Blue light-promoted photolysis of aryldiazoacetates.
Ontology highlight
ABSTRACT:
SUBMITTER: Jurberg ID
PROVIDER: S-EPMC5994880 | biostudies-other | 2018 Jun
REPOSITORIES: biostudies-other
Publications
Blue light-promoted photolysis of aryldiazoacetates.
Jurberg Igor D ID Davies Huw M L HML
Chemical science 20180522 22
Aryldiazoacetates can undergo photolysis under blue light irradiation (460-490 nm) at room temperature and under air in the presence of numerous trapping agents, such as styrene, carboxylic acids, amines, alkanes and arenes, thus providing a straighforward and general platform for their mild functionalization. ...[more]
Similar Datasets
Project description:Photoexcited dihydronicotinamides like NADH and analogues have been found to generate alkyl radicals upon reductive decarboxylation of redox-active esters without auxiliary photocatalysts. This principle allowed aliphatic photocoupling between redox-active carboxylate derivatives and electron-poor olefins, displaying surprising water and air-tolerance and unusually high coupling rates in dilute conditions. The orthogonality of the reaction in the presence of other carboxylic acids and its utility in the functionalization of DNA is presented, notably using visible light in combination with NADH, the ubiquitous reductant of life.
| S-EPMC7705967 | biostudies-literature
Project description:A metal-free scalable synthesis of functionalized ketenimines from alkyl α-(aryl/heteroaryl)-α-diazoacetates and alkyl isocyanides induced by blue light irradiation has been developed. The reaction proceeds at room temperature without any photocatalyst and provides ketenimines in moderate to good yields. Density functional theory (DFT) calculations and the experimental study showed that aryl(alkoxycarbonyl)carbenes in both singlet and triplet states can react with isocyanides but only the reaction of the former leads to the smooth formation of ketenimines. The obtained ketenimines were used for the synthesis of functionalized amidines under mild metal-free conditions.
| S-EPMC8928522 | biostudies-literature
Project description:One of the fundamental and highly valuable transformations in organic chemistry is the nucleophilic substitution of alcohols. Traditionally, these reactions require strategies that employ stoichiometric hazardous reagents and are associated with difficulty in purification of the by-products. To overcome these challenges, here, we report a simple route toward the diverse conversion of alcohols via an SN2 pathway, in which blue light-promoted iodination is used to form alkyl iodide intermediates from simple unreactive alcohols. The scope of the process tolerates a range of nucleophiles to construct C-N, C-O, C-S, and C-C bonds. Furthermore, we also demonstrate that this method can be used for the preparation and late-stage functionalization of pharmaceuticals, as highlighted by the syntheses of thiocarlide, butoxycaine, and pramoxine.
| S-EPMC7170005 | biostudies-literature
Project description:A tuberization inhibitor has long been postulated, but not yet found. We found that blue light inhibits tuberization in Norland, a day-neutral variety of Solanum tuberosum L. Tissue-cultured plants formed tubers within 8 weeks under continuous darkness, and white, red, or far-red light. Preliminary experiments indicated that a one- or two-day exposure to blue light after 3-4 weeks of dark treatment will inhibit tuber formation in ‘Norland’ plants. Using this system and expression profiling, we may be able to identify candidate tuberization inhibitors. 'Norland' plants (subcultured from existing cultures and grown for two weeks under continuous 100 umol/m2-s white fluorescent light) were placed in tuber-inducing media containing 6% sucrose, vitamins, MS salts, and kinetin (2.5 mg/L). Tubes containing plants were wrapped in two layers of aluminum foil. After 3 weeks and 2 days, half of the tubes were exposed to 6-7 umol/m2-s blue light. The other half of the tubes were left in darkness (controls). After 2 days, all plants were harvested and frozen in liquid nitrogen. Plants exposed to blue light were harvested under blue light. Control plants were harvested under < 2 umol/m2-s light conditions. All plant transfers were done at 1700 (5 PM) to avoid possible complications due to circadian effects. Experiments were performed four times, from subculture to harvest. RNA was extracted from stem and leaf tissue of plants using the Qiagen RNeasy Plant Mini kit. Extracted RNA was then converted to dsDNA using the Invitrogen protocol and reagents for double stranded cDNA synthesis. The resulting dsDNA was in vitro transcribed into amplified RNA using the Ambion procedure and reagents for in vitro transcription. cDNA was purified using Qiagen MinElute columns and protocol. Amplified RNA was purified using Ambion columns or Qiagen RNeasy columns and the Ambion protocol, and quantified using RiboGreen dye fluorometry. Keywords: Direct comparison
2008-02-13 | GSE10491 | GEO
Project description:PurposeThe aim of this study was to carry out blue light photography of fluorescein-stained corneas using a novel smartphone attachment.MethodsA smartphone attachment known as the cobalt blue light unit (C-BLU) was developed. It can filter out all wavelengths of light except the blue light emerging from the flashlight of a smartphone. A pilot study was carried out wherein the images captured with the C-BLU system were compared with slit-lamp photographs of the same patients. This setup was then used to photo document fluorescein-stained corneas in various clinical settings assembled at point-of-care.ResultsMany pathologies of the fluorescein-stained cornea were captured using the C-BLU filter. It was used effectively in various settings (remote eye camps, intensive care units (ICU), pediatric group, corneal trauma triaging, etc.). C-BLU was assembled and used by optometrists and ophthalmology residents. The images captured were used for documenting, assisting in the treatment, and also for telecommunication of the patients' findings.ConclusionC-BLU is a low-cost pocket-size filter which is easy to use with a modern smartphone without any technical expertise needed to obtain a clear image of fluorescein-stained pathological corneas.
| S-EPMC8597460 | biostudies-literature
Project description:Prodrug photolysis enables spatiotemporal control of drug release at the desired lesions. For photoactivated therapy, near-infrared (NIR) light is preferable due to its deep tissue penetration and low phototoxicity. However, most of the photocleavable groups cannot be directly activated by NIR light. Here, we report a upconversion-like process via only one step of energy transfer for NIR light-triggered prodrug photolysis. We utilize a photosensitizer (PS) that can be activated via singlet-triplet (S-T) absorption and achieve photolysis of boron-dipyrromethene (BODIPY)-based prodrugs via triplet-triplet energy transfer. Using the strategy, NIR light can achieve green light-responsive photolysis with a single-photon process. A wide range of drugs and bioactive molecules are designed and demonstrated to be released under low-irradiance NIR light (100 mW/cm2, 5 min) with high yields (up to 87%). Moreover, a micellar nanosystem encapsulating both PS and prodrug is developed to demonstrate the practicality of our strategy in normoxia aqueous environment for cancer therapy. This study may advance the development of photocleavable prodrugs and photoresponsive drug delivery systems for photo-activated therapy.
| S-EPMC10703928 | biostudies-literature
Project description:Cryptochrome is a group of flavin-type blue light receptors that regulate plant growth and development. The function of Arabidopsis cryptochrome 2 in the early photomorphogenesis of seedlings was studied by using transgenic plants overexpressing CRY2 protein, and cry2 mutant plants accumulating no CRY2 protein. It is found that cryptochrome 2 mediates blue light-dependent inhibition of hypocotyl elongation and stimulation of cotyledon opening under low intensities of blue light. In contrast to CRY1, the expression of CRY2 is rapidly down-regulated by blue light in a light-intensity dependent manner, which provides a molecular mechanism to explain at least in part that cryptochrome 2 functions primarily under low light during the early development of seedlings.
| S-EPMC19462 | biostudies-literature
Project description:Cryptochromes are photolyase-like blue light receptors originally discovered in Arabidopsis but later found in other plants, microbes, and animals. Arabidopsis has two cryptochromes, CRY1 and CRY2, which mediate primarily blue light inhibition of hypocotyl elongation and photoperiodic control of floral initiation, respectively. In addition, cryptochromes also regulate over a dozen other light responses, including circadian rhythms, tropic growth, stomata opening, guard cell development, root development, bacterial and viral pathogen responses, abiotic stress responses, cell cycles, programmed cell death, apical dominance, fruit and ovule development, seed dormancy, and magnetoreception. Cryptochromes have two domains, the N-terminal PHR (Photolyase-Homologous Region) domain that bind the chromophore FAD (flavin adenine dinucleotide), and the CCE (CRY C-terminal Extension) domain that appears intrinsically unstructured but critical to the function and regulation of cryptochromes. Most cryptochromes accumulate in the nucleus, and they undergo blue light-dependent phosphorylation or ubiquitination. It is hypothesized that photons excite electrons of the flavin molecule, resulting in redox reaction or circular electron shuttle and conformational changes of the photoreceptors. The photoexcited cryptochrome are phosphorylated to adopt an open conformation, which interacts with signaling partner proteins to alter gene expression at both transcriptional and posttranslational levels and consequently the metabolic and developmental programs of plants.
| S-EPMC3155252 | biostudies-literature
Project description:Sensory photoreceptors underpin light-dependent adaptations of organismal physiology, development, and behavior in nature. Adapted for optogenetics, sensory photoreceptors become genetically encoded actuators and reporters to enable the noninvasive, spatiotemporally accurate and reversible control by light of cellular processes. Rooted in a mechanistic understanding of natural photoreceptors, artificial photoreceptors with customized light-gated function have been engineered that greatly expand the scope of optogenetics beyond the original application of light-controlled ion flow. As we survey presently, UV/blue-light-sensitive photoreceptors have particularly allowed optogenetics to transcend its initial neuroscience applications by unlocking numerous additional cellular processes and parameters for optogenetic intervention, including gene expression, DNA recombination, subcellular localization, cytoskeleton dynamics, intracellular protein stability, signal transduction cascades, apoptosis, and enzyme activity. The engineering of novel photoreceptors benefits from powerful and reusable design strategies, most importantly light-dependent protein association and (un)folding reactions. Additionally, modified versions of these same sensory photoreceptors serve as fluorescent proteins and generators of singlet oxygen, thereby further enriching the optogenetic toolkit. The available and upcoming UV/blue-light-sensitive actuators and reporters enable the detailed and quantitative interrogation of cellular signal networks and processes in increasingly more precise and illuminating manners.
| S-EPMC6500593 | biostudies-literature
Project description:The cell viability and apoptosis of tumor U937 cells treated by blue light (BL) irradiation have been examined. BL irradiation can specially inhibit the proliferation and promote the apoptosis of U937 cells, relating to the production of reactive oxygen species (ROS) and the decline of mitochondrial membrane potential (??m). The apoptosis is further associated with varying downregulated B-cell lymphoma-extra large (Bcl-XL) and B-cell lymphoma 2 (Bcl-2) genes, upregulated Bcl-2-associated X (Bax) gene, the activation of caspase-3 and caspase-9, and the cleavage of poly (ADP-ribose) polymerase (PARP) by the BL irradiation process. Moreover, BL irradiation induced proliferation inhibition is higher than that treated by a common chemotherapeutic drug of homoharringtonine (HHT). When we synergize BL irradiation with HHT (BL-HHT), a higher proliferation inhibition is obtained than that treated by BL irradiation or HHT alone. These results are helpful for establishing a low toxicity and high efficiency strategy of BL irradiation for clinical treatment of acute myeloid leukemia, not limited to U937 cells.
| S-EPMC5983758 | biostudies-literature