Hasil untuk "Organic chemistry"

Takashi Tanaka, Hirotaka Umeki, Sachi Nagai et al.

A study with Pleurotus sajor-caju was conducted to: evaluate the nutritional and chemical composition of the fruiting bodies; optimize the preparation of bioactive phenolic extracts; and characterize the optimized extract in terms of bioactive compounds and properties. P. sajor-caju revealed an equilibrated nutritional composition with the presence of hydrophilic (sugars and organic acids) and lipophilic (tocopherols and PUFA) compounds. p Hydroxybenzoic, p -coumaric and cinnamic acids were identi fi ed in the extract obtained with ethanol (30 g/l ratio) at 55 °C for 85 min. This extract showed antioxidant properties (mainly reducing power and lipid peroxidation inhibition), antibacterial activity against MRSA and MSSA and cytotoxicity against NCI-H460, MCF-7 and HeLa. Furthermore, as the extract showed capacity to inhibit NO production in Raw 264.7 macrophages, molecular docking studies were performed to provide insights into the anti-in fl ammatory mechanism of action, through COX-2 inhibition by the phenolic acids identi fi ed.

C. Diercks, O. Yaghi

Ming Yan, Yuki Kawamata, P. Baran

Ming-Xue Wu, Yingwei Yang

Hugo Bronstein, C. Nielsen, B. Schroeder et al.

W. Gong, Zhijie Chen, Jinqiao Dong et al.

In the past two decades, metal-organic frameworks (MOFs) or porous coordination polymers (PCPs) assembled from metal ions or clusters and organic linkers via metal-ligand coordination bonds have captivated significant scientific interest on account of their high crystallinity, exceptional porosity, and tunable pore size, high modularity, and diverse functionality. The opportunity to achieve functional porous materials by design with promising properties, unattainable for solid-state materials in general, distinguishes MOFs from other classes of materials, in particular, traditional porous materials such as activated carbon, silica, and zeolites, thereby leading to complementary properties. Scientists have conducted intense research in the production of chiral MOF (CMOF) materials for specific applications including but not limited to chiral recognition, separation, and catalysis since the discovery of the first functional CMOF (i.e., d- or l-POST-1). At present, CMOFs have become interdisciplinary between chirality chemistry, coordination chemistry, and material chemistry, which involve in many subjects including chemistry, physics, optics, medicine, pharmacology, biology, crystal engineering, environmental science, etc. In this review, we will systematically summarize the recent progress of CMOFs regarding design strategies, synthetic approaches, and cutting-edge applications. In particular, we will highlight the successful implementation of CMOFs in asymmetric catalysis, enantioselective separation, enantioselective recognition, and sensing. We envision that this review will provide readers a good understanding of CMOF chemistry and, more importantly, facilitate research endeavors for the rational design of multifunctional CMOFs and their industrial implementation.

A. Mellouki, T. Wallington, Jianmin Chen

Isaura Borges-Silva, Marluce da Cunha Mantovani, Minh Danh Anh Luu et al.

Pancreatic islet transplantation offers great promise for the treatment of type 1 diabetes, yet the functional decline of islets after isolation remains a major obstacle. Increasing evidence highlights the endoplasmic reticulum (ER) as a critical regulator of islet cell survival under stress. We explored how ex vivo culture conditions affect encapsulated islet resilience under ER-stress. Two conditions were assessed: (i) incorporation of decellularized porcine pancreatic extracellular matrix (ECM) into alginate microcapsules, and (ii) free-fall dynamic pre-conditioning culture. Human islets were encapsulated in alginate with or without ECM, cultured under static or dynamic conditions, and exposed to acute ER-stress followed or not by a recovery period. Dynamic culture preserved viability and enhanced glucose responsiveness. ECM-containing capsules showed reduced inflammatory marker expression, while encapsulation in alginate-only capsules led to more pronounced changes associated with ECM remodeling. Under ER-stress, the dynamic culture, especially combined with ECM, maintained cell function and reduced cell death. Gene profiles indicated improved stress adaptation and ECM remodeling. These results highlight ECM enrichment and dynamic culture as good strategies to maintain islet survival and functionality.

Xuyuan Ma, Maozheng Shen, JiaYu Hu et al.

Abstract Background Mitochondrial dyshomeostasis plays an important role in neuronal damage after cerebral ischemia-reperfusion, and Miro1 is a core protein that regulates mitochondrial homeostasis. In this study, we aimed to investigate the neuroprotective effects of bone marrow-derived mesenchymal stem cells (BMSCs) via mitochondrial homeostasis in rats after cardiac arrest (CA), and to clarify the role that the protein Miro1 plays in this protective efficacy. Methods The study compared the effects of BMSCs in which Miro1 was overexpressed BMSCs (BMSCs-mirohi), knocked down (BMSCs-mirolo), and unmodified BMSCs on mitochondrial homeostasis in hippocampal neurons to evaluate their neuroprotective effects of these cells in a rat model of global cerebral ischemia-reperfusion injury. Rats underwent CA modeling for 5 min and received cardiopulmonary resuscitation (CPR). Two hours after the restoration of spontaneous circulation, 1 mL of PBS or 1 mL containing 1 × 106 BMSCs (normal, mirohi, or mirolo) were injected via the femoral vein. The neurological function of rats was assessed based on Neurological Disability Score (NDS) values. Brain histopathological examination was conducted to evaluate brain injury by measuring oxidative stress levels and the apoptosis rate of hippocampal neurons. Immunoblotting and transmission electron microscopy were applied to detect the expression of mitophagy-related proteins in hippocampal neurons. Immunofluorescence was used to track the mitochondria in BMSCs and observe mitochondrial transfer. Additionally, the membrane potential level, oxidative stress level, and ATP content of mitochondria in hippocampal neurons were measured to assess the impact of transplanted BMSCs on mitochondrial quality in these hippocampal neurons. Results Immunofluorescence staining revealed the presence of mitochondria from MitoTracker-labeled BMSCs in rat hippocampal neurons post-CPR. Additionally, the fluorescence intensity of TOMM20 was notably increased following the transplantation of BMSCs. Through immunoblotting experiments, we identified that BMSCs amplified the post-CPR protein expression of LC3, p62, PINK1 and parkin in hippocampal neurons. The number of autophagosomes significantly increased in hippocampal neurons following BMSC transplantation, as observed through transmission electron microscopy. Flow cytometry, Hematoxylin and Eosin (HE) staining, and NDS scoring indicated that BMSCs effectively reduced reactive oxygen species accumulation in hippocampal neurons and mitochondria after CPR. Furthermore, they restored mitochondrial membrane potential and ATP levels in the hippocampus while decreasing apoptosis, ultimately contributing to the restoration of neurological function. Additionally, unlike BMSCs-mirolo, BMSCs-mirohi were able to significantly enhance the efficiency of BMSC-mediated mitochondrial transfer and enhance mitophagy. This amplification, in turn, was found to bolster the protective impact of BMSCs on hippocampal neurons during CPR, thereby contributing to the restoration of rat neurological function. Conclusions These analyses revealed that BMSC transplantation has a dual protective effect by facilitating healthy mitochondrial transfer and promoting the autophagic degradation of damaged mitochondria, effectively enhancing hippocampal neuronal mitochondrial function following CA while reducing neuronal apoptosis, restoring neuronal function, and alleviating neuropathological damage. Moreover, Miro1 can enhance the efficiency of mitochondrial transfer and promote BMSC-mediated mitophagy induction, thereby optimizing the therapeutic effect of BMSCs.

Vladimir V. Parakhin, Gennady A. Smirnov

In order to discover of high-energy materials with characteristics that surpass modern benchmarks, it is necessary to study the widest range of potential structures. The design of energetic compounds using high-nitrogen cage scaffolds provides new opportunities. One of the promising representatives of polycyclic multinitragen cages is the hexaazaisowurtzitane, since the most powerful explosive CL-20 is based on it. In recent years, the synthesis of CL-20 analogues has been actively developed. This review presents progress in the synthesis, performance and study of the structure-property relationship for energetic polynitro hexaazaisowurtzitanes over the past decade.

Agnieszka Ziółkiewicz, Kamila Kasprzak-Drozd, Agnieszka Wójtowicz et al.

The phenol content of sorghum is a unique feature among all cereal grains; hence this fact merits the special attention of scientists. It should be remembered that before polyphenols can be used in the body, they are modified within the digestive tract. In order to obtain more accurate data on the level and activity of tested ingredients after ingestion and digestion in the in vivo digestive tract, in vitro simulated digestion may be used. Thus, the aim of this study was to determine the content of polyphenols, flavonoids, and individual phenolic acids, as well as the antiradical properties, of sorghum and sorghum-enriched pasta before and after in vitro simulated gastrointestinal digestion. We observed that the total content of polyphenols decreased after gastric digestion of sorghum, and slightly increased after duodenal digestion. Moreover, the flavonoid content decreased after the first stage of digestion, while antioxidant properties increased after the first stage of digestion and slightly decreased after the second stage. The digestion of polyphenolics in sorghum is completely different to that in pasta—both in varieties with, and without, the addition of sorghum. For pasta, the content of total polyphenols and flavonoids, and free radical scavenging properties, decrease after each stage of digestion.

Claudia Riccardi, Antonella Campanella, Daniela Montesarchio et al.

Ruthenium(III) complexes are very promising candidates as metal-based anticancer drugs, and several studies have supported the likely role of human serum proteins in the transport and selective delivery of Ru(III)-based compounds to tumor cells. Herein, the anticancer nanosystem composed of an amphiphilic nucleolipid incorporating a Ru(III) complex, which we named DoHuRu, embedded into the biocompatible cationic lipid DOTAP, was investigated as to its interaction with two human serum proteins thought to be involved in the mechanism of action of Ru(III)-based anticancer drugs, i.e., human serum albumin (HSA) and human transferrin (hTf). This nanosystem was studied in comparison with the simple Ru(III) complex named AziRu, a low molecular weight metal complex previously designed as an analogue of NAMI-A, decorated with the same ruthenium ligands as DoHuRu but devoid of the nucleolipid scaffold and not inserted in liposomal formulations. For this study, different spectroscopic techniques, i.e., Fluorescence Spectroscopy and Circular Dichroism (CD), were exploited, showing that DoHuRu/DOTAP liposomes can interact with both serum proteins without affecting their secondary structures.

Koen Van Aken, L. Strekowski,, L. Patiny et al.

Mengyue Ren, Yi Wang, Lin Lin et al.

α-Linolenic acid (ALA) is a natural essential fatty acid widely found in plant seed oils and beans, which shows positive anti-inflammatory and antiallergic effects. In our previous study, ALA was proven to bind tightly to the seven protein targets closely associated with allergic rhinitis (AR) by molecular docking, which indicates that ALA may have a potential role in the treatment of AR. A mouse model of AR induced by ovalbumin (OVA) was adopted in this study to explore the therapeutical effect and potential mechanism of ALA in treating AR. Results demonstrated that ALA remarkably relieved the nasal symptoms, reduced the OVA-sIgE level in the serum, relieved the histopathological injuries, and downregulated the mRNA expression levels of IL-6 and IL-1β in the nasal mucosa. ALA also remarkably moderated the imbalance of Th1/Th2 cells, increased the mRNA expression levels of T-bet and STAT1, and reduced GATA3 and STAT6. ALA was proven to have a substantial therapeutic effect on mice with AR, and the underlying mechanism was likely to be the regulation of Th1/Th2 imbalance through the JAK/T-bet/STAT1 and JAK/GATA3/STAT6 pathways. This study provides a specific experimental basis for the clinical use and drug development of ALA in the treatment of AR.

A. Kiendler‐Scharr, A. Mensah, E. Friese et al.

Jessica Hao, Ivana Stavljenić Milašin, Zeynep Batu Eken et al.

Zeolites and zeolitic imidazolate frameworks (ZIFs) are widely studied as drug carrying nanoplatforms to enhance the specificity and efficacy of traditional anticancer drugs. At present, there is no other systematic review that assesses the potency of zeolites/ZIFs as anticancer drug carriers. Due to the porous nature and inherent pH-sensitive properties of zeolites/ZIFs, the compounds can entrap and selectively release anticancer drugs into the acidic tumor microenvironment. Therefore, it is valuable to provide a comprehensive overview of available evidence on the topic to identify the benefits of the compound as well as potential gaps in knowledge. The purpose of this study was to evaluate the potential therapeutic applications of zeolites/ZIFs as drug delivery systems delivering doxorubicin (DOX), 5-fluorouracil (5-FU), curcumin, cisplatin, and miR-34a. Following PRISMA guidelines, an exhaustive search of PubMed, Scopus, Embase, and Web of Science was conducted. No language or time limitations were used up to 25th August 2021. Only full text articles were selected that pertained to the usage of zeolites/ZIFs in delivering anticancer drugs. Initially, 1279 studies were identified, of which 572 duplicate records were excluded. After screening for the title, abstract, and full texts, 53 articles remained and were included in the qualitative synthesis. An Inter-Rater Reliability (IRR) test, which included a percent user agreement and reliability percent, was conducted for the 53 articles. The included studies suggest that anticancer drug-incorporated zeolites/ZIFs can be used as alternative treatment options to enhance the efficacy of cancer treatment by mitigating the drawbacks of drugs under conventional treatment.

Celestine Vubangsi Gemuh, Burkhard Horstkotte, Petr Solich

We report on the hyphenation of the modern flow techniques Lab-In-Syringe and Lab-On-Valve for automated sample preparation coupled online with high-performance liquid chromatography. Adopting the bead injection concept on the Lab-On-Valve platform, the on-demand, renewable, solid-phase extraction of five nonsteroidal anti-inflammatory drugs, namely ketoprofen, naproxen, flurbiprofen, diclofenac, and ibuprofen, was carried out as a proof-of-concept. In-syringe mixing of the sample with buffer and standards allowed straightforward pre-load sample modification for the preconcentration of large sample volumes. Packing of ca. 4.4 mg microSPE columns from Oasis HLB^® sorbent slurry was performed for each sample analysis using a simple microcolumn adapted to the Lab-On-Valve manifold to achieve low backpressure during loading. Eluted analytes were injected into online coupled HPLC with subsequent separation on a Symmetry C18 column in isocratic mode. The optimized method was highly reproducible, with RSD values of 3.2% to 7.6% on 20 µg L⁻¹ level. Linearity was confirmed up to 200 µg L⁻¹ and LOD values were between 0.06 and 1.98 µg L⁻¹. Recovery factors between 91 and 109% were obtained in the analysis of spiked surface water samples.

Thomas Castanheiro, J. Suffert, Morgan Donnard et al.

Godfried Dougnon, Michiho Ito

The anxiolytic and antidepressant-like activities of the naturally occurring monoterpene 1,8-cineole and its structural isomer 1,4-cineole were evaluated in mice via inhalation administration at doses ranging from 4 × 10⁻⁶ to 4 × 10⁻¹ mg per 400 μL of triethyl citrate. Mice were tested for anxiety-like behaviours by using the light–dark box test (LDB) and marble-burying test (MBT) and for depression-like symptoms by using the forced swimming test (FST) and tail suspension test (TST). Diazepam and fluoxetine were used as standard drugs for anxiolytic and antidepressant tests, respectively. The results showed that 1,8-cineole at 4 × 10⁻⁴ mg, and 1,4-cineole at 4 × 10⁻⁴ and 4 × 10⁻³ mg significantly increased the amount of time spent in the light box and the number of entries in the light box in the LDB as well as reduced the number of marbles buried in the MBT relative to those in the control, suggesting an anxiolytic effect. Similarly, 1,8-cineole at 4 × 10⁻⁴ and 4 × 10⁻² mg and 1,4-cineole at doses of 4 × 10⁻⁴ to 4 × 10⁻² mg significantly reduced immobility times in the FST and TST relative to those of the control, suggesting an antidepressant activity. The role of the GABA_A/benzodiazepine receptor system in the anxiolytic effects of 1,8- and 1,4-cineole was investigated through co-administration of flumazenil, a GABAergic system antagonist. Flumazenil reversed the effects of diazepam and 1,8-cineole, suggesting that 1,8-cineole affects the GABA_A/benzodiazepine receptors. Collectively, the results suggest that inhaled 1,8- and 1,4-cineole prevented anxiety and depressive-like symptoms in classic mice models.

Dinesh J. Paymode, Chepuri V. Ramana