Crystallization Dotaz Zobrazit nápovědu
[1st ed.] ix, 586 s. : il.
- MeSH
- biopolymery MeSH
- krystalizace MeSH
- Konspekt
- Biochemie. Molekulární biologie. Biofyzika
- NLK Obory
- biologie
Nepenthesins are aspartic proteases secreted by carnivorous pitcher plants of the genus Nepenthes. They significantly differ in sequence from other plant aspartic proteases. This difference, which provides more cysteine residues in the structure of nepenthesins, may contribute to their unique stability profile. Recombinantly produced nepenthesin 1 (rNep1) from N. gracilis in complex with pepstatin A was crystallized under two different crystallization conditions using a newly formulated low-pH crystallization screen. The diffraction data were processed to 2.9 and 2.8 Å resolution, respectively. The crystals belonged to space group P212121, with unit-cell parameters a = 86.63, b = 95.90, c = 105.40 Å, α = β = γ = 90° and a = 86.28, b = 97.22, c = 103.78 Å, α = β = γ = 90°, respectively. Matthews coefficient and solvent-content calculations suggest the presence of two molecules of rNep1 in the asymmetric unit. Here, the details of the crystallization experiment and analysis of the X-ray data are reported.
The text is a contemporary continuation of an earlier publication, Kratochvíl B.: Chem. Listy 101, 3 (2007). It describes mainly the nucleation process (two-step nuclea-tion of active substances in pharmacy) and crystallization control processes (seeded crystallization and sonocrystalli-zation). The focus of the work is the description of the nucleation process monitoring by modern analytical tech-nologies, i.e., Focused Beam Reflectance Measurement (FBRM) and the BlazeMetrics system. Both methods pres-ently provide the best available information for a deeper understanding of the nucleation process mechanism in crystallizing active substances. The work is documented by high quality and original photographic attachments of the crystallizing material.Full text English translation is available in the on-line version.
- Klíčová slova
- systém Blaze, nukleace,
- MeSH
- farmaceutická technologie klasifikace metody přístrojové vybavení MeSH
- krystalizace * klasifikace metody přístrojové vybavení MeSH
- lasery MeSH
- výzkumný projekt MeSH
- Publikační typ
- přehledy MeSH
sv.
- MeSH
- biologie MeSH
- matematika MeSH
- Konspekt
- Přírodní vědy. Matematické vědy
- NLK Obory
- biologie
- NLK Publikační typ
- elektronické časopisy
A new co-crystal of pharmaceutical active ingredient Apremilast was successfully designed in this work. The discovered co-crystal with benzoic acid significantly improves key properties like the dissolution and stability of an otherwise poorly soluble Apremilast. A crystallization process was developed, which includes efficient solvent selection and ternary phase diagram construction to minimize risks during scale up. To increase efficiency, we propose that both steps be combined into a single methodology based on solubility data. A suitable solvent for the co-crystallization process was selected and ternary phase diagrams were constructed using three different modifications of thermodynamic model of solid-liquid equilibria. Based on the obtained information, the co-crystallization process was scaled-up to 100 mL. This provides a feasible process to produce larger amounts of this promising pharmaceutical solid form of Apremilast necessary for further drug development.
The text is a contemporary continuation of an earlier publication, Kratochvíl B.: Chem. Listy 101, 3 (2007). It describes mainly the nucleation process (two-step nuclea-tion of active substances in pharmacy) and crystallization control processes (seeded crystallization and sonocrystalli-zation). The focus of the work is the description of the nucleation process monitoring by modern analytical tech-nologies, i.e., Focused Beam Reflectance Measurement (FBRM) and the BlazeMetrics system. Both methods pres-ently provide the best available information for a deeper understanding of the nucleation process mechanism in crystallizing active substances. The work is documented by high quality and original photographic attachments of the crystallizing material.
- Klíčová slova
- systém Blaze, nukleace,
- MeSH
- farmaceutická technologie klasifikace metody přístrojové vybavení MeSH
- krystalizace * klasifikace metody přístrojové vybavení MeSH
- lasery MeSH
- výzkumný projekt MeSH
- Publikační typ
- přehledy MeSH
The newly discovered di-haem cytochrome c4 from the purple sulfur photosynthetic bacterium Thiocapsa roseopersicina is the first cytochrome c4 to be crystallized from an anaerobic organism. It was crystallized using the addition of metal-ion salts to the standard vapour-diffusion method. Coloured well shaped three-dimensional crystals with dimensions of approximately 0.6 x 0.05 x 0.02 mm grew within 3-4 d at pH 5 and diffracted to 1.72 angstroms without radiation damage. Cytochrome c4 crystallized in space group P4(1)2(1)2 as a primitive tetragonal system with unit-cell parameters a = b = 75.29, c = 37.12 angstroms, alpha = beta = gamma = 90 degrees.
The present work reviews the liquid antisolvent crystallization (LASC) to prepare the nanoparticle of pharmaceutical compounds to enhance their solubility, dissolution rate, and bioavailability. The application of ultrasound and additives is discussed to prepare the particles with narrow size distribution. The use of ionic liquid as an alternative to conventional organic solvent is presented. Herbal compounds, also known for low aqueous solubility and limited clinical application, have been crystalized by LASC and discussed here. The particle characteristics such as particle size and particle size distribution are interpreted in terms of supersaturation, nucleation, and growth phenomena. To overcome the disadvantage of batch crystallization, the scientific literature on continuous flow reactors is also reviewed. LASC in a microfluidic device is emerging as a promising technique. The different design of the microfluidic device and their application in LASC are discussed. The combination of the LASC technique with traditional techniques such as high-pressure homogenization and spray drying is presented. A comparison of product characteristics prepared by LASC and the supercritical CO2 antisolvent method is discussed to show that LASC is an attractive and inexpensive alternative for nanoparticle preparation. One of the major strengths of this paper is a discussion on less-explored applications of LASC in pharmaceutical research to attract the attention of future researchers.
The endonuclease TBN1 from Solanum lycopersicum (tomato) was expressed in Nicotiana benthamiana leaves and purified with suitable quality and in suitable quantities for crystallization experiments. Two crystal forms (orthorhombic and rhombohedral) were obtained and X-ray diffraction experiments were performed. The presence of natively bound Zn2+ ions was confirmed by X-ray fluorescence and by an absorption-edge scan. X-ray diffraction data were collected from the orthorhombic (resolution of 5.2 Å) and rhombohedral (best resolution of 3.2 Å) crystal forms. SAD, MAD and MR methods were applied for solution of the phase problem, with partial success. TBN1 contains three Zn2+ ions in a similar spatial arrangement to that observed in nuclease P1 from Penicillium citrinum.
- MeSH
- deoxyribonukleasy chemie genetika MeSH
- ionty chemie MeSH
- konformace proteinů MeSH
- krystalizace MeSH
- krystalografie rentgenová MeSH
- molekulární sekvence - údaje MeSH
- rekombinantní proteiny chemie genetika MeSH
- rostlinné proteiny chemie genetika MeSH
- Solanum lycopersicum chemie genetika MeSH
- zinek chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
