2), L(3)=2-chloro-6-[(2-methoxybenzyl)amino]-9-isopropylpurine (3) and 2-[(chloropropyl)amino]-6-benzylamino-9-isopropylpurine (6)} has been synthesized by the reaction of PdCl(2) with L(n) in a 1:2 molar ratio. In contrast, the same reaction followed by recrystallization of the product from N,N'-dimethylformamide (DMF) leads to trans-[Pd(L(n))(2)Cl(2)] x nDMF {L(3), n=0 (4), n=1(4( *)DMF); L(4)=2-chloro-6-[(2,3-dimethoxybenzyl)-amino]-9-isopropylpurine, n=0 (5), n=1.5 (5( *)DMF). The compounds have been characterized by elemental analyses, conductivity measurements, electrospray mass spectra in the positive ion mode (ES+MS), FTIR, (1)H and (13)C NMR spectra, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Moreover, the complexes 2 and 6 have been also investigated by (15)N NMR spectroscopy. The molecular structures of L(5), {(H(2+)L(5))(Cl(-))(2)} x H(2)O, i.e. the protonated form of L(5), trans-[Pd(L(3))(2)Cl(2)] (4) and trans-[Pd(L(4))(2)Cl(2)] (5) have been determined by single crystal X-ray analysis. NMR data and X-ray structures revealed that the organic molecules are coordinated to Pd via N7 atom of a purine moiety. All the complexes and the corresponding ligands have been tested in vitro for their cytotoxicity against four human cancer cell lines: breast adenocarcinoma (MCF7), malignant melanoma (G361), chronic myelogenous leukaemia (K562) and osteogenic sarcoma (HOS). Promising in vitro cytotoxic effect has been found for cis-[Pd(L(2))(2)Cl(2)] (2), having the IC(50) values of 12, 10, 25, and 14 microM against MCF7, G361, K562, and HOS, respectively, and for trans-[Pd(L(3))(2)Cl(2)].DMF (4) with the IC(50) value of 15 microM against G361.

• MeSH
• financování organizované MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• inhibiční koncentrace 50 MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• nádorové buňky kultivované MeSH
• organokovové sloučeniny farmakologie   chemická syntéza   chemie   MeSH
• protinádorové látky farmakologie   chemická syntéza   chemie   MeSH
• puriny farmakologie   chemická syntéza   chemie   MeSH
• screeningové testy protinádorových léčiv MeSH
• Check Tag
• lidé MeSH

The Pt(II) and Pd(II) complexes of the types cis-[Pt(L(1))(2)Cl(2)].H(2)O (1), cis-[Pt(L(2))(2)Cl(2)].3H(2)O (2), trans-[Pd(L(1))(2)Cl(2)].H(2)O (3), trans-[Pd(L(2))(2)Cl(2)].H(2)O (4), trans-[Pd(L(3))(2)Cl(2)].2DMF (5) and trans-[Pd(L(4))(2)Cl(2)].2DMF (6) (L(1)-L(4)=cyclin-dependent kinase inhibitors derived from 6-benzylamino-9-isopropylpurine) have been prepared and characterized. The complexes have been studied by elemental analyses, conductivity measurements, ES+ MS, FT-IR, (1)H, (13)C and (195)Pt NMR spectra, differential scanning calorimetry and thermogravimetric analysis. The molecular structures of L(1), trans-[Pd(L(3))(2)Cl(2)].2DMF (5) and trans-[Pd(L(4))(2)Cl(2)].2DMF (6) have been determined by single crystal X-ray analysis. The complexes have been tested in vitro due to their presumable anticancer activity against the following human cancer cell lines: K-562, MCF7, G-361 and HOS. Satisfying results were obtained for the complex 1 with IC(50) values of 6 microM acquired against G-361 as well as against HOS cell lines. The lowest values of IC(50) were achieved for the complexes 3 and 4 against MCF 7 cell line with IC(50) 3 microM(for 3) and also 3 microM (for 4).

• MeSH
• cyklin-dependentní kinasy antagonisté a inhibitory   MeSH
• diferenciální skenovací kalorimetrie MeSH
• financování organizované MeSH
• hmotnostní spektrometrie s elektrosprejovou ionizací MeSH
• inhibitory enzymů farmakologie   chemie   MeSH
• krystalografie rentgenová MeSH
• magnetická rezonanční spektroskopie MeSH
• molekulární modely MeSH
• palladium farmakologie   chemie   MeSH
• protinádorové látky farmakologie   chemie   MeSH
• sloučeniny platiny farmakologie   chemická syntéza   chemie   MeSH
• spektrofotometrie infračervená MeSH