Phenolic compounds such as thymol have an effective role in suppressing cancer, however, their low solubility in aqueous solution has limited their use. This study aimed to prepare thymol (TY)-loaded bovine serum albumin (BSA) nanoparticles surface-modified with polyethylene glycol (PEG) conjugated with folic acid (FA) and evaluate the inhibitory activity of them on cancer cells. The TY-BSA-PEG-FA was characterized using DLS, FESEM, and FTIR. The effects of nanoparticles against cancer cells investigated by MTT, AO/PI, flow cytometry, and qPCR methods. The results showed that the spherical morphology of TY-BSA-PEG-FA with an average size of 70.0 nm, a PDI of 0.32, a zeta potential of -11.3 mV, and an EE of 89%. Gastric cancer cells eported to be the most vulnerable to treatment, while pancreatic cancer cells and normal skin cells would be the most resistant. The SubG1 phase arrest and increase in apoptotic cells in fluorescent staining, along with decreased expression of Bcl-2 and increased expression of BAX gene demonstrated the induction of apoptosis in treated cells. The powerful inhibitory effect of nanoparticles in inhibiting ABTS (IC50=82µg/ml) and DPPH (IC50=844µg/ml), the synthesized nanoparticles may be suitable for further investigation in the treatment of cancer, notably gastric cancer.
Monthly Archives: October 2023
Synthetic Applications of Photochemically Generated Radicals from Protic C(sp3)–H Bonds
The utilization of photo-induced processes in C–H functionalization via radical pathways has emerged as a highly promising strategy for the preparation and modification of complex organic compounds. While current methods for generating carbon-centred radicals from C–H bonds primarily focus on hydridic C–H bonds to yield nucleophilic radical species, the reactivity and potential applications of electrophilic radicals derived from protic C–H bonds remain largely unexplored. In this review, we aim to shed light on the seminal findings regarding the activation of protic C(sp3)–H bonds while also showcasing noteworthy examples of this radical formation process. Mechanistically diverse modes of activation are discussed, unified by proton-coupled electron transfer (PCET) concepts.
Synthesis of Functional Isosorbide‐Based Polyesters and Polyamides by Passerini Three‐Component Polymerization
A new family of functional isosorbide-based polyesters and polyamides with high glass transition temperature are prepared via Passerini-three component polymerization (P-3CP). To optimize the P-3CP conditions, the influence of the polymerization solvent, temperature, feed ratio on the molar mass of final polymers are investigated. The higher molar mass (up to 10100 g/mol) and yield (>70%) are achieved under mild conditions (30 °C, standard atmosphere). Functional side groups, such as alkenyl, alkynyl and methyl ester, were introduced into polymer structure via P-3CP by using functional isocyanides. The obtained polyesters and polyamides are characterized by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopies, differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). All polymers are thermal stable and amorphous with variable glass transition temperatures (Tg). The obtained polyester has Tg up to 87.5 °C, while the Tg of polyamides (ISPA-2) is detected to be 97.5 °C depending on the amide bonds in the polymer backbone and the benzene ring side groups. The cytotoxicity is investigated by the CCK-8 assay against mBMSC cells to confirm the biological safety. Overall, this novel strategy provides an efficient approach to produce functional isosorbide-based polyesters and polyamides, which are promising prospect for being applied to biodegradable materials.
New protocol for the synthesis of S‐thioesters from benzylic, allylic and tertiary alcohols with thioacetic acid
A new one-pot solvent-less reaction to convert benzylic, allylic, ferrocenyl or tertiary alcohols into S-thioesters, bench-stable and less odorous precursors of the corresponding thiols, which is based on reactions in neat thioacetic acid in the presence of tetrafluoroboric acid, is presented. Reaction monitoring by NMR and GC of the benzyl alcohol conversion indicated the intermediate formation of benzyl acetate and benzyl thionoacetate (PhCH2OC(S)CH3) prior to the slower conversion to the final S-benzyl thioacetate product. Increasing the HBF4 concentration enhanced the reaction rate, giving good to excellent yield (up to 99%) for a large scope of alcohols. Control experiments, with support of DFT calculations, have revealed a thermodynamically favorable, though requiring HBF4-activation, disproportionation of CH3C(O)SH to CH3C(O)OH and CH3C(S)SH, the latter immediately decomposing to H2S and (MeC)4S6 but also generating the hitherto unreported [MeC(O)C(Me)S]2(µ-S)2. Kinetic investigations demonstrated that the rate of benzyl alcohol conversion is second-order in [PhCH2OH] and second order in [HBF4], while the rate of conversion of the benzyl acetate intermediate to S-benzyl thioacetate is second order in [PhCOOMe] and fourth order in [HBF4]. The DFT calculations rationalize the need to two alcohol molecules and two protons to generate the reactive benzyl cation.
[ASAP] Structure and Electrochemical Properties of Bronze Phase Materials Containing Two Transition Metals
Chemistry of Materials
DOI: 10.1021/acs.chemmater.3c01860
Targeted single‐cell RNA sequencing analysis reveals metabolic reprogramming and the ferroptosis‐resistant state in hematologic malignancies
Abstract
Hematologic malignancies are the most common hematopoietic diseases and a major public health concern. However, the mechanisms underlying myeloid tumors remain unknown owing to the intricate interplay between mutations and diverse clonal evolution patterns, as evidenced by the analysis of bulk cell-derived omics data. Several single-cell omics techniques have been used to characterize the hierarchies and altered immune microenvironments of hematologic malignancies. The comprehensive single-cell atlas of hematologic malignancies provides novel opportunities for personalized combinatorial targeted treatments, avoiding unwanted chemo-toxicity. In the present study, we performed transcriptome sequencing by combining single-cell RNA sequencing (scRNA-seq) with a targeted oncogenic gene panel for acute myeloid leukemia, overcoming the limitations of scRNA-seq in detecting oncogenic mutations. The distribution of oncogenic IDH1, IDH2, and KRAS mutations in each cell type was identified in the bone marrow (BM) samples of each patient. Our findings suggest that ferroptosis and metabolic reprogramming are involved in the tumorigenesis and chemotherapy resistance of oncogenic mutation-carrying cells. Biological progression via IDH1, IDH2, and KRAS mutations arrests hematopoietic maturation. Our study findings provide a rationale for using primary BM cells for personalized treatment in clinical settings.
Cold Plasma for Green Advanced Reduction/Oxidation Processes (AROPs) of Organic Pollutants in Water
Plasma activation: These extremely reactive milieux attack any organic compound, including the most refractory environmental pollutants, leading to their mineralization. Depending on the specific target, suitable plasma sources can be developed for best performance. Cold plasmas offer the promise of novel technologies for PFAS degradation in water under ambient conditions using only (green) energy.
Abstract
Cold plasma is gaining increasing attention as a novel tool to activate energy demanding chemical processes, including advanced reduction/oxidation processes (AROPs) of organic pollutants in water. The very complex milieu generated by discharges at the water/plasma interface comprises photons, strong oxidants and strong reductants which can be exploited for achieving the degradation of most any kind of pollutants. Despite the complexity of these systems, the powerful arsenal of mechanistic tools and chemical probes of physical organic chemists can be usefully applied to understand and develop plasma chemistry. Specifically, the added value of air plasma generated by in situ discharge with respect to ozonation (ex situ discharge) is demonstrated using phenol and various phenol derivatives and mechanistic evidence for the prevailing role of hydroxyl radicals in the initial attack is presented. On the reduction front, the impressive performance of cold plasma in inducing the degradation of recalcitrant perfluoroalkyl substances, which do not react with OH radicals but are attacked by electrons, is reported and discussed. The widely different reactivities of perfluorooctanoic acid (PFOA) and of perfluorobutanoic acid (PFBA) underline the crucial role played in these processes by the interface between plasma and solution and the surfactant properties of the treated pollutants.
Zn‐Based Metal–Organic Frameworks Using Triptycene Hexacarboxylate Ligands: Synthesis, Structure, and Gas‐Sorption Properties
Two types of zinc MOF, Zn-X2Trp and Zn-X2PET (X=H, F, Cl, Br, I, Me, Et, Pr), with difunctionalized triptycene-hexacarboxylate ligands H6X2Trp and H6X2PET that differ in size have been synthesized. All of these Zn-MOFs show high thermal stability as well as H2- and CO2-adsorption capacities. Moreover, MOFs with smaller pore size showed higher H2 and CO2 adsorption. Thus, the introduction of methyl, chloro, and bromo substituents at the bridgehead positions of the triptycene ligands enhances the H2- and CO2-adsorption capacities.
Abstract
A series of metal–organic frameworks (MOFs) based on zinc ions and two triptycene ligands of different size have been synthesized under solvothermal conditions. Structural analyses revealed that they are isostructural 3D-network MOFs. The high porosity and thermal stability of these MOFs can be attributed to the highly rigid triptycene-based ligands. Their BET specific surface areas depend on the size of the triptycene ligands. In contrast to these surface-area data, the H2 and CO2 adsorption of these MOFs is larger for MOFs with small pores. Consequently, we introduced functional groups to the bridge-head position of the triptycene ligands and investigated their effect on the gas-sorption properties. The results unveiled the role of the functional groups in the specific CO2 binding via an induced interaction between adsorbates and the functional groups. Excellent H2 and CO2 properties in these MOFs were achieved in the absence of open metal sites.
Aluminium and Gallium Silylimides as Nitride Sources
Terminal aluminium and gallium silylimides have been accessed for the first time by exploiting the oxidative reactions of anionic aluminium(I)/gallium(I) (‘aluminyl’/’gallyl’) reagent with silylazides. These compounds feature minimal M=N π-bonding and can be shown to act as sources of the nitride ion, [N]3− in reactions with CO or N2O.
Abstract
Terminal aluminium and gallium imides of the type K[(NON)M(NR)], bearing heteroatom substituents at R, have been synthesised via reactions of anionic aluminium(I) and gallium(I) reagents with silyl and boryl azides (NON=4,5-bis(2,6-diisopropyl-anilido)-2,7-di-tert-butyl-9,9-dimethyl-xanthene). These systems vary significantly in their lability in solution: the N(SiiPr3) and N(Boryl) complexes are very labile, on account of the high basicity at nitrogen. Phenylsilylimido derivatives provide greater stabilization through the π-acceptor capabilities of the SiR3 group. K[(NON)AlN(SitBuPh2)] offers a workable compromise between stability and solubility, and has been completely characterized by spectroscopic, analytical and crystallographic methods. The silylimide species examined feature minimal π-bonding between the imide ligand and aluminium/gallium, with the HOMO and HOMO-1 orbitals effectively comprising orthogonal lone pairs centred at N. Reactivity-wise, both aluminium and gallium silylimides can act as viable sources of nitride, [N]3−, with systems derived from either metal reacting with CO to afford cyanide complexes. By contrast, only the gallium system K[(NON)Ga{N(SiPh3)}] is capable of effecting a similar transformation with N2O to yield azide, N3 −, via formal oxide/nitride metathesis. The aluminium systems instead generate RN3 via transfer of the imide fragment [RN]2−.
Beryllium‐Mediated Halide and Aryl Transfer onto Silicon
Ring opening of hexamethylcyclotrisoloxane with BeBr2, BeI2 and BePh2 was observed. These reactions yielded previously unknown diorgano bromo and iodo silanolates, [Be3Br2(OSiMe2Br)4] and [Be3I2(OSiMe2I)4], respectively, as well as [Be3Ph2(OSiMe2Ph)4]. Hydrolysis of these beryllium silanolates revealed that dimethyl bromo and iodo silanol are unstable and react to various cyclic cyclosiloxanes.
Abstract
The reactivity of hexamethylcyclotrisiloxane (D3) towards BeCl2, BeBr2, BeI2 and [Be3Ph6]3 was investigated. While BeCl2 only showed unselective reactivity, BeBr2, BeI2 and [Be3Ph6] cleanly react to the trinuclear complexes [Be3Br2(OSiMe2Br)4], [Be3I2(OSiMe2I)4] and [Be3Ph2(OSiMe2Ph)4]. These unprecedented bromide, iodide and phenyl transfer reactions from a group II metal onto silicon offer a versatile access to previously unknown diorgano bromo and iodo silanolates.