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排序方式: 共有257条查询结果,搜索用时 31 毫秒
161.
Olha Mykhailenko Vilma Petrikaite Michal Korinek Fang-Rong Chang Mohamed El-Shazly Chia-Hung Yen Ivan Bezruk Bing-Hung Chen Chung-Fan Hsieh Dmytro Lytkin Liudas Ivanauskas Victoriya Georgiyants Tsong-Long Hwang 《Molecules (Basel, Switzerland)》2022,27(1)
Crocus sativus L. (saffron) has been traditionally used as a food coloring or flavoring agent, but recent research has shown its potent pharmacological activity to tackle several health-related conditions. Crocus sp. leaves, and petals are the by-products of saffron production and are not usually used in the medicine or food industries. The present study was designed to determine the chemical composition of the water and ethanolic extracts of C. sativus leaves and test their cytotoxic activity against melanoma (IGR39) and triple-negative breast cancer (MDA-MB-231) cell lines by MTT assay. We also determined their anti-allergic, anti-inflammatory, and anti-viral activities. HPLC fingerprint analysis showed the presence of 16 compounds, including hydroxycinnamic acids, xanthones, flavonoids, and isoflavonoids, which could contribute to the extracts’ biological activities. For the first time, compounds such as tectoridin, iristectorigenin B, nigricin, and irigenin were identified in Crocus leaf extracts. The results showed that mangiferin (up to 2 mg/g dry weight) and isoorientin (8.5 mg/g dry weight) were the major active ingredients in the leaf extracts. The ethanolic extract reduced the viability of IGR39 and MDA-MB-231 cancer cells with EC50 = 410 ± 100 and 330 ± 40 µg/mL, respectively. It was more active than the aqueous extract. Kaempferol and quercetin were identified as the most active compounds. Our results showed that Crocus leaves contain secondary metabolites with potent cytotoxic and antioxidant activities. 相似文献
162.
Organelle-specific targeting enables increasing the therapeutic index of drugs and localizing probes for better visualization of cellular processes. Current targeting strategies require conjugation of a molecule of interest with organelle-targeting ligands. Here, we propose a concept of dynamic covalent targeting of organelles where the molecule is conjugated with its ligand directly inside live cells through a dynamic covalent bond. For this purpose, we prepared a series of organelle-targeting ligands with a hydrazide residue for reacting with dyes and drugs bearing a ketone group. We show that dynamic hydrazone bond can be formed between these hydrazide ligands and a ketone-functionalized Nile Red dye (NRK) in situ in model lipid membranes or nanoemulsion droplets. Fluorescence imaging in live cells reveals that the targeting hydrazide ligands can induce preferential localization of NRK dye and an anti-cancer drug doxorubicin in plasma membranes, mitochondria and lipid droplets. Thus, with help of the dynamic covalent targeting, it becomes possible to direct a given bioactive molecule to any desired organelle inside the cell without its initial functionalization by the targeting ligand. Localizing the same NRK dye in different organelles by the hydrazide ligands is found to affect drastically its photodynamic activity, with the most pronounced phototoxic effects in mitochondria and plasma membranes. The capacity of this approach to tune biological activity of molecules can improve efficacy of drugs and help to understand better their intracellular mechanisms.We introduce a concept of dynamic covalent targeting of organelles, where a dye/drug molecule is conjugated with its targeting ligand inside live cells by a reversible hydrazone bond, revealing organelle-dependent photodynamic action. 相似文献
163.
Valentyna P. Tokar Mykhaylo Yu. Losytskyy Tymish Y. Ohulchanskyy Dmytro V. Kryvorotenko Vladyslava B. Kovalska Anatoliy O. Balanda Igor M. Dmytruk Vadym M. Prokopets Sergiy M. Yarmoluk Valeriy M. Yashchuk 《Journal of fluorescence》2010,20(4):865-872
Spectral-fluorescent properties of benzothiazole styryl monomer (Bos-3) and homodimer (DBos-21) dyes in presence of DNA were
studied. The dyes enhance their fluorescence intensity in 2–3 orders of magnitude upon interaction with DNA. Studied styrylcyanines
in DNA presence demonstrate rather high values of two-photon absorption (TPA) cross-section, which are comparable with the
values of TPA cross section of the rhodamine dyes. An applicability of the styrylcyanines as probes for the fluorescence microscopy
of living cells was studied. It was shown that both dyes are cell-permeable but homodimer dye DBos-21 produces noticeably
brighter staining of HeLa cells comparing with monomer dye Bos-3. Molecules of DBos-21 initially bind to the nucleic acids-
containing cell organelles (presumable mitochondria) and are able to penetrate into the cell nucleus. Thus, homodimer styryl
DBos-21 dye is viewed as efficient stain for single-photon and two-photon excitation fluorescence imaging of living cells. 相似文献
164.
We present theoretical study of morphology of Fe islands grown at Mo(110) surface in submonolayer MBE mode. We utilize atomistic
SOS model with bond counting, and interactions of Fe adatom up to third nearest neighbors. We performed KMC simulations for
different values of adatom interactions and varying temperatures. We have found that, while for the low temperature islands
are fat fractals, for the temperature 500 K islands have faceted rhombic-like shape. For the higher temperature, islands acquire
a rounded shape. In order to evaluate qualitatively morphological changes, we measured average aspect ratio of islands. We
calculated dependence of the average aspect ratio on the temperature, and on the strength of interactions of an adatom with
neighbors.
相似文献
165.
Maye MM Nykypanchuk D van der Lelie D Gang O 《Journal of the American Chemical Society》2006,128(43):14020-14021
A regulation of the kinetic behavior in DNA-based nanosystems is required for emerging applications in sensing, nanodevice assembling, and gene delivery. Here we describe a broadly applicable method for controlling the kinetics of DNA-mediated nanoparticle self-assembly by tailoring the DNA-capping between single-stranded and partially rigid double-stranded designs. An effect of enhanced assembly kinetics was facilitated by the added rigidity which reduced chain entropy while extending crucial linker segments away from the nanoparticle interface where they are known to coordinate. 相似文献
166.
We review the construction of the AdS/CFT dressing factor, its analytic properties, and several checks of its validity. 相似文献
167.
Meijer JM Hagemans F Rossi L Byelov DV Castillo SI Snigirev A Snigireva I Philipse AP Petukhov AV 《Langmuir : the ACS journal of surfaces and colloids》2012,28(20):7631-7638
The vertical deposition technique for creating crystalline microstructures is applied for the first time to nonspherical colloids in the form of hollow silica cubes. Controlled deposition of the cubes results in large crystalline films with variable symmetry. The microstructures are characterized in detail with scanning electron microscopy and small-angle X-ray scattering. In single layers of cubes, distorted square to hexagonal ordered arrays are formed. For multilayered crystals, the intralayer ordering is predominantly hexagonal with a hollow site stacking, similar to that of the face centered cubic lattice for spheres. Additionally, a distorted square arrangement in the layers is also found to form under certain conditions. These crystalline films are promising for various applications such as photonic materials. 相似文献
168.
Dmytro V. Yarmoliuk Dmytro Serhiichuk Vladyslav Smyrnov Andriy V. Tymtsunik Oleksandr V. Hryshchuk Yuliya Kuchkovska Oleksandr O. Grygorenko 《Tetrahedron letters》2018,59(52):4611-4615
An efficient approach towards the synthesis of monoprotected azabicyclo[5.1.0]octane-derived conformationally restricted γ-amino acids and diamines is reported. Optimization of the conditions for the key Corey–Chaykovsky reaction allowed the construction of two isomeric methanoazepane frameworks on a multigram scale in 55–65% yield. Additionally, the developed approach was used in the three-step synthesis of 3,4-methano-β-proline and its diamine derivatives. 相似文献
169.