meta-C-H functionalization of phenylethyl and benzylic alcohol derivatives via Pd/NBE relay catalysis.

The transition metal-catalyzed meta-C-H functionalization of alcohols and their hydroxylamine derivatives remains underdeveloped. Herein, we report an efficient meta-C-H arylation of both phenylethyl and benzylic alcohols and their hydroxylamine derivatives using a readily removable oxime ether directing group. Using electronically activated 2-carbomethoxynorbornene as the transient mediator and 3-trifluoromethyl-2-pyridone as the enabling ligand, this reaction features a broad substrate scope and good functional group tolerance. More importantly, with this oxime-directed meta-C-H functionalization, this method provides a dual approach for efficient access to both meta-substituted alcohols and hydroxylamines using two sets of simple deprotection conditions. This protocol leads to the efficient synthesis of bioactive compounds possessing promising reactivities for the treatment of pulmonary fibrosis.

Synthesis of chiral α-amino acids via Pd(ii)-catalyzed enantioselective C-H arylation of α-aminoisobutyric acid.

Non-natural chiral α,α-disubstituted α-amino acids (α,α-AAs) constitute an attractive α-aminoisobutyric acid (Aib) replacement for improving bioavailability of linear peptides as therapeutics due to the ability of these amino acids to induce the peptides to form helical structures. Enantioselective ß-C(sp3)-H arylation of Aib could potentially provide a versatile one-step strategy for accessing diverse α,α-AAs, but the installation and removal of external directing groups was found in our previously reported work to reduce the efficiency of this approach. Herein we report a Pd(ii)-catalyzed enantioselective C-H arylation of N-phthalyl-protected Aib enabled by a N-2,6-difluorobenzoyl aminoethyl phenyl thioether (MPAThio) ligand, affording α,α-AAs with up to 72% yield and 98% ee. Use of this newly developed chiral catalyst has also significantly improved enantioselective C(sp3)-H arylation of cyclopropanecarboxylic acids by expanding the substrate scope to heterocyclic coupling partners and increasing enantioselectivity to 99% ee.

Ruthenium Complex Suppresses Proliferation of Residual Hepatocellular Carcinoma after Incomplete Radiofrequency Ablation Therapy.

BACKGROUND: Radiofrequency ablation (RFA) is an effective therapy for hepatocellular carcinoma (HCC). However, incomplete radiofrequency ablation (IRFA) can promote the progression of residual cancer cells, which is a serious problem in the clinical application of RFA. Therefore, it is of great significance to explore the mechanism and countermeasures of the progression of residual tumors after IRFA. Our previous study confirmed that IRFA can activate the hypoxia/ autophagy pathway of residual tumors in mice and then induce the proliferation of residual tumor cells. Additionally, we found a metal ruthenium complex [Ru(bpy)2(ipad)](ClO4)2 (Ru, where bpy = 2,2'-bipyridine and ipad = 2-(anthracene-9,10-dione-2-yl)imidazo[4,5-f][1,10]phenanthroline) can effectively inhibit hypoxia-inducible factor (HIF-1α) and has good anti-tumor effect in a hypoxic environment; however, whether Ru could suppress the proliferation of residual tumor cells after IRFA is unknown. OBJECTIVE: This study intends to evaluate the effect of Ru in suppressing the proliferation of residual hepatocellular carcinoma after IRFA in a mice model. METHODS: The Hepa1-6 xenograft mouse model was established in C57BL/6 mice to simulate clinical IRFA. H&E staining was used to evaluate the biosafety of major organs in the treated mice. TUNEL assay was employed to assess the antitumor effect. Immunohistochemically and immunofluorescence staining was performed to detect the expression of HIF-1α and autophagy-related proteins. The ELISA assay was used to examine the cytokines of interferon-gamma (IFN-γ) and interleukin 10 (IL-10). RESULTS: Our findings revealed that the residual tumor relapsed via the HIF-1α/LC3B/P62 autophagy- related pathway after IRFA, while Ru could suppress this process. In addition, it was demonstrated that Ru could effectively activate the immune system of the mice and reverse the tumor immune suppression microenvironment after IRFA. CONCLUSION: The ruthenium complex Ru could suppress the proliferation of residual hepatocellular carcinoma cells after IRFA in the mice model. This study introduces a novel approach that combines the use of ruthenium complexes with IRFA, offering a potential solution to address the reoccurrence of residual liver cancer following IRFA in clinical settings.

Conventional Hydrothermal Synthesis of MFI Zeolite in Methanol Solution.

The synthesis of zeolites through more efficient, environmentally friendly, and cost-effective methods was deemed significant in both industrial applications and academic fields. Conventional hydrothermal synthesis strategies have encountered difficulties in producing pure silica MFI zeolite (silicalite-1) under amine-free conditions. This was primarily attributed to the competitive growth of quartz, keatite, or magadiite during the crystallization process. In this work, it was found that the lack of nucleation ability was an important reason for the poor crystallization stability of the methanol solution. Well-crystallized silicalite-1 zeolites with uniform particle sizes were achieved through the cooperative guidance of methanol and seed crystals. Large-scale experiments with silicalite-1 zeolite demonstrated good reproducibility. Combined with the TG-IR and N2 adsorption-desorption results, it was observed that, when an extremely small amount of seed (0.97 wt %) was introduced, methanol could play a role as a crystallization promoter in the hydrothermal synthesis system. Furthermore, a lower alkaline-to-silica ratio and water-to-silica ratio were conducive to the progression of the crystallization process. In summary, this work presented a hydrothermal synthesis strategy for the synthesis of silicalite-1 zeolite in a methanol solution without the need for a large amount of seeds and provided an effective pathway for the low-cost, large-scale production of silicalite-1 zeolite.

[Improving effect of selenium on spermatogenesis in mice with cyclophosphamide-induced spermatogenic impairment and its underlying mechanism].

OBJECTIVE: To investigate the effect of selenium on cyclophosphamide (CTX)-induced spermatogenic impairment (SI) in mice and its underlying mechanism. METHODS: We equally randomized 36 male KM mice into 3 SI model and 3 control groups, the first 3 treated by intraperitoneal injection of CTX at 100 mg/kg (the SI model control group), CTX plus SI model control group, selenium deficient model group (－Se SI), selenium supplemented model group (+Se SI), while latter 3 by intraperitoneal injection of normal saline (the normal control), selenium deficiency control group (－Se control), selenium addition control group (+Se control), respectively, all once a week for 6 successive weeks. Then we observed the histopathological changes in the testes of all the mice by HE staining, obtained the sperm count in the epididymides, determined the expressions of glutathione peroxidase 4 (GPx4) and SLC7A11 proteins by Western blot and ferroptosis-related genes by RT-qPCR, and examined the changes in the expressions of ferroptosis-related proteins and genes in the GC2-spd cells treated with ferroptosis inhibitors and inducers in combination with different concentrations of inorganic sodium selenite (SeS) and organic selenomethionine (SeM). RESULTS: Compared with the normal controls, the SI model mice showed significantly decreased testicular and prostatic organ coefficients, reduced spermatogenic layers, increased voids, decreased serum ferritin concentration (P<0.05), and elevated transferrin concentration (P<0.05). The organ coefficients were significantly higher in the +Se SI and +Se control than in the －Se SI and －Se control groups (P<0.05, P<0.01), with evident pathological improvement of the testis tissue in the +Se controls. The expressions of the GPx4 and solute carrier family 7 members 11（SLC7A11） genes in the testis were dramatically down-regulated in the SI model controls (P<0.01), but up-regulated in the +Se SI and +Se control compared with those in the －Se SI and －Se control group (P<0.01 and P<0.05), but there were no statistically significant differences between their protein expressions. The results of in vitro GC2 spd cell experiments indicated that the GPx4 gene and GPx4 protein levels in the - Se group were significantly lower than those in the normal control group (P<0.05), while the SLC7A11 gene level decreased (P<0.01). Different doses of SeS and SeM significantly increased the GPx4 protein expression compared to the average Se group. Low doses of SeM promoted a significant increase in GPx4 gene levels, while high doses of SeS increased the expression levels of SLC7A11 gene and SLC7A11 protein (P<0.05, P<0.01). The Se group showed a significant decrease in the levels of acsl4 and ptgs2 genes compared to the normal control group. SeM promoted the expression of acsl4, while SeS promoted the expression of ptgs2 and fth1 (P<0.01, P<0.05). The intervention results of GC2 spd showed that the Erastin group had a decrease in ptgs2 compared to the normal control group, while the SeS+Erastin and SeM+Erastin groups had an increase in ptgs2 gene expression compared to the Erastin group. However, the ptgs2 expression of Fer-1 was lower than that of the normal control group, and the ptgs2 gene level of SeS+Fer-1 and SeM+Fer-1 groups was lower than that of Fer-1 group (P<0.05); The gene quantity of GPx4 in the SeM+Erastin and SeM+Fer-1 groups increased compared to the Erastin and Fer-1 groups (P<0.01, P<0.05); SeM+Erastin and SeS+Erastin showed a decrease in SLC7A11 compared to the Erastin group, as well as SeM+Fer-1 and SeS+Fer-1 groups compared to the Fer-1 group, accompanied by an increase in acsl4 and fth1 (P<0.01). CONCLUSION: Selenium deficiency causes the reduction of the SLC7A11 and GPx4 gene levels, disorder of ferroptosis-related genes and down-regulation of the GPx4 protein expression in the mouse testis and spermatocytes. Selenium can promote the expression of GPx4, up-regulate the level of SLC7A11, and improve spermatogenesis in the testis of the mouse with SI. There are differences between organic SeM and inorganic SeS in regulating the ferroptosis pathway-related genes.

Effect analysis of 847 nasopharyngeal carcinoma cases treated with intensity modulated radiation: Experience and suggestions.

OBJECTIVES: To identify the failure patterns and prognostic factors of nonmetastatic nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era. METHODS: Data on 847 patients with newly diagnosed, non-disseminated NPC treated by IMRT between 2012 and 2016 were retrospectively reviewed. Survival outcome, failure patterns and prognosis factors were analyzed. RESULTS: The 5-year local relapse-free survival, nodal relapse-free survival, distant metastasis-free survival, disease-free survival, and overall survival rates were 94.3%, 95.3%, 84.8%, 76.5% and 85.7%, respectively. The major local recurrence sites were the nasopharynx (91.5%, 43/47) and skull base (68.1%, 32/47); 39 patients had in-field failures, four had marginal failures, and four had out-field failures. Level IIb (62.2%, 23/37) was the most frequent regional recurrence site, followed by IIa (35.1%, 13/37) and retropharyngeal region (32.4%, 12/37); 35 cases had in-field failure alone, one had out-field failure alone, and one had both in- and out-field failure. TNM stage was the most significant factor for prognosis prediction. 402 (47.5%) patients had acute adverse events of grade 3 or 4; leukopenia (31.5%) and mucositis (26.7%) was the most common hematological and non-hematological event, respectively. Late complications were slight or moderate damages; xerostomia (647/847, 76.4%) and hearing impairment (422/847, 49.8%) remained the most troublesome. CONCLUSION: NPC patients treated with IMRT obtained satisfactory survival outcomes. The key failure pattern was distant metastasis. The main pattern of local-regional failure was in-field failure. Screening high risk patients with distant metastases and optimizing radiotherapy targets should be studied.

Phillyrin promotes autophagosome formation in A53T-αSyn-induced Parkinson's disease model via modulation of REEP1.

BACKGROUND: The preservation of autophagosome formation presents a promising strategy for tackling neurological disorders, such as Parkinson's disease (PD). Mitochondria-associated endoplasmic reticulum (ER) membranes (MAM) serve not only as a focal point linked to various neurological disorders but also play a crucial role in supporting the biogenesis of autophagosomes. PURPOSE: This investigation aimed to elucidate the neuroprotective properties of phillyrin against PD and its underlying mechanisms in promoting autophagosome formation. METHODS: ER and mitochondria co-localization was assessed via fluorescent staining. Annexin V-fluorescein isothiocyanate (FITC) fluorescence was employed to quantify accessible cardiolipin (CL) on mitochondrial surfaces. The levels of CL within the MAM fraction of SH-SY5Y cells were evaluated using a CL probe assay kit. Monodansylcadaverine staining was utilized to detect autophagosome formation in SH-SY5Y cells. In an A53T-alpha-synuclein (αSyn)-induced PD mouse model, the anti-PD properties of phillyrin were assessed using open field, pole climbing, and rotarod tests, as well as immunohistochemistry staining of TH+ neurons in the brain sections. RESULTS: In A53T-αSyn-treated SH-SY5Y cells, phillyrin facilitated autophagosome formation by suppressing CL externalization and restoring MAM integrity. Phillyrin enhanced the localization of receptor expression-enhancing protein 1 (REEP1) within MAM and mitochondria, bolstering MAM formation. Increased REEP1 levels in mitochondria, attributed to phillyrin, enhanced the interaction between REEP1 and NDPK-D, thereby reducing CL externalization. Furthermore, phillyrin exhibited a dose-dependent enhancement of motor function in mice, accompanied by an increase in the abundance of dopaminergic neurons within the substantia nigra. CONCLUSIONS: These findings illuminate phillyrin's ability to enhance MAM formation through upregulation of REEP1 expression within MAM, while concurrently attenuating CL externalization via the REEP1-NDPK-D interaction. These mechanisms bolster autophagosome biogenesis, offering resilience against A53T-αSyn-induced PD. Thus, our study advances the understanding of phillyrin's complex mechanisms and underscores its potential as a therapeutic approach for PD, opening new avenues in natural product pharmacology.

One-Step Synthesis of Chiral 9,10-Dihydrophenanthrenes via Ligand-Enabled Enantioselective Cascade ß,γ-Diarylation of Acids.

Pd(II)-catalyzed enantioselective C-H activation has emerged as a versatile platform for constructing point, axial, and planar chirality. Herein, we present an unexpected discovery of a Pd-catalyzed enantioselective cascade ß,γ-methylene C(sp3)-H diarylation of free carboxylic acids using bidentate chiral mono-protected amino thioether ligands (MPAThio), enabling one-step synthesis of a complex chiral 9,10-dihydrophenanthrene scaffolds with high enantioselectivity. In this process, two methylene C(sp3)-H bonds and three C(sp2)-H bonds were activated, leading to the formation of four C-C bonds and three chiral centers in one pot. A plausible catalytic pathway starts with enantioselective ß,γ-dehydrogenation to form chiral ß,γ-cyclohexene. Intriguingly, this olefin serves as a norbornene-type reagent (presumably assisted by the carboxyl directing effect), relaying two successive Catellani arylation reactions and a C-H arylation reaction to furnish chiral 9,10-dihydrophenanthrenes along with meta-selective homocoupling products of iodoarene.

Trifolium repens L. recruits root-associated Microbacterium species to adapt to heavy metal stress in an abandoned Pb-Zn mining area.

Root-associated microbiota provide great fitness to hosts under environmental stress. However, the underlying microecological mechanisms controlling the interaction between heavy metal-stressed plants and the microbiota are poorly understood. In this study, we screened and isolated representative amplicon sequence variants (strain M4) from rhizosphere soil samples of Trifolium repens L. growing in areas with high concentrations of heavy metals. To investigate the microecological mechanisms by which T. repens adapts to heavy metal stress in abandoned mining areas, we conducted potting experiments, bacterial growth promotion experiments, biofilm formation experiments, and chemotaxis experiments. The results showed that high concentrations of heavy metals significantly altered the rhizosphere bacterial community structure of T. repens and significantly enriched Microbacterium sp. Strain M4 was demonstrated to significantly increased the biomass and root length of T. repens under heavy metal stress. Additionally, L-proline and stigmasterol could promote bacterial growth and biofilm formation and induce chemotaxis for strain M4, suggesting that they are key rhizosphere secretions of T. repens for Microbacterium sp. recruitment. Our results suggested that T. repens adapted the heavy metal stress by reshaping rhizosphere secretions to modify the rhizosphere microbiota.

A Peritrophin-44 gene in Litopenaeus vannamei is involved in disease resistance.

Peritrophic membrane (PM) is a pellicle structure present in the midgut of some invertebrates, such as insects and crustaceans. It could isolate harmful components and pathogens in food from intestinal epithelial cells; and it also plays a role in improving digestion and absorption efficiency. So PM is important for survival of its owner. In current study, 44 PM proteins were identified in Litopenaeus vannamei by PM proteome analysis. Among these PM proteins, the Peritrophin-44 homologous protein (LvPT44) was further studied. Chitin-binding assay indicated that LvPT44 could bind to colloidal chitin, and immunoeletron microscopy analysis shown that it was located to PM of L. vannamei. Furthermore, LvPT44 promoter was found to be activated by L. vannamei STAT and c-Jun. Besides, LvPT44 was induced by ER-stress as well as white spot syndrome virus infection. Knocked-down expression of LvPT44 by RNA inference increased the cumulative mortality of shrimp that caused by ER-stress or white spot syndrome virus. These results suggested that LvPT44 has an important role in disease resistance.