crystal synthesis
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Nemoc z ukládání krystalů calcium pyrofosfát dihydrátu (CaPPD) patří mezi krystaly indukovaná onemocnění. U tohoto onemocnění nebyla zjištěna systémová metabolická odchylka ve fosfokalciovém metabolizmu, ale v kloubu byly zjištěny změny, při kterých dochází k lokálně zvýšené tvorbě inorganického pyrofosfátu. Rozeznáváme formu onemocnění sporadickou, familiární a asociovanou s jiným onemocněním. Výskyt pyrofosfátové artropatie stoupá s věkem a je častější u žen. Nejčastější klinickou manifestací je akutní synovitida nebo pyrofosfátová artropatie, či kombinace obou. Akutní synovitida (pseudodna) je prudký, epizodický zánět připomínající dnu, ale který nepostihuje I. MTP ale jiné klouby převážně na nohou, a to ve formě mono, či oligoartritidy. Pyrofosfátová artropatie je chronické onemocnění připomínající osteoartrózu, s tím že prediktivně postihuje jiné klouby než osteoartróza (OA) (zápěstí, ramena, lokty, kotníky). Při diagnostice nemoci z ukládání krystalů CaPPD se jednak prokazují krystaly v synoviální tekutině nebo typické kalcifikace na rentgenovém snímku. Krystaly CaPPD jsou v polarizačním mikroskopu slabě pozitivně dvojlomné. Kalcifikace postihují nejprve chrupavky vazivové, později i hyalinní. Nejčastější lokalizací jsou menisky kolen, triangulární disk na zápěstí a symfýza. Kalcifikace hyalinních chrupavek vytvářejí typické dvojité kontury kloubů. Pyrofosfátová artropatie probíhá jako osteoartróza s jinou lokalizací. Někdy bývá silně destruktivní. V terapii se při akutní synovitidě aplikují intraartikulárně kortikosteroidy nebo se podávají systémově protizánětlivé léky. Chronická artropatie se léčí jako osteoartróza (OA).
The Calcium pyrophosphate dihydrate (CaPPD) crystal deposition disease belongs to the group of crystal-induced arthropathies. To date, no systemic change to the phospho-calcium metabolism has been identified, but changes to the local intraarticular metabolism leading to an increased synthesis of inorganic pyrophosphate have been discovered. The disease occurs in three forms: sporadic, familiar, and associated with other diseases. The incidence of pyrophosphate arthropathy is increasing with age and is more common in women than in men. The most frequent clinical manifestation is acute synovitis, pyrophosphate destructive arthropathy or both. Acute synovitis (pseudo-gout) is an acute, episodic attack mimicking gout, yet not affecting the first MTP joint, but other feet joints in the form of mono- or oligoarthritis. Pyrophosphate arthropathy is a chronic disease similar to osteoarthrosis (OA), but with different predilection than that in OA (affecting wrists, shoulders, elbows, ankles). For the diagnosis of the CaPPD crystal deposition disease the authors have used either the findings of CaPPD crystals in synovial fluid or radiographic calcifications. CaPPD crystals display minor positive birefringence under polarized microscope. The calcifications initially affect the ligament cartilage and afterwards the hyaline cartilage. The most frequently affected areas are the meniscus of the knee joint, the triangular disc of the wrist, and the symphysis. Hyaline cartilage calcifications form typical double contours of the joints. Pyrophosphate arthropathy demonstrates the same progression as osteoarthrosis with a different localization. It can be strongly destructive. The therapy of acute synovitis involves the application of intraarticular corticosteroids or systemic anti-inflammatory drugs. Chronic arthropathy is treated as OA.
- Klíčová slova
- pseudodna, kalcifikace, krystaly indukovaná onemocnění,
- MeSH
- analgetika terapeutické užití MeSH
- antiflogistika nesteroidní terapeutické užití MeSH
- chondrokalcinóza diagnóza epidemiologie terapie MeSH
- chronická nemoc MeSH
- cvičení MeSH
- hormony kůry nadledvin terapeutické užití MeSH
- klouby patologie MeSH
- kolenní kloub patologie MeSH
- krystalizace MeSH
- krystalografie metody MeSH
- lidé MeSH
- progrese nemoci MeSH
- pyrofosforečnan vápenatý metabolismus MeSH
- radiografie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- synoviální tekutina chemie metabolismus MeSH
- synovitida diagnóza terapie MeSH
- věkové faktory MeSH
- zdravotní výchova MeSH
- Check Tag
- lidé MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Publikační typ
- kazuistiky MeSH
- přehledy MeSH
A mononuclear cadmium(II) complex of formula [Cd(5,5'-dmbipy)2(OAc)2]·2H2O (5,5'-dmbipy = 5,5'-dimethyl-2,2'-bipyridine and OAc = acetato ligand) has been synthesized and characterized by FT-IR, UV-Vis, 1H-NMR, elemental analysis and single-crystal X-ray structure analysis. The molecular structure of the complex shows a distorted tetragonal antiprism CdN4O4 coordination geometry around the cadmium atom, resulting in coordination by four nitrogen atoms from two 5,5'-dmbipy ligands and four oxygen atoms from two acetate anions. The interaction of this complex to FS-DNA (fish sperm DNA) has also been studied by electronic absorption, fluorescence and gel electrophoresis techniques. Binding constant (Kb), Stern-Volmer constant (Ksv), number of binding sites (n) and bimolecular quenching rate constant (kq) have been calculated from these spectroscopic data. These results have revealed that the metal complex can bind effectively to FS-DNA via groove binding. The calculated thermodynamic parameters (ΔH°, ΔS° and ΔG°) show that hydrogen bonding and van der Waals forces have an important function in the Cd(II) complex-DNA interaction. The antibacterial effects of the synthesized cadmium complex have also been examined in vitro against standard bacterial strains: one Gram-positive (Staphylococcus aureus, ATCC 25923) and one Gram-negative (Escherichia coli, ATCC 25922) bacteria, using disk diffusion and macro-dilution broth methods. The obtained results show that the Cd(II) complex exhibits a marked antibacterial activity which is significantly better than those observed for its free ligand and metal salt for both Gram-positive and Gram-negative bacteria. However, this metal complex is a more potent antibacterial agent against the Gram-positive than that of the Gram-negative bacteria.Communicated by Ramaswamy H. Sarma.
- MeSH
- algoritmy MeSH
- antibakteriální látky chemie farmakologie MeSH
- Bacteria účinky léků MeSH
- DNA chemie MeSH
- kadmium chemie MeSH
- krystalografie rentgenová MeSH
- ligandy MeSH
- magnetická rezonanční spektroskopie MeSH
- mikrobiální testy citlivosti MeSH
- molekulární modely * MeSH
- molekulární struktura MeSH
- pyridiny chemická syntéza chemie farmakologie MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- techniky syntetické chemie MeSH
- termodynamika MeSH
- vodíková vazba MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
NMR spectroscopy, X-ray diffraction analysis, and quantum chemical calculations were used for conformational behavior study of partially alkylated thiacalix[4]arenes bearing methyl (1), ethyl (2), or propyl (3) groups at the lower rim. The conformational properties are governed by two basic effects: (i) stabilization by intramolecular hydrogen bonds, and (ii) sterical requirements of the alkoxy groups at the lower rim. While the monosubstituted derivatives 1a and 3a adopt the cone conformation in solution, distally disubstituted compounds 1b, 1'b, 2b, 2'b, 3b, and 3'b exhibit several interesting conformational features. They prefer pinched cone conformation in solution, and, except for 3'b, they form also 1,2-alternate conformation, which is flexible and undergoes rather fast transition between two identical structures. The crystal structures of the compounds 1b, 2b, 2'b, and 3b revealed yet quite rare 1,2-alternate conformation forming molecular channels held together by pi-pi interactions. Different channels-with hexagonal symmetry, 0.26 nm wide-are formed in the crystal structure of the pinched cone conformation of 3b. An uncommon hydrogen bonding pattern was found in dimethoxy and dipropoxy derivatives 1'b and 3'b that adopt distorted cone conformations in crystal. Trialkoxy-substituted compounds 1c and 3c adopt the partial cone conformation in solution. A higher mobility of methyl derivative 1c enables also existence of the cone conformer.
Clinoptilolite is a natural mineral with exceptional physical characteristics resulting from its special crystal structure, mainstreamed into a large zeolite group called heulandites. An overall view of the research related to the synthesis, modification and application of synthetic clinoptilolite is presented. A single phase of clinoptilolite can be hydrothermally synthesized for 1-10 days in an autoclave from various silica, alumina, and alkali sources with initial Si/Al ratio from 3.0 to 5.0 at a temperature range from 120 to 195 °C. Crystallization rate and crystallinity of clinoptilolite can be improved by seeding. The modification of clinoptilolite has received noticeable attention from the research community, since modified forms have specific properties and therefore their area of application has been broadening. This paper provides a review of the use of organic compounds such as quarter alkyl ammonium, polymer, amine and inorganic species used in the modification process, discusses the processes and mechanisms of clinoptilolite modification, and identifies research gaps and new perspectives.
- MeSH
- krystalizace MeSH
- organické látky chemie MeSH
- teplota MeSH
- zeolity chemická syntéza chemie MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Pharmacological inhibition of cyclin-dependent kinases has emerged as a possible treatment option for various cancer types. We recently identified substituted imidazo[1,2-c]pyrimidin-5(6H)-ones as inhibitors of cyclin-dependent kinase 2 (CDK2). Here, we report the synthesis of derivatives modified at positions 2, 3, 6 or 8 prepared using Suzuki-Miyaura cross-coupling, halogenation, Dimroth-type rearrangement and alkylation as the main synthetic methods. The compounds displayed micro- to submicromolar inhibition of CDK2/cyclin E activity. Binding of the most potent compound 3b to CDK2 was determined using isothermal titration calorimetry. The co-crystal structure of 3b in complex with fully active CDK2 was solved, revealing the binding mode of 3b in the ATP pocket and a hydrogen bonding interaction with hinge region residue Leu83. Evaluation against leukaemia cell lines revealed low cytotoxicity, which is in line with the high selectivity towards CDK2. This study demonstrates that substituted imidazo[1,2-c]pyrimidines can be exploited for future kinase inhibitor development.
- MeSH
- cyklin-dependentní kinasa 2 antagonisté a inhibitory metabolismus MeSH
- imidazoly chemie metabolismus farmakologie MeSH
- inhibitory proteinkinas chemická syntéza metabolismus farmakologie MeSH
- kontrolní body buněčného cyklu účinky léků MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- proliferace buněk účinky léků MeSH
- protinádorové látky chemická syntéza metabolismus farmakologie MeSH
- pyrimidiny chemie metabolismus farmakologie MeSH
- simulace molekulární dynamiky MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vodíková vazba MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- buněčné dělení účinky léků MeSH
- finanční podpora výzkumu jako téma MeSH
- krystalografie MeSH
- lidé MeSH
- palladium chemie MeSH
- protinádorové látky farmakologie chemie MeSH
- puriny farmakologie chemická syntéza chemie MeSH
- sloučeniny železa chemie MeSH
- transformované buněčné linie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
Fungal β-N-acetylhexosaminidases are enzymes that are used in the chemoenzymatic synthesis of biologically interesting oligosaccharides. The enzyme from Aspergillus oryzae was produced and purified from its natural source and crystallized using the hanging-drop vapour-diffusion method. Diffraction data from two crystal forms (primitive monoclinic and primitive tetragonal) were collected to resolutions of 3.2 and 2.4 Å, respectively. Electrophoretic and quantitative N-terminal protein-sequencing analyses confirmed that the crystals are formed by a complete biologically active enzyme consisting of a glycosylated catalytic unit and a noncovalently attached propeptide.
